ministry of agriculture oromia bureau of ...preface irrigated agriculture and, consequently, food...

MINISTRY OF AGRICULTURE OROMIA BUREAU OF AGRICULTURE OROMIA PASTORAL AREA DEVELOPMENT COMMISSION SOMALI LIVESTOCK, CROP AND RURAL DEVELOPMENT BUREAU

RURAL RESILIENCE ENHANCEMENT PROJECT

IN THE FEDERAL DEMOCRATIC

REPUBLIC OF ETHIOPIA

TECHNICAL MANUALS FOR IRRIGATED AGRICULTURE

JANUARY 2015

JAPAN INTERNATIONAL COOPERATION AGENCY (JICA)

SANYU CONSULTANTS INC.

RD

JR

15-014

PREFACE

Irrigated agriculture and, consequently, food production depend among other factors on the proper management of water and farm practices. The proper management of the irrigation water and the farming practices are an integral component that needs serious attention and consideration in the crop production system.

This Manuals aspires to further strengthen the engineering, agronomic, economic and environmental aspects of the irrigated agriculture development in Somali region. The emphasis is directed towards the engineering as well as agricultural aspects for smallholder irrigation, in view of the limited practical references in Gode area.

It is also intended for development agents (DA) to assist in agricultural extension services and irrigation experts at the kebele and woreda levels who want to increase their ability to deal with farm-level irrigated agriculture practices. It in fact attempts to introduce the knowledge, providing a bridge between the various disciplines involved in irrigated agriculture development.

Subjects incorporated in this Manuals are knowledge and technique necessary for the improvement of irrigated agriculture in Gode area and by large in Somali region. This Manuals includes such topics as planning, designing, operation and maintenance, on-farm water management, and also plant science, farming plan, fertilization, pests, disease, weed control, and finally recommended agronomic practices.

Primary users of this Manuals are to be the government officers concerned, i.e., the officers of the Livestock, Crop and Rural Development Office, Cooperative Office, Somali Region Pastoral and Agro-pastoral Research Institute, and Das. The readers are expected to utilize this Manuals in respect of each condition, but also to try out the disciplines asserted throughout the text in practice.

We wish to express our deep gratitude to the concerned government offices both at the Somali region as well as at woreda level for the leading role of facilitating the process of producing this Manuals. We hope this Manuals will serve as a means of achieving high and stable production of irrigated agriculture in the Gode area as well as in Somali region.

JAPAN INTERNATIONAL COOPERATION AGENCY (JICA)

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CONTENTS PREFACE

PART I IRRIGATION

CHAPTER 1 IRRIGATION DESIGN ........................................................................................ I-1-1

1.1 Water Resources Development in Somali Region .............................................................. I-1-1 1.1.1 Rainfall in Gode Area ............................................................................................ I-1-1 1.1.2 Necessity of Irrigated Agriculture in Gode Area .................................................... I-1-1 1.1.3 Water Source in Gode Area a ................................................................................. I-1-1

1.2 Type of Irrigation System ................................................................................................... I-1-2 1.3 Water Requirement ............................................................................................................. I-1-3

1.3.1 Evapo-transpiration ................................................................................................ I-1-3 1.3.2 Crop Coefficient and Crop Development ............................................................... I-1-4 1.3.3 Crop Water Requirements ...................................................................................... I-1-5 1.3.4 Irrigation Water Requirement ................................................................................. I-1-5 1.3.5 Different Types of Efficiencies in Irrigation Scheme ............................................. I-1-6 1.3.6 Calculated Water Requirement (WR)..................................................................... I-1-6

1.4 On-Farm Irrigation Method ................................................................................................ I-1-8 1.4.1 Classification of Irrigation Methods ...................................................................... I-1-8 1.4.2 Surface Irrigation Methods .................................................................................... I-1-8 1.4.3 Sprinkler Irrigation ............................................................................................... I-1-11 1.4.4 Drip Irrigation ...................................................................................................... I-1-11 1.4.5 Selection for Suitable Irrigation Methods in Gode Area ...................................... I-1-12

CHAPTER 2 OPERATION AND MAINTENANCE ................................................................ I-2-1

2.1 Organization ........................................................................................................................ I-2-1 2.1.1 Role of Water Users Association (WUA) ............................................................... I-2-1 2.1.2 Internal Set-up of Water Users’ Association .......................................................... I-2-3

2.2 Operation ............................................................................................................................ I-2-4 2.2.1 Pump Operation ..................................................................................................... I-2-4 2.2.2 Water Distribution System ..................................................................................... I-2-5 2.2.3 Field Intake Methods ............................................................................................. I-2-7 2.2.4 Basin Irrigation ...................................................................................................... I-2-7 2.2.5 Irrigating Furrows .................................................................................................. I-2-9 2.2.6 Irrigating Borders ................................................................................................. I-2-10

2.3 Maintenance ...................................................................................................................... I-2-11 2.3.1 Maintenance of Irrigation Scheme ....................................................................... I-2-11 2.3.2 Canal Maintenance and Repair ............................................................................ I-2-13

CHAPTER 3 ENVIRONMENTAL AND SOCIAL CONSIDERATION ................................. I-3-1

3.1 Environmental Legislative and Institutional Framework in Ethiopia ................................. I-3-1 3.2 Environmental Examination Level for Irrigation Development Projects ........................... I-3-1 3.3 Procedure of Environmental Examination .......................................................................... I-3-2

3.3.1 Scoping of the Environmental Impact .................................................................... I-3-2 3.3.2 Environmental and Social Examination ................................................................. I-3-3 3.3.3 Mitigation Measures and Monitoring ..................................................................... I-3-5

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PART II AGRICULTURE

CHAPTER 1 INTRODUCTION ................................................................................................ II-1-1

1.1 Botany ............................................................................................................................... II-1-1 1.1.1 Stems .................................................................................................................... II-1-1 1.1.2 Leaves .................................................................................................................. II-1-1 1.1.3 Root ...................................................................................................................... II-1-1 1.1.4 Flowers ................................................................................................................. II-1-1 1.1.5 Fruit ...................................................................................................................... II-1-1

1.2 Environmental Factors that Affect Plant Growth .............................................................. II-1-2 1.2.1 Water (humidity) .................................................................................................. II-1-2 1.2.2 Soil and Nutrition ................................................................................................. II-1-2 1.2.3 Nutrition ............................................................................................................... II-1-3 1.2.4 Climate: Sunlight, Air and Temperature .............................................................. II-1-3

CHAPTER 2 FARMING PLAN ................................................................................................. II-2-1

2.1 Analysis of the agricultural situation ................................................................................ II-2-1 2.1.1 Environmental condition ...................................................................................... II-2-1 2.1.2 Farming situation ................................................................................................. II-2-1 2.1.3 People’s needs and Marketing .............................................................................. II-2-2

2.2 Different cropping systems and patterns ........................................................................... II-2-3 2.2.1 Cropping system .................................................................................................. II-2-3 2.2.2 Crop rotation ........................................................................................................ II-2-5

2.3 Elaboration of cropping system ........................................................................................ II-2-5 2.3.1 Selecting of crops ................................................................................................. II-2-5 2.3.2 Selection the right varieties .................................................................................. II-2-6 2.3.3 Planning of crop rotation ...................................................................................... II-2-7

2.4 Farming Plan recommended in Gode................................................................................ II-2-8 2.4.1 Agricultural Situation at Present .......................................................................... II-2-8 2.4.2 Recommended Cropping System and Pattern ...................................................... II-2-9

CHAPTER 3 FERTILIZATION ................................................................................................ II-3-1

3.1 Chemical fertilizer ............................................................................................................ II-3-1 3.1.1 Types of chemical fertilizer .................................................................................. II-3-1 3.1.2 Method of fertilizer application ........................................................................... II-3-2

3.2 Organic fertilizer ............................................................................................................... II-3-3 3.3 Time of fertilizer application ............................................................................................ II-3-3

3.3.1 Nitrogen ............................................................................................................... II-3-4 3.3.2 Phosphorus ........................................................................................................... II-3-4 3.3.3 Potassium ............................................................................................................. II-3-4

CHAPTER 4 CONTROL OF PEST, DISEASES AND WEED ............................................... II-4-1

4.1 Types of Pest, Diseases and Weed .................................................................................... II-4-1 4.1.1 Pests ..................................................................................................................... II-4-1 4.1.2 Disease ................................................................................................................. II-4-1 4.1.3 Weeds ................................................................................................................... II-4-1

4.2 Control measures .............................................................................................................. II-4-1 4.2.1 Preventive measures ............................................................................................. II-4-2 4.2.2 Chemical control .................................................................................................. II-4-2

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CHAPTER 5 RECOMMENDED AGRONOMIC PRACTICE WITH IRRIGATION ........ II-5-1

5.1 Points of agronomical practice in Gode ............................................................................ II-5-1 5.2 Cereals .............................................................................................................................. II-5-3

5.2.1 Maize (Zea mays L., Graminaceous / Poaceae family) ........................................ II-5-3 5.2.2 Sorghum (Sorghum bicolor) ................................................................................. II-5-5

5.3 Pulse crops: Haricot bean (Phaseolus vulgaris.L) ............................................................. II-5-7 5.4 Oil crops ............................................................................................................................ II-5-9

5.4.1 Sesame (Sesamum indicum.L) ............................................................................. II-5-9 5.4.2 Ground nuts (arachis hypogaea.L) ..................................................................... II-5-11

5.5 Vegetable ......................................................................................................................... II-5-13 5.5.1 Onion (Allium cepa L.) ...................................................................................... II-5-13 5.5.2 Tomato (Lycopersicon esculeutum) ................................................................... II-5-14

5.6 Fodder crop ..................................................................................................................... II-5-15

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ACRONYMS AND ABBREVIATIONS

CEO Chief Executive Officer CRV Central Rift Valley DA Development Agent DM Dry Matter EIA Environmental Impact Assessment EIAR Ethiopian Institute of Agriculture Research EPA Environmental Protection Authority FAO Food and Agriculture Organization Ea Field Application Efficiency Eb Field Canal Efficiency Ec Conveyance Efficiency Ep Overall Project Efficiency ER Effective Rainfall ET Evapo-Transpiration Etc Crop Water Requirement FAO Food and Agriculture Organization IRg Gross irrigation Requirements IRn Net Irrigation Requirement JICA Japanese International Cooperation Agency MOA Ministry of Agriculture MP Muriate of Potash PA Preliminary Assessment RREP Rural Resilience Enhancement Project SoRPARI Somali Region Pastoral and Agro-pastoral Research Institute TOR Terms of Reference TSP Triple Super Phosphate WR Water Requirement WUA Water User Association

UNIT CONVERSIONS

1 meter (m) = 3.28 feet 1 kilometer (km) = 0.62 miles 1 hectare (ha) = 2.47 acres 1 acre = 0.405 ha 1 foot = 12 inches (30.48 cm) 1 inch = 2.54 cm

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PART I LIST OF TABLES

CHAPTER 1 IRRIGATION DESIGN Table 1.1.1 Seasonal Evapo-transpiration (ET) Requirements of different Crop ........................ I-1-1 Table 1.3.1 ETo for Gode Area, computed by CROPWAT 8.0 .................................................... I-1-3 Table 1.3.2 Crop Development Stage and Crop Coefficients ...................................................... I-1-5 Table 1.3.3 Monthly Total Rainfall Recorded at Gode Station

and Calculated Effective Rainfall ............................................................................. I-1-5 Table 1.3.4 Calculated Water Requirement (l/s/ha) for Maize .................................................... I-1-7 Table 1.3.5 Calculated Water Requirement (l/s/ha) for Sesame .................................................. I-1-7 Table 1.3.6 Calculated Water Requirement (l/s/ha) for Beans .................................................... I-1-7 Table 1.4.1 Criteria for Basin Size Determination (FAO, Irrigation Manual, 2002) ................... I-1-9 Table 1.4.2 Basin Area in m2 for Different Stream Sizes and Soil Types

(FAO, Irrigational Manual,2002) .............................................................................. I-1-9 Table 1.4.3 Recommended Furrow Lengths for Different Slopes, Soil Types

and Water Application ............................................................................................ I-1-10 Table 1.4.4 Technical Factors Affecting Selection of Irrigation Method .................................. I-1-12

CHAPTER 2 OPERATION AND MAINTENANCE Table 2.3.1 Procedure of Reducing the Permeability ................................................................ I-2-13 Table 2.3.2 Procedure of Repairing of a Leak ........................................................................... I-2-14 Table 2.3.3 Procedure of Reshaping and Widening of an Eroded Cross-Section ...................... I-2-15 Table 2.3.4 Procedure of Repairing of Cracks and Gullies in a Canal Embankment ................ I-2-15

CHAPTER 3 ENVIRONMENTAL AND SOCIAL CONSIDERATION Table 3.2.1 Project Types subject to Environmental Impact Assessment .................................... I-3-1 Table 3.3.1 Example of Environmental Evaluation for Gode Irrigation Project ......................... I-3-3 Table 3.3.2 An Example of Mitigation Measures ........................................................................ I-3-5 PART I LIST OF FIGURES

CHAPTER 1 INTRODUCTION AND PURPOSE Figure 1.1.1 Monthly Total Rainfall Recorded at Gode Station .................................................... I-1-1 Figure 1.1.2 Wabe Shebele Revier Basin ...................................................................................... I-1-2 Figure 1.1.3 Relation between Rainfall and River Flow at Gode Station ..................................... I-1-2 Figure 1.3.1 Typical Four Growing Stages ................................................................................... I-1-4 Figure 1.3.2 Crop Efficient Carve (Maize, Grain) ........................................................................ I-1-4 Figure 1.4.1 Example of a Border Strip Irrigation ........................................................................ I-1-8 Figure 1.4.2 Layout of Basin Irrigation (Source: FAO, 1985) ...................................................... I-1-9 Figure 1.4.3 Layout of Furrow Irrigation .................................................................................... I-1-10 Figure 1.4.4 Typical Sprinkler Irrigation System ........................................................................ I-1-11 Figure 1.4.5 Components of Drip Irrigation System ................................................................... I-1-11

CHAPTER 2 OPERATION AND MAINTENANCE Figure 2.1.1 Irrigation System Managed by WUA ....................................................................... I-2-2 Figure 2.1.2 Internal Organization Setting-up for the Irrigators’ Association .............................. I-2-3 Figure 2.2.1 Breaches.................................................................................................................... I-2-7 Figure 2.2.2 Siphons ..................................................................................................................... I-2-7 Figure 2.2.3 Spiles ........................................................................................................................ I-2-7

vi

Figure 2.2.4 Direct Method of Water Supply ................................................................................ I-2-8 Figure 2.2.5 Cascade Method of Water Supply ............................................................................ I-2-8 Figure 2.2.6 Ideal Wetting Pattern ................................................................................................ I-2-8 Figure 2.2.7 Alternate Furrow Irrigation....................................................................................... I-2-9 Figure 2.2.8 Different Wetting Patterns in Furrows, Depending on the Soil Type ....................... I-2-9 Figure 2.2.9 Ideal Wetting Pattern .............................................................................................. I-2-10 Figure 2.2.10 Effect of a Cross-slope on the Water Movement in a Border ................................. I-2-10 Figure 2.2.11 Stream Size too Smalls ........................................................................................... I-2-11 Figure 2.2.12 Stream Size too Large ............................................................................................. I-2-11 Figure 2.3.1 Weeding, Cleaning and De-silting .......................................................................... I-2-12 PART II LIST OF TABLES

CHAPTER 2 FARMING PLAN Table 2.1.1 Check Items for Environmental Condition ............................................................. II-2-1 Table 2.1.2 Check Items for Farming Situation ......................................................................... II-2-2 Table 2.1.3 Check Items on the People’s Needs and Marketing ............................................... II-2-2 Table 2.2.1 Different Ways of Intercropping ............................................................................. II-2-4 Table 2.3.1 Family Name and Crop Combination ..................................................................... II-2-8 Table 2.4.1 Example of Cropping Pattern for 2 sub-plots Case .............................................. II-2-10 Table 2.4.2 Example of Cropping Pattern for 3 sub-plots Case .............................................. II-2-11 Table 2.4.3 Example of Cropping Pattern for 4 sub-plots Case .............................................. II-2-12

CHAPTER 5 RECOMMENDED AGRONOMIC PRACTICE WITH IRRIGATION Table 5.2.1 Recommended Agronomic Practice of Maize ........................................................ II-5-3 Table 5.2.2 Released Improved Maize Varieties for Low Rainfall Area in Ethiopia................. II-5-4 Table 5.2.3 Recommended Agronomic Practices of Sorghum .................................................. II-5-5 Table 5.2.4 Released Improved Sorghum Varieties for Low Rainfall Area in Ethiopia ............ II-5-6 Table 5.2.5 Recommended Agronomic Practices of Haricot Beans .......................................... II-5-7 Table 5.2.6 Released Improved Haricot Bean Varieties for Low Rainfall Area in Ethiopia ..... II-5-8 Table 5.2.7 Recommended Agronomic Practices of Sesame .................................................... II-5-9 Table 5.2.8 Released Improved Sesame Varieties for Low Rainfall Area in Ethiopia ............ II-5-10 Table 5.2.9 Recommended Agronomic Practices of Groundnuts ............................................ II-5-11 Table 5.2.10 Released Improved Sesame Varieties for Low Rainfall Area in Ethiopia ............ II-5-12 Table 5.2.11 Recommended Agronomic Practices of Onion ..................................................... II-5-13 Table 5.2.12 Recommended Agronomic Practices of Tomato ................................................... II-5-14 Table 5.2.13 General Practices of Fodder Crops ....................................................................... II-5-15 PART II LIST OF FIGURES

CHAPTER 1 INTRODUCTION Figure 1.1.1 Principal Parts of a Vascular Plant .......................................................................... II-1-1 Figure 1.1.2 Maize Roots ............................................................................................................ II-1-1 Figure 1.1.3 Germination of Monocotyledon and Dicotyledonous ............................................ II-1-2 Figure 1.2.1 Composition of the Soil .......................................................................................... II-1-2 Figure 1.2.2 Relative Size of Soil Particles................................................................................. II-1-3

vii

CHAPTER 2 FARMING PLAN Figure 2.2.1 Examples of Crop Rotation in Different Region in Ethiopia .................................. II-2-5 Figure 2.3.1 Different Crops Have Different Types of Roots ..................................................... II-2-6 Figure 2.3.2 Schematic Summary of Crop Rotation Planning .................................................... II-2-7 Figure 2.3.3 2-year Rotation of Cereals, Cowpeas and Legumes ............................................... II-2-7 Figure 2.3.4 Example of Rotation Cycle ..................................................................................... II-2-8

CHAPTER 5 RECOMMENDED AGRONOMIC PRACTICE WITH IRRIGATION Figure 5.1 Timing of Agronomic Practice by Crop Recommended in Gode ........................... II-5-2

PART I

IRRIGATION

Ethiopia Rural Resilience Enhancement Project

JICA I-1-1 MOA

CHAPTER 1 IRRIGATION DESIGN

1.1 Water Resources Development in Somali Region

1.1.1 Rainfall in Gode Area

The climate in Somali Region belongs to an equatorial semi-arid type. It is characterized by mean annual rainfall of about 260 mm distributed in two rainy seasons, high temperatures and whereby consequently high evaporation. Inter-annual irregularity of rainfall is considerable. The average monthly rainfall for the Gode station is given in Figure 1.1.1. From the figure, it is obvious that there are two rainy seasons; the first, the longer one, is called “Gu” between March to May and the second is “Der” between October to November. This is considered due to an effect of “inter tropical convergence zone”.

Month Monthly Rainfall (mm)

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total

Average 0.3 2.8 13.7 76.1 52.9 0.7 0.9 0.1 4.6 60.6 43.8 3.2 260

1.1.2 Necessity of Irrigated Agriculture in Gode Area

Table 1.1.1 shows the seasonal evapo-transpiration (ET) requirements of each crop. According to the Table 1.1.1, all the crops require more than 300mm water each season. Especially the Maize (grain) as the staple food in Gode area need to be over 500mm water each season. Because the total rainfall mount is about 260mm in Gode area, it is necessary to practice irrigated agriculture in Gode and Somali Region by large.

Table 1.1.1 Seasonal Evapo-transpiration (ET) Requirements of different Crop Crop Seasonal ET (mm) Crop Seasonal ET (mm)

Banana (tropical), 1200-2200 Pepper (fresh) 600-900

Bean (green) 300-500 Potato 500-700

Cabbage 380-500 Rice 350-700

Cotton 700-1300 Sorghum 450-650

Grape 500-1200 Sugarcane 1500-2500

Groundnut 500-700 Tomato 400-600

Maize (grain) 500-800 Watermelon 400-600

Onion (dry) 350-550 Wheat 450-650

Source: Yield response to water. Irrigation and drainage paper No.33, FAO crop coefficients, (modified).

1.1.3 Water Source in Gode Area

In order to practice the irrigation in Gode area, we have to acquire the water source. There may be two options in terms of water source; one is groundwater while the other one is Wabe Shebele River. Since

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Figure 1.1.1 Monthly Total Rainfall Recorded at Gode StationSource: Gode Meteorological Station Data (1966-2010)

“Gu”

“Der”

Rural Resilience Enhancement Project Ethiopia

MOA I-1-2 JICA

Figure 1.1.3 Relation between Rainfall and River Flow at Gode Station Source: Gode Meteorological Station Data (1966-2010)

Relation Rainfall and River f low

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Wabe Shebele River Totalmonthly f low s (m6)

irrigation requires much amount of water, the groundwater yield to be required is usually very big. There should be an aquifer which can yield as much as 200 l/s for a typical 100 ha irrigation farmlands. In fact, aquifer which can yield such big amount of groundwater rarely exists over the world and of course no such aquifer has been reported in and around Gode area.

Wabe Shebele River, on the other hand, is the only perennial river in Somali region, which accordingly should be the water source for irrigation. The total area of the basin arrives at about 202,220 km2 (see Figure 1.1.2). The flow of Wabe Shebele river shows bimodal peaks as shown in Figure 1.1.3; one in April and the other in October corresponding to the rainfall pattern over the catchment area. The flow ratio changes very significantly throughout year. For example, the lowest flow shows up in January with only 20.3 m3/s while the maximum in August with 226.7 m3/s, presenting more than 10 times different by month. The mean annual flow of Wabe Shebele river near the Gode Town is estimated at 113.0 m3/s, and annually available volume of water therefore comes to about 3.5 billion cum per year.

Month Wabe Shebele River Mean monthly flows (m3/s)

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ave.

Average 20.3 31.9 61.6 190.6 202.8 78.4 106.6 226.7 179.7 145.0 68.6 38.7 113.0

1.2 Type of Irrigation Systems

Wabe Shebele river bed slope around Gode area is found at 1:2,500, meaning very gentle slope. The depth and width are also found ranging from 8m to 14m and 80m to as wide as 150m respectively. The irrigable land is also very flat and its gradient is only 1:2,500 same as that of the river. With this condition, if an irrigation engineer plans gravity irrigation system with a diversion weir upstream, the length of main canal is to be more than 20km in order to absorb the elevation difference between the diversion point and the potential irrigable area spread around Gode town area.

It is therefore clear that the installation of gravity irrigation scheme by constructing a diversion weir in the Gode area is not feasible from the view points of maintenance and also the construction cost. Therefore, it is necessary to select other irrigation method which can be adaptable to the area. The only

Figure 1.1.2 Wabe Shebele Revier Basin Source: OCHA


JICA I-1-3 MOA

option is pump irrigation wherein pumps should be installed near the target irrigation area, directly pumping up the river water for the irrigated farming.

