conceptual and locational aspects of land...

Chapter - VII

CONCEPTUAL AND LOCATIONAL

ASPECTS OF LAND DEGRADATION 7.1 INTRODUCTION

7.2 CONCEPTS OF LAND DEGRADATION

7.3 SALT AFFECTED LAND

7.4 LOSS OF TOPSOIL OF ARABLE LAND BY BRICK

MAKING INDUSTRY

7.5 LAND DEGRADATION BY SALT ACCUMALATION

(KHARLAND)

7.6 EROSION PRONE AREAS

7.7 UNSUITABLE CULTIVATION METHODS

Chapter VII – Conceptual and Locational Aspects of Land Degradation and Analysis

190

Chapter- VII

CONCEPTUAL AND LOCATIONAL ASPECTS OF

LAND DEGRADATION AND ANALYSIS

7.1 INTRODUCTION

The present chapter is devoted to the concept and locational patterns

of land degradation and its analysis. This study includes the locational aspects

land degradation. Salt affected lands, loss of top soil for brick making industry,

salt accumulated lands (khar lands), soil erosion and unsuitable cultivation

practices are the main causes observed in the study region.

7.2 CONCEPT OF LAND DEGRADATION

Land degradation is a comprehensive term often used to denote the

decrease in biological productivity, fertility status and property of land in

general. The term degradation as used in geomorphology indicates

disintegration or decomposition of rock material is loosely used to denote

deterioration of the status of the environment. Winfred (1986) defined it as,

‘weathering down of the land surface’. Whittos (1984) stated that, ‘the process,

by which soil becomes weathered or more highly leached,’ denotes

degradation. According to Oxford English Dictionary degradation is, ‘a

condition of being lowered of lowering in character, quality of reduction to an

inferior state or a conversion into lower form’.

More precisely, land degradation refers to ‘the disturbances in the

natural structure and properties of soil due to direct or indirect anthropogenic

(human) influences’. They may be caused not only by improper methods and

means of soil development, but also by violating the rations between natural

and cultivated lands’ (Zone, 1986). The wasteland or degraded land is defined

by Stamp (1968) as, ‘the land which has been previously used but now

abandoned and no further use has been found for such lands’. Vink (1975) has


191

included soil erosion, salinasation soil pollution and misuse of land, etc under

the term ‘land degradation’; adding further that it (land degradation) is the

conglomeration of all these processes together. According to Agrawal (1982),

‘the lands producing much less than their potential and which are economically

unproductive, ecologically unstable and subject to environmental deterioration

are degraded lands’. Ministry of Food and Agriculture, Government of India

(1962) defined this term as, the lands available for cultivation but not taken up

for cultivation or abandoned after a few years for some reason or other’.

According to Rao (1987), land degradation is ‘an unfavorable alteration of the

ecological surrounding resulting in the contamination of the soil and emergence

of degraded landscapes’.

To conclude, a piece of land which is not being utilized at present, in any

manner may be called a degraded land and includes the lands which are left

fallow over a period of time and unutilized , underutilized for cultivation of any

crop or plant due to various constraints. These lands are, at times, ecologically

unstable or have lost top fertile soil or whose productivity has declined more

than 50 per cent due to misuse and overuse by human being. Any such land

should be treated as degraded only if; its biological productivity is less than

what it ought to be with reference to the availability of soil nutrients, water and

other inputs. Over population, overgrazing, over exploitation of soil and water

resources, intense demand for fuel and other forest resources, unsuitable

cultivation, intensive input applications, etc are. Some of the factors are

responsible for the emergence of degraded landscapes.

In the present study land degradation thus viewed as ‘the land which

are disturbed by natural causes or man trade problems, environmentally

degraded, utilized or over utilized and producing less than 50 percent of their

productivity due to various factors.’ These lands can be used for land use in

future by using different remedial measures and soil management techniques

with increasing capability of nutrients. This study mainly focused on

agricultural land degradation.


192

Raigarh district is not a homogeneous in respect of topography, slope,

temperature and other resource endowment. It us witness ecological diversities.

