India has to depend on crop nutrient, whether chemical or organic, to produce enough foodgrains for self-sustainability as in all tropical climate the organic carbon in the soil is not more than 1 per cent, experts said. However, as the immediate need for crop nutrient is so high that without chemical fertilisers, organic nutrients alone cannot meet the entire demand, the experts said.
On the sidelines of a global conference on soil science, inaugurated in New Delhi on Tuesday, Director-General of Indian Council of Agricultural Research (ICAR) Himanshu Pathak said to produce 1 tonne of rice, 20 kg of nitrogen (N) and potash (K), each, is required besides 3.5 kg of phosphorus (P). “To maintain the current productivity of 5-6 tonnes/hectare in rice, 100-120 kg of N and K, each will be needed. That crop nutrient has to be applied either through chemical or organic form if yield level has to be maintained.”
Changing ratio
Some agriculture scientists attending the conference said the availability of organic manure is not that high to replace chemical fertilisers completely. But, to improve the soil health conditions, both organic and inorganic crop nutrients have to be applied, they said.
Pathak explained that from the current organic carbon available in the soil, 40 kg of N can be made available, which leaves the requirement of another 60 kg N for paddy on one hectare, based on a yield estimate of 5 tonnes/hectare. As 100 kg of organic manure can produce 0.5-1 per cent N, there will be a huge requirement.
Addressing media on the sidelines, ICAR’s deputy director-general (natural resource management) S K Chaudhari said that according to a study in 2023, there 90 per cent deficiency in N and P in 90 per cent of the agricultural land, while 50 per cent of land is deficient in potash.
He said the crop nutrient ratio (N:P:K) which was at 8:4:1 in 2019 has come down to 5:1.8:1 which is close to the recommended level of 4:2:1. He credited the soil health scheme, which effectively started rolling out from 2017, for the change brought about in the usage of fertilisers.
Zinc deficiency
Chaudhary also saidzinc deficiency has been reduced to 40 per cent (of the total cultivable land) now from 50 per cent a decade ago.
Further, the DDG said the practice of natural farming, which is different from organic farming, at some places show that the productivity level of crops could be maintained after a few years if a farmer shifts from chemical farming.
Earlier, inaugurating the conference - “Caring Soils Beyond Food Security: Climate Change Mitigation and Ecosystem Services,”, Union Agriculture minister Shivraj Singh Chouhan emphasised the critical importance of soil health in ensuring food security and achieving global sustainability. He highlighted the government’s proactive efforts to integrate soil health management into broader climate action policies, underscoring soil’s role in mitigating climate change and supporting ecosystem services.
Silent crisis
Chouhan urged scientists, policymakers, and practitioners to collaborate in developing actionable, farmer-centric solutions to enhance soil productivity and resilience while leveraging innovative technologies to combat challenges such as soil degradation and nutrient loss.
Addressing the conference, organised by Indian Society of Soil Science (ISSS), NITI Aayog Member Ramesh Chand highlighted the journey of soil science from traditional farming practices to modern, technology-driven approaches and how innovations in soil management have played a pivotal role in boosting food production. Pointing to the growing economic consequences of soil degradation, he described it as a silent crisis with far-reaching implications.
He said deteriorating soil health is not only reducing agricultural productivity but also leading to significant financial losses for farmers and national economies. Chand said that tackling soil degradation requires a multi-pronged strategy encompassing innovation, research, and collaborative policymaking to safeguard productivity and sustainability for future generations.