1.3 Water Requirement

1.3.1 Evapo-transpiration

In a cropped field, water can be lost from the soil surface and wet vegetation through a process called evaporation (E), whereby liquid water is converted into water vapor and removed from the evaporating surface. There is another process of water loss called transpiration (T), whereby liquid water contained in plant tissues vaporizes into the atmosphere through small openings in the plant leaf. The combination of these two separate processes is called evapo-transpiration (ET). Evaporation and transpiration occur simultaneously and there is no easy way of distinguishing the two processes.

The main factors affecting evapo-transpiration are climatic parameters, crop characteristics, management practices and environmental aspects. The main climatic factors affecting evapo-transpiration are solar radiation, air temperature, air humidity and wind speed. The crop type, variety and development stages affect evapo-transpiration. Differences in crop resistance to transpiration, crop height, crop roughness, reflection, canopy cover and crop rooting characteristics result in different evapo-transpiration levels under identical environmental conditions.

The evapo-transpiration from a reference surface not short of water is called the reference crop evapo-transpiration and is denoted by ETo. ETo can be calculated from meteorological data only. FAO Penman-Monteith method is now recommended as the sole standard method for the definition and calculation of the reference crop evapo-transpiration. It has been found to be a method with a strong likelihood of correctly predicting ETo in a wide range of locations and climates. The method provides values that are more consistent with actual crop water use worldwide.

Accordingly, in this manual the FAO Penman-Monteith method is used to determine reference evapo-transpiration (ETo) for the irrigation project under planning. Data used in estimating the potential evapo-transpiration using Penman-Monteith method are the mean monthly values of temperature, relative humidity, ratio of actual sunshine duration to the maximum possible one, and wind speed. The ETo together with the climate data recorded at Gode meteorological station is summarized below:

Table 1.3.1 ETo for Gode Area, computed by CROPWAT 8.0

Monthly Reference Evapo-transpiration ETo according Penman-Monteith

Meteorological station : Local climate estimator (Gode) Country : Ethiopia Altitude : 260 m. Coordinates : N 5o 58’ , E43o 30’

Month Min

Temp (0C) Max

Temp (0C) Humidity

(%) Wind

(km/day) Sunshine (hours)

Radiation (MJ/m2/day)

ETo Penman (mm/day)

Jan 21.2 35.3 48 184 9.7 22.6 6.08

Feb 22.1 36.4 46 196 10.2 24.5 6.75

Mar 23.9 37.1 47 205 9.9 24.8 7.12

Apr 23.9 35.8 59 165 8.2 22.0 5.89

May 23.9 34.5 62 187 8.1 21.1 5.64

June 23.5 33.9 56 294 7.2 19.3 6.28

July 23.1 33.2 54 339 6.6 18.6 6.53

Aug 23.0 33.6 54 327 7.4 20.4 6.73

Sep 23.5 35.2 52 258 8.6 22.6 6.86

Oct 23.0 34.4 58 159 7.6 20.6 5.44

Nov 21.5 33.8 58 135 9.0 21.7 5.12

Dec 21.0 34.9 51 151 9.7 22.1 5.54

Average 22.8 34.84167 54 217 8.5 21.7 6.2

Source: JICA Study Team


MOA I-1-4 JICA

1.3.2 Crop Coefficient and Crop Development

In order to calculate the water requirement of the individual crops being considered, the ET Crop should be calculated. Appropriate crop coefficients Kc are used, which represent the relationship between the reference crop water requirement and evapo-transpiration (i.e. ETo x Kc = ET crop). Crop coefficient should be calculated taking into account four growing stages of a crop. Many factors affect Kc, namely crop type, changing crop characteristics over the growing season and, to a limited extent, the prevailing weather conditions. More arid climates and conditions of greater wind speed will have higher values for Kc.

The Kc for a given crop changes over the growing period as the groundcover, crop height and leaf area change. Four growth stages are recognized for the selection of Kc: initial stage, crop development stage, mid-season stage and the late season stage (See Figure 1.3.1). The Kc value at the end of the late season stage (Kc end) reflects crop and water management practices. The Kc end value is high if the crop is frequently irrigated until harvested fresh. If the crop is allowed to senescence and to dry out in the field before harvest, the Kc end value will be small. Hence, the calculation of ETc consists of the following general steps:

identification of the crop growth stages, determination of their lengths and selection of the corresponding Kc values,

adjustment of the selected Kc values for frequency of wetting or climatic conditions during each stage,

construction of the crop coefficient curve (allowing one to determine Kc values for any period during the growing period), and

calculation of ETc as the product of ETo and Kc.

FAO (1998) gives general lengths for the four distinct growth stages and total growing period for various types of climates and locations. In Gode area, crop is planted under irrigation 2 times in a year in general. One is 3 months (90 days) from April to June, and the other is from October to December. Given this condition, the crop coefficients are exampled for maize (grain), sesame and beans as shown below, which are commonly cultivated in and around Gode.

Figure 1.3.1 Typical Four Growing Stages Source: FAO (1998)

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Kc=0.78

Kc=1.15 Stage3

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Kc=0.35 Stage1

Stage2

Stage4

Figure 1.3.2 Crop Efficient Carve (Maize, Grain)Source: Crop Water Requirements No.24 FAO Irrigation and Drainage Paper


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Table 1.3.2 Crop Development Stage and Crop Coefficients

Crop Crop development stages / Kc

Total Growing Period Initial

Crop Development

Mid Season Late Season

Maize days

Kc 16

0.35 26

0.78 29

1.15 19 0.6

90

Sesame days

Kc 20

0.35 30

0.78 40

1.15 20 0.6

100

Beans days

Kc 20 0.5

30 0.78

30 1.05

10 0.9

90

Source: Crop Water Requirements No.24 FAO Irrigation and Drainage Paper

1.3.3 Crop Water Requirements

Whereas crop water requirement refers to the water used by crops, the irrigation requirement is the water that must be supplied through the irrigation system to ensure that the crop receives its full crop water requirement. If irrigation is the sole source of water supply for the plant, the irrigation requirement will be at least equal to the crop water requirement. If the crop receives some of its water from other sources (rainfall, etc.), then the irrigation requirement can be less than the crop water requirement. Crop water requirements can be calculated from climatic and crop factors data as ETc = ETo x Kc.

1.3.4 Irrigation Water Requirement

Irrigation water requirement is calculated using the crop requirements but takes into account the effective rainfall. It is derived from the formula ETc- ER (effective rainfall). Not all rainfall is effective and some may be lost through surface runoff, deep percolation or evaporation. Essentially effective rainfall is that proportion of the rain which is stored in the root zone and therefore available to the plants. To calculate the effective rainfall for Gode area, the following FAO/AGLW formula can be referred:

Pe= 0.6 Ptot - 10 (for Ptot≤ 70 mm/month)

Pe= 0.8 Ptot - 24 (for Ptot > 70 mm/month)

Note; Pe and Ptot are respectively monthly mean effective rainfall and monthly mean measured rainfall in mm.

Table 1.3.3 Monthly Total Rainfall Recorded at Gode Station and Calculated Effective Rainfall Monthly Rainfall (mm)

Month

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total

Average Rainfall

0.3 2.8 13.7 76.1 52.9 0.7 0.9 0.1 4.6 60.6 43.8 3.2 260

Effective Rainfall

- - - 21.6 21 - - - - 26 16 -

Source: Gode Meteorological Station Data (1966-2010), JICA Study Team

As it is seen from the Table 1.3.3, the values of effective rainfall calculated in the majority of the months are negative. Even if in the remaining few months the values are positive, their amounts are not significant to be considered. Therefore it is recommended for most of the irrigation project in and around Gode area that the effective rainfall can be set at nil, meaning no effective rainfall is considered in irrigation planning.

Net Irrigation Requirement (IRn) is the depth of water needed to bring the soil moisture level in the effective root zone to field capacity from the soil moisture. It is calculated by using the relationship between crop water requirement (ETc) and effective rainfall. On the other hand, gross irrigation requirements account for losses of water incurred during conveyance and application to the field. This is expressed in terms of efficiencies when calculating project gross irrigation requirements from net irrigation requirements, i.e.;


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IRn = ETc- ER

IRg = IRn/Ep

IRg : Gross irrigation requirements (mm) IRn : Net irrigation requirements (mm) ER : Effective rainfall (mm) ETc : Crop water requirement (mm) Ep : Overall project efficiency

1.3.5 Different Types of Efficiencies in Irrigation Scheme

Irrigation efficiency is an indicator of degree of effectiveness of that irrigation system. The performance of this system is determined by the efficiency with which water is conveyed to the scheme from the pumping station, distributed within the scheme and applied to the field, and by the adequacy and uniformity of application in each field. It is the overall irrigation efficiency which includes all these factors.

1) Conveyance Efficiency (Ec)

Conveyance efficiency is the ratio of water received at the inlet to a block of fields to the water released from the project pumping station. Factors affecting this efficiency include canal lining, evaporation of water from the canal, technical and managerial facilities of water control, etc. Conveyance efficiency is higher when water is conveyed in a closed conduit than when it is conveyed in an open one, since water in the latter is very much exposed to evaporation.

2) Field Canal Efficiency (Eb)

This is the ratio of water received at the field inlet to the water received at the inlet to a block of fields. Among other factors, this efficiency is affected by the types of lining in respect to seepage losses, by the length of canals and by water management. Piped systems have, of course, higher field canal efficiencies than do open canal systems for reasons explained above.

3) Field Application Efficiency (Ea)

This is the ratio of water directly available to the crop to water received at the field inlet. It is affected, for example, by the rate of supply, infiltration rate of soil, storage capacity of the root zone, land levelling, etc. For furrow and border strip irrigation, water is mostly lost through deep percolation at the head end and through runoff at the tail end, while for basin irrigation it is mostly through deep percolation and evaporation, since the basin is closed.

4) Overall Irrigation Efficiency (Ep)

The overall or project irrigation efficiency of an irrigation scheme is the ratio of water made available to the crop to that released at the pumping station. It is the product of three efficiencies; namely, conveyance efficiency (Ec), field canal efficiency (Eb) and field application efficiency (Ea), and is expressed as below. With reference to No.24 FAO Irrigation and Drainage Paper, a conveyance, distribution, application and an overall project efficiency of 90%, 80%, 60% and 45 % for surface pump irrigation scheme can be adopted in and around Gode area respectively.

Ep = Ec x Eb x Ea (90%, 80%, and 60% can be applied for each of the efficiency)

1.3.6 Calculated Water Requirement (WR)

Table 1.3.4 to Table 1.3.6 show the water requirements for maize, sesame and beans. As shown in the tables, the peak water requirement shows up in June within the crop cultivation period. Given the maximum ETo of 6.28 mm/day with the crop coefficient of 1.15 in June, the design water requirement


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per second per hector unit is given below:

WR = ETo x Kc / Ep = 6.28 mm / day x 1.15(Kc) / Ep (0.9 x 0.80 x 0.6) = 16.7 mm/day = 16.7 mm/day /(60 x 60 x 24) x 10000 = 1.93 l/s/ha (24-hour irrigation) in June = 2.32 l/s/ha (20-hour irrigation) in June = 2.4 l/s/ha (designed unit water requirement, 20-hour irrigation applied)

Table 1.3.4 Calculated Water Requirement (l/s/ha) for Maize Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Min Temperature (°C) 21.2 22.1 23.9 23.9 23.9 23.5 23.1 23.0 23.5 23.0 21.5 21.0

Max Temperature (°C) 35.3 36.4 37.1 35.8 34.5 33.9 33.2 33.6 35.2 34.4 33.8 34.9

Relative Humidity (%) 46 47 59 62 56 54 54 52 58 58 51 51

Wind speed (km/day) 196 205 165 187 294 339 327 258 159 135 151 151

Sunshine (hours) 10.2 9.9 8.2 8.1 7.2 6.6 7.4 8.6 7.6 9.0 9.7 9.7

Radiation (MJ/m2/day) 24.5 24.8 22 21.1 19.3 18.6 20.4 22.6 20.6 21.7 22.1 22.1

ETo (mm/day) 6.75 7.12 5.89 5.64 6.28 6.53 6.73 6.86 5.44 5.12 5.54 5.54

Crop coefficient Kc 0.78 1.15 1.15 0.78 1.15 1.15 1.15

ET x Kc (mm/day) 4.59 6.49 7.22 4.24 5.89 6.37 6.37

Conveyance Efficiency Ec 0.9 0.9 0.9 0.9 0.9 0.9 0.9

Field Canal Efficiency Eb 0.8 0.8 0.8 0.8 0.8 0.8 0.8

Field Application Efficiency Ea 0.6 0.6 0.6 0.6 0.6 0.6 0.6

Irrigation hour (hour) 20 20 20 20 20 20 20

Water requirement 24 hours

(l/s/ha) 1.23 1.74 1.93 1.14 1.58 1.71 1.71


(l/s/ha) 1.48 2.09 2.32 1.37 1.9 2.05 2.05

Source: JICA Team, referring to Crop water requirements No.24 FAO irrigation and drainage paper

Table 1.3.5 Calculated Water Requirement (l/s/ha) for Sesame Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec



Relative Humidity (%) 48 46 47 59 62 56 54.4 54 52 58 58 51

Wind speed (km/day) 184 196 205 165 187 294 339 327 258 159 135 151

Sunshine (hours) 9.74 10.2 9.9 8.2 8.1 7.2 6.59 7.4 8.6 7.6 9.0 9.7

Radiation (MJ/m2/day) 22.6 24.5 24.8 22 21.1 19.3 18.6 20.4 22.6 20.6 21.7 22.1

ETo (mm/day) 6.08 6.75 7.12 5.89 5.64 6.28 6.53 6.73 6.86 5.44 5.12 5.54

Crop coefficient Kc 1 0.78 1.15 1.15 1 0.78 1.15 1.15

ET x Kc (mm/day) 6.08 4.59 6.49 7.22 6.53 4.24 5.89 6.37

Conveyance Efficiency Ec 0.9 0.9 0.9 0.9 0.9 0.9 0.9 0.9

Field Canal Efficiency Eb 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8

Field Application Efficiency Ea 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6

Irrigation hour (hour) 20 20 20 20 20 20 20 20


(l/s/ha) 1.63 1.23 1.74 1.93 1.75 1.14 1.58 1.71


(l/s/ha) 1.96 1.48 2.09 2.32 2.10 1.37 1.9 2.05


Table 1.3.6 Calculated Water Requirement (l/s/ha) for Beans Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec



Relative Humidity (%) 48 46 47 59 62 56 54 54 52 58 58 51

Wind speed (km/day) 184 196 205 165 187 294 339 327 258 159 135 151

Sunshine (hours) 9.7 10.2 9.9 8.2 8.1 7.2 6.6 7.4 8.6 7.6 9.0 9.7

Radiation (MJ/m2/day) 22.6 24.5 24.8 22 21.1 19.3 18.6 20.4 22.6 20.6 21.7 22.1

ETo (mm/day) 6.08 6.75 7.12 5.89 5.64 6.28 6.53 6.73 6.86 5.44 5.12 5.54


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Crop coefficient Kc 0.78 1.05 0.9 0.78 1.05 0.9

ET x Kc (mm/day) 4.59 5.92 5.65 4.24 5.38 4.99

Conveyance Efficiency Ec 0.9 0.9 0.9 0.9 0.9 0.9

Field Canal Efficiency Eb 0.8 0.8 0.8 0.8 0.8 0.8

Field Application Efficiency Ea 0.6 0.6 0.6 0.6 0.6 0.6

Irrigation hour (hour) 20 20 20 20 20 20


(l/s/ha) 1.23 1.59 1.51 1.14 1.44 1.34


(l/s/ha) 1.48 1.91 1.81 1.37 1.73 1.61


1.4 On-Farm Irrigation Method

Proper irrigation water management aims at optimum and efficient use of water for best possible crop production keeping water losses to the minimum. Water is applied to the soil surface by a number of various irrigation methods. These irrigation methods are adopted to irrigate crops with the main objective to store water uniformly in the effective root zone soil with the maximum quantity required and ensured water losses to the minimum and sustain crop production with desired quality of produce.

1.4.1 Classification of Irrigation Methods

The principal methods used for applying irrigation water to irrigated crops are broadly grouped under: 1) Surface irrigation (border, basin and furrow); 2) Sprinkler irrigation (resembling artificial rain); and 3) Drip irrigation (or trickle irrigation or sometimes called it localized irrigation). In general, each irrigation method has certain advantages and disadvantages and should be adopted based on certain principles. The choice of the most appropriate method should thus be based on a set of criteria that serve to minimize water losses while ensuring increased crop yields.

1.4.2 Surface Irrigation Methods

Surface irrigation methods irrigate fields by gravity allowing water to flow over the soil surface from a supply channel at the upper reach of the field. It is the dominant and widely practiced method of irrigation, which accounts for about 95% of irrigation systems worldwide and has been used for thousands of years to irrigate a wide range of crops on different soil types. This method, particularly in Ethiopia, is considered as the most dominant irrigation method being used among the subsistence farmers. There are border irrigation, basin irrigation and furrow irrigation under this method.

1) Border Irrigation

Border irrigation is a controlled flood irrigation in which the land is divided into parallel border strips demarcated from one another by earth ridges. Water is successively delivered into each strip from a head or field ditch at its upper end. The method is designed in such a way that a sheet of water advances down the border and covers all the plots uniformly. A field is divided by borders into a series of strips 3 to 30 m wide and generally from 60 to 300 m long. In terms of slope, the optimum is in between 0.2 to 0.4 percent, although steeper slopes are possible with great care by applying small volumes of water.

The land is leveled between side ridges to make the irrigation water run in a narrow sheet from the upper to the lower end of the field. When irrigation starts, Figure 1.4.1 Example of a Border Strip Irrigation

(Source: Kay, 1986)


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the infiltration rate is high at the upper end of the border, but as the soil becomes saturated, the leading edge of the water continues to move down. The levees or ridges forming the borders to the strips should be 20 to 25 cm high on average. When irrigating, each strip is flooded at the upper end and when the irrigation water has progressed to about 80 percent of the length of the border, cut- off the irrigation water and let the residue pound to irrigate the lower end.

Border method is suited to soils having moderately low to moderately high water intake rates. This type of irrigation is best suited for close growing crops, such small grains as heat and barley, maize, potato, some vegetables, beet, radish, alfalfa and grasses. The main advantages are: less land is wasted for making ridges and channels; efficiency of water application is relatively high; and labor requirement is quite low. The limitations are: precise land leveling is essential; initial cost of land preparation and land grading is high; and the method is unsuitable for uneven and undulating land with shallow soils.

2) Basin Irrigation

A basin is a horizontal area of land surrounded by earthen bunds and totally flooded during irrigation. Basin irrigation is the most common type of surface irrigation. It is particularly used in rice cultivation, where the fields are submerged, but it is equally suitable for other crops like cereals, fruit trees and pastures – as long as water logging conditions do not last for too long. Ideally, the water logging should not last longer than 24-48 hours. It is also used for the leaching of salts by deep percolation in the reclamation of saline soils. A basin irrigation system layout is illustrated in Figure 1.4.2.

The size of basin is critical in the design of this irrigation method, and in general basins are best adapted to regular field shapes (square or rectangular). Table 1.4.1 shows in summary the general criteria for selecting a basin size, and further Table 1.4.2 smmarizes the reccomended basin size according to the scale of strem (volume of flow) together with soil types. It is noted that basin size can increase with larger stream scale, because water will spread more rapidly over the basin.

Table 1.4.1 Criteria for Basin Size Determination (FAO, Irrigation Manual, 2002) Criteria Basin size small Basin size large

Soil type Sandy Clay

Stream size Small Large

Irrigation depth Small Large

Land slope Steep Gentle or flat mechanized

Field preparation Hand or animal traction

Table 1.4.2 Basin Area in m2 for Different Stream Sizes and Soil Types (FAO, Irrigational Manual,2002) Stream size (I/sec) Basin Area in square meter

Sand Sandy loam Clay loam Clay

5 35 100 200 350

10 65 200 400 650

15 100 300 600 1000

30 200 600 1200 2000

60 400 1200 2400 4000

90 600 1800 3600 6000

Figure 1.4.2 Layout of Basin Irrigation (Source: FAO, 1985)


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3) Furrow Irrigation

Furrow irrigation refers to irrigating land by constructing furrows between two rows of crops. In contrast to basin and border irrigations, it involves only wetting part of the surface of the soil and water in the furrow moves laterally by capillaries to the unwetted areas below the ridge and also downward to wet the root zone soil. This reduces evaporation losses, improves aeration of the root zone, less puddling of the soil surface and permits earlier cultivation after irrigation.

In general, furrow lengths range from 60 m to 300 m or more. In principle, furrow lengths are shorter in coarse soils and longer in heavier soils. In this regard, furrow length is as short as 10- 20 m long in vegetable gardens, while for large mechanized irrigation scheme it may be up to 500 m. Efficient furrow irrigation always involves run-off and surface drainage system is required down at the end of the furrow perpendicular to it. The recommended maximum furrow lengths for different soil types and slopes are given in Table 1.4.3.

Table 1.4.3 Recommended Furrow Lengths for Different Slopes, Soil Types and Water Application

Furrow Slope,

(%)

Maximum flow of

water per second

(l/s)

Furrow Length (m)

Soil types and available soil moisture in mm/m depth of soil

Clays Loams Sands

50 75 150 100 150 50 75 100

0.05 3.0 120 300 400 270 400 60 90 150

0.10 3.0 180 340 440 340 440 90 120 190

0.20 2.5 220 370 470 370 470 120 190 250

0.30 2.0 280 400 500 400 500 150 220 280

0.50 1.2 280 400 500 370 470 120 190 250

1.00 0.6 250 280 400 300 370 90 150 190

1.50 0.5 220 250 340 280 340 80 120 190

2.00 0.3 180 220 270 250 300 60 90 150

Source: Irrigation Agronomy Manual, Revised Version, former MoA /ADD, March 1990, Addis Ababa

Furrow irrigation adapts better than any other method to crops that are grown in rows with more than 30 cm spacing such as vegetables, maize, groundnut, sugarcane, cotton, and potatoes. Furrows are usually V-shaped in cross section, 25- 30 cm wide at the top, and 15- 20 cm deep, shallower in lighter soils and deeper in heavier soils. Usually, the spacing between furrows is narrower in sandy soils and wider in heavy soils. Furrow spacing in sandy soils is in a range of 60 to 80 cm, whereas in clay soils 75 to 150 cm and in loam soils 60 to 90 cm. Shallow rooted and transplanted crops using seedlings require small width and shallow depth, while deep rooted crops have wide and deep furrow depth.

Advantages of furrow irrigation are great saving of water as compared to other surface methods, variable size of flow can be used, the water application efficiency is high as compared to other surface methods, wide range of soils can be irrigated using the method, only part of the land is wetted and losses of water by evaporation, runoff and deep percolation are reduced, and salts are accumulated at the upper parts of ridges, not significantly affected the growing crop on the middle of the ridges.

Figure 1.4.3 Layout of Furrow Irrigation Source: Doneen, L.D., and Wescot, D.W. Irrigation Practice and Water Management.

FAO, Irrigation and Drainage Paper. Rome, 1984.


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1.4.3 Sprinkler Irrigation

Sprinkler irrigation refers to the application of irrigation water under pressure in which water is sprinkled in the form of spray or simulating artificial rains. This is achieved by distributing the water under pressure through a system of overhead perforated pipelines to various types of sprinkler heads or nozzles fitted to a riser pipes attached to the system of pipes laid on the ground and spray the water from above onto the crop and land. Sprinkler systems can be fixed in place, portable, semi-portable, or mobile. Sprinkler nozzle types and numbers are selected depending on designed application rates and wetting patterns.

Sprinkler irrigation has advantages over surface irrigation; however, there are certain disadvantages associated with the method as: high capital investment for initial installation of the system; operating cost of sprinkler is high due to cost of energy; technical personnel for its operation and maintenance are required; clean water is required in order to avoid clogging of nozzles; sensitivity of the system to windy conditions that distort the uniform distribution of water; water losses by evaporation from soil surface and plant canopy; hazard of salt accumulation on wetted foliage and requires much more sophisticated design skills and on- farm support, etc.

