The state of Andhra Pradesh in India has been promoting chemical-free agriculture under a programme launched in 2016. In the last six years, it has worked with 0.63 million farmers across six districts on Zero Budget Natural Farming (ZBNF). Researchers from the University of Reading in the UK and Rythu Sadikara Samstha, a non-profit set up by the government, carried out a study on the programme. Controlled field experiments were established in twenty-eight farms across six districts, spanning over 800 km, over three cropping seasons. Comparisons were made in terms of yield, soil pH, temperature, moisture content, nutrient content and earthworm abundance. Data showed that when compared to conventional agriculture, yields were maintained in the case of organic farming and increased in ZBNF. Conventional treatment involves the use of synthetic pesticides and fertilisers. Organic treatment does not use any synthetic pesticides or fertilisers and mulch, but uses purchased organic inputs, such as farmyard manure and vermicompost. ZBNF does not use any synthetic pesticides or fertilisers, but uses home-made inputs such as cow dung and urine with mulch. It also uses a combination of practices like reduced tillage and intercropping. It does not involve any purchase of inputs. Apart from the higher yield, nutrient availability was also unaffected in ZBNF. It has been estimated that if ZBNF covered 25 per cent of the total crop area in Andhra Pradesh, $70 million would be saved in fertiliser subsidies every year.