The west coast of the district is under intense pressure of salinisation while

eastern hilly region is under the pressure of deforestation, erosion, unsuitable

cultivation and overgrazing. Following are the major causes are identified as

the locational aspects of land degradation in Raigarh district.

1. Salt affected lands by over use of chemical fertilizers.

2. Loss of top soil by brick making industry.

3. Salt accumulation on coastal agricultural land (Kharland)

4. Soil erosion.

5. Unsuitable cultivation practices.

Irrigation is not much developed in the region thus salinisation by

excessive irrigation has not observed in the district.

7.3 SALT AFFECTED LAND

Salt affected lands are the land left unused or underused due to excessive

salt accumulation in the upper layer of the soil. It is a combine effect of

excessive use of fertilizers, over use of water, absence of surface drainage

facilities, etc

Raigarh district is basically is a agricultural district of Maharashtra. It

is a important region for rice cultivation. The temperature, rainfall and soil is

suitable for paddy cultivation. Thus more than 60 per cent area is under rice.

Rice crop requires flooding during cultivation, for this purpose farmers restricts

the water movements in the farm land by constructing the bands surrounding

the farm, resulting in upward movement of salts due to capillary action.

Excessive uses of chemical fertilizers help to increase the accumulation of salt

in the soil. The chemical fertilizers are one of the most effective means of the

increasing crop production but the unwise and over use of the chemical

fertilizers leads to the degradation of soil. Table 7.1 display the consumption of

Chemical fertilizers. It shows the increasing trend of using fertilizes amongst


193

the farmers. As a combine effect of these activities resulting in water stagnation

for a longer period and excessive accumulation of salt in upper layer.

Table – 7.1

Raigarh District

Consumption of Chemical Fertilizers

Consumption

( in tones)

Year Average Use

(Kg/Per hectare)

N P K

1999 - 2000 69.0 12171 1811 1036

2000 - 2001 71.2 12313 2536 1497

2001 - 2002 80.2 13712 2121 478

Source: Socio-economic Review and Statistical Abstract of Raigarh District (1999-2002)

7.3.1. Analysis of Land Degradation of on the basis of Chemical

Composition (Acid Content)

On the basis of chemical composition of the salt affected land based

on three tier classification of determination of soil ph, soil can be divided in to

acidic and alkaline soil. Following chart shows the classification of soil pH

Classification Chart soil pH

pH Range Rating

Soil pH < 6.0 Acid soil

Soil pH 6.0 – 8.5 Good soil

Soil pH > 8.5 Alkali soil

Source- Krishi Vigyan Kendra, Babhaleshwar, Rahata

The lands which are less the 6 pH value are highly acidic in reaction

and harmful to the crops. These soils are likely to be unproductive soil can not

be used for cultivation, spread all over in the region. The study region records

approximately 4.26 percent of the total cultivated area in the region.


194

Table 7.2

Raigarh District

Salt Affected Land on the Basis of pH

Source- Compiled by Author on the basis of data collected from District Soil Testing

Laboratory, Alibaug

# - The data of the Tala tahsil is included in Mangaon tahsil.

Table 7.2 shows the salt affected land of the district, distributed among

all tahsils of the district. The highest salt affected land has observed in Roha

tahsil with 46.79 percent area due to coastal marshy land and water logging by

rivers. The lowest salt affected area has observed in 3.35 percent in Mangaon

tahsil.

Sr.

No.

Tahsil Salt affected lands

(area in Hectares.)

< 6.00 pH

Area in

Percentage

1 Alibaug 3200 13.37

2 Uran 560 11.10

3 Panvel 940 5.43

4 Karjat 499 3.73

5 Khalapur 1050 14.14

6 Pen 2450 15.84

7 Sudhagad 590 6.68

8 Roha 6350 46.79

9 Mangaon 920 3.35

10 Mahad 13320 42.15

11 Poladpur 4070 39.85

12 Mhasla 2030 35.39

13 Shrivardhan 620 6.87

14 Murud 1950 19.49

15 Tala # #

District 38549 32.41


195

Moderate salt affected land (30 to 45 per cent) is observed in three

tahsils namely Mahad (42.15 per cent), Poladpur (39.45 per cent), Mhasala

(35.39 per cent) tahsils.

