Reversing degradation of land

Prime Minister Narendra Modi has urged the farmers in his recent Independence Day address to curtail or stop the use of fertilisers to keep soils healthy and save Mother Earth. This plea has significant implications for agriculture and, therefore, needs to be weighed cautiously. While the PM’s concern for deterioration of soil quality due to chemical pollution is well founded, the solution offered by him seems rather simplistic. Chemical fertilisers alone are not responsible for degradation of land and its fertility. Nor a reduction in their use alone would check this menace.  

Several chemical, physical and biological factors are vitiating the land resource. These have been elaborated in a “policy brief” on soil health, issued by the National Academy of Agricultural Sciences (NAAS) in May 2018. The significant among these are: Improper tillage; inept on-farm land and water management; soil erosion; water logging; salinity, alkalinity; imbalanced nutrient application; deteriorating biological and microbial profile of soils and, most importantly, the neglect of organic manures. A simultaneous attack on all these fronts — and not piecemeal action on one or a few of them — is imperative to preserve health and productivity of the soils.

Prior to the green revolution, the use of fertilisers was almost negligible. But the farm production was also too meagre to meet the needs of the population. It was, indeed, the fertiliser-responsive high-yielding crop varieties which brought about the green revolution that made the country surplus in most agri-products. Such high-output varieties normally require larger amounts of soil nutrients which farmyard manures alone cannot provide. These manures are, however, essential to supply micronutrients which the chemical fertilisers generally lack. Farm experts, therefore, recommend the conjunctive use of chemical fertilisers and organic composts for best results. Studies have shown that fertilisers, if applied in the right quantity, at the right time and at the right place (root zone), along with adequate doses of organic manures, tend to preserve soil productivity rather than spoil it.

That said, the fact also is that the government’s approach towards fertilisers and soil health seems rather paradoxical. While on the one hand it intends to discourage chemical fertilisers, but on the other, it offers hefty subsidies on them — more than 70 per cent in the case of urea — to push up their consumption. There are problems also with the subsidies. These are neither rational nor uniform for different types of fertilisers. These, therefore, result in the imbalanced use of nutrients to the detriment of soil health. Moreover, while phosphatic, potassic and mixed fertilisers have been brought under the nutrient-based subsidy (NBS) scheme, the most-consumed urea has, for inexplicable reasons, been left out of it. The price of urea, too, has been kept unreasonably low. Steps like rationalisation of subsidies and decontrol of urea prices by bringing it under the NBS regime are vital to ensure balanced application of nutrients.

The need truly is to curb the injudicious use of fertilisers and promote their need-driven application. Some steps have already been underway to ensure that. Introduction of the soil health cards system and mandatory neem-coating of urea can be the typical cases in point. The next logical step would be to incentivise the production and use of organic manures and bio-fertilisers by offering fiscal sops at par with those of chemical fertilisers.

The Indian Council of Agricultural Research (ICAR) has recently developed a liquid bio-NPK formulation which can augment the supply of all the three major plant nutrients (N or nitrogen, P or phosphate and K or potash) without harming the soils. This liquid solution contains three different, but compatible, kinds of microbes. Of these, Azotobacter chroococuum is capable of fixing atmospheric nitrogen into the soil while the other two, Paenibacillus tylopili and Bacillus decolorationis, can solubilize phosphate and potash, respectively, to improve their availability to the plants at a very low cost. Such steps can help achieve the objective set forth by the PM without any deleterious impact on agricultural production.
 

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