Indian Agriculture is passing through a difficult phase. Economic crisis due to ever increasing costs, ecological crisis due to exploitation of natural resources and coupled with climate change has led us to a new emergency. While in 1960s increasing food production to meet the needs was the driver, in 2020s sustainability is the new driver. While agriculture is responsible for nearly 20-25% of the Green House Gas (GHG) emissions, shift towards sustainable agriculture can also help to act as sink for atmospheric GHGs in addition to reducing the contributions and increasing the adaptation.
The diverse challenges and constraints as growing population, increasing food, feed and fodder needs, natural resource degradation, climate change, shifts in land use patterns, increasing desertification, decreasing factor productivity, agriculture becoming economically unviable, increasing farmer suicides, growing small and marginal farmers demand a paradigm shift in formulating and implementing the agricultural programmes in India.
Generating three centimetres of top soil takes 1,000 years, and if current rates of degradation continue all of the world’s top soil could be gone within 60 years, a senior UN official said recently and Indian situation is not very different. Land degradation assessment undertaken by the various Central and State agencies shows that about 148 m.ha to 180 m.ha of land is affected. The land degradation is in various forms like water and wind erosion, water logging, increased soil salinity/alkalinity/acidity, decreasing soil fertility and a complex of all these. Loss of crop productivity, one of many negative impacts of soil erosion by water, has serious consequences for country’s food, livelihood and environmental security. Major rainfed crops in India suffer an annual production loss of 13.4 Mt due to water erosion which amounts to a loss of Rs. 205.32 billion in monetary terms. About 5334 m.t. of soil is lost every year in India and the area affected is about 83 m.ha. In addition saline and sodic soils account for about 6 m.ha. A recent study by Indian Institute of Soil Science (IISS) found that the soils of as many as 174 districts across 13 states were deficient in secondary nutrients like sulphur and micronutrients like zinc, boron, iron, manganese and copper which are impacting on the yields. Chemical fertilisers use is seen as the only major approach to build soil fertility.
A simple regression analysis between the foodgrain production and fertilizer consumption during 1960- 61 to 1999-00 showed that the partial factor productivity of fertilizers has been continuously declining. The data available from some centres under the Project Directorate of Cropping Systems Research (PDCSR), Modipuram also indicate a reduction in crop response to fertilizer application, specially when balanced fertilization is not practiced. This is supported by the fact that the farmers in the rice-wheat cropping system belt (specially Punjab, Haryana and Western U.P.) are forced to apply more and more
fertilizer to obtain the same crop yields as in the preceding years. The data from the trials on the farmers’ fields conducted by the PDCSR, Modipuram during 1999-2003 showed that the average response of cereals to fertilizer was 8-9 kg grain/kg fertilizer. The efficiency of fertilizer nitrogen is only 30-40% in rice and 50-60% in other cereals, while the efficiency of fertilizer phosphorus is 15-20% in most crops. The efficiency of K is 60-80%, while that for S is 8-12%. As regards the micronutrients, the efficiency of most of them is below 5% (NAAS, 2006). The latest budget also allocated Rs. 79,900 for chemical fertiliser subsidy. The fertiliser subsidy caused its own distortions. For eg Punjab which has less than 1% area under cultivation consumes more than 12% of chemical fertilisers and hence 12% subsidy which roughly amounts to Rs. 8,000 cr. While there is lot of discussion around shifting towards balanced nutrition and government of India runs a large program on Integrated Nutrient Management, the NPK use ratio is still at 6.7: 2.7:1 and soil organic matter is going down significantly and more than 66% of Indian soils rank low with in it 49% being very low.
Another important dimension of the problem is about the link between chemical fertiliser use and the contribution to climate change. This is particularly with the Nitrogenous Fertilisers. In the manufacturing of Nitrogenous fertilisers required high energy use to combine Nitrogen and Hydrogen in the air. Coal, Naptha are main sources of producing this energy. Total greenhouse gas emissions (GHG) from the manufacturing and transport of fertiliser are estimated at 6.7 kg CO2 equivalent (CO2, nitrous oxide and methane) per kg N. How long this can continue is a big question. Estimates show that we have already reached peak use of coal reserves and petroleum products. We may runout of these in another 50-60 years. In addition to these emissions in production, in use there are losses. About 1.25 kg of N2O emitted per 100 kg of Nitrogen applied Globally, an average 50% of the nitrogen used in farming is lost to the environment as N2O to the air as a potent GHG (310 x CO2) and as nitrate polluting wells, rivers, and oceans Volatilization loss.
This approach is a synthesis of the experiences of CSA and other organizations over decades. These principles and practices needs to be locally adapted based on the need and available resources.
Centre for Sustainable Agriculture has over 16 years’ experience in developing sustainable models in agriculture and establishing farmers collectives to improve the last mile delivery of services and first mile aggregation of produce to deal with the markets.