DESIGN OF A SOLAR-POWERED DRIP IRRIGATIOIN SYSTEM FOR GROWING

MANGOES IN BURA NANIGHI.

PRESENTER : TERER DUNCAN KIPKIRUI

F21/3964/2009

SUPERVISORS : DR. DUNCAN O MBUGE

Eng ORODI ODHIAMBO

INTRODUCTION

• Dry areas are often faced with critical soil moisture deficit hence carrying out productive agriculture is increasingly difficult.

• Percentage of land under irrigation in Kenya.• Need for food security and increasing the amount of land

under agriculture in.• The benefits associated with this project include improved

food productivity.

PROBLEM STATEMENT AND ANALYSIS

• Agricultural production in semiarid areas is largely constrained by low rainfall, poor or low nutrient soils, high temperatures, high solar radiation, and low precipitation.

• The ever-increasing population is also creating a strain on the existing food sources and thus putting food security of the area in jeopardy

• The area experience severe annual food deficits, due to the use of traditional techniques of farming that produce crops that hardly meet the subsistence requirements

OVERALL OBJECTIVETo design a solar powered drip irrigation system for

growing mangoes

SpecificTo design a drip-irrigation system layout for a 30 hectare piece of landTo design and determine the system specifications which comprises of the pump, the solar trackers and the amount of flow required

SITE ANALYSIS

Site analysis contd• Rainfall is highly variable and occurs in the March–May and

the November–December seasons. • The area is mainly covered with open bush and rather dense

shrub vegetation.

Month Jan Feb Mar April May June July Aug Sept Oct Nov Dec Year

Mean

Temp (mm)

28.6 29.5 30.1 29.5 28.5 26.8 26.3 26.4 27.1 28.4 28.8 28.4 28.2

Mean

Rainfall, r

(mm)

16.1 5.1 53.2 101.

7

21.7 12.1 6.8 4.1 7.7 22.6 101.6 64.6 417.3

Mean,Eo

(mm)

205 201 227 210 214 211 209 225 235 214 192 173 2543

Et (mm) 137 134 151 140 143 141 139 150 157 161 128 115 1696

r-Et-121 -129 -98 -38 -121 -129 -132 -146 -149 -138 -26 -50 -1277

INVENTORY

G.I PIPESPumpPVC pipesPV arraypump controllerwiringdischarge tubing or piping

valves emitters drip lines solar panels mounting racks

LITERATURE REVIEW

Design parameters•Area to be irrigated should be known .soil type identified, type of crop to be planted, crop spacing and number of crops per unit area should be put into consideration.•Peak water requirement of crop per day should be known.•Selection of emitter type, number of emitters per plant and amount of water discharge per hour through each emitter should be calculated.•Layout of the system considering -topography, field shape and location of the water source.•Design of main and lateral drip lines. This depends upon friction head losses.•Selection of filters and other equipment that will be used in the system.

Literature review contdCultivation of mangoes• Climatic requirements –Temperature ( 5- 45)–Humidity and rainfall (average 105 mm)Solar Water Pumping Principles• Solar pumping system, the capacity to pump water is a function of

three main variables: pressure, flow, and power to the pump.A solar-powered pumping system has the following minimum

components:a) PV arrayb) array mounting bracket and rackc) pump controllerd) electrical ground for controllere) wiringf) discharge tubing or piping

Literature review contd

Solar power comes from photovoltaic (PV) cells that convert the sun’s energy into usable DC electricity. A module consists of

PV cells and an array consists of several modules.Drip irrigation system components1.Control station (head control unit2.Main and submain pipelines3.Offtake hydrants4.Hydrants5.Manifold (feeder) pipelines6.Dripper laterals7.Emitters

PRODUCT DESIGNMETHODOLOGY•Desk Study

– included the study of area map and the general information about the area.

•Field Method – Land divided into four quadrants.