1.4.4 Drip Irrigation

Drip irrigation refers to the application of water into the soil at slow rates just drop by drop, but frequent and with precise quantities through a small-sized opening called emitters located at, or just above ground level (up to 300 mm and above) directly to the soil surface to irrigate a limited area around each plant. The system suits areas of high temperatures and limited water resources or having high water costs. Drip irrigation is suitable for most soil types and most types of topography. This system allows for the accurate application of water with minimal loss that might occur, due to evaporation, poor distribution and seepage, or over- watering.

It is the most advanced irrigation method with the highest application efficiency of 90 to 95%. The water is delivered continuously in drops at the same point and moves into the soil and wets the root zone vertically by gravity and laterally by capillary action forming a wetted area like an onion shape. The planted area is only partially wetted. Drip irrigation improves the growth rates of high value crops by delivering moisture directly to their root zones. This saves water because only the important parts of the plants are irrigated. Weed growth is reduced since only the plant is irrigated, and working between the plants is easier because of the dry soil.

However, drip irrigation system has also its limitations. Initial cost is high, particularly for installation

Figure 1.4.4 Typical Sprinkler Irrigation System

Source: FAO, Irrigation and Drainage Paper. Rome, 1984

Figure 1.4.5 Components of Drip Irrigation System Source: FAO, Irrigation and Drainage Paper. Rome, 1984


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of the conventional drip system; required more skilled labor in design, management and maintenance; clogging of emitters and lateral blockage from sand and silt, chemical precipitation from groundwater and algae from surface water is the most serious problem; restricted root zone and the plant may be susceptible to logging, due to poor plant anchorage; salt accumulation in the root zone that requires leaching periodically; exposed to mechanical damages; lack of influence on the micro-climate and poor germination may result.

1.4.5 Selection for Suitable Irrigation Methods in Gode Area

Factors to be taken into consideration in selecting the most appropriate irrigation methods are: 1) type of crops to be grown and their rooting depth; 2) sol characteristics of the land to be irrigated such as type, depth and infiltration; 3) available sources of water and size of the flow supplying irrigation water; 4) amount of water to be applied during each irrigation; 5) labor requirements and its availability; 6) energy demand; 7) initial investment cost, etc. Table 1.4.4 summarizes the irrigation methods by those factors, out of which this manual recommends Basin and Furrow Irrigation Method in Gode area especially taking into account the beneficiaries being subsistence farmers:

Table 1.4.4 Technical Factors Affecting Selection of Irrigation Method

Method Crops Soils Labor

(h/ha/irrig.)Energy demand

Potential efficiency, %

Capital cost

Border all crops except rice clay, loam 3.0 low

60 Low Basin all crops clay, loam 0.5 - 1.5 low

Furrow all crops except rice & drilled crops clay, loam 4.0 low

Sprinkler all crops except rice loam, sand 1.5- 3.0 high 75 medium

Drip row crops, orchards all soils 0.2- 0.5 medium 90 High

Source: Guidelines for water management and irrigation development, FAO, 1996.


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CHAPTER 2 OPERATION AND MAINTENANCE

2.1 Organization

2.1.1 Role of Water Users Association (WUA)

A Water Users Association (WUA) is a voluntary, nongovernmental, nonprofit entity established and managed by a group of farmers for the irrigation scheme. Water users consist of farmers who combine their financial, material and technical resources to improve the productivity of irrigated farming through equitable distribution of water and efficient use of the irrigation systems. The farmers, by joining a WUA can have some, or all of the following benefits:

Equitable water distribution among farmers regardless of their location, type of farm, or size of the farm,

More reliable water supply,

Water supply more responsive to crop needs,

Quick dispute resolution at the local level,

Well-maintained canals (decreasing the time of irrigation due to less fluctuation of discharges, reduced losses, etc.), and

Less water theft/ stealing.

1) Objective of WUA

The WUA being the management structure at site (scheme) level and being the owner of the irrigation scheme, it has various objectives, responsibilities and functions in the development process of the irrigation scheme. Among the various objectives, the main ones are:

To coordinate the participation and involvement of the beneficiary communities for equitable irrigation water distribution among the farmers at outlet command basis,

To process and carry out resource mobilization (irrigation water fee, labour contribution, material contribution, etc.),

To avoid disputes and conflicts among the beneficiaries, that may arise due to improper water utilization,

To co-ordinate and carry out regular maintenance activities, and

To facilitate irrigation extension and drainage control work where required in the service area or canal network.

2) The Role of a WUA

The broad role of a WUA is to enable the beneficiaries within the irrigation scheme to pool their resources (financial, human power and expertise) to more effectively carry out water-related activities. The establishment of a WUA will also assist in achieving the purposes of the by-laws and regulations established for the scheme. It firstly enables the members to benefit from addressing their needs in terms of promoting irrigated agriculture. The following are the roles of the WUA:

Protect the interests of all WUA members and other water users within its operational area,

Assure reliable distribution of water among water users,

Resolve disputes that concern water use and management of the irrigation scheme in an appropriate,


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transparent, and democratic manner,

Manage financial and other assets of the WUA,

Maintain, rehabilitate and improve the irrigation scheme in the WUA operational area,

Procure, replace and maintain irrigation equipment,

Take measures to protect the environment, manage pollution, salinization and water logging, as they may affect the performance of the irrigation scheme, and

Train members in the rational use of irrigation water and promote new management techniques and technologies.

3) Participatory Irrigation Management System

Figure 2.1.1 below attempts to summarize how, in theory, WUAs should translate into a stream of benefits. The establishment of WUAs comes with two major issues for farmers: the need to organize and the need to mobilize their own resources, in kind (e.g. voluntary labor) and in cash (irrigation service fee). These two issues are clearly a cost to farmers.

On the benefit side, however, there are better maintenance of infrastructure through both financial and in kind contribution and also –possibly- participation in the planning and execution of related works. In addition, better coordination between managers (supply) and farmers (demand) is likely to result in an increase in efficiency and reliability of irrigation water supply. Conflict mediation and local water management by WUAs should also result in more equitable water distribution. All these outcomes should translate in concrete benefits to farmers in terms of yield increase, possibility to diversify out to cash crops, and ultimately higher incomes.

4) The Operational Principles of a WUA

The operation principles of a WUA are given of the following;

Figure 2.1.1 Irrigation System Managed by WUA


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Encourage WUA member participation in the operation and management of irrigation systems,

Adhere to democratic principles, fairness, and equity, and consider suggestions, ideas and opinions from all the members,

Provide operational and financial information to all the WUA members,

Assure accurate and equal distribution of water among WUA members, and

Ensure careful and efficient use of irrigation water.

2.1.2 Internal Set-up of Water Users’ Association

Role and authority on planning, decision-making and implementation should be clearly defined in a WUA as indicated in the Figure 2.1.2. For example, when an WUA thinks about the following dry season crop, they go through a process of planning of water use and allocation, decision-making of the plan, and execution of the approved plan. Authority for these three aspects must be independent at the levels of Planning Committees, General Assembly, and Executive Committee.

The highest organ in the WUA should be the General Assembly as indicated in the above Figure 2.1.2, which shall be composed of all the WUA members. This is the supreme organ in the WUA especially vested in the decision making power. All the plans shall be forwarded to the general assembly and the decision shall be made in this assembly, meaning all the important decision shall be made by the entire member themselves.

Under the general assembly, there should be the executive committee in charge of responsibility of execution and day-to-day management of the irrigation scheme. The members of the executive committee shall, of course, be selected by the general assembly, and in general the members would be composed of; 1) chairperson, 2) vice chairperson, 3) O&M responsible, 4) treasurer, 5) auditor, and 6)

General Assembly

Executive Committee

Decision Making

Planning

Sub-Group-4

Member, Member, Member, Member,




Member, Member,





Member, Member,





Member, Member,





Member, Member,

Sub-Group-1 Sub-Group-2 Sub-Group-3

Implementation

Any plan should be forwarded to the General Assembly for its Approval.

Agriculture Dev. Committee

Figure 2.1.2 Internal Organization Setting-up for the Irrigators’ Association

Financial Mgt Committee

Water Management Committee

Any decision made by the General Assembly shall be executed by all the members under the supervision of the Management Committee.


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members. This composition can be modified as the general assembly is to decide.

Planning will be done by a committee like agriculture development committee or water management committee depending upon the issue formed by volunteers or elected persons within the association (see the 3rd row from the top in Figure 2.1.2 above). These committees can be led by the members of the executive committee; e.g., vice chairperson may lead the Agriculture Development Committee, O&M responsible person may lead the Water Management Committee, and likewise treasurer may lead the Financial Management Committee. The basic role of the planning committees is to prepare for a plan, and forward it to the General Assembly.

The members included in the executive committee shall be the leaders of sub-groups (see 4th row from the top). The sub-groups are established by irrigation block, namely irrigation area commanded by specific field canals. There are 4 sub-groups to be established per scheme. This sub-group is in charge of their own irrigation area in terms of operation, maintenance, and management. For example, though the maintenance of the main canal shall be done by all the members, or selected members from each sub-group, such maintenance pertinent to the irrigation block shall all be made within the sub-group members.

The lowest cadre of the WUA is the members, i.e. general membership. They are organized under their respective sub-group. They are located at the lowest cadre of the association, while they can discharge their supreme power at the level of the general assembly whenever they are to do some important decision making. They are the element of the supreme organ of the association; namely, general assembly, while they are the implementers at the lowest cadre. They are the highest in terms of decision making while they the base in terms of implementation.

In above regard, executive committee is, in principle, in charge of execution or day-to-day management of the irrigation scheme. It means that the executive committee shall be in charge of supervision of implementation activities. The implementation is in fact carried out according to the decision made by the general assembly. The executive committee shall have no power in decision making, but have the power to supervise the implementation. In this sense, the chairperson of the executive committee is a CEO, chief executive officer.

2.2 Operation

2.2.1 Pump Operation

There are several types of pumps available on the market. All pump manufacturers provide users' operation and maintenance manuals specific to their pumps. These have to be closely adhered to in order to ensure the most efficient operation of the pump and avoid unnecessary pump breakdowns. In view of the wide variety of operational instructions, which can be expected for different pumps, only general guidelines can be provided here.

1) Pump Start-up

There are certain procedures that are recommended by pump manufactures before any pump start-up. Some of the pre-start-up inspections recommended immediately after the pump installation are checking for correct pump-motor wiring connections, valve connections, shaft and gland clearance. It has to be remembered that starting a pump under dry condition will cause seizing or destructive wear between the pump components. Therefore, pumps that are not self-priming or those with a positive suction lift should be primed before they are started.

2) Starting the Pump

Pump is started with the gate valve closed. This is because the pump operates at only 30-50% of full


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load when the discharge gate valve is closed. Only in cases where the pump is below the water source, the pump can be started with an open gate valve. To avoid water hammer, the gate valve has to be opened gradually until it is fully opened. Before starting the pump, such tasks must be performed as; 1) open the suction valve, and 2) open any recirculation or cooling lines.

3) Pump Operation

General considerations which need attention during pump operation are as follows:

Vary the capacity with the regulating valve in the discharge line. Never throttle the flow from the suction side since this can result in decreased performance, unexpected heat generation, and equipment damage.

Do not overload the driver since such driver overload can result in unexpected heat generation and equipment damage. The driver can overload only in such circumstances as; 1) the specific gravity of the pumped fluid is greater than expected, and 2) the pumped fluid exceeds the rated flow rate.

Make sure to operate the pump at or near the rated conditions. Failure to do so can result in pump damage from cavitation or recirculation. Monitor all gauges to ensure that the pump is running at or near rating and that the suction screen (when used) is not clogged.

Never operate any pumping system with a blocked suction and discharge. Operation, even for a brief period under these conditions, can cause confined pumped fluid to overheat, which may result in a violent explosion. Pump operation must take all necessary measures to avoid this condition.

4) Shut-down (Stopping) the Pump

The first step for stopping pumps is to close the gate valve. This eliminates surges that may occur in case of an abrupt closure. When this has been done, the prime mover is then closed or shut down. If the pump remains idle for a long time after it is stopped, it gradually looses its priming. Thus the operator should re-prime the pump every time before start-up. The two main steps to shut down the pump are; 1) slowly close the discharge valve (gate valve), and 2) shut down and lock the driver to prevent accidental rotation.

2.2.2 Water Distribution System

Water flowing in a main irrigation canal can be divided over the secondary (field) canal network in several ways. One way is to divide the flow proportionally over these secondary canals; another is to divide the time of supply and thus to divert the flow to each secondary canal in turn; and a third way is to supply a secondary canal with water upon request.

1) Proportional Distribution

Proportional distribution of irrigation water means that flow in a canal is divided equally between two or more smaller (field) canals. The flows in these canals are proportional to the areas to be irrigated by each of them. Each canal is given a portion of the flow. These portions correspond to the portion of the total area, which is irrigated by that canal. This is so considered that the flow in a main canal is divided among the secondary (field) canals.

2) Rotational Distribution

Rotational distribution of irrigation water means that the whole flow in the main irrigation canal is diverted to the secondary (field) canal in turn. For instance, in the case of secondary (field) canals, it means that each secondary canal is without water for part of the time and, when supplied, it transports the whole “primary” flow. The same can apply to the distribution of the flow of secondary canals into on-farm canals, and rotational distribution can be carried out within the on-farm canals.


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3) Delivery on Demand

Delivery on demand can be based on requests from farmers or a group of farmers. In such a delivery system, water is directed only to those canals where farmers have announced that they need water. Since the demand varies, the duration or the size of flow, or both, need to be controlled to accommodate this variation. In order to control the flows to the requests, so-called ‘cross regulators’ are needed in the canal network.

< Example of Gode Irrigation Development Scheme >

Gode irrigation development scheme has selected a “Rotational Distribution” system. The service area is divided into 4 areas, (each 25 ha area, totaling 100 ha), and the irrigation water is supplied to the 4 areas by rotation every 4-day. The water delivery plan of the Gode irrigation development scheme is illustrated below:

Area : 4 area x 25 ha =100ha Interval of water supply: Every 4-day

Irrigation (1st day)

Irrigation (2nd day) Irrigation (3rd day)

Irrigation (4th day)

Water supply area

Water supply area

Water supply area

Water supply area


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2.2.3 Field Intake Methods

1) Breaches

A breach (see Figure 2.2.1) is a cut in the channel (on-farm canal) embankment to allow water to flow into the field. After completing the irrigation, the farmer is supposed to close the embankment again. This has to be done carefully to prevent leakage and erosion. This is the most common method of releasing water from a channel, but it can also be the most damaging. Not only is it difficult to control the discharge, but there can be serious erosion of the channel embankment often difficult to repair.

2) Gated Intake

A gated intake structure is made of wood, masonry or concrete, and is equipped with a gate. Such a structure enables the farmer, or gate operator, to control the water inflow. However, in comparison with the aforementioned breach, it is expensive since it requires artificial materials such as cement, iron bars, and steel, etc. On the other hand, the intake can well control the water flow with minimum working load.

3) Siphons

Siphons are small diameter pipes used to convey water over the channel embankment (see Figure 2.2.2). At least several numbers of pipes should be prepared and progressively used from the upstream side towards the downstream side. As it does not require breach in the embankment of channel unlike the one shown in Figure 2.2.2, it can entail the protection of the bank.

4) Spiles

Spiles are small pipes buried in the ditch bank (see Figure 2.2.3). The system is very simple but needs to prepare for material(s) in order to clog the pipes when the water is not needed for irrigation. The materials to be used for clogging the pipes are in most cases just clod of clay soils, rugged cloths, etc.

2.2.4 Basin Irrigation

1) Direct Method

Irrigation water is led directly from the on-farm channel into the basin through breaches, siphons, or spiles as discussed above. Figure 2.2.4 below shows that "Direct Method of Water Supply" is irrigated and so on. This method can be used for most crop types and is suitable for most soils.

Figure 2.2.2 Siphons Source :FAO Irrigation Water Management

Figure 2.2.3 Spiles Source :FAO Irrigation Water Management

Figure 2.2.1 Breaches Source :FAO Irrigation Water Management


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Figure 2.2.6 Ideal Wetting PatternSource :FAO Irrigation Water Management

2) Cascade Method

On sloping land, where terraces are used, the irrigation water is supplied to the highest terrace, and then allowed to flow to a lower terrace and so on. In Figure 2.2.5, the water is supplied to the highest terrace and is allowed to flow through terrace until the lowest terrace is filled. The intake of terrace is then closed and the irrigation water is diverted to terrace until (b.1), (b.2) and (b.3) are filled, and so on.

This is a good method to use for those farm lands where percolation and seepage losses are low. However, for other crops on sandy or loamy soils, percolation losses can be excessive while water is flowing through the upper terraces to irrigate the lower ones and it also exposes the land for serious erosion and at the same time diseases can easily transfer from one terrace to other terraces.

3) Wetting Patterns

If crops receive too little water, they will suffer from drought stress, and yield may be reduced. If they receive too much water, then water is lost through deep percolation and, especially on clay soils, permanent pools may form, causing the plants to drown. How the irrigation water can be evenly distributed in the root zone is therefore an issue.

To obtain a uniformly wetted root zone, the surface of the basin must be leveled and the irrigation water must be applied quickly. Figure 2.2.6 shows an ideal wetting pattern: the basin is level and the right quantity of water has been supplied with the correct size. As can be seen from Figure 2.2.6, it is not possible to have the wetting pattern and root zone coincide completely.

Figure 2.2.5 Cascade Method of Water SupplySource :FAO Irrigation Water Management

b.3

b.2

a.3

a.2

a.1 b.1 c.1

c.2

c.3

Figure 2.2.4 Direct Method of Water SupplySource :FAO Irrigation Water Management

Direct Method of Water Supply in Gode Demonstration Farm


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4) Maintenance of Basins

Bunds are susceptible to erosion which may be caused by, for example, rainfall, flooding or the passing of people when used as footpaths. Rats may dig holes in the sides of the bunds. It is therefore important to check the bunds regularly, notice defects and repair them instantly, before greater damage takes place. Before each growing season, the basins should be checked to see that they remain level. During pre-irrigation it can easily be seen where higher and lower spots are, and therefore there should be smoothed out. Also, the field channels should be kept free from weeds and silt deposits.

2.2.5 Irrigating Furrows

1) Method of Irrigating Furrows

Water is supplied to each furrow from the field canal, using siphons or spiles. When there is a water shortage, it is possible to limit the amount of irrigation water applied by using 'alternate furrow irrigation'. This involves irrigating alternate furrows rather than every furrow. Instead of irrigating every furrow after 10 days, furrows 1, 3, 5, etc. are irrigated after 5 days and furrows 2, 4 and 6, etc. are irrigated after 10 days. Thus the crop receives some water every 5 days instead of a large amount every 10 days. Small amounts applied frequently in this way are usually better for the crop than large amounts applied after longer intervals of time.

Runoff at the ends of furrows can be a problem on sloping land. This can be as much as 30 percent of the inflow, even under good conditions. Therefore a shallow drain should always be made at the end of the field, to remove excess water. When no drain is made, plants may be damaged by water logging. Light vegetation allowed to grow in the drain can prevent erosion. Excessive runoff can be prevented by reducing the inflow once the irrigation water has reached the end of the furrows. This is called cut-back irrigation. It may also be possible to reuse runoff water further down the farm.

2) Wetting patterns

In order to obtain a uniformly wetted root zone, furrows should be properly spaced, have a uniform slope and the irrigation water should be applied rapidly. As the root zone in the ridge must be wetted from the furrows, the downward movement of water in the soil is less important than the lateral (or sideways) water movement. Both lateral and downward movement of water depends on soil type as can be seen in Figure 2.2.8.

Figure 2.2.7 Alternate Furrow IrrigationSource :FAO Irrigation Water Management

Figure 2.2.8 Different Wetting Patterns in Furrows, Depending on the Soil Type Source :FAO Irrigation Water Management

(a) Soil Type (SAND)

(b) Soil Type (LOAM) (c) Soil Type (CLAY)


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Figure 2.2.10 Effect of a Cross-slopeon the Water Movement in a Border Source :FAO Irrigation Water Management

In an ideal situation, adjacent wetting patterns overlap each other, and there is an upward movement of water (capillary rise) that wets the entire ridge (Figure 2.2.9), thus supplying the root zone with water.

To obtain a uniform water distribution along the furrow length, it is very important to have a uniform slope and a large enough stream size so that water advances rapidly down the furrow. In this way large percolation losses at the head of the furrow can be avoided. The quarter time rule is used to determine the time required for water to travel from the farm channel to the end of the furrow, in order to minimize percolation losses. Poor wetting patterns

3) Maintenance of Furrows

After construction, the furrow system should be maintained regularly; during irrigation it should be checked if water reaches the downstream end of all furrows. There should be no dry spots or places where water stays ponding. Overtopping of ridges should not occur. The field channels and drains should be kept free from weeds.

2.2.6 Irrigating Borders

1) Method of Irrigating Borders

Borders are irrigated by diverting a stream of water from the channel to the upper end of the border. The water flows down the slope. When the desired amount of water has been delivered to the border, the stream is turned off. This may occur before the water has reached the end of the border. There are no specific rules controlling this decision. However, if the flow is stopped too soon there may not be enough water in the border to complete the irrigation at the far end. If it is left running for too long, then water may run off the end of the border and be lost in the drainage system. As a guideline, the inflow to the border can be stopped as follows:

・ On clay soils, the inflow is stopped when the irrigation water covers about 60% of the border. If, for example, the border is 100 m long a stick is placed 60 m from the farm channel. When the water front reaches the stick, the inflow is stopped.

・ On loamy soils, it is stopped when 70 to 80% of the border is covered with water.

・ On sandy soils, the irrigation water must cover the entire border before the flow is stopped.

2) Wetting Patterns

As with the other irrigation methods, it is important to ensure that adequate irrigation water is supplied to the borders so that it fills the root zone uniformly. However, there are many common problems which result in poor water distribution. These include Poor land grading, wrong stream size, stopping the inflow at the wrong time.

Figure 2.2.9 Ideal Wetting PatternSource :FAO Irrigation Water Management


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2.1) Wrong Stream Size

A stream size which is too small will result in deep percolation losses near the field channel (Figure 2.2.11), especially on sandy soils.

If the stream size is too large the water will flow too quickly down the border and the point where the flow should be stopped is reached before sufficient water has been applied to fill the root zone (Figure 2.2.12). In this situation the flow will need to be left running until the root zone has been adequately filled and this results in considerable losses from surface runoff. Large stream sizes may also cause soil erosion.

2.2) Inflow Stopped at the Wrong Time

If the inflow is stopped too soon, the water may not even reach the end of the border. In contrast, if the flow is left running too long, water will run off the border at the downstream end and be lost in the drainage system.

3) Maintenance of Borders

Maintenance of borders consists of keeping the border free from weeds and uniformly sloping. Whatever damage occurs to the bunds must be repaired and the field channel and drains are to be weeded regularly. By checking frequently and carrying out immediate repairs where necessary, further damage is prevented.

2.3 Maintenance

A newly-built irrigation scheme is expected to function for thirty years or more. Items such as a car or a motorcycle have a much shorter life expectancy, often less than ten years. Yet, in many places where irrigation schemes can be seen which have deteriorated after only a few years of service, cars and motorcycles can also be found that are fifteen or twenty years old and still running. This story entails how important maintenance works are.

