Land texture: Salinity, alkalinity make lands in Andhra Pradesh infertile

July 15, 2008
By Syed Akbar
Hyderabad, July 14: A severe environment crisis looms large over Andhra Pradesh if the latest Environment Atlas of the Union Ministry of Environment and Forests is any indication.
The Environment Atlas of Andhra Pradesh paints a grim ecological picture for this progressive State with as much as 203 lakh hectares of land being either saline or alkaline. This is three times the total land under agriculture in the State. The extent of saline and alkaline tracts in irrigated areas (under canal and tank or reservoir command areas) is about 5,30,000 hectares.
For a piece of land to be fit for growing greenery, the soil should be neutral. If it is saline or alkaline, it becomes unfit for agriculture. The problem gets compounded as the levels of salinity or alkalinity goes up. In soils with extreme levels of salinity or alkalinity, even grass does not grow.
The Atlas, released recently, describes such lands as "problem soils" and blames the damage to the soil texture on indiscriminate use of inorganic and chemical pesticides and fertilisers.
"While agriculture has spatially and by way of yield per hectare grown more slowly than industry and services, per hectare consumption of chemical fertilisers (mainly N-P-K) has gone up for the principle crops by 100 per cent. The constant, unabashed use of chemical fertilisers has left the soil in a totally bad shape. Soil degradation continues as natural way of soil enrichment has been pushed aside in keeping with the times calling for quick results. The salinity and alkalinity of soils has gone up. In fact the total salt affected area in our state is found to be 203 lakh hectares," the reports points out.
The area under Nagarjunasagar right bank canal is the worst hit with as much as 6.92 lakh hectares affected by salinity and 1.45 lakh hectares hit by alkalinity. The NS left bank canal occupies the second slot with 2.65 lakh hectares of soils being declared saline and 8,000 alkaline. Under Tungabhadra dam as much as 1.47 lakh hectares is saline and 5,000 alkaline.
Saline soils have been found in large areas overlying the coastal sands in the coastal districts. Saline-alkali soils are noticed to an appreciable extent in the coastal districts and Anantapur and Kurnool districts of Rayalaseema and in many parts of Telangana districts.
"In Telangana region, especially in Nalgonda and Mahbubnagar districts, soils have turned alkali due to irrigation with poor quality waters, which are loaded with residual sodium carbonate," said senior environment activist S Koteswara Rao.
Various forms of soil degradation observed in Andhra Pradesh are salinisation, alkalisation, laterisation and inundation. O the total area of 18.52 million hectares in 14 districts surveyed so far, 19.6 per cent suffers from soil degradation of one type or the other.
Current records indicate that 1,14,000 hectares of land is affected by water logging and salinity in Guntur and Prakasam districts. More than 60,000 hectares are alkaline in the districts of Anantapur, Kurnool, Medak, Nalgonda and Mahbubnagar.
Another peculiar phenomenon has been that of soil loss. This is happening and widely too due to both natural as well as man-made factors. Dryland agriculture in the state has to focus more on this soil loss as more arid tracks mean more impoverished people.
"Toxic bio-accumulation of chemical fertilisers and pesticides in water and soil has left a cumulative non-linear adverse effect on water quality, soil productivity as well as on human and animal health. Chemically induced and protected agriculture coupled with subsidised irrigation and energy use, have encouraged the wasteful practice of supporting mono-culture crops with ever-increasing doses of resources use per unit area of production, regardless of the actual crop-need," the Union Environment Ministry's report noted.