'Conservation agriculture' boosts yields and incomes
[LUSAKA] Poor farmers in developing countries can substantially improve both their yields and livelihoods by adopting resource-conserving practices, says a large international study to be published next month.
The study reviewed 286 recent attempts to introduce such practices on more than 12 million farms in 57 countries, mostly in Africa.
It assessed how yields change when farmers using approaches such as less tilling to conserve soil, integrated pest management — which favours ecological pest control over pesticide spraying — and improved management of soil nutrients.
According to the study, adopting such approaches meant yields increased by an average of 79 per cent and harvests of some crops such as maize, potatoes and beans doubled.
As well as causing less damage to the environment, 'conservation agriculture' also improved farmers' wealth by, for instance, reducing their reliance on costly pesticides.
Sustainable farming practices also demand less water, says lead researcher Jules Pretty of the University of Essex, United Kingdom, who points out that by 2025 most developing countries are predicted to face water shortages.
The study concludes that while it is not clear whether these techniques can meet future food needs in developing countries, poor households have most to gain from adopting them.
It adds that combining these approaches with widespread improvements in crop varieties and livestock breeds would further boost productivity.
Pretty told SciDev.Net that African countries are leading the development of many successful sustainable agricultural systems: "What they need is more policy and institutional support to help these good ideas spread."
Keith Jones of CropLife International, which represents the world's biggest pesticide manufacturers, told SciDev.Net that its members "fully support integrated pest management (IPM) and conservation technologies, recognising the benefits they can bring to farmers, including those in developing countries".
"IPM aims to eliminate the unnecessary use of inputs, including pesticides, not eliminate their necessary use," said Jones. "Whilst IPM focuses on preventing pest build-up and growing a healthy crop, pests regularly reach levels where they need to be controlled and pesticides are often the most effective option available to farmers."
The study will be published in the 15 February issue of Environmental Science & Technology.