2.3.1 Maintenance of Irrigation Scheme

1) Routine Maintenance

Daily routines which do not require special skills are; 1) greasing of gates; 2) removing vegetation

Figure 2.2.11 Stream Size too SmallSource :FAO Irrigation Water Management

Figure 2.2.12 Stream Size too LargeSource :FAO Irrigation Water Management


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from embankments, canals and drains; 3) removing silt from canals, drains and structures. On the other hand, daily routines which require skilled artisans, such as a mechanic, a mason, a carpenter and a painter are; 1) repairs to gates and measuring structures; 2) repainting of steel structures; 3) installation of water level gauges; 4) maintenance and small repairs of pumps and engines.

In addition to above works, such off-season maintenance are required as; 1) major repair or replacement of gates, pumps, and engines; 2) large-scale silt clearance from canals and drains; and 3) large-scale maintenance of roads and embankments

2) Emergency Works

Emergency works require immediate and joint action by government staff and farmers, to prevent or reduce the effects of unexpected events such as; 1) breach or overtopping of canal embankment or river dike, causing flooding; 2) critical failure of pumps or head works, causing interruption of irrigation water supply; and 3) natural disasters such as floods, earthquakes or typhoons.

3) Scheme Improvement

The routine maintenance and emergency repairs described above are all aimed at keeping or restoring the technical infrastructure in the condition it was in when it was newly built. There are a number of reasons, however, not just to maintain the scheme in its original condition, but to gradually improve it. The main reasons are:

A newly constructed scheme is hardly ever perfect. Some alterations are usually necessary to make it fully operational.

It is sometimes better to construct a scheme at minimum capacity, with low cost structures. Then, if the scheme proves to be a success, it can be gradually expanded and the structures replaced with more permanent ones.

Conditions change, both inside and outside the scheme. Improvements are necessary to ensure that the scheme continues to deliver services that correspond to farmers’ needs.

4) Management of Maintenance Activities

The objectives of maintenance management in an irrigation scheme are; 1) to keep the scheme in good operating condition so that it will provide uninterrupted service; 2) to extend the useful life of the scheme; and 3) to achieve the lowest possible cost of maintenance. The need for repair for an irrigation scheme may be the result of; 1) routine inspection by operator/beneficiaries, 2) periodic inspection by government staff, 3) breakdown, and 4) emergency requirement (flood, pump failure, etc.).

5) Planning Maintenance

Planning maintenance activities means deciding what activities should be done, who should do them, and when. The maintenance needs identified at an annual inspection will not all have the same degree of urgency. Other activities, such as silt or vegetation removal from a canal, may safely be planned a few months later. The main factors to consider when setting priorities are mainly; 1) safety/risk to human life and risk of structural failure; and 2) effect on crop production due to interruption of water deliveries.

Figure 2.3.1 Weeding, Cleaning and De-siltingSource :FAO Irrigation Water Management


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2.3.2 Canal Maintenance and Repair

1) Introduction

Irrigation canals function well so long as they are kept clean and if they are not leaking. If no attention is paid to the canal system, plants may grow and the problem of siltation may arise. Even worse, the canals may suffer from leakages. Even when a canal is well maintained, serious technical problems may arise. These problems need to be solved by repair or improvement works. A repair should usually be done as soon as possible, depending on the severity of the problem. Improvements may be postponed until the end of an irrigation season, when canals are dry and farmers have more time available.

2) Canal Maintenance

A good maintenance programme can prolong the life of canals. A routine and thorough maintenance works should be kept conducted every year and season. Maintenance of an irrigation canal system is usually carried out in between two irrigation seasons, or at times of low water demand. It consists of cleaning, weeding, desilting, re-shaping, and executing minor repairs (refer to Figure 2.3.1).

3) Reduction of Seepage Losses

Parts of a canal bank or the entire bank can be highly permeable to water. Water that seeps through the banks will be lost for irrigation and may create water logging in the fields and roads adjacent to the canal. There are two ways to overcome seepage problems, either reduce the permeability of the canal bank or line the canal.

4) Reducing the Permeability of a Canal Bank

The permeability of a canal bank can be reduced by compacting the center, or core of the embankment. The core is first excavated by digging a narrow trench, and then replaced with soil in layers, compacted each layer. The compacted core should extend above the water level. The procedure is shown Table 2.3.1.

Table 2.3.1 Procedure of Reducing the Permeability

Step Figure

Step 1:

Remove the vegetation on the canal bank and the top of

the bank.

Step 2:

Excavate a narrow trench near the inner side of the canal

bank. A trench is excavated in the permeable section of the

canal. The width of the trench is at least 0.5 x the water

depth in the canal. The bottom of the trench should be

some 20 cm below the original ground surface elevation.


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Step 3:

Compact the bottom of the trench with a manual tamper

and replace the soil in layers of about 5 to 10 cm each.

Step 4:

Fill and compact the trench until the top is reached.

Source: FAO Irrigation Water Management

5) Repairing of a Leak

Most irrigation canals will leak. A hole or a crack in the bank of a canal, through which water is leaking, is easily observed since the fields adjacent to the leaking canal will get wet. A hole or a crack in the bed of a canal is difficult to see, unless the canal is dry and the bed is inspected very carefully. Leaks should be repaired immediately after they have been observed. The procedure for repairing a leak is shown Table 2.3.2.

Table 2.3.2 Procedure of Repairing of a Leak

Step Figure

Step 1:

Empty the canal and indicate the location of leakage with

pegs. They are placed at its entrance in the canal bed and

at its exit in the outer bank.

Step 2:

Remove the vegetation and keep it apart. Excavate the

canal bank to well below and besides the leak. The canal

bank which leaks is excavated in steps, with the smallest

step well below the leak.

Step 3:

Rebuild the canal bank by filling the bank in layers with

moist soil, and compact each layer well.


6) Reshaping an Eroded Cross-section

The reshaping and widening of an eroded cross-section involves the following steps (Table 2.3.3).


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Table 2.3.3 Procedure of Reshaping and Widening of an Eroded Cross-Section

Step Figure

Step 1:

Construct a wooden template. If the original side

slopes had been constructed too steeply and thus

were unstable, make the template so that the new

side slopes are flatter. The top width of the canal is

then larger while the bed width remains the same.

Care must be taken to avoid narrowing the original

canal bank crest widths.

Step: 2

Hammer in reference pegs to indicate the original

level of the canal banks on each side of the canal.

Excavate the bed and sides of the eroded canal

section in steps until they reach slightly below the

actual bed level so that the new soil to be placed will

make better contact with the original ground surface.

Step: 3

Fill and compact moist soil layer by layer, using the

template for final shaping. Each layer to be

compacted should not be thicker than 5 to 10 cm.

Step 4:

Check the cross-section and bank levels with the

template and the reference pegs.


7) Repair of Cracks and Gullies in a Canal Embankment

The repair of cracks and gullies in a canal embankment involves the following steps (Table 2.3.4).

Table 2.3.4 Procedure of Repairing of Cracks and Gullies in a Canal Embankment

Step Figure

Step 1:

Remove any plants from banks which show cracking

and in which small gullies have been formed by

overtopping water or by heavy rainfall.

Step 2:

In the case of deep cracks and gullies, excavate the

bank partly. Small cracks are to be filled with fine

textured soil, moistened and compacted.


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Step 3:

Rebuild the bank by filling in layers and compacting

the moist soil.


< Example of Gode Irrigation Development Scheme >

In Gode area of Somali region, there is a severe sand storm taking place from June to September. Such schemes constructed in Gode area, Somali region, must be prepared for and maintained against the sand sediment for main and field canals. Since the sand is very fine, it can be easily brought about into the canals by wind. Therefore, schemes in the area shall be equipped with windbreak as shown below enclosing the irrigation area, and also periodical maintenance for dredging the sand shall be carried out every prior to the commencement of irrigation season.

Windbreak

Dredging the main canal

Dredging the field canal


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CHAPTER 3 ENVIRONMENTAL AND SOCIAL CONSIDERATION

3.1 Environmental Legislative and Institutional Framework in Ethiopia

Constitution of the Federal Democratic Republic of Ethiopia-1995 stipulates that the design and implementation of programs and projects of development shall not damage or destroy environment, and the government and citizens shall have the duty to protect the environment (Article 92). In addition, the Environmental Policy of Ethiopia-1997 sets policies for environmental assessment, among which are:

1) To ensure that preliminary and full environmental impact assessment for the projects are undertaken by the relevant implementing agency (public or private sector) as well as to ensure regular monitoring of the implemented projects,

2) To ensure that environmental impact assessment consider not only physical and biological impacts but also address socio-economic conditions, and

3) To ensure that development projects and programs recognize any environmental impacts early and incorporate their containment into the development design process.

Environmental Protection Authority (EPA), initially established in the year 1997 and reorganized in 2002 through Proclamation Number 295, is the sole responsible body for dealing with environmental issues in Ethiopia. The Authority is headed by the Director General, who is assisted by a Deputy and Special Adviser. The objective of EPA is to formulate policies, strategies, laws and standards which foster social and economic development in a manner that enhances the welfare of humans and safety of the environment sustainably, and to spearhead in ensuring the effectiveness of the process of their implementation.

3.2 Environmental Examination Level for Irrigation Development Projects

A proclamation No.299/2002 was issued as the Environmental Impact Assessment Proclamation. This proclamation states: definitions of environmental related terms, considerations to determine the environmental impacts, projects requiring EIA, duties of the proponent, required EIA report, validity of approval, public participation, etc. With respect to the ‘projects requiring EIA’, this proclamations only states that every project which falls in any category listed in any directive issued pursuant to this Proclamation shall be subject to environmental impact assessment.

Accordingly, the government issued a Directive No.1/2008 which determines projects subject to environmental impact assessment. Table 3.2.1 summarizes the projects requiring EIA, in which one can see what irrigation development projects require EIA. The table specifies that irrigation development projects requiring EIA are those ones whose irrigated area is 3,000 ha or more. None of such projects would in most cases be implemented in Somali region, especially Gode area. In addition, it can be noted that the potential irrigable areas in Somali region, especially Gode area, are not suited in any of environmentally sensitive areas and ecosystem (national park, wildlife reserve and sanctuaries, habitant of rare/endangered or threatened plants and animals) as related to No.17 in the table.

Table 3.2.1 Project Types subject to Environmental Impact Assessment No. Project Types 1. Mine Exploration that is subject to Federal Government Permit 2. Dam and Reservoir Construction

Dam height 15 meter or more, or Reservoir storage capacity 3 million m3 or more, or Power generation capacity 10 MW (Mega Wat) or more.

3. Irrigation Development Irrigated area of 3,000 ha or more


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4. Construction of Roads (Design Standard DS1, DS2 and DS3) with a traffic flow of 1000 or more Railway Construction

5. Taking Fish from Lakes on a commercial Scale 6. Horticulture and Floriculture Development expert 7. Textile Factory 8. Tannery 9. Sugar Refinery

10. Cement Factory 11. Tyre Factory with Production Capacity of 15,000 Kg/day or more 12. Construction of Urban and industrial waste disposal facility 13. Paper Factory 14. Abattoir Construction with Slaughtering Capacity of 10,000/year or more 15. Hospital Construction 16. Basic Chemicals and Chemicals products Manufacturing Factory 17. Any project planned to be implemented in or near areas designated as protected 18. Metallurgical Factory with a Daily Production Capacity of Equal or More 24,000 Kilogram. 19. Airport Construction 20. Installation for the Storage of Petroleum with a Capacity of 25,000 Liters or more. 21. Establishment of Industrial Zone 22. Condominium Construction

Source: Directive No.1/2008, A Directive issued to determine projects subject to environmental impact assessment

Besides, Environmental Impact Assessment Procedural Guideline Series 1 (2003) published by EPA stipulates only those projects that are likely to entail significant adverse environmental impacts require full environmental impact assessment (EIA) while the others just need preliminary assessment (PA). According to this document, agricultural (irrigation) activities carried out over a land area less than 500 hectares do not require EIA, but need PA only. In fact, projects to be carried out in Somali region, especially in Gode area, would not deal with any more than 500 ha agriculture (irrigation) development. Therefore, most of the irrigation development projects carried out in Somali region, and especially in Gode area, are not subject to full EIA but PA only.

In above regards, this Guideline deals only with irrigation development projects not requiring full EIA but PA only. Preliminary assessment (PA), or any environmental examination procedure, starts with scoping of the probable environmental impacts, followed by establishment of terms of reference for the environmental examination for those items identified through the scoping, environmental and social examination which is the main part of PA, setting up of mitigation measures for those negative impacts, and finally monitoring plan establishment.

3.3 Procedure of Environmental Examination

3.3.1 Scoping of the Environmental Impact

Scoping is carried out at an early step in the environmental and social examination upon the planned irrigation development project. The purpose of scoping is to identify: 1) the important issues to be considered in an environmental and social examination, 2) the appropriate time and space boundaries of the environmental study, 3) the information necessary for decision-making whether the project should be carried out, with modification when required, or cancelled, and 4) the significant effects and factors to be studied in detail under the environmental and social examination.

Scoping matrix for the environmental and social impacts associated with the irrigation project shall be prepared for. The scoping shall be carried out covering not only construction phase but also operation phase separately, and the environmental parameters can be decided with reference to similar examples and also by referring to guidelines (e.g. JICA environmental guideline, April 2010). The scoping usually identifies that no serious negative impact is expected by the project, while some parameters may be identified to have some negative impact as indicated by –B.

Those parameters identified as –B during the construction could be: Land use and utilization of local resources, Local conflict of interests, Heath and sanitation, spread/outbreak of water-borne and water


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related diseases, Soil contamination, and Accidents. Such environmental parameters identified as –B should go through the environmental examination with mitigation measures when required. Prior to the examination, of course, TOR for the examination shall be prepared.

There may be unknown parameters at this scoping stage, which may be Inequity in benefit distribution, Water rights and rights of common, Surface and groundwater quality, Soil erosion, Hydrological situation, River flow, Air pollution, Water pollution, Waster, Noise and vibration, Siltation/ sedimentation, etc. These parameters shall also be examined whether they give negative impact or not, and if so, mitigating measures have to be proposed.

3.3.2 Environmental and Social Examination

Following the terms of reference (TOR) established on basis of the results of scoping, Environmental and Social Examination should be carried out for those environmental parameters identified ‘negatively affected’ or ‘unknown’. The examination is in general carried out based on information obtained through field surveys; output of workshops; inquiry to people in the project area; and technical discussions with officials concerned. The examination should undertake not only negative impacts but also positive impacts which are to be brought about by the irrigation project.

Examination results regarding the environmental and social impacts shall be so summarized as to compare those at scoping stage. An example is given of the following Table 3.3.1, in which environmental parameters are firstly listed up, and then results at the scoping stage are shown in a 4-level as A – D, followed by the results again classified by the 4-level at this examination stage, together with reasons/remarks. Note that the results for both scoping and examination stages are further explored by construction phase and operation phase.

Table 3.3.1 Example of Environmental Evaluation for Gode Irrigation Project

Soc

ial E

nviro

nmen

t

No. Environmental

Parameters

Scoping Evaluation Examination Results

Reason Const’n phase

Operation phase

Const’n phase

Operation phase

1 Involuntary Resettlement

D D D D No resettlement is planned. The irrigated land was not owned by anyone and allocated by the government for the development.

2 Local economy such as employment and livelihood, etc.

+B +B +B +B Construction creates job employment opportunity, and also irrigation provides farming livelihood.

3 Land use and utilization of local resources

-B -B -B -B Occurrence of local conflicts on project advantages may arise. Especially selection of the beneficiaries may entail this problem.

4 Social/traditional decision-making institutions

D D D D It is a scale project, and no impact to the traditional decision making system is expected.

5 Existing social infrastructures and services

D D D D Around the project area, no social infrastructure exists.

6 The poor, indigenous and ethnic people

D D D D Not applicable for the indigenous and ethnic people. For the poor people in the beneficiary villages, priority land allocation is arranged.

7 Inequity in benefit distribution

C C -B -B Some people may get more benefits while the other less, especially in terms of land allocation.

8 Cultural heritage D D D D Not applicable


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9 Local conflict of interests

-B -B -B -B Conflicts on project benefits on the land allocation, and also the selection of beneficiaries.

10 Water Rights and Rights of Common

C C D D There is much amount of water in the river, so all the beneficiaries can access to the water

11 Heath and Sanitation

-B C -B D During operation stage, no impact is expected except for No.12.

12 Spread/outbreak of water-borne and water related diseases

-B -B -B -B With irrigation water, some water related disease, such as Malaria may spread

Nat

ural

Env

iron

men

t

13 Topography/Geographical features

D D D D Irrigation facilities are small, whereby no impact is expected.

14 Surface and groundwater quality

C C -B -B Use of agrochemicals may deteriorate the quality of surface water and groundwater if excessively used.

15 Soil Erosion C C D -B When excessive water is applied, soil erosion will take place in the fields.

16 Hydrological situation

D C D D Water pumped up from the River is very small amount as compared to the river flow amount.

17 River flow D C D D ditto

18 Flora, Fauna and Biodiversity

D D D D Not applicable

19 Meteorology D D D D Not applicable

20 Landscape D D D D Irrigation canals and water structures are small scale whereby no big change is expected.

21 Global Warming D D D D Not applicable

Pol

lutio

n

22 Air Pollution C C D D It is a very minimal level, so no impact is given to surround areas. Also, no pubic facilities where people gather around the construction sites.

23 Water Pollution C C D D It is a small construction and small scale irrigation project, so no impact is expected.

24 Soil Contamination -B -B -B -B Due to construction works and use of agrochemicals in irrigated lands.

25 Waste C D -B D During construction works, contractor may discharge waste if not properly regulated..

26 Noise and Vibration

C C D D Around the construction sites, no public facilities where people gather are located, so claim takes place.

27 Ground Subsidence

D D D D Not applicable

28 Offensive Odor D D D D Not applicable

29 Siltation/ Sedimentation

D C D -B +B

As a result of use of turbid river water, siltation will take place along canal. On the other hand, turbid water will enrich the fields.

30 Accidents -B C -B D During construction stage, accidents may take place if the contractor does not pay attention to passers-by. During operation, since very little traffic is expected, no impact will take place.

Rating: -A: Serious negative impact is expected. +A: Positive impact is expected. - B: Some negative impact is expected. + B: Some positive impact is expected. C: Extent of impact is unknown, but impacts may become clear as study progresses. D: Not Applicable (No impact is expected).


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3.3.3 Mitigation Measures and Monitoring

Through the above procedure, some negative impacts by the project may be anticipated. To minimize the probable negative impacts, mitigation measures shall be prepared in advance of the construction of the project. The mitigation measures shall, of course, be prepared for by environmental parameter which is expected to have negative effect, the contents of the measure, and the implementing entity of the measure as well as the entity in charge of monitoring. Some of the negative impacts may be limited to only during construction stage, e.g. air pollution, waste and noise/vibration, and those mitigation measures shall be undertaken by the construction company engaged. Following table presents an example of mitigation measures.

Table 3.3.2 An Example of Mitigation Measures

Environmental Parameters Proposed Environment Management Plan

Implementing organization

Monitoring /responsible organizationConstruction phase Operation phase

3 Land use and utilization of local resources

There should be a land allocation committee composed of beneficiary representatives and government officers, and they should take into account the priority given to poorer household, so that they can have a mean of improving their livelihood.

Land Allocation committee

Gode Kelafo Office

7 Inequity in benefit distribution

Ditto for the land allocation. For the irrigation water distribution, water user association established in the scheme will carry out rotational irrigation whereby equal water allocation can be made.

Land Allocation committee

Water use association

Gode Kelafo Office

12

Spread/outbreak of water-borne and water related diseases

During the construction, avoid of making standing water. Proper drainage should be prepared by the Contractor.

1) During operation, continuous irrigation should be avoided, so that the canals can be dried up preventing the water-borne diseases. 2) Avoid water stagnation in the field, through regular leveling works by farmers.

Construction company

Water use association

Health center

Gode Kelafo Office

15 Soil Erosion

- Train pump operator to provide designed irrigation water, avoiding excessive water application.

Gode Kelafo Office

Gode Kelafo Office

30 Accidents

1) Monitor and check the Contractor to follow the standard safety measures, and also employ guards who prevent villagers from coming into the construction sites. 2) Designate corridor for movement of vehicles and machinery, to prevent accidents.

- Construction company

Gode Kelafo Office

Source: JICA Project Team

During the constructing and operation stages, some negative environmental and social impacts are anticipated, and also mitigation measures are proposed as aforementioned. Monitoring shall be done in order to check any mitigation measures proposed have been duly applied to minimize anticipated environmental impacts. To strictly implement the monitoring, a monitoring plan shall be established following the establishment of mitigation measures. The plan should clearly indicates the environmental parameters, relevant to those listed in Table 3.3.2, method of monitoring, timing/ interval of monitoring, and responsible entity who carries out the monitoring.

PART II

AGRICULTURE


JICA II-1-1 MOA

CHAPTER 1 INTRODUCTION

1.1 Botany

In order to gain a working knowledge of agriculture, it is necessary to understand the structure and function of plants and the environmental factors that affect plant growth.

1.1.1 Stems

Stems are structures which support buds and leaves and serve as conduits for carrying water, minerals, and sugars. The three major internal parts of a stem are the xylem, phloem, and cambium. The xylem and phloem are the major components of a plant’s vascular system.

1.1.2 Leaves

The blade of a leaf is the expanded thin structure on either side of the midrib. It varies in length and may be lacking entirely in some cases where the leaf blade is described as sessile or stalk less. The principal function of leaves is to absorb sunlight for the manufacturing of plant sugars in a process called photosynthesis. Leaves develop as a flattened surface in order to present a large area for efficient absorption of light energy.

1.1.3 Root

The principal functions of roots are to absorb nutrients and moisture, to anchor the plant in the soil, to furnish physical support for the stem, and to serve as food storage organs. In some plants they may be used as a means of propagation.

The quantity and distribution of plant roots is very important because these two factors have a major influence on the absorption of moisture and nutrients. The depth and spread of the roots is dependent on the inherent growth characteristics of the plant and the texture and structure of the soil.

1.1.4 Flowers

The sole function of the flower, which is generally the showiest part of the plant, is sexual reproduction. As the reproductive part of the plant the flower contains the male pollen and/or the female ovule plus accessory parts such as petals, sepals, and nectar glands.

1.1.5 Fruit

Fruit consists of the fertilized and mature ovules, called seeds, and the ovary wall, which may be fleshy, as in the mango, or dry and hard as in a maple fruit. The only parts of the fruit which are genetically representative of both the male and female flowers are the seeds (mature ovules). The rest of the fruit arises from the maternal plant, and is therefore genetically identical to that parent.

The seed or matured ovule is made up of three parts. The embryo is a miniature plant in an arrested state of development. Most seeds contain a built-in food supply called the endosperm (orchid are an exception). The endosperm can be made up of proteins, carbohydrates or fats. The third part is a hard outer cover called seed coat. It protects the seed from disease and insects, and prevents water from entering the seed which would initiate the germination process before the proper time.

Figure 1.1.2 Maize Roots Source:http://article.sapub.org/10.5923.j.ija

f.20120203.09.html

Figure 1.1.1 Principal Parts of a Vascular PlantSource: Arizona Master Gardener Manual, College

of Agriuculture, the University of Arizona


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1.2 Environmental Factors that Affect Plant Growth

Plant growth and distribution are limited by the environment. If anyone environmental factor is less than ideal it will become a limiting factor in plant growth. Limiting factors are also responsible for the geography of plant distribution. For example, only plants adapted to limited amounts of water can live in deserts. Most plant problems are caused by environmental stress, either directly or indirectly. Therefore, it is important to understand the environmental aspects that affect plant growth. These factors are water (humidity), soil (nutrition), and climate (light and temperature).

1.2.1 Water (Humidity)

Water is a primary component of plant growth specifically to photosynthesis. It maintains the turgor pressure or firmness of tissue and transports nutrients throughout the plant. Water also provides the pressure to extend roots through the soil. Among water’s most critical roles is that of a solvent for minerals moving into the plant and for carbohydrates moving to their site of use or storage.