Low salt affected land (15 to 30 per cent) had recorded in two tahsils

namely Murud (19.49 per cent) and Pen (15.85 per cent) tahsils.

Very low salt affected area (less than 15 per cent) has seen in nine

tahsils namely Mangaon (3.35 per cent), Karjat (3.73 per cent), Panvel (5.43

per cent), Sudhagad (6.68 per cent), Shrivardhan (6.87 per cent), Uran (11.10

per cent), Alibaug (13.37 per cent) and Khalapur (14.14 per cent) tahsil.

7.3.2. Analysis of Land Degradation the Basis of Electrical

Conductivity

Electrical conductivity is one of the features of the soil. Increasing

electrical conductivity of the soil caused severe damage to the seed. It may

affect on emergence of the seed. Following chart shows the Electrical

conductivity rating and effects of it.

Classification Chart of Electrical Conductivity of soil

EC Range Rating

< 1 mmhos/cm Good soil

1 - 2 mmhos/cm Poor seed emergence

2 - 3 mmhos/cm Harmful for some crops

3 - 4 mmhos/cm Harmful for most of the crops

Source- Krishi Vigyan Kendra, Babhaleshwar, Rahata


196

Fig. 7.1


197

Fig. 7.2


198

Table 7.3

Raigarh District

Salt Affected Land on the Basis of Electrical Conductivity

Source- Compiled by Author on the basis of data collected from District Soil Testing

Laboratory, Alibaug

# - The data of the Tala tahsil is included in Mangaon tahsil.

(Critical)

EC 1.0 - 2.0

Sr.

No.

Tahsil

Affected land (In Hectares)

Affected land ( Percentage to NSA )

1 Alibaug 4210 17.59

2 Uran 910 18.04

3 Panvel 100 0.57

4 Karjat 310 2.32

5 Khalapur 80 1.07

6 Pen 620 4.00

7 Sudhagad 90 1.02

8 Roha 440 3.23

9 Mangaon 130 0.47

10 Mahad 90 0.28

11 Poladpur 20 0.19

12 Mhasla 210 3.65

13 Shrivardhan 20 0.22

14 Murud 800 7.99

15 Tala # #

District 8030 6.75


199

Electrical conductivity of the soil affects the production of crops.

Electrical conductivity more than 1 mmhos/cm caused for poor seed

emergence, if increased, may lead the problems for reproductive system of

plants. Table 7.3 and Fig.7.3 show the land degradation by increasing the

electrical conductivity of the soil. The district observed 8032 hectares land,

more than 1 mmhos/cm electrical conductivity which is 6.75 per cent of the net

sown area of the district. Alibaug tahsil has highest area under high electrical

conductivity covers 4210 hectares area with 17.59 per cent. Alibaug tahsil is

near the coast thus the high salinity and wetness in the soil resulted into high

electrical conductivity in the soil and Poladpur tahsil lies to Ghat region thus

there is a low electrical conductivity. High soil electrical conductivity has

observed in Alibaug (17.59 per cent) and Uran (18.4 per cent) tahsil due to the

coastal location. Moderate soil electrical conductivity is observed only in one

tahsil named Murud tahsil with 7.99 per cent.

Low soil electrical conductivity has observed in Mhasala (3.65 per

cent), Pen (4.00 per cent) and Roha (2.23 per cent) while very low conductivity

observed in Karjat ( 2.32 per cent ), Sudhagad (1.23 per cent), Panvel ( 0.57 per

cent), Shrivardhan (0.22 per cent), Mangaon and Tala ( 0.47 per cent). Mahad

(0.28 per cent) and Poladpur tahsil with only 0.17 per cent.

