lR;eso t;rs - Ministry of Environment and Forests

Table 2.1.2: All India Consumption of Fertilizers in
Terms of Nutrients (N, P & K)
Source: Agriculture Statistics at a Glance, 2006-07,
Ministry of Agriculture
Agricultural Waste Residue Burning
Burning of wheat and rice straw and other agricultural residue
has also contributed to loss of soil fertility, apart from causing air
pollution. Open field burning of straw after combine harvesting
is a common practice in states like Punjab, Haryana and Uttar
Pradesh in order to ensure early preparation of fields for the next
crop. Punjab alone produces around 23 million tonnes of rice
straw and 17 million tonnes of wheat straw, annually. This straw
is rich in nitrogen, phosphorus and potassium. However, instead
of recycling it back into the soil by mulching, it is burnt in the
fields. This raises the temperature of the soil in the top three
inches to such a high degree that the carbon: nitrogen equilibrium
in soil changes rapidly. The carbon as CO is lost to the
2
atmosphere, while nitrogen is converted into a nitrate. This leads
to a loss of about 0.824 million tonnes of NPK from the soil. This
is about 50 per cent of the total fertilizer consumption in the state.
Considering that 90 per cent of rice straw and 30 per cent of the
wheat straw is available for recycling, it will be equivalent to
recycling of 0.56 million tonnes of nutrients worth Rs. 4 billion.
Moreover, agriculture experts also maintain that fire in the fields
kills friendly fauna and bacteria.
Soil Erosion
( 1000 tonnes)
Year N P K Total
2000-01 10920.2 4214.6 1567.5 16702.3
2001-02 11310.2 4382.4 1667.1 17359.7
2002-03 10474.1 4018.8 1601.2 16094.1
2003-04 11077.0 4124.3 1597.9 16799.1
2004-05 11713.9 4623.8 2060.6 18398.3
2005-06 12723.3 5203.7 2413.3 20340.3
2006-07 13772.9 5543.3 2334.8 21651.0
Soil is a unique non-renewable natural resource that supports life
on planet Earth. It is estimated that one-sixth of the world's soil
has already been degraded by water and wind erosion. In India,
approximately 130 Mha. of land area (or 45 percent of the total
geographical area) is affected by serious soil erosion through
ravines and gullies, shifting cultivation, cultivated wastelands,
sandy areas, deserts and water logging (Govt. of India, 1989).
Excessive soil erosion with consequent high rate of
sedimentation in the reservoirs and decreased fertility has
created serious environmental problems with disastrous
economic consequences.
In India, the Ganga, Brahmaputra and Kosi rivers carry huge
amounts of eroded soil in the form of heavy silt, which deposits
as sediments on the river bed. While soil erosion by rain and river
in hilli areas causes landslides and floods, deforestation,
overgrazing, traditional agricultural practices, mining and
incorrect siting of development projects in forested areas have
resulted in exposing the green cover to severe soil erosion.
Ravines and gullies account for 4 Mha. of land erosion. The area
subjected to shifting cultivation reported 4.9 Mha. of eroded
land.
In India, erosion rates range from 5 to 20 tonnes per hectare,
sometimes going up to 100 tonnes per hectare. Nearly 93.68
million hectares are affected by water erosion and another 9.48
million hectares are affected by wind erosion annually in India.
Thus, erosion leads to impoverished soil on one hand, and silting
up of reservoirs and water tanks on the other.
Apart from checking soil erosion, the problem of conserving soil
moisture is also of immense importance in the extensive regions
of low and uncertain rainfall, forming parts of Punjab, Madhya
Pradesh, Maharashtra, Andhra Pradesh and Karnataka. These
tracts are characterized by scanty, ill-distributed and highly
erosive rains, undulating topography, high wind velocity and
generally shallow soils. The period of heavy downpour from
August to October is also the period of severe erosion in these
regions. About 76 per cent of Rajasthan's arid region is affected
by wind erosion of different intensities, and 13 per cent by water
erosion. In fact, 4 per cent of Rajasthan's arid area is affected by
water logging and salinity or alkalinity.
In India, very little area is free from the hazard of soil erosion. It is
estimated that out of 305.9 million hectares of reported area, 146
million hectares is in dire need of conservation measures.
Change in Forest Cover
Forests are not just trees, but part of an ecosystem that underpins
life, economies and societies. Forests provide a wide range of
services which include prevention of soil erosion, floods,
landslides, maintenance of soil fertility, and fixing carbon from
the atmosphere as biomass and soil-organic carbon.
The total forest cover of the country, as per the 2005 assessment,
is 677,088 sq. km. which constitutes 20.60 per cent of the
geographic area of the country (Table 2.1.3 and Figure 2.1.4).
Dry Deciduous Forests of the Melghat Tiger Reserve
State & Trends of the Environment-Land
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