1.2.2 Soil and Nutrition

Soil contains fundamental elements as water (25%), air (25%) and mineral matter including organic matter (50%), and furnishes mechanical support and nutrients for growing plants. It is made up of weathered rock fragments and decaying remains of plants and animals (organic matter).

1) Soil profile and composition

The soil particles seem to touch each other, but in reality have spaces in between. These spaces are called pores. When the soil is "dry", the pores are mainly filled with air. After irrigation or rainfall, the pores are mainly filled with water. Living material is found in the soil. It can be live roots as well as beetles, worms, larvae etc. They help to aerate the soil and thus create favorable growing conditions for the plant roots.

2) Physical properties

The physical properties of a soil are those characteristics which can be seen with the eye or felt between the thumb and fingers. They are the result of soil parent materials being acted upon by climatic factors (such as rainfall and temperature), and affected by topography (slope and direction, or aspect) and life forms (kind and amount, such as forest, grass, or soil animals) over a period of time.

Figure 1.1.3 Germination of Monocotyledon and Dicotyledonous Source:Arizona Master Gardener Manual, College of Agriuculture,the University of Arizona

Figure 1.2.1 Composition of the Soil Source: Irrigation Water Management:

Introduction to irrigation

Soil particle

WaterAir

Root


JICA II-1-3 MOA

Important physical properties of a soil are color, texture, structure, drainage, depth, and surface features (stoniness, slope, and erosion).

2.1) Color

When soil is examined, color is one of the first things noticed. It indicates extremely important soil conditions. In general, color is determined by: i) organic matter content, ii) drainage conditions, and iii) degree of oxidation (extent of weathering).

2.2) Texture

Texture refers to the relative amounts of differently sized soil particles, or the fineness/coarseness of the mineral particles in the soil. Soil texture depends on the relative amounts of sand, silt, and clay. In each texture class, there is a range in the amount of sand, silt, and clay that class contains.

Soil textural classes take their names from the particle size categories (sand, silt, and clay) and also from the category called loam. Loam is a textural class of soil that has moderate amounts of sand, silt, and clay. It is smooth to the touch when dry, but when moist, it becomes somewhat slick or sticky.

2.3) Structure

Soil structure refers to the grouping of soil particles (sand, silt, clay, organic matter and fertilizers) into porous compounds. These are called aggregates. Soil structure also refers to the arrangement of these aggregates separated by pores and cracks. When present in the topsoil, a massive structure blocks the entrance of water; seed germination is difficult due to poor aeration. On the other hand, if the topsoil is granular, the water enters easily and the seed germination is better. Unlike texture, soil structure is not permanent. By means of cultivation practices (ploughing, ridging, etc.), the farmer tries to obtain a granular topsoil structure for his fields.

1.2.3 Nutrition

Plants need 18 elements for normal growth. Carbon, hydrogen, and oxygen are found in air and water. Nitrogen (N), phosphorus (P), potassium (K), magnesium, calcium, and sulfur are found in the soil. The latter six elements are used in relatively large amounts by the plant and are called macronutrients. There are nine other elements that are used in much smaller amounts; these are called micronutrients or trace elements. The micronutrients, which are found in the soil, are iron, zinc, molybdenum, nickel, manganese, boron, copper, cobalt, and chlorine. All 18 elements, both macronutrients and micronutrients, are essential for plant growth.

1.2.4 Climate: Sunlight and Temperature

1) Sunlight

Sunlight has three principal characteristics that affect plant growth: quantity, quality, and duration. Quantity refers to the intensity or concentration of sunlight and varies with the season of the year. Quality refers to the color or wavelength reaching the plant surface. Duration or photoperiod refers to the amount of time that a plant is exposed to sunlight.

2) Temperature

Temperature affects the productivity and growth of a plant depending upon whether the plant variety is

Figure 1.2.2 Relative Size of Soil Particles Source: Arizona Master Gardener Manual, College of

Agriuculture, the University of Arizona


MOA II-1-4 JICA

a warm-season or cool-season crop. If temperatures are high and day length is long, cool-season crops such as cabbage and barley will bolt rather than produce the flower. Temperatures that are too low or high for a warm-season crop will prevent fruit set. Temperatures that are too high for warm-season crops such as pepper or tomato can cause pollen to become enviable and not pollinate flowers.


JICA II-2-1 MOA

CHAPTER 2 FARMING PLAN

Plant can grow up anywhere as long as the environmental condition like water, soil and climate is favorable. For instance, Maize requires hot weather and sable-loom soil, by contrast Onion prefers relatively to cool weather and loom-clay soil.

‘Crop production’ is a human act to grow plants as a food or for other purposes by adjusting biological characteristic of plant to environmental condition or in a reverse way. Thus it is even possible to grow different type of crop in same field such as Maize and Onion by using appropriate varieties and techniques. In order to maximize yield from the crop production, a Farming Plan should be examined and elaborated based on the actual agricultural situation.

Starting from the introduction of the agricultural situation analysis, this chapter shows different cropping system and patterns, and then the examples of farming plan in Gode.

2.1 Analysis of Agricultural Situation

To understand an actual agricultural situation, it is necessary to check at least those 3 points namely; environmental condition, actual farming situation and marketing.

2.1.1 Environmental Condition

Plant grows depending on water, light, air and nutrition, etc. as previously explained. According to those factors, crops cultivated and/or possible to grow are different. Among the environmental condition, Climate, Soil and Water resources define the above factors, so the plant growth. The essential points to be checked are shown in the following table:

Table 2.1.1 Check Items for Environmental Condition Contents

Means Climate Soil Water resource

Appearance and touch

⁃ Seasons and its features ⁃ Vegetation type ⁃ Wind

⁃ Color ⁃ Hardness ⁃ Topography

⁃ Type ⁃ Location ⁃ Availability

Measurement ⁃ Hours of sunlight ⁃ Temperature ⁃ Humidity ⁃ Precipitation (rainfall)

⁃ pH ⁃ Nutrient(NPK) ⁃ Structure ⁃ Water holding capacity

⁃ Volume of water ⁃ Contents of minerals

Related issue ⁃ Elevation ⁃ Climate change evolution

⁃ Vegetation ⁃ Livelihood ⁃ Land ownership

⁃ Vegetation ⁃ Livelihood ⁃ Regulation of water use

Source: RREP team

The items in row ‘Appearance’ can be checked by eyes and hand or interviews to concerned farmers, whereas those in the row ‘Measurement’ should be measured by using tools such as thermometer, rain-gauge and so on or should be analyzed in a specific laboratory.

If all items could be checked, it would be better to make an appropriate farming plan. However it is not necessarily to cover all for making a farming plan. With items checked by those appearances such as seasons, soil color and hardness, availability of water can give some hints to know the agricultural situation.

The points are to recognize which natural factors and phenomena determine crop, cropping pattern, agronomical practices and yield and to think how to develop and improve the agricultural situation by taking effectively into account the environmental condition.

2.1.2 Farming Situation

Needless to say, understanding actual farming situation based on the environmental condition is necessary to make a good farming development plan. The following table shows examples of check


MOA II-2-2 JICA

items about farming situation:

Table 2.1.2 Check Items for Farming Situation

Agricultural production Land use Agronomic practice &

techniques Others

⁃ Main crops and those physical features

⁃ Production area by crop ⁃ Average size of farm holding

(ha/HH) ⁃ Yield per ha or HH ⁃ Potential yield per unit ⁃ Problems and constraints

⁃ Cropping calendar ⁃ Cropping system ⁃ Cropping pattern ⁃ Land use regulation ⁃ Farming facilities used

and needed

⁃ Major agronomical practice of famers

⁃ Utilization levels of improved agro-inputs

⁃ Possession of machine, tools and animals for agriculture

⁃ post-harvest handling

⁃ Agricultural input prices

⁃ Extension service ⁃ Existence of

Cooperatives and associations

Source: RREP team

Relevant government agricultural offices and institutes must have statistical data on the agricultural production and the information of all other items above mentioned. However, interviewing farmers and checking farmland are required to understand real situation on farming whenever a farming plan is elaborated.

That is because the farming situation and needs on agriculture are always diversified according to the climate change, technical assistances and marketing issues, etc. Needless to say, understanding actual farming situation is essential not only for making a farming plan but also for elaborating agricultural extension plan.

2.1.3 People’s Needs and Marketing

Although the environmental condition and other constraints limit crop production, a farming plan must meet the people needs and market demands as far as people produce crops mainly for home consumption and/or for cash income by selling the products. To understand the people’s needs and market situation, the following items need to be checked;

Table 2.1.3 Check Items on the People’s Needs and Marketing Socio-economic situation Food security Marketing Others

⁃ Basic socio-economic characteristics of farmers (age, household size, educational level etc.)

⁃ Income and expenditure per HH ⁃ Secondary activity information

and subsistence level

⁃ Crops types and quantities produced

⁃ Rate of self-consumption and sale of produced crops

⁃ Accessibility to food ; quantity and quality

⁃ Crop loss (crop type basis).

⁃ Monthly food price movements ⁃ Farm gate and extra-farm gate

losses ⁃ Domestic and International

prices of tradable commodities, ⁃ Structure of annual food import

and cost

⁃ Access to credit, insurance, etc.

Source: RREP team

People in Gode grow the crops not only for human consumption but also for livestock. In the past, they were ex-pastoralists, had grown maize, but mainly its leaves for feeding their livestock and for gaining cash. For that reason, the government agricultural institutes and offices recently started introducing fodder crops as animal feed and encouraging the people to produce maize grain as their staple food. Reflecting such situation, the farming plan should be elaborated considering rural development.

Necessary information can be collected only by interviewing farmers, traders and persons who work with them in rural area. Group interview is also possible to obtain farmers’ voices. In any case, questionnaires are needed to conduct interview smoothly. The questionnaires should be of simple questions, not too many and not too few in order to let informants answer easily and not to tire them. Before entering the interview for many farmers or their groups, a trail interview called ‘pre-interview’ is highly recommended to check the contents of questionnaire and modify as needed.


JICA II-2-3 MOA

2.2 Different Cropping Systems and Patterns1

Many combinations of crop may be observed in Gode and Somali region, and farmers manage each combination in a different way. For example, a farmer may grow papaya close to his/her house, using manure and supplemental irrigation, with a fence around the plot to protect it. Another farmer may plant cereals in fields further away, without irrigation but using improved seed and chemical fertilizer.

Farmers have many reasons for making these choices. Fields are different by size, have different types of soil, and may be on a slope or on a flat land. Perhaps some farmers do not have the time to plant or weed at certain times of year. What they plant depends on how much moisture and nutrient are in the soil, timing of rains or availability of water pump. Of course, it depends on what famers want to grow for their own consumption and for the livestock, and to sell. Following present how to select crops, and then various cropping systems and patterns.

2.2.1 Cropping System

Farmers can choose from many different types of crops, and sow them in different combinations. Here are some options:

1) Mono cropping

Example: Planting maize year after year in the same field.

This is a farm where the field is used to grow only one crop season after season (see Photo 2.1). This has several disadvantages: it is difficult to maintain cover on the soil; it encourages pests, diseases and weeds; and it can reduce the soil fertility and damage the soil structure. Therefore, mono cropping should be avoided unless there is any countermeasure against such problems. It is much better to rotate crops, or use intercropping or otherwise strip cropping.

2) Crop rotation

Example: Planting maize one year, and sesame the next.

This means changing the type of crops grown in the field by season, by cropping season or otherwise by year (or changing from crops to fallow). Crop rotation is a key principle of conservation agriculture since it improves the soil structure and fertility, and because it helps control weeds, pests and diseases (see 2.2.2 more detail).

3) Sequential cropping

Example: Planting maize in the long rains, then beans during the short rains.

This involves growing two crops in the same field, one after the other in the same year. In some places, the rainy season is long enough to grow two crops: either two main crops, or one main crop followed by a cover crop. Growing two crops may also be possible if there are two rainy seasons, or if there is enough moisture left in the soil to grow a second crop. If the crops are different, this is a crop rotation (see above).

1 ref: Chp.6 Conservation Agriculture by FAO

Photo 2.2.1 Mono Cropping of MaizeSource: RREP team

Photo 2.2.2 Crop Rotation Maize & SesameSource: RREP team


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4) Intercropping

Examples: Planting alternating rows of maize and beans, or growing a cover crop in between the cereal rows.

Intercropping means growing a two or more crops in the same field at the same time. A possible problem is that the intercrop may compete with the main crop for light, water and nutrients which may reduce the yields of both crops. Additionally, it will be possible to reduce weed but difficult to manage pest and disease. Besides those problems, there are unfavorable combinations; e.g. maize cannot grow well near tomato. It is possible to do the intercropping in different ways shown in the following table:

Table 2.2.1 Different Ways of Intercropping Ways of intercropping Description

Mixed intercropping: no rows

Broadcasting the seeds of both crops, and dibbling the seeds without any row arrangement. This is called mixed intercropping. It is easy to do but makes weeding, fertilization and harvesting difficult. Individual plants may compete with each other because they are too close together.

Row intercropping with alternate rows of maize and beans

Planting the main crop in rows and then broadcasting the seeds of the intercrop (such as a cover crop).

Row intercropping with alternate rows of a cereal and a grass cover crop

Planting both the main crop and the intercrop in rows. This is called row intercropping. The rows make weeding and harvesting easier than with mixed intercropping.

Source: Chp.6 Crop and cropping systems, Conservation Agriculture, FAO

5) Stripe /relay cropping

Example: Planting alternating strips of maize, beans and sorghum.

This involves planting broad strips of several crops in a field. Each strip is 3–9 m wide. On slopes, the strips can be laid out along the contour to prevent erosion. The next year, the farmer can rotate crops by planting each strip with a different crop.

Strip cropping has many advantages of intercropping: it produces a variety of crops, the legume improves the soil fertility, and rotation helps reduce pest and weed problems. The residues from one strip can be used as soil cover for neighboring strips. At the same time, strip cropping avoids some of the disadvantages of intercropping: managing the single crop within the strip is easy, and competition between the crops is reduced.

If the sowing time is delaying some weeks among the crops in strip cropping, it is called Relay

Photo 2.2.3 Stripe Cropping with Sorghum,

Cowpea and Maize Source:

http://r4dreview.org/2010/09/ the-quiet-revolution


JICA II-2-5 MOA

cropping. This delay helps avoid competition between the main crop and the intercrop. It also uses the field for a longer time, since the cover crop usually continues to grow after the main crop is harvested.

2.2.2 Crop Rotation

Crop rotation is one dimension of the art and science of farm management, which refers to the sequence of crops grown in a specific field, including cash crops, cover crops and green manures. Some example of crop rotation plan in Ethiopia is shown in Figure 2.2.1. These plans are made to adopt the environmental condition and characteristic of crops. For instance, the short maturing crops are selected for short rainy season. Moreover in order to supply the nitrogen to plow layer, leguminous crops are selected for the cultivation.

Factors such as crop family, plant rooting depths and crop fertility needs should be considered when developing a crop rotation schedule. Rotations are the changing of crops over both space and time. Crop rotation has several advantages such as:

It improves the soil structure: Some crops have strong and deep roots. They can break up hardpans (hard, unbroken ground), and tap moisture and nutrients from deep in the soil. Others have many fine and shallow roots. They tap nutrients near the surface and bind the soil. They form many tiny holes so that air and water can get into the soil.

It increases soil fertility: Legumes (such as groundnuts and beans) fix nitrogen in the soil. When their green parts and roots rot, this nitrogen can be used by other crops such as maize. The result entails higher and more stable yields, without the need to apply expensive inorganic fertilizer.

It helps control weeds, pests and diseases: Planting the same crop season after season encourages certain weeds, insects and diseases. Planting different crops breaks their life cycle and prevents them from multiplying.

It produces different types of output: Growing a mix of grain, beans, vegetables and fodder means a more varied diet and more types of produce to sell.

It reduces risk: A single crop may fail because of drought. It may be attacked by pests. Or its market price may be low when time comes to sell it. Producing several different crops reduces these risks.

In some ways, crop rotation takes the place of ploughing the soil: it helps aerate the soil, recycles nutrients, and helps control weeds, pests and diseases.

2.3 Elaboration of Cropping System

2.3.1 Selection of Crops

Most of people in Gode are not much experienced in crop production and need to know and try

Figure 2.2.1 Examples of Crop Rotation in Different Region in Ethiopia Source: RREP team based on Chp.6 Crop and cropping systems, Conservation Agriculture, FAO

1st YearLong rainy season

1st YearShort rainy season

2nd YearLong rainy season

2nd YearShort rainy season

Dire dawa

Oromia lowland

Oromia highland Teff+Wheat

Maize+Haricot bean/Teff

Maize+Haricot bean

Field pea/Faba bean

Haricot bean

Chick pea

Wheat/Barley

Maize+Wheat

Maize+Sweetpotato

Teff

Check pea

Maize


MOA II-2-6 JICA

different crops to improve their livelihood. On the account, the governmental officers and agricultural institute researchers occasionally try to introduce new crops, but it is hardly known which crops can be suitable in Gode and/or in individual farmland condition. For this question, the results on agricultural situation analysis above mentioned in 2.1 gives hints. According to the results, when choosing crops, the following things shall be considered;

What does it produce? What should be intensified and introduced? Crops obviously produce many different things: food, fodder, firewood, and even used as medicines. Some commercial farmers grow some crops (such as onion) mostly for cash income purpose. For other crops, such as cereals or sesame, they may be able to sell what the farmers do not use for themselves. It is important to identify necessary crops by considering food security and farmers economic situation and by making sure there is a market for the excessive output.

What are the roots like? Tall cereals (maize, sorghum), finger millets and some legumes (e.g., pigeon pea) have strong roots that penetrate deep into the soil up to 1.2 m. Their roots improve the soil structure and porosity, so are a good choice if the soil is compacted.

Will it grow well? This depends on the results on the ‘Environmental condition’; the amount of rain and water provided for irrigation, or moisture and structure of soil, nutrition and climate. What inputs are needed? How much work does it take to grow the crop? Can farmers get seed? Do farmers need other inputs, such as fertilizer or insecticide?

Does it improve the soil fertility? Legumes improve the soil fertility by fixing nitrogen from the air. They use part of it for their own needs, and leave the rest in the soil. Cereals and other plants can use this nitrogen if they are intercropped with the legume, or if they are grown as the next crop in the rotation.

Does it cover the soil well? Tall cereals do not cover the soil well because they have upright leaves and they are planted far apart. Short grasses and many legumes (haricot beans, groundnut, and cowpea) cover the ground very quickly after they are planted. When their main use is indeed to provide cover, we call them cover crops. If their main use is to provide food, we call them food legumes (haricot beans, groundnuts).

Does it work with other crops? Try to find combinations of crops that complement each other well. For example, cereals grow well with legumes (either food legumes or cover crops): the cereals benefit from the nitrogen fixed by the legume. Two different legumes or two different cereals do not usually work well together. If farmers have problems with Striga weed in the field, such farmers may want to grow trap crops such as Crotalaria or Tephrosia to encourage the Striga to germinate and die when they do not find any suitable plants (such as maize or sorghum) they can live off.

It may be difficult to find the right combination of crops for the situation in Gode or in individual farmland condition. With farmers, the government agricultural experts and development agents can try out new combinations to see which ones better work. Or farmers can check with those experts, development agents and researchers or advanced farmers in other villages to see what they suggest.

2.3.2 Selection of Right Varieties

Farmers may know that not all maize is the same. Some varieties grow quickly and produce a yield in

Figure 2.3.1 Different Crops having Different Roots Source: RREP team based on Chp.6 Crop and cropping

systems, Conservation Agriculture, FAO


JICA II-2-7 MOA

a short time. Others take longer time until harvest. Some are taller than others, or produce more leaves. Some respond better to fertilizer, and some are more tolerant to drought or birds. The same is true for other crops.

Those differences among varieties are more remarkable when comparing improved varieties. The improved varieties perform much better than the local ones in terms of yield or risk tolerance. However it is not recommended to introduce carelessly those varieties unless distribution system is already established and farmers have capacity to buy them. As much as possible, even among the local varieties, it is important to choose a variety that the farmers and/or market needs and also the quality seed is available.

2.3.3 Planning of Crop Rotation2

Rotation should take into account what crops should be sown next year, and the year after that. Crop rotations require multidimensional thinking and rotation management requires understanding both the whole farm and each individual field and balancing field- and farm-scale decisions. On successful farms, rotation planning is a rolling and responsive process shown in the Figure 2.3.2.

1) Divided farmland and crop family

For ease of planning, it is good to design rotational sections of the same size. These sections can then be further subdivided based on production size and land required by each crop, or to incorporate shorter rotational cropping plans.

Crops should be divided by family, so the same or closely related crops are not grown in direct succession. It may also prove beneficial to subdivide crops by cultural and management requirements, architectural structure, growth pattern, harvest date, etc. In a short-rotation system, changes should be introduced whenever possible; this may include changes in crop variety or the addition of cool-season cover crops or green manures.

2 Crop Rotation; Annette Wszelaki, Sarah Broughton, Department of Plant Sciences

Figure 2.3.3 2-year Rotation of Cereals, Cowpeas and Legumes Source: RREP based on Chp.6 Crop and cropping systems, Conservation Agriculture, FAO

Figure 2.3.2 Schematic Summary of Crop Rotation Planning, Source: Crop Rotation on

Organic Farm, Planning Manual, Cherles L. Mohler& Sue Ellen Johnson


MOA II-2-8 JICA

2) Crop families and rotation cycle

Crops within the same family are generally susceptible to the same insect pests and diseases. More than four-year rotation using crops not susceptible to the same pathogens will generally minimize problems from soil-borne pathogens, with some exceptions. Although two-year is considered enough to reduce the incidence of foliar diseases and insect pests, some crops such as tomato, watermelon and cabbage need 3 - 5 years interval to reduce these problems.

The intervals of susceptible crops are different by crops depending on the environmental conditions. However, though the necessary intervals are even clarified, it is difficult to follow all of them because of farmers’ interests. If people need more protein due to lack of nutrition, they might produce some beans every cropping season.

The point of the crop rotation is to avoid mono cropping and susceptible cropping as much as possible. Further, it is recommended to produce crops which entail a good combination before and after as shown in Table 1.3.1; e.g. if you grow maize this season, Haricot beans is good for next season. It is often helpful to map out where the crop families will be located and how much of each will be planted.

Table 2.3.1 Family Name and Crop Combination

Family name Crops Good combination after the crops

in the second column

Poaceae Maize, Sorghum, Soudan grass, Panicum Haricot bean, Tomato, Cabbage

Alliaceae Onion Watermelon Tomato, Cabbage

Cucurbitaceae: Water melon, Cucumber, Melon, Pumpkin Maize, Onion

Fabaceae Haricot beans, Soy bean, Cowpea Maize, Sorghum, Soudan grass, Panicum

Apiaceae Carrot, Parsley Onion, Cabbage

Solanaceae Potato, Tomato, Pepper, Eggplant Cabbage

Convolvulaceae Sweet potato Sesame

Source: Crop Rotation; Annette Wszelaki, Sarah Broughton, Department of Plant Sciences

2.4 Farming Plan recommended in Gode

2.4.1 Agricultural Situation at Present

The agriculture in Gode area is characterized as tropical dry type, with relatively high temperatures and aridity throughout the year. Thus crops like maize, sorghum, sesame seed, haricot beans, tomato, watermelon, onion and fodder crops adapted to tropical conditions are produced. The cultivations are generally practiced twice a year, during the long rain season from March to May called ‘Gu’, and the short rain season from October to November called ‘Der’. Cereal crops and sesame are often grown under rain-fed cultivation mostly during Gu.

