Wider adoption of zero budget natural farming (ZBNF), which the Central government is seeking to promote as a way to help farmers double their income, can actually lead to India not being able to meet its requirement for food for all its population in coming decades, a new study has claimed.

In a paper published in the journal Nature Sustainability , a team of researchers from the University of Aberdeen and the James Hutton Institute at Aberdeen in the UK, who carried out first-ever scientific assessment of ZBNF, propounded by Subhash Palekar, a Maharahstra-based farmer, found that it can improve yield for farmers who use low-inputs, but may have an impact on India's ability to feed its rising population in the decades to come.

The population of India, which is currently 17.71 per cent of the total world population, is predicted to increase by 33 per cent from 1.2 billion in 2010 to 1.6 billion in 2050. Under ‘business-as-usual’ scenario, by 2050, 60 per cent of India’s population, equivalent to over 10 per cent of the people on Earth, will experience severe deficiencies in calories, digestible protein and fat, the scientists have claimed in the paper.

To meet increased demands for food on a shrinking area of agricultural land, efficiency of crop production must increase, but climate change, soil degradation and depopulation present further challenges to increasing the efficiency of Indian agriculture.

In her maiden Union Budget speech in July last year, Finance Minister Nirmala Sitharaman hailed ZBNF as an innovative model and said adopting this could help Indian farmers to double their income by 2022, which happens to be the 75th of Independence.

ZBNF is making waves in Andra Pradesh, where 5,23,000 farmers, about 13 per cent of farmers in the State, have already embraced the technique. Promoters of ZBNF claim that the soil already contains all the nutrients needed for plant growth and that the action of microbial cultures added to the soil releases these nutrients from the soil itself. However, if only nitrogen was provided by stimulating release from the topsoil, there would be an associated loss of organic matter, and all organic matter would be lost from the topsoil within 20 years. This would result in a sharp decline in crop production and make soils less resilient to droughts, argued the scientists.

“Zero budget natural farming started as a grassroots movement, aiming to provide multiple benefits, both to the environment and to farmers. However, there are conflicting opinions about how it should be developed for widespread use. This report provides scientific evidence on the potential for scale-up,” said Jagadeesh Yeluripati from the James Hutton Institute who is also the co-author of the study.

The lead author of the study, Jo Smith of the Unviersity of Aberdeen, said contrary to the fears of many scientists, this system could support improved food production for low-input farmers. In addition, because inputs of crop residues are high, the soil is unlikely to degrade.

“However, the maximum potential nitrogen supply is likely to be only 52–80 per cent of the average fertiliser application rate. This means that yield penalties are likely in higher input systems; so widespread conversion of farms from all sectors to zero budget natural farming is not recommended,” Smith said.