Water quality testpHTurbidity, N.T.UDissolved solids, mg/lSuspended solids, , mg/l

RESULTS AND ANALYSIS

• Bulk density

QUADRANT

(CM)

Weight of

can & lid +

wet

weight (g)

Weight of

can & lid

+ Dry

weight (g)

Weight of

can +lid

(g)

Mass of

oven

dried soil

(g)

Bulk

Density

(g/cm3)

A 0-25 271.44 255.17 107.11 148.06 1.508127

25-50 180.26 170.70 100.49 70.21 0.715153

B 0-25 213.12 202.54 110.89 91.65 0.933539

25-50 182.04 173.19 108.03 65.16 0.663714

C 0-25 233.42 222.55 106.58 115.97 1.181260

25-50 223.69 209.05 110.49 98.56 1.003923

D 0-25 209.63 195.32 108.41 86.91 0.88525

25-50 21.56 195.09 99.84 95.29 0.970616

Results and analysis contd

Moisture Content

QUADRANT

(cm)

Mass

of can

(g)

Weight

of can

+ wet

weight

(g)

Weight

of can +

Dry

weight

(g)

Moistur

e

content

(g)

Mass of

Dry soil

( g)

Moistur

e

(%)

A 0-25 23.79 106.22 98.42 7.8 74 10.54

25-50 32.16 81.99 77.73 4.26 45.57 9.35

B 0-25 24.91 102.54 96.57 5.97 71.66 8.33

25-50 22.58 106.57 99.77 6.8 77.19 8.81

C 0-25 23.32 99.42 92.53 6.89 69.21 9.96

25-50 16.44 95.62 88.94 6.68 72.5 9.21

D 0-25 25.17 144.37 134.00 10.37 108.83 9.53

25-50 25.03 110.01 102.27 7.74 77.24 10.02

Results and analysis contd

• The net scheme irrigation obtained from CROPWATT 8.0 is 4.959mm/day

• And the gross scheme irrigation is 5.742mm/day• Therefore Net Irrigation Requirement per crop = (4.959/1000) x 5 x 2 x 0.3 = 0.014877m3 or 14.877 l/crop/day• Area of wetted soil = Sp x Sr x Pw

Where Sp = distance between the plant within a rowSr = distance between plant rows or row spacing (m)

• Area of wetted soil = 5 x 2 x 0.6= 6 m2

Results and analysis contd

• Available soil moisture per crop = 140mm/m= (140/1000) x 0.6 =

= 0.084m3 or 84 l/crop• Readily available moisture for drip system to be

replenished by irrigation= 84 l/crop x 0.2= 16.8 l/crop

Results and analysis contd

Results and analysis contd

• Supply line and main line• Δ H = 15.27 (Q1.852) L D4.871

• Sub mains and laterals• Δ H = 5.35 (Q1.852) L D4.871

Results and analysis contd

• Suction lift 4.5 m• Supply line 1.14 m• Main line 2.58 m• Sub main 2.9814 m• Laterals 4.776 m• Sub Total 15.9774• Fitting 10% 1.59774• Difference in elevation 6.5 m• Total 24.07514

Power requirement = Q × H 360 × e = 19.36476 × 24.07514 360 × 0.40 = 3.237 Kw

DESIGN DRAWING

CONCLUSION AND RECOMENDATION

• The broad objectives of carrying out a survey of the area to determine its topographical characteristics was achieved which guided in the irrigation system layout.

• The irrigation system layout should be checked regularly to avoid clogging of pipes and emitters and the necessary repairs and maintenance should be carried out.

REFERENCE

• ASAE 1990 ASAE EP 405.1.Design and installation of micro-irrigation systems.

• FAO 1985 Water quality for agriculture.Fao Irrigation and Drainage Paper No 29,Rev.1.preparedby:Ayers,R.S&westcot DW Rome,Italy.

• Food and Agriculture Organization of the United Nations (2008) The State of Food Insecurity in the World 2008: High food prices and food security—threats and opportunities.

• Griesbach J. 1981. What you should know about mango growing. Kenya Farmer. Nairobi, Kenya: Agricultural Society of Kenya.

• Griesbach J. 1985. New mango types currently grown in Kenya.Kenya Farmer. Nairobi, Kenya: Agricultural Society of Kenya.

• http://www.ehow.com/list_7505003_hydrology-soil-types.html#ixzz2kqjmm44f

• http://www.thecommunityengineer.com/forum.html.

• THANK YOU