7.4 LOSS OF TOP SOIL OF ARABLE LAND BY BRICK

MAKING INDUSTRY

Growing urbanization also affects on agricultural land. Agricultural land

converted into non agricultural land (NA) used for construction of building,

road and other infrastructure but good agricultural land is utilized for brick

production. According to Agrawal (1982), the brick work for modest house for

a family of five, in an urban area, would require about 120 tones of soil. The

upper fertile soil, rich with organic matter and nutrients is very useful for plants

are used for brick making as a raw material. By paying little revenue the


200

valuable soil resource has converted thousands of hectares of fertile productive

agricultural land into waste land. Henceforth it will useless for cultivation.

Bricks are the need of construction industry required for urban

development. But the rate of exploitation of top soil for brick is very high and it

is accelerated in last ten years. Soil formation is a long, tedious and slow

process. It is a effect of weathering process and erosion developed by various

agents. It takes few years to several thousand years. Under most ideal soil

management system soil may form at a rate of one centimeter in about twelve

years and under normal agricultural condition approximately 3.75 tonnes of

topsoil is formed per hector per year. (Biswas 1979) Rapid increasing

urbanization multiplied demand for upper fertile layer of soil. Large number of

brick kilns near the urban centers caused for land degradation at considerable

level.

Raigarh district is in the proximity of Mumbai Metropolitan region.

Mumbai Metropolitan Region Development Authority (MMRDA) and CIDCO

started developing new urban centers in Raigarh district to reduce the burden

on Mumbai city. Development of road and railway network in the region

helped to accelerate the speed of urbanization. As a result of this there is large

demand for brick. Thus the region has large number of brick kilns.

Table 7.4 shows the distribution of land degradation by brick kilns in the

region. Raigarh district accounts for 1021 brick making units spread over entire

district. Normally one brick kiln occupies 0.20 to 0.30 hectares of land on an

average. The size of land depends on the capacity to make production, some

kilns have a capacity to make 50,000 to 5 lakhs brick per year. The brick

making units usually start after monsoon. Each labour makes about 1000 to

1200 bricks on an average 250 grams of soil clay per brick. Ten to twelve

workers per day roughly used 3.5 tonnes of fertile soil per day per brick unit. If

it calculated for whole season, it shows the severally of degradation.


201

Table - 7.4

Raigarh District

Number of Brick Kilns (2009-10)

Source – Tahsil Revenue Record

Fig. 7.3 revels that the distribution under brick industry in the district.

The highest land degradation by brick making industry has observed in Panvel

tahsil. It has occupied 116.62 hectares area under 155 brick kilns and occupied

0.96 per cent area of the total net sown area. The lowest area under 28 kilns

occupied 0.09 percent of the net sown area.

Sr.

No.

Tahsil No.

of

Kilns

Area in

Hectares

% To

TGA

% To

NSA

1 Alibaug 82 32.6 0.07 0.13

2 Uran 56 32 0.17 0.67

3 Panvel 155 116.62 0.20 0.69

4 Karjat 102 82.21 0.13 0.56

5 Khalapur 95 72.35 0.18 0.94

6 Pen 79 35.98 0.07 0.23

7 Sudhagad 63 34.40 0.08 0.32

8 Roha 28 15.92 0.03 0.09

9 Mangaon 83 42.26 0.06 0.22

10 Mahad 93 61.21 0.08 0.20

11 Poladpur 59 45.10 0.12 0.38

12 Mhasla 41 26.29 0.08 0.43

13 Shrivardhan 23 14.26 0.05 0.18

14 Murud 39 23.36 0.09 0.23

15 Tala 23 11.81 0.05 0.28

District 1021 646.37 0.09 0.32


202

Fig. 7.3


203

Fig. 7.4


204

The high land degradation (above 0.6 percent) by brick making industry

has observed in two tahsils. Panvel tahsil recorded highest area (116.62

hectares) with 155. Kilns occupied and 0.96 per cent of the total net sown area.

Khalapur tahsil having 95 brick kilns covering 72.35 hectares area which is

0.94 percent of the net sown area. Khalapur and Panvel tahsils are in the close

proximity of Navi Mumbai city and these tahsils supply the bricks for

construction of new buildings on a large scale.

