Soil degradation world-wide is a major cause for concern as it not only depresses crop productivity but it can reach such extremes that the process becomes irreversible and vast tracts of land can be lost forever. Whilst research on reduced and zero tillage systems has been conducted for over a century, it was not until the 1970s that some farmers in South America began to develop production systems that not only conserved the soil but also allowed yields to be maintained and even significantly increased. The holistic approach involves reducing soil tillage to the minimum needed to place the seed or plant into the ground. The soil is protected by maintaining it covered as far as possible and ideally throughout the entire year using residues, cover crops or by relaying the crops. Crop rotations and or intercropping are other important aspects of the system to assist in improving fertility and to mitigate the effects of pests and diseases.
These three pillars of conservation agriculture have also been described simply as replacing mechanical and classical soil tillage with “biological tillage”. But CA is much more than just zero tillage because that alone will not restore and conserve the soil. Indeed thousands of farmers for instance throughout the Sahel, plant their seeds directly into the ground immediately after the rains without resorting to digging or ploughing – but their yields are disastrously low, particularly in times of drought.
True CA practices not only conserve the soil, but also the soil moisture. They capture Carbon and are entirely compatible with the axioms of Sustainable Land Management. It is estimated that CA is practised on over 100 million ha worldwide, with the practices having gradually been introduced in Africa and Asia over the past decade. CA has been shown to work with a wide range of food and cash crops. It can also be used for plantation crops, agro-forestry being only one example. Climatically, it has been practised in the Mongolia and DPR Korea, in the Sahel and in many parts of eastern and Southern Africa.
Community of Practice for Conservation Agriculture -- CA-CoP
A Soil Health Workshop was held at FAO, Rome in July 2008 where there was a strong call for the establishment of a global network of 'Community of Practice' (CoP) in support of Conservation Agriculture (CA) as a foundation for sustainable agriculture and facilitating the acceleration of farmers' uptake of CA. This has now been established and registration is encouraged by interested parties. For more info, visit http://www.fao.org/ag/ca/10.html