The area is favored with the potential agricultural environments such as temperature, soil and topographic condition. By contrast, there are a variety of problem issues. The biggest concern is the insufficiency of food and cash from crops production by the farmers. It is said because of lack of necessary agricultural input and techniques, the production in Gode area is always low even though there seems to be some assistance of agricultural inputs and techniques by the governmental offices and research institute. Additionally, lack of big market also limits agricultural production and trades.

Coupled with the appropriate basic farming technologies and high awareness on farming activities, the

Figure 2.3.4 Example of Rotation CycleSource: Setting up and running a school

garden, FAO


JICA II-2-9 MOA

improvement in agricultural productivity and production in the area could be achieved at an early date. If the farmers could increase productivity, they get enough food from their cereal and pulse production at first, and then they could be interested in producing more cash crops such as sesame and onions. Having already got high reputation of the cash crops in Gode, if that kind of agricultural development is accomplished, the market situation could also be enlarged.

2.4.2 Recommended Cropping System and Pattern

Cropping systems and patterns proposed in Gode area aim to produce maize to manage an annual consumption of grain per household and to improve haricot beans and sesame production for self-consumption and also for income. The proposed cropping patterns are hence fixed as centered by maize, haricot bean and sesame supplemented by other crops in the form of rotational cropping and inter-cropping where growing periods and particular characteristics of other crops be fully used, and the farming as a whole could be practiced with lower labor input and cost.

Regarding the yield of maize per unit area under irrigation, it is estimated to attain 4.0 t/h with reference to the interview results at relevant institutes if an improve seed is used. However, at the beginning of an irrigated agriculture, it is estimated at 2.4 t/ha, equivalent to 60% of the target yield, and over a 5-year period it can be planned to reach the 4.0 t/ha as the unit yield of maize.

According to a government policy, as large as 1.0 ha each of irrigable farm land plot is to be distributed to a settler people in Gode area. However, as all the farming works are done by manual labor, and depending on the availability of labor force of each household, some parts of farm land may remain not cultivated. As such, the idea is that the 1.0 ha farm land given shall be divided into 4 sub-plots and farmers be guided to plant at least for 2 sub-plots (0.5 ha). Cropping patterns shall be set, therefore, for cases of different numbers (2-4) of sub-plots cultivable land in a way that farmers can select their crops depending on the household conditions.

1) Cropping pattern for 2 sub-plots case (using mainly 0.5ha)

Crop cultivation is practiced in 2 sub-plots (0.5ha in total) among 1ha of farmland divided into 4 plots. One is for maize cultivation of early matured variety in consideration of unexpected drought situation. By double cropping of this, 1.2-2.0 t/year can be secured per household (2.4-4.0 t/ha x 0.25 ha=0.6-1.0 t/ha). Another sub-plot is planted with cash crops adaptable to those different climate conditions where increase of cash income is sought with high yield varieties being different for Gu (long rainy season from March to May) and Dyer (short rainy season from October to November).

As an example for the cash crops, sesame and haricot beans are introduced in the 2 sub-plots. The target yield is set at 1.5 t/ha and 3.5 t/ha respectively according to interviews at relevant research institutes. These target yields can be attained over 5-year period starting with 60% of those. Lastly, of the sub-plots uncultivated, one basically remains as fallow and rotational cropping shall be practiced for 2 years with the former 2 sub-plots. For the remaining sub-plot, perennial fodder crop can be introduced and expected to secure animal feed with the minimum labor input. The recommended cropping patterns and techniques are shown below:


MOA II-2-10 JICA

Table 2.4.1 Example of Cropping Pattern for 2 sub-plots Case

Cropping pattern Details on cultivation

1st c

ropp

ing

seas

on

1st year’s Gu (Long rainy season) Plot-1: Basically remains as fallow but possible to plant vegetables for

home consumption. Plot-2: Sesame cropping for cash income, early matured and high yield

variety like E-variety is the most applicable. Plot-3: Fodder crop of Sudan grass and Guinea grass which are of

drought tolerant and high yielding. Plot-4: Maize for home consumption. To lessen irrigation risks, early

matured Melkasa-1 is recommended. However, Melkasa-4 is possible if irrigation supply is secured.

2nd c

rop

cro

ppin

g s

easo

n

1st year’s Der (Short rainy season) Plot-1: Early matured Haricot bean for home consumption Plot-2: Der is a short rainy season and early matured maize variety be

planted. Plot-3: To harvest stalk and phyllome from the fodder crop planted. Plot-4: Leave as fallow area. For small scale cropping, beans and leaf

vegetables with short growing period be introduced.

3rd c

ropp

ing

seas

on

2nd year’s Gu (Long rainy season) Plot-1: Utilizing the nitrogen content fixed by the former cropping, maize

shall be planted. Varieties shall be selected depending on the irrigation situation.

Plot-2: Remain basically as fallow, but possible to plant small scale vegetable for home consumption purpose.

Plot-3: Harvest stalk and leaf from the fodder crop planted previously. Plot-4: Sesame cropping for cash income purpose. Early matured and

high yielding variety like E-variety is most applicable.

4th c

ropp

ing

seas

on

2nd year’s Der(Short rainy season) Plot-1: Remain basically as fallow, but possible to cultivate vegetables

for home consumption. Plot-2: Introduce early matured Haricot bean for self-consumption. Plot-3: Harvest stalk and leaf from the standing fodder crop. Plot-4: Plant early matured maize variety

Source: RREP team

After four cropping seasons, namely two years, fodder crop shall be shifted to the sub-plot 4 and the others plot by plot so as to practice the rotational cropping by 3 sub-plots as shown by the arrows as indicated in the figure for the 4th cropping season.

2) Cropping pattern for 3 sub-plots case (using mainly 0.75 ha)

Under this pattern, different crops for each sub-plot shall be planted for every cropping with 1 sub-plot planted for 2 years period perennial fodder crops. Among 3 sub-plots, the cereal crop for self-consumption and the cash crop are introduced by one sub-plot respectively. The remaining one shall be of mixed cropping or inter-cropping by maize or sorghum and beans (haricot bean, cowpea and ground nuts etc.) for home consumption purpose. For the purpose of self-sufficiency of food,


JICA II-2-11 MOA

expected harvests are 0.7 t/ha (2.8 t/ha x 0.25 ha) for maize planting plot and 0.35 t/ha for the mixed farming plot so as to secure 2.1 t/year by 2 cropping per year.

In the mixed cropping plot, by combining the Gramineae family plants typed as upright stem and deep root system and Fabaceae family typed as prostrate stem and shallow root system together, reducing of weeds and improvement in soil physical properties can be expected in addition to the favorable effect of fixing nitrogen content, implying lessening of the farm work.



1st c

ropp

ing

seas

on

1st year’s Gu (Long rainy season)

Plot-1: Sesame as cash crop. Sarkamo variety is recommended for

its high yielding advantage.

Plot-2: Mixed farming (Inter-cropping) of self-consumption food grain

and beans. Introduce sorghum with tolerance to birds damage

or early matured maize variety.

Plot-3: Fodder crops of drought tolerant and high yielding like Sudan

grass or Guinea grass

Plot-4: Cultivation of maize for home consumption. With having

countermeasures for irrigation risk in other sub-plots,

introduce high yielding variety (Example: Melkasa-2)

2nd c

ropp

ing

sea

son

1st year’s Der (Short rainy season)

Plot-1: Mixed farming of self-consumption food grain and beans. Der

is short period rainy season and early matured maize is

recommended.

Plot-2: Increase in maize harvest shall be sought with the uses of

nitrogen fixed by previous crop and high yielding variety.

Plot-3: Harvesting stalk and leaf from the standing fodder crop.

Plot-4: In view of good marketability, onion is recommended but any

other cash crops can be planted except Gramineae and

Fabaceae.

3rd c

ropp

ing

seas

on

2nd year’s Gu (Long rainy season)

Plot-1: Increase in maize harvest shall be sought with the uses of

nitrogen fixed by previous crop and high yielding variety.

Plot-2: Sesame as cash crop with applying Sarkamo variety with high

yielding nature.

Plot-3: Harvest of stalk and phyllome from the standing fodder crop.

Plot-4: Mixed farming of self-consumption grain and beans. Either

sorghum tolerant to damage by birds or early matured, maize

shall be introduced.

4th c

ropp

ing

seas

on

2nd year’s Der(Short rainy season)

Plot-1: Mixed farming or inter-cropping of food grain and beans. Der

is a short rainy season and preference is given to early

matured maize than sorghum.

Plot-2: By utilizing the nitrogen fixed by the previous crop, maize

cultivation is introduced.

Plot-3: Harvesting of stalk and phyllome from standing fodder crop.

Plot-4: From the higher marketability, onion is recommended.

However, any other cash crops with shorter growing period

can be planted except the Gramineae family and Fabaceae

family. Source：RREP team

The sub-plot for fodder crop shall be shifted after the four cropping seasons; namely, at third year shall apply the same manner as noted for the case of 2 sub-plots, and the three cropping sub-plots as shown


MOA II-2-12 JICA

by the arrows as indicated in the figure for the 4th cropping season.

3) Cropping pattern for 4 sub-plots case (using mainly 1.0 ha)

In case all 4 sub-plots can be cultivated, it is more efficient if rotational cropping could be practiced introducing as many crops as possible. In this case, however, the combination of crops becomes rather complicated and an easier/simpler system similar to the present practice shall be proposed, e.g. where maize for food and sesame for cash income are centered. Under the cropping pattern using the full 4 sub-plots, as much as 2.5 t/year of maize is to be produced.



1st c

ropp

ing

seas

on

1st year’s Gu (Long rainy season) Plot-1: Cultivation of maize for self-consumption. With having

countermeasure for irrigation risk, introduce high yielding variety (Example: Melkasa-2)

Plot-2, Plot-3: Cultivation of sesame as cash crop. As requiring seeds for 2 sub-plot area, locally available Kelafo-74 is most recommended.

Plot-4: To prepare for possible irrigation risk, 50:50 cultivation by maize and sorghum is planned. For sorghum, variety with tolerance to damage by birds is necessary.

2nd c

rop

cro

ppin

g s

easo

n

1st year’s Der (Short rainy season) Plot-1: From the marketability potential, onion is recommended. But

any kind of cash crops with shorter growing period except Gramineae and Fabaceae family are possible.

Plot-2, Plot-3: Cultivate early matured maize Plot-4: Introduce bean family crops to maintain soil fertility. If requiring

feed for livestock, introduce cowpea.

3rd c

ropp

ing

seas

on

2nd year’s Gu (Long rainy season) Plot-1: To prepare for possible irrigation risk, 50:50 cultivation by

maize and sorghum is planned. Sorghum variety shall be tolerant to damage by birds.

Plot-2, Plot-3: Sesame as cash crop. To secure seeds for 2 sub-plot area, locally available Kelafo-74 is most recommended.

Plot-4: Maize cultivation for self-consumption. With countermeasure taken for irrigation risk, high yielding variety (Example: Melkasa-2) shall be applied.

4th c

ropp

ing

seas

on

2nd year’s Der(Short rainy season) Plot-1: From positive marketability, onion is recommended. However,

any kind of cash crops with shorter growing period can be applied except Gramineae and Fabaceae family.

Plot-2, Plot-3: Early matured maize be cultivated. Plot-4: To maintain soil fertility, bean family crops shall be introduced.

In case of need for feed for livestock, cowpea is to be cultivated.

Return to the 1st crop from the following year

Source：RREP team

Same as the other cropping patterns, the cultivating crops and rotation pattern shall be changed every 2


JICA II-2-13 MOA

years as shown by the arrows as indicated in the figure for the 4th cropping season. In this pattern, especially, two sub-plots such as plot-2 and 3 in the table are to be only planted maize and sesame for 2 years and cannot receive the benefit from rotation with pulse crop and onion which can improve soil condition. The plot-2, for example, shall be replaced from maize to onion in the third year, and then maize/sorghum-pulse crops-maize can be followed.


JICA II-3-1 MOA

CHAPTER 3 FERTILIZATION1

Nutrient deficiencies are one of the most common ways, in which land degradation affects production. Therefore, it is essential for the agricultural extension worker to be aware of the evidence of such deficiencies in growing plants. In most cases, by the time nutrient deficiencies are evidenced by abnormalities in the visual presentation of a plant, it is already too late to correct the deficiency in time to affect current yields. Nevertheless, if further productivity is to be maintained or increased, it is important to identify, as far as it is possible, the cause of the abnormalities.

Thus, fertilizers are used to increase crop production by adding to the soil those nutrients that are in short supply and to restore and maintain the soil fertility, since a large percentage of plant nutrients are removed from the soil with harvesting. Fertilizers are broadly divided into chemical fertilizers and organic fertilizers. Plants can only absorb their required nutrients only if they are present in easily dissolved chemical compounds. Both of chemical and organic fertilizers provide the same needed chemical compounds.

3.1 Chemical Fertilizer

Chemical fertilizer, in other words artificial fertilizer, is composed of synthetic and artificial ingredients manufactured and ready to use by plants. Chemical fertilizers provide some advantages such as quick and high effects, easy to control the nutrient amount, cheap and easy to apply. However, it also provides some disadvantages such as damage of plant by high concentration and acidification of soil. To avoid these negative effects to soil, it is highly recommended to practice mixed using of organic and inorganic fertilizers.

3.1.1 Types of Chemical Fertilizer

Usually only three primary plants nutritious should be provided, which are Nitrogen (N), Phosphorus (P) and Potassium (K). The corresponding units for expressing fertilizer needs are:

N = Nitrate, P2O5 = Phosphorus pentoxide, K2O = Potash

An important secondary nutrient is Sulphur (S), which is present in many fertilizers. Another secondary nutrient Calcium (Ca) may be present in certain fertilizers. In very special cases, trace elements such as Boron (B) are incorporated in fertilizer.

Distinction is made between ‘straight’ fertilizers, containing one of the primary elements only, ‘incomplete mixtures’ containing two elements (N+P, N+K or P+K), and ‘complete mixtures’, containing all the three elements. Latter ones are also called ‘compound fertilizer’.

Examples of straight fertilizers are:

・ Nitrogenous fertilizer:

Ammonium Nitrate: NH4NO3 with 34.5% N Urea: NH2CONH2 with 45-46% N Ammonium Sulphate: (NH4)2SO4 with 20.5-21% N, 23-24% S Ammonium Chloride: NH4CL with 25-26% N Sodium Nitrate: NaNO3 with more than 16% N Calcium Cyanamide: CaCN2 with 20-23% N

・ Phosphatic fertilizer:

Single Super Phosphate: 14-20% water soluble P2O5 in Ca(N2PO4)2 H2O + CaSO4 2H2O

1 Agronomic Aspects of Irrigated Crop Production, Irrigation Manual Module 3, FAO 2002.


MOA II-3-2 JICA

・ Potash fertilizer:

Muriate of potash: KCL 61-63% K2O Potassium sulfate: K2SO4 50-53% K2O

Following fertilizers can be found for the compound:

・ Compound C Fertilizer = 6 : 17: 15 (6%N, 17%P2O5, 15%K2O)

・ Compound D Fertilizer = 8 : 14 : 7 (8% N, 14%P2O5, 7%K2O)

・ Compound J Fertilizer = 15 : 5 : 20 (15% N, 5%P2O5, 20%K2O) + 3.4%S + 0.04%B

・ Compound L Fertilizer = 5 : 18 : 10 (5% N, 18%P2O5, 10%K2O) + 0.25%B

・ Compound S Fertilizer = 6 : 17 : 6 (6% N, 17%P2O5, 6%K2O) + 0.04%B + 9%S

Complete mixtures are the most expensive per nutritive unit, while they are easier to apply with less chance of mistakes compared to ‘straights’. They are very popular with inexperienced users, since the presence of just one or two nutritive component is enough to bring about a significant yield increase. They can be used as ‘all-purpose mixture’ for stallholders engagied in commercial production and home gardening of food crops, vegetables and fruit trees.

3.1.2 Method of Fertilizer Application2

The chemical fertilizers are generally applied to crops by following different method:

1) Broad casting

Fertilizers are spread by hand onto the soil with last preparatory tillage just before sowing of seed or planting of seedlings. This method is known as “broadcast application”, and there are two types of broadcasting method of fertilizer application depending on the time of application as follows:

・Broad Casting at Planting: Fertilizers are broadcast to soil just before planting. Applied fertilizers are incorporated to soil by ploughing, and then followed by planting.

・Top-Dressing: Application of fertilizer in standing crop is known as ‘Top-dressing’. In general, nitrogenous and potassic fertilizers are applied to crop as this top dressing.

2) Placement

It is a method of placing fertilizer in the soil before sowing or after sowing the crop. Following are the common methods of this category:

・ Plough Sole Placement: Fertilizers are placed in the plough sole after opening the furrow by plough and these furrow are covered immediately upon the next furrows having been turned.

・ Deep Placement: Especially nitrogenous fertilizers are placed deep in reduced layer to block denitrification.

・ Sub-Soil Placement: Phosphatic and patassic fertilizers are placed in the sub-soil with a help of heavy machinery to avoid their fixation in strongly acidic soil.

3) Localized placement

It is a method to place fertilizer into the soil close to seed or plant. The roots of young plant can obtain nutrition as per their requirement from the fertilizer applied by this method. This method is usually employed when relatively small quantity of fertilizer is applied. Localized placement reduces fixation of phosphorus and potassium.

2 Agronomy Facts & Approaches, Dr. A.K. and Dr. P. Das, 2013.


JICA II-3-3 MOA

3.2 Organic Fertilizer

Continuous cropping without any addition or return of fresh or decomposed organic matter will result in a decrease in soil organic matter and a decline in the soil structure. High temperatures in the tropics and subtropics cause a rapid decomposition and mineralization of organic matter. To maintain the humus level of the soil, around 15 tons/ha organic manure (30% dry matter) is in fact required yearly, depending on the prevailing temperatures. Unfortunately, these amounts are not generally available to smallholder farmers. It is the best way to reserve the quantities available for fruits and vegetables, since these crops give the highest return to organic manuring. There are different types of organic manure as follows:

Farmyard manure: These are solid and liquid excreta of livestock, generally mixed with litter used for their bedding. The composition and quantities vary widely, according to the kind of animal, its feeding and the type of litter used. The annual amount of fresh matter produced by a well-fed adult dairy cow can be 10 tons (30% dry matter). For local cattle kept as draught animals, this quantity is in the order of 2-3 tons only, usually with somewhat higher dry-matter content.

Compost: Compost consists of partially decomposed materials of plant, animal or human origin, alone or in combination. The composing of sufficiently rich manure or waste should lead to temperatures of over 60 Celsius degrees, which will kill disease and pest organisms inside the compost heap.

Industrial organic manures: These types of manures mainly consist of by-products of vegetable oil processing and animal products. Oil cake of sesame seed can be produced in Gode area as a good material for organic manure.

Crop residues: Crop residues are important suppliers of organic matter to the soil. Considerable quantity of residues remains in the farmland by last crop. Growing of local maize varieties, for example, may result in 2-3 tons/ha of straw.

Green manure crops: Practice of turning un-decomposed green plant tissue into the soil is referred to as green manuring and the manures obtained by this method are known as green manure. Leguminous green manure crop is more useful in comparison to non-legumes as more nitrogen is added by legumes, advantageous for the soils as well as crops growing after green manuring3.

3.3 Time of Fertilizer Application4

Timing of application of both chemical and organic fertilizers plays a vital role in determining their effective utilization by plants. The optimum timing of fertilizer application should be determined by the need to make nutrients available over the period or periods at which the crop need them at the same time minimizing the risk of losses of available nutrients from the top layer of soil, where active nutrient uptake is taking place by crop root.

The appropriate time of applying a fertilizer depends on the soil, climate, nutrients and crop itself. With respect to the soil factor, soils differ greatly in the speed of water infiltration and their capacity to fix plant nutrients. Climate is important in any consideration of fertilizer application. The amount of rainfall or the availability of irrigation water between the time of application and the time of utilization by the plant will influence the efficiency of the material. In addition, temperature affects the availability of certain elements; for example, release of nitrogen, phosphorus and sulfur from organic matter. It also affects nitrification and the absorption of phosphorus and potassium by plants.

3 Agronomy Facts & Approaches, Dr. A.K. and Dr. P. Das, 2013. 4 Guideline on Irrigation Agronomy, Ministry of Agriculture Ethiopia, 2011.


MOA II-3-4 JICA

The nature of the crop itself will determine the need for split application. Different crops need different nutrients at different stage of growth and crop development. In this regard, particularly for organic manure it should be applied at least 2-3 months before planting and incorporated with the soil in order to have sufficient time for mineralization and release nutrients easily available for plants. The time of application for mineral fertilizer is discussed below:

3.3.1 Nitrogen

Nitrogen should be applied when farmers cultivate or transplant. In this way, the fertilizer will be well used more efficiently. Most short duration crops have a small demand of nitrogen in the seedling stages of growth, followed by a major demand during the major vegetative growth period. Nitrogen is a very mobile nutrient and is subjected to loss by volatilization and leaching if applied well before the crop can take it up and use it.

Under low or moderate rainfall conditions and with a rapidly growing crop it can be quite satisfactory to apply all nitrogen fertilizer during the last seedbed preparation. On the other hand, where rainfall can be high during crop growth, or where the period or growth is prolonged, a split application with a small dressing to the seedbed and one or more top-dressings during the crop growth will be more effective. This is particularity true under irrigation condition.

3.3.2 Phosphorus

Annual crops require phosphorus predominantly in the early stage of growth. Young seedlings need a high concentration of P in their tissues for early growth and root development. In contrast to nitrogen, it is not mobile in the soil, instead it has the characteristics of being rapidly fixed to soil colloids and is best applied to the soil and incorporated with it during cultivation. It is the best way to apply the water soluble phosphorus to the seedbed preparation or at the time of planting. If a water insoluble phosphorus fertilizer such as rock phosphate is used, the application should be made few weeks before sowing the seed in order to readily utilize the phosphorus available for plant. Additionally, it is important to remember that applying P in combination with N helps stimulate P uptake.

3.3.3 Potassium

Potassium is required by crop over a longer period of time than phosphorus, but it is seldom subjected to serious loss because it is existing in the soil or supplied by irrigation water. Potassium mixed fertilizer application to the seedbed provides the nutrition effectively to the crop with no appreciable risk of loss.


JICA II-4-1 MOA

CHAPTER 4 CONTROL OF PEST, DISEASES AND WEED1

4.1 Types of Pest, Diseases and Weed

4.1.1 Pests

Pests are insects, arachnids, rodents and snails that cause damage to a crop to an extent resulting in a noticeable reduction in yield or the total destruction of the crop. As far as insects are concerned, for practical purposes it is convenient to distinguish between sucking (S) and chewing (C) insect pests. Sucking pests are aphids (soft, pear-shaped insects), and white and black flies. Besides inflicting damage by sucking, they can also transmit more harmful virus diseases, and their sugary honey dew excretions make affected parts sticky and susceptible to soury fungus growth.

Other sucking pests are spider mites, mealy bugs, scales, stainers, stink bugs and thrips (small, elongated and rather fast moving insects with piercing mouths). All sucking pests compete for assimilates, and cause early wilting and shedding of leaves and buds. Chewing pests include seedling, leaf and fruit caterpillars (moth larvae or worms), stem and fruit borers, beetles and weevils, grasshoppers, crickets, locusts and some ants that attack seedlings. Nematodes, unsegmented parasitic worms having an elongated, cylindrical body such as eelworm and roundworm, are very harmful to crops.

4.1.2 Disease

A reduction in crop growth may be the result of an insufficient supply of minerals that the plant needs or of the activity of toxins produced by bacteria, fungi and viruses. The internal nature of most diseases means that considerable damage is usually done before the symptoms become noticeable, which makes control very difficult. Many bacterial diseases of vegetables are soil-borne. Therefore crop rotation can work in a preventive manner. Improvement of the drainage condition of the land can also have favorable effects. Infested plants wilt and die rapidly.