Medium land degradation between 0.3 to 0.6 percent) by brick industry

is found in four tahsils. In Karjat tahsil 82.21 hectares land has occupied for

brick industry under 102 brick which covers 0.56 percent of the net sown area.

Sudhagad tahsil covers 34.40 hectares land accounting 0.32 percent area under

net sown with 63 brick kilns. Mhasla tahsil accounting 0.43 per cent and

Poladpur tahsil accounting 0.38 percent of net sown area with 41 and 59 brick

klins respectively.

Low land degradation (less than 0.3 percent) has found in nine tahsils.

Low area under brick industry is found in Tala 0.28 per cent with kilns, Uran

0.27 per cent with 18 kilns, Pen 0.23 per cent with 72 kilns. Mangaon 0.22 per

cent with 83 kilns, Mahad 0.20 per cent with 93 kilns, Murud 0.23 per cent

with 23 kilns, Shrivardhan 0.18 per cent with 23 kilns, Alibaug 0.13 per cent

with 82 klinsand Roha tahsil covers 0.09 per cent area under 28klinsin the

district.

7.5 LAND DEGRADATION BY SALT ACCUMALATION

(KHARLAND)

Khar land refers the land occurs due to periodical inundation of

cultivated land by sea or creek water during the high tide. Such periodical

inundations render the otherwise fertile soils progressively saline and in time

make it completely damaged for growing any crop. This salt affected land is

locally known as khar land or khajna land. Even if the encroachment of creek

water is stopped by putting an embankment, the brackish water from the water-


205

table rises through capillaries due to evaporation and enriches the upper crust

of soil with salts.

Raigarh district has 240 kilometer coast line. The coastal saline soil in

the district spread over two agro climate zones. The very high rainfall, non-

lateritic soil (VRN) derived from basalt rock spread over the northern coastal

part and the very high lateritic soil (VRL) covers southern coastal part of

Raigarh district. These soils are good for cultivation but due to percolation of

sea water it become saline and fertility of these soils is reduced to the large

extend. This soil contains adequate available manganese and copper. Increase

in the salinity has been observed in the coastal lands since past few years. The

very gentle slope and fine clay looms, percolation of sea water, poor drainage

system, salt rich water table and lack of fresh irrigation water and fertilizer

applications caused these lands for salt accumulation.

Table - 7.5

Raigarh District

Salt Accumulated Land (Kharland) 2009-10

Sr. No. Tahsil Name of the

Creek

Area in

Hectares

1 Panvel Panvel 1460

2 Uran Mora 1774

3 Pen Karanja 3086

4 Alibaug Dharamtar 19052

5 Murud Revdanda 5147

6 Roha Rajpuri 727

7 Mhasla Bankot

8 Shrivardhan Bankot

1348

Total 32526

Source – Water Resource Department, Kharland Survey and

Investigation Division, Pen, Raigarh


206

The salt affected area in the study region is attributed by the following-

i) Tidal water inundation with salty water during high tides rendering the

land saline.

ii) Very poor drainage causing water logging in rainy season.

iii) Lack of irrigation facilities owing to unavailability of good quality of

water during dry season.

iv) High soil salinity due to close proximity of salt rich water table to soil

surface.

Moreover these soils showed variation in their properties. This soil had

fine texture and very poor hydraulic conductivity in VRN zone and VRL zone

had course texture and moderate conductivity. Though rain fall in this region is

effective in reducing soil salinity, it was revealed that it is not the total rainfall

but its distribution which matters in reducing the soil salinity. In the monsoon

the surface salt either washed out, diluted or leached and the soil becomes fit

for growing crops after monsoon, from the month of November the salinity

starts increasing up again.

Alibaug tahsil has highest area under salt accumulated land (19052

hectares) followed by Murud tahsil with 5147 hectares. Lowest salt

accumulated land is observed in Roha tahsil with 727 hectares land.

