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
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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
Chapter VII – Conceptual and Locational Aspects of Land Degradation and Analysis
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.
Chapter VII – Conceptual and Locational Aspects of Land Degradation and Analysis
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
Chapter VII – Conceptual and Locational Aspects of Land Degradation and Analysis
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.
Chapter VII – Conceptual and Locational Aspects of Land Degradation and Analysis
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
Chapter VII – Conceptual and Locational Aspects of Land Degradation and Analysis
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
Chapter VII – Conceptual and Locational Aspects of Land Degradation and Analysis
196
Fig. 7.1
Chapter VII – Conceptual and Locational Aspects of Land Degradation and Analysis
197
Fig. 7.2
Chapter VII – Conceptual and Locational Aspects of Land Degradation and Analysis
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
Chapter VII – Conceptual and Locational Aspects of Land Degradation and Analysis
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
Chapter VII – Conceptual and Locational Aspects of Land Degradation and Analysis
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.
Chapter VII – Conceptual and Locational Aspects of Land Degradation and Analysis
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
Chapter VII – Conceptual and Locational Aspects of Land Degradation and Analysis
202
Fig. 7.3
Chapter VII – Conceptual and Locational Aspects of Land Degradation and Analysis
203
Fig. 7.4
Chapter VII – Conceptual and Locational Aspects of Land Degradation and Analysis
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-
Chapter VII – Conceptual and Locational Aspects of Land Degradation and Analysis
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
Chapter VII – Conceptual and Locational Aspects of Land Degradation and Analysis
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
Chapter VII – Conceptual and Locational Aspects of Land Degradation and Analysis
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.
Chapter VII – Conceptual and Locational Aspects of Land Degradation and Analysis
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