School of Earth and Environment

Conservation Agriculture

16.11.2017 - 10:26

Irrigating fields, Novu, Malawi. Credit: Andy Dougill.


Can conservation agriculture help farmers in sub-Saharan Africa handle the man-made problem of climate change? Professor Andy Dougill believes it’s possible, but much more co­ordinated planning and further evidence is needed.

For over a decade now, most development organisations have been advocating conservation agriculture (CA) as a ‘climate smart’ approach. The idea behind CA is that farmers maximise organic matter in their soil and reduce CO2 release by limiting or eliminating tillage altogether, using crop rotations and keeping a permanent organic coverage on the fields. In return, the argument goes, they get improved yields and crops are more resilient to the impacts of climate change.

There is some evidence to suggest the former is true, but we’re a long way yet from proving the latter. Why is the evidence base still so poor, given that CA - sometimes billed as ‘farming God’s way’ - has been promoted to farmers for so long?

A threefold problem

Part of the problem is the patchy take up of CA. Many farmers are reluctant to change to this method of farming or, once started, fail to maintain it. The reasons for this are threefold: practical, cultural and institutional.

On the practical side, CA can be more labour intensive, requiring more weeding and more work to sow a crop. Leaving organic matter on the surface, such as maize stalks, can encourage pests such as mice, which are deterred when the stalks are burned. Because the benefits take a while to come through, farmers can easily be put off by these more immediate ‘negatives’.

Culturally, many farmers in southern Africa believe that conventional agriculture, where the ground is ploughed and reseeded with the same crop each year, is the most modern, and therefore the best, approach.

And at an institutional level, take up of CA is often incentivised through provision of additional fertiliser and new seed, which makes it hard to strip out the impact of the change in farming method alone. But when the incentives end, for the reasons above, farmers often revert to their former methods.

Mixed messages

Although CA has been promoted across Africa for many years, this has been done by many different organisations - governmental and non-governmental - in different ways and for different reasons, resulting in confused messages as to why farmers should take up the practice and sometimes even what the practice should be. One of our recent studies, looking at how policy on CA is implemented in Malawi, highlights the need for better communication and collaboration between all relevant parties within a country: government departments, local government and NGOs. Effective implementation of CA requires government departments responsible for agriculture to move outside their traditional responsibilities and link with departments working on climate change adaptation, meteorology, health and water distribution.


Given these limitations, what reliable evidence do we have of the benefits that CA can bring, particularly in relation to climate resilience? Research has shown that CA can increase organic carbon levels in the soil and improve overall yield, but this work has been mainly undertaken on government research stations rather than in the ‘real world’ of farming. And what is still missing is robust findings to determine whether these benefits will hold up in the face of climate change.

The theory is that organic matter in and on the soil will help retain moisture - critical in the early stages of crops such as maize. Drought is just one of the problems caused by our changing climate. This year’s El Nino caused severe drought in Malawi, but flooding in Kenya and the frequency of large El Ninos is expected to increase as the climate warms.

Climate resilience

We’ve been working with farmers in Malawi for the last ten years, and know many of those who have taken up CA - currently around 2-3 percent. Those connections are helping us run a fast-turnaround research project, comparing how the crops of CA farmers in Malawi survived the drought compared to those using conventional methods. This work, funded by the UK government through the National Environment Research Council and the Department for International Development, should help us understand just how ‘climate smart’ CA can be.

This research also looks at the impact of El Nino in Kenya, working with the University of Bern to assess whether CA helped farmers retain yields in the face of the floods there.

Interim results from Malawi indicates that where the drought was most severe, all farmers lost their crops, but in more marginal areas, CA did provide some benefit.

Research like this will start to provide a much-needed evidence base to show farmers when it is in their interest to move to CA. Farmers need a clear message to help them understand which practices will work best for them, so they can make an informed decision - and we need both the evidence, and better collaborative working amongst key organisations, to make that happen.

Andy Dougill is Professor of Environmental Sustainability and Dean of the Faculty of Environment at the University of Leeds. His research integrates a range of disciplines including soil science, ecology, development studies and environmental social sciences.