7.6 Erosion Prone Areas

Soil erosion, as induced by man, is a disruption of the steady state of

normal (natural) erosion which increases with time (Vink, 1983). Intensity of

rain, permeability of soil, chemical and physical properties of rocks, depletion

of vegetation, nature of relief and degree slopes etc. some of the factors

responsible for this process. In addition to these human activities through

deforestation, overgrazing, unsuitable cultivation methods along with slopes

etc. adds to aggravate the problems.

The term soil erosion in the present context is the sheet, gully and rill

erosion in combination. The data of such is not available with any agency, thus


207

the soil erosion is not studied by any technical method. The observations made

during the survey of ten sample villages, discussion with soil conservation

departments, satellite photographs etc are used for the explanation.

The eastern part of the district includes the Karjat, Khalapur, Mahad and

Poladpur shows heavy soil erosion due to the steep slope. The average slope of

the land is more than 70 in this region. This region has heavy rainfall; high

altitudes and higher degree of slope caused for higher soil erosion in the

district. Erosion is the common type of erosion observed in this region.

Central forested hills comprises part of Panwel, Alibaug, Pen, Mangaon,

Tala, Murud, Mhasala and Shrivardhan tahsils have also medium degree of

slope with heavy rainfall. Soil erosion is also observed in this region.

Sheet erosion has observed in Karjat tahsil, near Morambe village and

near Dodhani village in Panvel tahsil. Gully erosion has commonly observed in

rainy season on the slope of mountains and hills due to heavy rainfall.

7.7 Unsuitable Cultivation Methods

During the visit to the sample villages in various tahasils spread over the

village, it is noticed that most of the farmers are uneducated and unaware the

proper cultivation methods of farming. It is observed that the farmers are

ploughing the land parallel to the slopes causes the soil erosion from the farms.

The small earthen bands surrounding to the farms are also not well maintained

by the farmers. It helps to accelerate the process of erosion of the agricultural

land.


208

REFERENCES

1. Agarwal Anil (1982): “The State of Indian Environment – A Citizens

Report”, Centre for Science and Environment, Delhi, pp. 4-7.

2. All India Soil Land Survey organization, Soil Survey Manual, New

Delhi, Indian Agricultural Research Institute, 1970, pp.50-52 and 58-64.

3. Andhalkar C.V. (1984): “Micronutrient status of the Coastal Saline

Soil”, M.Sc. Agri. Thesis submitted to Konkan Krishi Vidyapeeth,

Dapoli, p. 11.

4. Arakeri, H.R., Chalam, G.V.,Satyanarayana, P., & Donhur, R.L. (1967):

“Soil Management in India”, Asia Publishing House, Bombay, p. 21.

5. Biswas, T.D., Mukherjee 91994): “Soil Science”, Tata McGrew-Hill

Pub. Ltd. New Delhi. pp. 1-2, 90-92, 222, 361-36

6. District Census Handbook, Raigarh 1981 and 1991, Part-XII-A&B

7. District Socio-economic Review and Statistical Abstract, Raigarh

District, 1980 -2009

8. http/www.mah.nic.in

9. http://maharashtraonline.in/Profile/Districts/Raigad.asp Report of Water

Resource Department, Kharland Survey, Investigation Division, Pen,

Raigar

10. Rao S. and Choudhari D.V. (1987): “Degradation of Agro-eco System –

An Exploratory study of Cotton Farming”, Indian Journal of

Agricultural Economics, Vol. XLII, No. 3, Bombay, pp. 410-415.

11. Reports of District Soil Testing Laboratory, Alibaug

12. Sharma, J.P. (1972): “Problems of Land Utilization in the Himalayan

Ravi-Chenab Duab”. Geographical Review of India, Vol.34, No.4,

pp.354-368

13. Vink, A.P.A. (1975): “Landuse in Advancing Agriculture”, Springer

Velag. .Newyork, P.3,168.171

14. Winfred, E.H. (1997): Methods for Assessment of Soil Degradation”,

CRC Press, London, pp-1-7

15. Zone S.V. (1986): “Tropical and Subtropical Soil Science”, Mir

Publishers, Moscow, pp. 389-390.


209

conceptual and locational aspects of land...

Documents