A major paper led by Iris Berger, a PhD student in our Agroecology Group, co-authored by group leader Prof Lynn Dicks, is published in Nature Ecology and Evolution today.
The paper, entitled, "India's agroecology programme, 'Zero Budget Natural Farming'”, analyses one of the world’s biggest agroecological transitions; the shift to government-incentivised 'Zero Budget Natural Farming' (ZBNF) in Andhra Pradesh, India.
The paper’s message is that ZBNF, more than doubles farmer profits, does not reduce food production relative to chemical farming, andZBNF farms support more wild birds, especially groups providing pest control benefits like insectivores. So, at least in rice-dominated small farms in south India, ZBNF is a 'win-win' solution.
Importantly, the paper also shows that the agroecological farmland is no substitute for natural forest in the same landscape, in terms of bird conservation.
Prof Dicks said, 'We counted wild birds and measured food production and profits, but there are very likely to be other benefits from this approach to farming - benefits to soil health, water quality and human health, especially from reduced synthetic chemical inputs.
‘If international development organisations and governments want to support sustainable and resilient food production around the world, everyone should be looking very carefully at the ZBNF system.' ZBNF has similarities to approaches like 'regenerative agriculture' in Europe and the US.'
Iris Berger summed up hopes for ZBNF, ‘Ultimately, ZBNF is an agricultural strategy that seems to work for both people and nature, generating hope that it might be possible to feed the world whilst reversing biodiversity loss.’
ZBNF to PhD: the story behind Iris’s Cambridge research
Iris told us more about her interest in ZBNF and how that led to the research for her PhD, based here in Cambridge:
I first learned about the land sharing-land sparing framework during my Master's. It made me acutely aware of the difficulty of improving the biodiversity value of agricultural landscapes without displacing other land system objectives, most importantly food production, to somewhere else. I began to wonder to what extent it might be possible to achieve high crop yields sustainably by effectively harnessing nature's contribution to food production.
I came across Zero Budget Natural Farming (ZBNF) and was intrigued by anecdotal reports that yields were higher than conventional, agrichemical-based farming. I was astonished by the scale at which this agroecological transition was happening: the policy aim is to convert all six million farmers in the state to ZBNF, but there was virtually no robust evidence on the impacts of ZBNF. I therefore decided to spend 14 months in India conducting fieldwork to investigate whether ZBNF might be able to reduce trade-offs between food production and biodiversity conservation – ultimately delivering both land sparing and land sharing.
That ZBNF does not match forests in terms of their bird conservation value is not surprising, as most specialist species simply cannot persist in agricultural landscapes. However, it was still important to demonstrate this with robust data, especially as agricultural expansion has substantially reduced forest cover in this part of India over the last few decades. We have previously held a multi-stakeholder workshop and found that agricultural and biodiversity conservation policies are poorly aligned, so efforts to ensure that the ZBNF transition is better integrated with landscape-scale conservation strategies are needed.
A lot of work remains to be done. We need a far better understanding of the mechanisms by which ZBNF affects yield and ecological functions. With ZBNF being adopted by tropical countries across the world, we need to understand how it performs in different socioecological contexts.
Read the paper: Iris Berger, Ajit Kamble, Oscar Morton, Varsha Raj, Sayuj R. Nair, David P. Edwards, Hannah S. Wauchope, Viral Joshi, Parthiba Basu, Barbara Smith and Lynn V. Dicks India's agroecology programme, 'Zero Budget Natural Farming' Nat Ecol Evol (2025)
Photo: Iris Berger and co-author Ajit Kamble surveying birds in forests in Andhra Pradesh, India. Photo by: Oli Broadhead.