Fungal diseases may appear as blotching on leaves and fruits (for example, downy mildew), as a powdery coating of leaves and fruits (for example, powdery mildew), as the stem or root rots causing wilting and dying, as black rots of veins or stems causing dying, or as lesser leaf spots, moulds, rusts or wilts. Very serious fungal diseases can appear as Panama disease (Fusarium spp.) in banana, as soil-borne stem or root rots (Phytophthora) linked with water-logging in citrus, or with contaminated nurseries in avocado, papaya, and pineapple. Further, viral diseases may be caused by virus infection. They result in loss of vigor, yield and quality, which can be accompanied by rapidly changing coloring.

4.1.3 Weeds

Weeds compete with crops for moisture, nutrients and light, which results in lower crop yields. They are also hosts to a number of pests and diseases. In extreme cases, exudates from the weeds’ roots can have a poisonous effect on the crop plant. The competition of gramineous weeds is more severe than that of broad-leaved weeds. Crops are most sensitive to weed competition in their early stages of growth. Competition during the first quarter of the growing period can cause irreparable damage to the crop and often results in total crop failures.

4.2 Control Measures

There are various methods for controlling pests, diseases and weeds: preventive measures, chemical controls, and biological controls. Ideally, integrated controls should be applied in such a way that all possible measures are used in an environmentally sound and, for the farmer, economically viable way. 1 Agronomic Aspects of Irrigated Crop Production, Irrigation Manual Module 3, FAO 2002.


MOA II-4-2 JICA

4.2.1 Preventive Measures

The most important preventive measures are crop rotation and to keep crop hygiene. Crop hygiene includes burning or hot composting of affected materials and removal of crop residues, stalks and stumps after harvest. It is also important to obtain seeds from reliable sources, to treat the seed or plant material and to improve seedbed management. Resistant or tolerant varieties should be used. Planting and drainage methods that prevent water-logging should be applied. A balanced mineral supply should also be provided.

Preventive measures in weed control are meant to prevent further spreading of weeds. There are several methods which include early cultivation and the use of uncontaminated seed, eradication of weeds before seeding is started, keeping irrigation canals clean, proper composting of manure and the prevention of soil and water runoff.

4.2.2 Chemical Control

Chemical control refers to the use of chemicals to destroy pests and disease-causing organisms, to control their activity or prevent them from causing damage. Chemicals are often specified by the name of the active substance. However, farmers, development agents and shopkeepers are more familiar with its trade name. People often seem to be too careless with dangerous products. It is harmful to human being if it is applied by an inappropriate way. Therefore, it is significant to understand the prescribed proper use of it and use it accordingly. Depending on the pests and diseases to be controlled, the following pesticides can be used:

・ Insecticides: Insects ・ Molluscicides: Snails, slugs ・ Rodenticides: Mice, rats ・ Acaricides: Spiders ・ Herbicides: Weeds ・ Nematicides: Nematodes ・ Fungicides: Fungi ・ Bactericides: Bacteria

Pesticides can be classified according to their mode of action as follows:

・ Contact pesticide: it controls when it comes in contact with pest; doesn’t trans-locate. ・ Stomach pesticide: it must be eaten by a pest in order to control the pest. ・ Systemic pesticide: it is absorbed and trans-located within a plant or animal. ・ Fumigant: it produces a gas, fume or smoke to destroy insects, bacteria and rodents

Pesticides can appear in the following forms:

・ Emulsifiable Concentrate (EC): Liquid formulation in which the active ingredient is dissolved in a petroleum solvent, plus an emulsifier.

・ Wettable Powder (WP): A solid powder formulation added to water forms a suspension used for spraying.

・ Granules (G): Small dry pellets, low concentrate mixtures of pesticides and inert carriers, used as it is.

・ Bait (B): Edible material that contains a pesticide and is attractive to the pest.

・ Dust (D): Finely-ground mixtures combining a low concentration with an inert carrier (talc, clay, ash).

・ Flowable (F): Finely-ground solid material, which is suspended in a liquid and


JICA II-4-3 MOA

usually in high concentration, that requires dilution with water.

・ Fumigant: Pesticide in the form of gas that can kill when absorbed or inhaled.


JICA II-5-1 MOA

CHAPTER 5 RECOMMENDED AGRONOMIC PRACTICE WITH IRRIGATION

5.1 Points of Agronomical Practice in Gode

Agronomical practice is a series of farm works such as land/seedbed preparation, planting/sowing, weeding/cultivation, fertilizer application, pest and disease control, harvest and water management, etc. Actually the practices and the tips are almost similar among all crops. However the timing and the frequency of each farm work are different dependent on crop type and variety, and the environmental condition where the farmland is located.

Based on the present agricultural situation, the recommended crops in Gode are maize, sorghum, haricot beans, sesame, tomato, onion and fodder crops. Due to potential, groundnut can also be added as an alternative of haricot bean or sesame as oil crop. For each recommended crops, the timing of irrigated agronomical practices are shown in the following figure (for some points of agronomic practice by crops, refer to the following section’s discussions).

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Figure 5.1.1 Timing of Agronomic Practice by Crop Recommended in Gode

Raining season

Watering

AgronomicalPractice

Watering

AgronomicalPractice

Watering

AgronomicalPractice

Watering

AgronomicalPractice

Watering

AgronomicalPractice

Watering

AgronomicalPractice

Watering

AgronomicalPractice

Watering

AgronomicalPractice

JanFeb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Onion(Adama red)

Fodder crops(Sudan Grass)

Maize(Melkassa-4)

Sorghum(Meko-1)

Sesame(Kelafo)

Haricot Bean(Ayenew)

Ground nut(Batisedi)

Tomato(Heinz-1350)

Gu DerSandstorm

Fieldmaintenance Important Important Not to be soil too arid that leads

quality degradation

Weeding,Top dressing & Ridging

Land preparation& Fertilization

Pest, Disease and Bird Attack controlSowing

Harvesting Weeding,Top dressing & Ridging

Land preparation &Fertilization


Harvesting




Harvesting

Fieldmaintenance

Important Important



Pest & Disease controlSowing

Harvesting

Fieldmaintenance Watering by rain or irrigation every 10-15daysFast light irrigation

Land preparation &Fertilization Pest & Disease control

Weeding &Top dressing

Sowing

Harvesting

Watering by rain or irrigation every 10-15days


Pest & Disease control

Weeding &Top dressing

Sowing

Harvesting


Pest & Disease control without chemicals

Weeding & Ridging at least every 15-25days , especiallyessential in vegetation stage before establishing canopy

Sowing

Harvesting

Watering by rain orirrigation every 4 days

Watering by rain or irrigation every 7days, not to too dry and wet

Weeding & PruningNursery

preparation&Fertilization

Fieldpreparation &Fertilization


Top dressing Top dressing

Cutting top bud

SowingTransplanting

Harvesting


Watering by rain orirrigation every 6-14 days

Watering by rain or irrigationevery 6-14 days

Watering short interval

Watering by rain or irrigationevery 4-5 days


Weeding

Nurserypreparation&Fertilization

Field preparation&Fertilization


Top dressingSowing Transplanting

Harvesting tillMarch

Fieldmaintenance Watering by rain and irrigation

Land preparation&Fertilization

Pest & Disease control if necessary

Weeding & Top dressing if necessary

Sowing Harvesting tillers when it grows 100cm for 2-3years

Fieldmaintenance Important Important Not to be soil too arid that leads

quality degradation

Fieldmaintenance

Fieldmaintenance

Fieldmaintenance

Fieldmaintenance

Fieldmaintenance


JICA II-5-3 MOA

5.2 Cereals

5.2.1 Maize (Zea mays L., Graminaceous / Poaceae Family)

Maize has the highest yield potential of all cereal crops. In general, it grows well under strong sunshine, dry air and well-drained soil condition. However, there are numerous kinds of varieties adaptable for different environmental conditions. In order to grow the crop successfully, it is important to take into consideration the selection of more appropriate varieties adaptable to the existing growing seasons and area. Early matured varieties like Melkassa-1 and 4 are suitable in and around Gode area.

Table 5.2.1 Recommended Agronomic Practice of Maize

Agronomic practices Points Remarks

Land preparation Remove all residues and weeds. More than 2-3times ploughing much earlier

sowing. Level the filed Clean up the main and field canal

Tilling the field favors break up of clods, incorporates the organic matter in to the soil and kills the weeds to create more favorable seed bed conditions.

Fertilization Better to use organic fertilizer such as Farm Yard Manure or Compost

Recommendable to apply chemical fertilizer such as Urea and DAP are 50-100kg/ha and 100-175kg/ha respectively

Top dressing: 40-45days after sowing and before emergency of ear

Quantity of top dressing is depend on the maize variety and growing pace

Sowing Seeding rate 25-30 kg/ha Spacing: btw. Rows 75cm & btw plant 25cm 2-3 seeds per pocket Row planting is indispensable for irrigated

agriculture

Preparing a good seed preparation enables the seed to come in close contact with moist soil and begin its growth under favorable conditions.

Use of treated seeds and known of its history

Water management Irrigation frequency: once a 21days but; Sowing - 40-45days: somewhat less 45days - Flowering tassel: normal Flowering - Harvest: somewhat more

Irrigation schedule should be based on avoiding water deficits during flowering and yield formation period respectively.

Water logging should also be avoided since maize is very sensitive.

Weeding, Thinning & Ridging

Weeding should be done every 2-3 weeks 20 - 30days after sowing: Weeding and

Thinning (remove weak plants and remain vigor one)

45 - 50days after sowing: Weeding and Ridging (earthen up plant root)

Trying to avoid them before flowering Parthenium (congress weed) is big

problems in Gode. They are very invasive and can easily expand.

Pest and Diseases control

Decomposition of Crop debris Use approved maize varieties Rotation-rotate with maize with non-cereal Elimination of weedy grass hosts Proper plant

population Use of chemicals to control army worms

Main Pests: Stalk borer, Army worm, Termite, Grubs (in high manure changed farm land).

Main Diseases: Head Smut disease, Gray leaf spot, Northern or Turcicum leaf blight

Harvest Harvest as soon as the maize cobs are mature, change color from green to white. Black layer formation and hanging down of the cob are the main symptom of maturity

Store the dried cobs in cribs and wrap the legs of the cribs with smooth metal sheets to prevent rodents from climbing up in to the cribs; spray the cribs and the cobs at regular intervals

Threshing is a process of separating seed from cobs and making the seed ready for use

Time of harvesting depends on: Type of maize variety planted (extra-early, early, intermediate or late) and utilization (fresh cobs, grains).

Dry the remaining cobs on a flat concrete surface; the cobs are properly dried if the kernels scatter when the cobs are dropped on a concrete surface or land that is plastered by animal dung

Maize can be processed for food in different forms. It can be eaten roasted, boiled or other in forms separately or mixed with other crops

Source: Directory of released crop varieties& their recommended cultural practices (EIAR), Guide on Irrigation Agronomy (MOA), Comprehensive Registry of Research Technologies: for Somali Region and Other Same Agro-ecological Area in Ethiopia (SoRPARI)

Source: RREP team


MOA II-5-4 JICA

Table 5.2.2 Released Improved Maize Varieties for Low Rainfall Area in Ethiopia

Name of Variety Main Description Best adaptation areas

Melkassa-1 Maturity 85 days; flowering 48 days; Plant height 150–170cm; Yield 2.5–3.5 t/ha in research center;

farmers’ field 2.5–3.5 t/ha; 1000 seed weight 300–320 g; Seed color, yellowish; tolerant to rust

and blight; extra-early maturing.

Well adapted to low rainfall semi-arid areas of Ethiopia with rainfall ranging 450–570 mm.

Melkassa-2 Maturity 130 days; days to anthesis 65 days; Plant height 170–190 cm; Seed color white; Yield 4.5–5.5 t/ha in research center;

farmers field 4–4.5 t/ha; 1000 seed weight 360–410 g; Resistant to rust and blight.

Central Rift Valley (CRV), kobo and Meiso and similar agro-ecological areas.

Melkassa-3 Maturity 125 days; days to silking 64; Plant height 165–180 cm; Seed color white; Yield in research center 4.5–5.5 t/ha;

farmers field 4.0–5.0 t/ha; 1000 seed eight 380–420 g; Resistant to rusts and blight.

CRV areas, Kobo, Yabelo, Sirinka andMieiso.

Melkassa-4 Maturity 105 days; flowering 53 days; Plant height 40–165 cm; Resistance to rust-less tolerant; Cooks faster; Seed color white; Seed shape -semi dent; Yield 3.5–4.5 t/ha in research center;

farmers’ fields 3–3.5; 1000 seed weight 350–400g.

Released for drought stressed mid altitude areas of Ethiopia, Melkassa, Mieiso, Ziway, Wolenchiti.

Melassa-5 Maturity 125 days; anthesis 60 days; Plant height 185 cm; resistance to rust-less tolerant; cooks faster; Seed color -white; Seed shape -semi dent; Yield is 3.5–4.5 t/ha; 1000 seed weight 380–400g.

Released for drought stressed mid altitude areas of Ethiopia, Melkassa, Mieiso, Ziway, Wolenchiti and Shewa Robit,

Rainfall ranging from 600–800 mm.

Melkassa-6 Early maturing about 120 days; Yield 3–4 t/ha in research center;

farmers’ fields 3–4 t/ha; 1000 seed weight 300–320 g.

Recommended for low rainfall areas (500–800 mm) which include Melkassa, Mieiso, Ziway, Wolenchiti and Shewa Robit and other similar areas.

Melkassa-7 Early maturing about 120 days, yield 4.5–5 t/ha in research center; in farmers field is 3–4 t/ha; 1000 seed weight 300–320 g; tall with good forage yield.

Recommended for low rainfall areas (500–800 mm) which include Melkassa, Mieiso, Ziway, Wolenchiti and Shewa Robit and other similar areas.

Source: Agricultural based livelihood systems in drylands in the context of climate change, FAO


JICA II-5-5 MOA

5.2.2 Sorghum (Sorghum Bicolor)

Not only for food but also for forage, sorghum can be produced even in small scale, if the field is suitable and available for it. This crop is called ‘camel of crops’ since it can resist drought greatly, so that it is mainly cultivated in semi-arid zone in Ethiopia. Specifically, It is suitable for Alluvial soil often found in Gode area and can grow better under dry and hot conditions; requirement of annual precipitation of 325-425 mm and of temperature of 27-35 Celsius degrees. However, moisture stress, poor soil fertility and susceptibility to plant damages as shoot fly, lodging, charcoal rot and cold are the major yield constraints.

Table 5.2.3 Recommended Agronomic Practices of Sorghum

Agronomic practice Points Remarks

Land preparation Remove all residues and weeds. Necessary to clean and plow field

thoroughly, 3 - 5times at least for levelling. Clean up the main and field canal

Tilling the field favors break up of clods, incorporates the organic matter in to the soil and kills the weeds to create more favorable seed bed conditions.

Fertilization 100kg/ha of DAP to be applied basally 100kg/ha of Urea should be applied in two

splits; First split 2/3(65kg)at the mid tilling 1/3(35kg) at the flowering stage

Manure application is highly recommended in order to increase the production

Sowing Broadcasting is possible in the case of rain-fed, but it is highly recommended row planting especially in the case of using irrigation.

Seed rate(blanket):25kg/ha Spacing: btw rows75cm and btw plant

25cm Necessary to be sown at very shallow

depth or just on top of ploughed land

Use certified seeds and known its origin or from research institute or reliable seed companies.

Seed rate is a great point: the low may result in poor stand and the high results in high competition, which end up by low productivity and quality.

For uniform sowing distribution, better to mix with sand and sowing to the direction of wind.

Water management Irrigation frequency: once a 21days but; Sowing - 40-45days: somewhat less 45days - Flowering tassel: normal Flowering - Harvest: somewhat more

Sorghum requires adequate and well-distributed moisture through growing season for maximum yields.


Two hand weeding, first during 20-29daysafter crop emergence and second weeding during 40-50days after sowing.

2,4-D at 1litre/ha (post emergence) for controlling Striga and other annual broadleaf weeds.

Yield of sorghum is highly affected by Stringa weed infestation.

Regular weed control and management is required for increasing production of sorghum

Pest, Diseases and Birds control

The biggest enemy of sorghum is Quella birds.

Less affected by different diseases, but common sorghum diseases are leaf blight, smuts, and leaf anthracnose.

Visit the field regularly to detect pest and disease incidence and also frequent weeding is important

Harvest Entire crop is cut close to the ground level. The leaves are bundled, taken to the threshing floor.

Heads are removed, dried and grains are separated manually, using cattle or machinery. Stover is harvested separately.

Common storage Sorghum pests are Cryptolestes Ferrugineus, Ephestia Cautella and Tribolium confusum

Yellowing leaves, drying of grains or pods and bursting of bolls are the general symptoms for taking up harvest

Time of harvesting is important to avoid losses during harvest

It is advantageous to harvest the crop at physiological maturity


Source: ttp://www.businessdailyafrica.com/ Corporate-News/Pressure-piles-on-Ethiopia-to-lift-trade-barriers/


MOA II-5-6 JICA

Table 5.2.4 Released Improved Sorghum Varieties for Low Rainfall Area in Ethiopia


Gambela-1107 Yield potential ranges from 2.5–3 t/ha. Utilization - good for injera making. It is relatively resistant to most pest and diseases

of sorghum.

Well adapted to low elevations (<1600ml) with more than 600 mm of rainfall annually in semi-arid areas including Gambella, Yabello, Jijga Kobo, Shewa robit.

76-T1-23

A very early maturing variety (60–70 days to anthesis) which fits well to the dry semi-arid areas.

Utilization – good quality for making injera with high preference of customers.

North Wello in Kobbo Alamata area, Cheffa area, north Shewa and Meiso area.

Melko-1 An early maturing, drought and heat resistant variety.

Utilization - white seed with good for injera making quality.

Also high biomass production therefore is good for animal feed.

Dry semi-arid areas with short growing season.

It is released for north Shewa, Kobbo and other similar areas.

Gubiye and Abshir Similar in characteristics to Melko-1 in terms maturity.

Drought and heat resistance and utilization. Additional attribute is its resistance to the

parasitic weed called striga.

North Shewa, Kobbo and Meiso areas and well adopted by farmers and other dry-semi-arid areas.

Macia High yield potential of about 3 t/ha. This variety stays green, has broad leaves with

juicy thick stem and good quality crop residue used for livestock fodder.

It is widely adapted in semi-arid areas and short growing areas with elevation of less than 1600 m.

Seredo Bird resistant, drought tolerant, with high tannin content and very good for arekie making (local drink).

All dry semi-arid of the lowlands particularly in the rift valley areas where problem is a major constraint for sorghum production.

Teshale Early, days to maturity 100–120. Yield 3.0–4.5 t/ha, high biomass production used

for feed.

Dry lowland with altitude less than 1600 m, lowlands of north wello and north Shewa.

WSU-387-Melkam Early, days to maturity 118, Yield 3.7–5.8 t/ha, high biomass production used

for feed.

Dry lowland with altitude less than 1600 m, lowlands of north wello and north Shewa.

Area Yeju Early, days to maturity 120, Yield more than 5.0 t/ha.

Lowlands of welo and similar <1600 m, dry semi-arid areas.

Raya Early, days to maturity 130, Yield 3.0–3.8 t/ha.

Lowlands of wello, SIrinka area <1600 m, dry semi-arid areas.

Misiskir Early, days to maturity 126, yield 4.1 t/ha. Lowlands of wello, SIrinka area <1600 m, dry semi-arid areas.

Girana-1 Early, days to maturity 122, yield 4.1 t/ha. Lowlands of wello, SIrinka area <1600 m, dry semi-arid areas.

Gedo Early, days to maturity 134, yield 4.1 t/ha. Lowlands of wello, SIrinka area <1600 m, dry semi-arid areas.

Abshir Days to maturity 100–120, Yield 1.5 –2.5 t/ha.


Gobie Days to maturity 100–120, Yield 1.9 –2.7 t/ha, striga resistant.


Birhan Days to maturity 100–120, Yield 4 t/ha.0striga resistant.


Harmat Days to maturity 100–120, Yield 1.5–2.5 t/ha, striga resistant.


MACIA Days to maturity 110–130, Yield 3.0–4.5 high yielding, malt type.


Redsazi Days to maturity 106–112, Yield 2.0–4.0 t/ha, malt type.




JICA II-5-7 MOA

5.3 Pulse Crops: Haricot bean (Phaseolus vulgaris.L)

Haricot bean is one of the lowland pulse crops produced in the Somali region. Even though it is one of the suitable areas for the production and eaten as a staple food, it is not yet known in the most parts of the region, except for some pocket areas in the Jijiga plains. The crops has many advantages; it can be grown in short period (2-3 months only), barely deteriorate for the seed quality for certain years because of self-pollinated nature, and fix atmospheric nitrogen in the soil. It is necessary to grow it with 2 - 4 cropping seasons interval and/or to use improved seed resistant for soil sickness.

Table 5.2.5 Recommended Agronomic Practices of Haricot Beans


Land preparation The land for H/bean and the surrounding area have to be cleared thoroughly.

Plow 2-3times to easy drainage. Fine seed bed has to be prepared for H/ bean

for better germination and seedling establishment.

Weeding and cultivation usually starts three weeks after planting.

Smooth cultivation can be also recommended as inter cultivation and thinning if the seed has sown in raw but in the time small seedling.

Fertilization Not require high fertilization but application of fertilizer, especially manure facilities high yield.

The crop can fix atmospheric nitrogen by itself.

If Chemical fertilizer is applied, 100kg/ha of Urea and DAP respectively are recommended.

Sowing Seed rate: approx.45kg/ha. Sowing in row is recommended but

broadcasting is also possible. Spacing: 40cm between raw and 10cm between

plants.

Raw planting is favorable for well growth: economize seed amount makes crop management easier, increases productivity, etc.

Leave plants at suitable distance usually 10cm apart so that plants not crowded and 40 cm between rows.

Water management Drainage is important: water logging devastates haricot beans.

Irrigation must be done every 21 days depends on the rainfall: not to wet and not to dry.

Dry planting is not recommended because of risks of law germination due to damage, weak seedling and weed load, etc.


Inter-cultivation and weeding is essential: highly susceptible to weed infestation. Parthenium or congress weed is big problem.

Not inter cultivation after vines are creeping.

Trying to avoid them before flowering. Weed control and management is very

important for the increase of haricot bean production.


Visit the field regularly to detect pest and disease incidence.

Chemical control like use of triamefon and mancozeb spray were effective in controlling.

Cultural control like intercropping with maize on the incidence of rust.

Common haricot bean diseases are rust other names bean rust, rust of beans and brown bean rust.

Use of resistant varieties and good cultural practices like crop rotation, appropriate seed bed preparation, field sanitation (weeding).

Harvest Harvesting is done by cutting or uprooting the crop and the produce is dried in the threshing floor.

Harvest should be done at stage of maturity, when bean pods lose their color.

Drying seeds to reduce moisture before storage out of H/beans for immediately self-consumption and for sale.

Storage loss of seed and grain is one of the main problems of crop production.

Hand picking of matured pods is also practiced. Normally hand picking is done 2-3 times.

Store in cool places. Storage life of haricot bean seed is usually short if not stored in cold store.

Store has to be well ventilated. Cleaning the storage and avoiding

mixing of the seed and/grain with the previous grain.


Source: http://californiamediterraneandiet.com/ category/heirloom-foods/


MOA II-5-8 JICA

Table 5.2.6 Released Improved Haricot Bean Varieties for Low Rainfall Area in Ethiopia


Nasir Days to maturity are 88. early maturing grain. Yield ranges from 2.3–2.5 t/ha. The seed is small size.

All bean growing regions.

Dimtu Days to maturity are 86. early maturing. Grain yield ranges from 2.0–2.3 t/ha. The seed is small size.


Goberasha Days to maturity are 90–95. early maturing. Grain yield ranges from 2.2–2.5 t/ha; The seed is small size.

Jimma and similar areas in SW Ethiopia.

Ayenew Days to maturity are 90–95. early maturing. Grain yield ranges from 2.2–2.4 t/ha. The seed is medium size.

East and West Hararghe.

Gofta Days to maturity are 90–95. early maturing. Grain yield ranges from 2.2–2.4 t/ha. The seed is large size.

East and West Hararghe.

Tabor Days to maturity are 80–90. early maturing. Grain yield ranges from 2.0–2.4 t/ha. The seed is small size.

Southern Ethiopia.

Wedo Days to maturity are 74–84. early maturing. Yield ranges from 1.2–2.2 t/ha. The seed is large size.

North eastern Ethiopia.

Melka-Dima Days to maturity are 91. Yield ranges from 1.8–2.3 t/ha. The seed is large size.

Central Rift Valley and similar environments.

Ibado Days to maturity are 90–120. Yield ranges from 2.0–2.9 t/ha. The seed is large size.

Southern Ethiopia.

Omo-95 Days to maturity are 90–120. Yield ranges from 1.7–3.2 t/ha. The seed is large size.

Southern Ethiopia.

Haramaya Days to maturity are 100. Yield ranges from 2.0–3.2 t/ha. The seed is large size.

Eastern Haraghe and similar areas.

Dinknesh Days to maturity are 92. Yield ranges from 2.5–3.2t/ ha. The seed is large size.

Central Rift Valley and similar areas.

Batu Days to maturity are 75–85. Yield ranges from 1.8–2.5t/ha. The seed is large size.


Dame Days to maturity are 90–115. Yield ranges from 1.8–3.0 t/ha. The seed is large size.


Awash-1 Grown mainly as an export crop and is highly preferred by the farming community.

Yield potential in research center ranges 2.0–2.4 t/ha and 1.2–1.5 t/ha in farmers’ fields.

Adaptation areas: The variety is adapted semi-arid areas with low elevation and rainfall and it has short growing period (very maturating 75–90 days)

It is preferred to growing in Nazareth, Awassa and other similar areas.

It can be exported to other country.Awash Melka Days to maturity 95–100.

Yield ranges from 2.2–3.2 t/ha. Almost all semi-arid areas of the country

including the adaptation areas mentioned above.

It can be exported to other country.Argene Days to maturity 85–90.

Yield ranges from 2.0–2.2 t/ha. The seed is small size.

It is well adapted to the central rift valley and similar areas.

It can be exported to other country.TA01JI

Days to maturity 85–90. Yield ranges from 2.2–2.5 t/ha. The seed is small size.

Central rift valley and similar areas, fit areas with short growing period.

It can be exported to other country.Source: Agricultural based livelihood systems in drylands in the context of climate change, FAO


JICA II-5-9 MOA

5.4 Oil crops

5.4.1 Sesame (Sesamum indicum.L)

Sesame is basically a crop of tropics and sub-tropics region, but newer cultivars have extended its range into more temperate regions, though considered to have originated in central Africa, most probably Ethiopia. The crop thrives well on soils that are moderately fertile and well-drained, but it thrives just as well on rich, sandy, or mixed ground. The crop is grown in areas along Wabe Shebele river-banks by small scale farmers, and the farmers use local varieties that have poor yielding potential. Presently, several varieties of sesame adapted to the existing environmental conditions have been identified and promoted to the farmers in the river-banks in the southern part of the Somali including Gode area.

Table 5.2.7 Recommended Agronomic Practices of Sesame


Land preparation Thoroughly lands clearing is important: Pest and diseases which may attack sesame harbor in the soil.

More than 3-time deep tillage should be done for better germination and seedling establishment.

Good land preparation is essential for a good stand.

Sesame is a deep-rooted so needs deep tillage for efficient water and nutrient absorption.

Fertilization In principal, not require high fertilization. Application of fertilizer facilities high yield in

Somali but the application dose should be decided according to the water availability.

As a reference, in case of semi-irrigation with 200mm rainfed, 25kg/ha of urea and 50kg/ha of DAP can be applied: Half of both fertilizer for before sowing and the other half for when the buds are showing up in the pre-reproduction stage.

Sowing Row planting is favorable for well growth: fewer seed amount makes crop management easier, increases productivity, etc.

Seed rate: Ror 5kg/ha, broadcasting 7kg/ha Spacing: btw. Rows 40cm & btw plant 10cm.

Preferable to be sown on fine soil since the sesame seed is tiny.

Dry planting is not recommended because of risks of law germination due to damage, weak seedling and weed load.

Water management Essential to have good moisture at sowing: seeds need moisture around it for 3-5days.

After germination, once 10-15days with little rain, once a 21days with certain rain for 60-70days until end of maturing stage.

Yields are based on total amount of water in the soil profile before sowing and between planting and physiological maturity.

After ripping phase, watering do not increase yield and may delay harvest.


Weeding and inter cultivation which is highly susceptible to weed infestation usually starts 3-4 weeks after planting

Parthenium or congress weed is big problem.

Sesame tolerates throwing dirt up on the stalks-helps control small weeds coming in seed line and deepens irrigation furrow.

If plants look yellow from cold or too much rain, cultivation will help green up sesame.


Prevent pest and diseases by cultural and biological control as crop rotation.

Visit the field regularly to detect pest and disease incidence.

All varieties recommended in Gode are resistant pest and disease.

If damages are big , necessary to use chemicals according the symptoms and instructions

Harvest Recommended to cut whole stump not to by using plastic sheets not to spread the seeds.

Harvesting sesame below 6% of moisture critical; need the seeds dry for 10-15days.

Store in cool places. Storage life of sesame seed is usually short if not stored in cold store.

Cleaning the storage and avoiding mixing of the seed and/grain with the previous grain.

If storage chemicals used follow the instruction on container. Store has to be well ventilated.


Source: RREP Team


MOA II-5-10 JICA

Table 5.2.8 Released Improved Sesame Varieties for Low Rainfall Area in Ethiopia


T-85 It is drought resistant and also resistant to the major pests and disease in the drylands.

Early maturing and white seeded with high market potential.

Yield ranges research center 1.0 to 2.0 t/ha; farmer’s field about 0.5 t/ha.

Adapted to lowland areas up to 1250m, with rainfall of 500–700 mm.

Well adapted to the arid and dry semi-arid areas.

Kalafo-74 Early maturing and drought resistant. Yield ranges research center 0.6–1.2 t/ha;

farmer’s field about 0.3 t/ha.

Adapted to lowland areas up to 1250m, with rainfall of 500–700 mm.

Well adapted to the arid and dry semi-arid areas particularly the Kelafo area in the Somali region.

E Very early drought and pest tolerant. Yield ranges research center 0.6–1.2 t/ha,

farmer’s field about 0.3 t/ha.

Adapted to lowland areas up to 1250m, with rainfall of 500–700 mm and it can adapted most sesame growing areas.

Adi Early, short cycle drought and pest resistant. Yield research center 0.6–1.2 t/ha; farmer’s

field about 0.3 t/ha.

Adapted to lowland areas up to 1250m, with rainfall of 500–700 mm and it can adapt to most sesame growing areas.

S Yield under rain-fed is 0.4–1.0 t/ha and irrigation 1.2–1.6 t/ha;

Oil content 44–47%.

To area with short growing areas with days to maturity 90–115.

It may plant all of dryland areas in Ethiopia.

Mehado-80 Yield under rainfed is 0.4–1.0 t/ha and irrigation 1.5–2.2 t/ha.


Well adapted to areas with altitude, with days to maturity 90–110.

It may plant all of dryland areas in Ethiopia.

Abasena Yield under rainfed is 0.6–1.2 t/ha and under irrigation 1.2–1.9 t/ha.


Well adapted to dry lands with days to maturity 90–115.

Argene Yield under irrigation is 1.5–1.8 t/ha; Oil content 43–46%.

With days to maturity 95–105. It may plant all of dryland areas in Ethiopia.

Serkamo Yield under irrigation is 1.5–1.8 t/ha; Oil content 43–46%.

Days to maturity 95–105. It may plant all of dryland areas in Ethiopia.



JICA II-5-11 MOA

5.4.2 Ground nuts (arachis hypogaea.L)

Groundnut is a species in the legume family native to South America and an annual herbaceous plant growing to 30 to 50 cm tall. It is mainly produced for its oil worldwide and categorized under oil seed crops, but it is also for direct use as high protein meal. The crop has good drought resistance and heat tolerance nature and considered as one of the lowland oil crops and best growing in hot and warm climates, from 25 to 28 Celsius degrees, below 1600 m above sea level. The crop is becoming important both for home consumption and local market in the whole Ethiopia. Average yields of ground nuts in shells are about 800 kg/ha. The shells make up to 30% of the weight.

Table 5.2.9 Recommended Agronomic Practices of Groundnuts Agronomic practices

Points Remarks

Land preparation The land should be well prepared and leveled land for ease of irrigation water application and for uniform germination and rapid root development.

Cultivated 2-3 times in a depth of 25-30 cm. Necessary to prepare ridges spacing 60-80 cm

apart for irrigation water.

Best adapted to well-drained, friable, medium textured soils that are loose to allow the pegs to enter the soil easily and lifting of the crop at the time of harvest will be easy.

Well drained sandy loams are best for production of the crop.

Fertilization During land preparation crop residues should be incorporated in to the soil.

As a general guide, DAP at rate of 100 kg/ha is recommended to use.

Ground nut is not very demanding fertilizer use like other legume crops, most of the nitrogen requirement of ground nut is provided by fixation in the root nodules by symbiotic Rhizobium bacteria.

Sowing Row planting is highly recommended for ease of irrigation water application.

Plantation in rows with spacing of 60-75 cm between rows and 10-15 cm between plants and the average depth of sowing is about 5 cm deep.

Seed rates vary depending on the soil type and varietal characteristics and a range of 60-80 kg/ha of unshelled seeds/ or 20-40 kg/ha of shelled seeds/ is recommended to use /a reduced amount of seed rate is advisable for erected type of varieties.

Water management Irrigation interval: from 6-14 days up to 21 days for loam soils, depending on the level of crop evapotranspiration and water holding capacity of the soil.

With shorter intervals during flowering and early yield formation periods.

Excessive water application either through rainfall or irrigation limits the activity of N-fixing bacteria, due to lack of oxygen.


The first hand weeding will then take place after 30 days of sowing, while the second 40-50 days after planting and the third between 60-80 days after emergence.

Under irrigation conditions, three hand weeding are essential to reduce competition from weeds before the crop is well established.


To pest: 1/Early planting and 2/Removal of vines and trash from the field after harvest.

To disease: 1/fine seed bed preparation and incorporation of crop residue, 2/establish appropriate crop rotation cycle with stalk and vegetable crops, 3/removal of all plant residue promptly after harvest.

ABW, Aphids and beetles are among major insect pests.

Major disease: rust, leaf spot, southern blight, and viral and bacterial wilt.

Harvest Harvesting cannot be delayed until all the pods have matured or heavy losses will result from pod detachment from pegs and from premature sprouting.

Ground nut stores safely when moisture content of the nuts is brought down to about 10 % and the relative humidity of the storage room is about 60%.

The fruits do not all mature at once, because flowering occurs over 30-40 days and reach maturity about 60 days after flowering.

Source: Directory of released crop varieties& their recommended cultural practices (EIAR), Guide on Irrigation Agronomy (MOA), Comprehensive Registry of Research Technologies: for Somali and Same Agro-ecological area (SoRPARI)

Source: http://www.selfhelpafrica.org/ie/ethiopia/market-innovation-for-smallholder-groundnut-farmers


MOA II-5-12 JICA

Table 5.2.10 Released Improved Sesame Varieties for Low Rainfall Area in Ethiopia


Nc-4X Days to maturity 130 to 165. Drought, heat and disease resistant. Yield 5.0–6.5 t/ha under irrigation and

2.0–3.5 t/ha under rainfed. Oil content 44–49%.

Well to the Haraghie area including Bable, Besidimo dry semi-arid areas.

NC-343 Days to maturity 130 to 165. Drought, heat and disease resistant. Yield 5.0–7.0 t/ha under irrigation and



Roba Days to maturity 130 to 165. Drought, heat and disease resistant. Yield 5.0–6.5 t/ha under irrigation and



Sedi Days to maturity 130 to 165. Drought, heat and disease resistant. Yield 5.0–6.5 t/ha under irrigation and


Well to the Haraghie area including Bable, Besidimo dry semi-arid areas and rift valley areas.

Manipeter Days to maturity 130 to 165. Drought, heat and disease resistant. Yield 5.0–6.5 t/ha under irrigation and


Well to the Haraghie area including Bable, Besidimo dry semi-arid areas. And the rift valley areas.

E Days to maturity 130 to 165. Drought, heat and disease resistant. Yield 5.0–6.5 t/ha under irrigation and


Well to the Haraghie area including Bable, Besidimo dry semi-arid areas. And the rift valley areas.



JICA II-5-13 MOA

5.5 Vegetable

5.5.1 Onion (Allium cepa L.)

Onion has considerable importance in the daily Ethiopian diet and has a potential for domestic use and local processing industries as well. The crops are strongly influenced by day length and sunlight hours to produce bulbs and only short-day and sunshine varieties are adapted to Ethiopian. It can be grown on different soil types but well-drained medium textured rich in organic matter content are more preferred. For the initial growth period, cool weather and adequate water is advantageous for proper crop establishment, whereas during ripening warm, dry weather is beneficial.

Table 5.2.11 Recommended Agronomic Practices of Onion


Nursery management Bed preparation: the bed could be raised, sunken or flat depending on the climatic conditions. Width 1m and length 5-10m, seedling spaced 15cm in row.

Fertilizer: Well composed Manure or 100kg/ha of Urea.

Seed rate: 3-4kg/ha, 95% germination. Mulching: with dry grass for 15days

Highly recommended to make of furrow nursery which is located in a place with fertile soil, water logging free and no use of related crops for 2-3seasons.

The amount of fertilizers of DAP and Urea could be mixed together and applied during the seedbed preparation.

Plant management: chemical treatment could be applied for bacterial and fungus disease

Permanent field preparation

After ploughing and leveling, furrows at a spacing of 0.40 m for irrigation water application should be prepared. Then the field preferably pre-irrigated one or two days before transplanting.

Transplanting stage: seedling 13-15 cm height or 45-55days old, Spacing: 40 x 20 x 10 cm3 2rows/bad.

200kg/ha of Urea and 100kg/ha of DAP allied, half of them needs at time of transplanting, the other half for 45-50days.

Onions need above all potassium and phosphorus. Sulfur is often very useful too.

The amount of fertilizers in the form of DAP and Urea should be mixed together and applied during the seedbed preparation.

Nitrogen fertilizer should be given gradually and moderately, since excess nitrogen application causes the formation of thick collars to the bulbs and reduces keeping quality.

Water management For nursery, need water early in the morning and evening.

For filed, applied every 4-5days for the first weeks and every 7days then after.

For optimum yields onion requires 350-550 mm water throughout its growing period.

Onion is shallow rooted crop not more than 30 cm deep and it needs frequent but light irrigations.


Necessary to practice inter-row cultivated and weeded at least 3 times throughout the growth period.

The first cultivation and weeding should be done after 15 days of transplanting, the second and third on the 30 and 50 days after transplanting.

Weed control is highly essential for successful onion production. The slow growth rate of the onion in its initial stages, combined with its open growth habit of the crop and due to the shallow root system of the crop, competent from weeds can be very severe.


Cultural management like rotation and inter cropping could control pest and disease.

When 5-10 insects are observed per plant it is possible to control the pest by using of chemicals.

Downy mildew and purple blotch are the major diseases that attack onion severely; particularly during the rainy season and when the humidity is high.

Harvest Bulbs should be harvested before the tops are completely dried up, otherwise the bulb will decay on the root

Put bulbs in an open mesh bags to complete curing, if it rains, dry the onion under shelter.

Generally, Onion can be harvested within 80 to 100 days after transplanting

Advisable to harvest using appropriate hand tools such as forks and care should be taken not to damage the skin.


Source: RREP Team


MOA II-5-14 JICA

5.5.2 Tomato (Lycopersicon esculeutum) Tomato is the most important crop next to potato in Ethiopia. The production requires a lot of works and care because it is highly influenced by environmental factors, particularly temperature which has significant effect on all stages of the plant growth. In fact, tomato is day neutral but requires a day to night temperature change of at least 5 Celsius degrees during long days to be productive. It is noted to avoid fields where the previous crop was sweet potato or a solanaceous crop (tomato, pepper, eggplant or potato), or diseases and insects appear.

Table 5.2.12 Recommended Agronomic Practices of Tomato


Nursery management Seeds are sown in line on a well-prepared seedbed and lightly covered with soil.

After 7-10 days of sowing the young seedlings are transplanted on the second bed at a distance of 2-3 cm in both ways.

About 250-300g seed would provide sufficient seedlings to cover 1 ha of land.

Tomato seedlings are ready for planting when they are at 4-5 leaf stage in 4-5 weeks.

The seedlings should be protected from strong sun and heavy rains.

Three to four handful of urea dissolved in 30 litres of water can be sprinkled on nursery beds after about a week of transplanting the young seedlings in the second bed.

Tomatoes do very well on most mineral soils, but they prefer deep, well drained sandy loams.

Permanent field preparation

Should be planted in raised beds with well pulverized by ploughing first with soil turning plough and afterward with 4-5 ploughings.

Two rows are planted on a 1 m wide raised beds at a spacing of 60 x 60 cm. in the late afternoon followed by light

The crop can be added 15-20 tons organic manure, 300 kg urea, 200 kg TSP (Phosphate), and 150 kg MP (Potassium) per hectare to increase yield and quality.

The entire amount of organic manure and TSP and half of the MP are to be applied during land preparation.

Deep tillage can allow for adequate root penetration in heavy clay type soils which allows for production in these soil types.

Soils extremely high in organic matter are not recommended due to the high moisture content of this media and nutrient deficiencies.

The addition of organic matter to mineral soils will increase yield and improve the quality.

The remaining half MP and entire urea are to be applied in three equal installments, first at 15 days after planting, second at flowering and the third at fruiting.

Water management This crop has been observed to withdraw water from depths up to 2 m in a well-structured soil.

Irrigation Similarly providing irrigation late in the

season may result in watery fruits of poor quality.

Tomato needs very careful irrigation which should be sufficient in right time.

Erratic moisture conditions or heavy irrigation after a long dry spell may result in fruit cracking.

Staling and Pruning Staking of tomato plants with the help of wires or ropes is claimed to improve production & quality by keeping off the ground

Pruning side shoots and staking have claimed to have higher yield, uniform and larger fruits

Staking or training results in early ripening, higher yield of better quality fruits, lesser disease incidence, easier intercultural operation and harvesting.


Major prst: tomato fruitworm, cotton bollworm, Heliobis armigera, whitefly, cutwarms, stinkbugs and Namatoda

Major diseases: Early blight, late bright, septoria leaf spot, powdery mildow, Bacteria and Fusarium wilts

Very serious crop losses occur in tomatoes through failure to control but many diseases are difficult to control during the rainy season.

Recommended to produce tomato during the dry season under irrigation to minimize the risk of disease infection

Harvest Tomatoes for the fresh market are generally hand-picked.

Local sale of tomatoes may be vine ripened to a firm ripe or a full red color before harvesting.

Those picked to be shipped are picked at the mature green stage and sprayed with ethylene 48 hours prior to shipping.

Source: Directory of released crop varieties& their recommended cultural practices (EIAR), Guide on Irrigation Agronomy (MOA), Comprehensive Registry of research Technologies for Somali & other Same Agro-ecological area (SoRPARI)

Source: ttp://www.writeonnewjersey.com /2009/05/whatever-happened-to-the-jersey-tom


JICA II-5-15 MOA

5.6 Fodder Crop

Fodder crops are very important in Gode area for the people. The following table presents a brief outline of the main issues and common pitfalls in relation to pasture establishment and management.

Table 5.2.13 General Practices of Fodder Crops

Agronomic practices Points

1) Seed selection Seed variety & quarity: Be sure that the seed is really that of the variety you wish to plant. The best way to do this is to obtain seed from a reputable source. Quality is measured in terms of purity and germination.

Dormancy: Many grasses are subject to post-harvest dormancy, which means germination improves for up to 12 months after harvest, as germination inhibitors in the glumes break down.

Grass seed purity: The units that are referred to as seeds in grasses are actually spikelets that comprise one or more florets subtended by a pair of glumes. Sometimes there is no caryopsis (grain) formed in the spikelet although it still appears to be healthy seed.

Seed treatment: Scarification: The seed coat (testa) of legumes is often impermeable to water, thus slowing germination. It is best to ensure that the seed is scarified sufficiently to give about 50% germination in samples. Inoculation:. Where there is doubt that a suitable strain of rhizobium exists in the soil, a culture of the bacterium is introduced, usually on the seed, in a process called inoculation. On very acid soils or on others where molybdenum is likely to be deficient, and for species with a high Mo demand.

2) Land Preparation The most important aims of land preparation are providing a moist environment for germination, and minimizing competition for the developing seedling.

For effective germination, it is best to have moist soil pressed closely against the seed, which is best achieved with a fine, firm seedbed.

Sometimes cultivation is not possible due to the nature of the terrain, nor advisable, due to exposure to erosion hazard. In such cases, it is still important to eliminate competition from established plants, which is best achieved using a herbicide such as glyphosate.

3) Sowing More pasture plantings fail through sowing depth. Seed size and soil texture can determine sowing depth - the smaller seed and the heavier the soil, the shallower the planting depth.

While there are some large-seeded forage species with 5,000-50,000 seeds/kg, most forages have small to minute seeds (100,000 to >10 million seeds/kg).

In more arid areas, there may be advantage in planting more deeply to enable the developing seedling to access stored moisture more readily. However, a good practice is to broadcast seed on the surface, cover lightly by whatever means are available, and press the soil around the seed.

Sowing in rows has the advantage of facilitating hand-, chemical- or mechanical-weeding between the rows of developing seedlings.

4) Grazing/ defoliation management

Graze/cut as regularly as is feasible to obtain the highest feed quality. Feeding value declines rapidly with age of regrowth, as increasing amounts of lignin are laid down. Although longer intervals between grazing/cutting may result in higher DM yields, animal production is usually poorer.

Always maintain a green leaf residue after grazing/cutting. The rate of regrowth is initially directly related to the amount of leaf remaining to intercept light and support photosynthesis. With severe cutting or heavy grazing, there is a delay in active regrowth while plants redevelop sufficient foliage to support growth.

It is also important to retain a significant amount of leaf on legumes, because the amount of nitrogen fixed is related to the photosynthetic leaf area on the plant. The amount of nitrogen in a system drives the productivity of the system

5) Fertility management

All plants need the various plant nutrients for growth, but vary in the amount of each they require. However, they will only grow to the level set by the limiting nutrient.

Grasses have a high requirement for N and P, and also K for some species (e.g. Setaria sphacelata), which have luxury uptake of this nutrient.

Deficiencies of these and other nutrients can often be detected by the presence of deficiency symptoms such as leaf yellowing, full descriptions of which are available in the literature.

6) Weed management

Weeds at establishment can be controlled by hand-weeding, or spraying with selective herbicide. Non-selective herbicides such as glyphosate can be used if the sown species are in obvious rows. While weeds in established pastures can be similarly controlled, the most effective control is

adoption of more lenient defoliation management practices.


ministry of agriculture oromia bureau of ...preface irrigated agriculture and, consequently, food...

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