Rice residues in southeast Punjab, India, prior to the wheat season (photo on Flickr by Neil Palmer).
Why are most poor farmers in developing countries not adopting ‘no-till agriculture’ (also called ‘conservation agriculture’)—an eco-friendly, natural-resource-conserving technology that helps conserve soil fertility by eliminating ploughing and keeping the remains of crops on the ground after harvest? The simple and straightforward answer stares one in the face on small farms worldwide, that would be the face of a cow, goat, sheep or other hungry farm animal that consumes the stubble as an essential part of its seasonal feed resources.
Nicholas Magnan, in the OUPblog, has an interesting review of the value of ‘stubble’—also know as ’crop by-products’, aka crop wastes’, aka ‘crop residues’, aka ‘stover’. As scientists such as Michael Blümmel and Diego Valbuena at the International Livestock Research Institute (ILRI) and other organizations working in and for developing-country agriculture have been arguing for some time, the value of crop ‘wastes’—what remains of cereal and legume crops after their grains and pods have been harvested for human consumption—is invaluable for poor farmers raising farm animals as well as growing food crops.
‘No-till agriculture . . . offers many benefits to farmers and society. . . . [D]espite the benefits, small farmers in developing countries aren’t adopting no-till en masse. The potential explanations for the lack of no-till adoption are numerous. . . .
‘No-till requires farmers to keep stubble on the field after each harvest, so that it adds organic matter to the soil. But farmers in developing countries usually raise livestock in addition to cultivating crops, and stubble is an important source of livestock feed. The need to use the stubble for feed is particularly strong for small and isolated farmers without good alternatives. Farmers therefore face a tradeoff between leaving stubble in the field for no-till or feeding it to their livestock. The question then becomes, how steep is this tradeoff between the benefits of no-till agriculture and the cost of feeding one’s livestock?
‘Doug Larson, Ed Taylor, and I set out to quantify this tradeoff to see if small farmers are indeed stuck on stubble when it comes to no-till adoption in Morocco. In Morocco, Rachid Mrabet and others have shown no-till to perform as well as conventional methods when rainfall is good, and better than conventional methods when rainfall is poor (which occurs regularly in this drought-prone country). However, no-till adoption is scarce among small farmers, who almost always also raise sheep, goats, and cows. Employing unique livestock data gathered from the same farmers during a good rainfall year and a bad one, we found the economic value of stubble to farmers to be around one quarter of the total value of cereal production in a good year. In a drought year, when grain production was lower and livestock feed scarce, the value of crop stubble accounted for three quarters of the total value of cereal production.
In either case, the value of stubble as feed exceeded the upfront savings of no-till for most farmers.
‘. . . On a larger scale we also see evidence of the how differences in the availability of feed influences no-till adoption. Diego Valbuena and colleagues found that in multiple sites across Africa and South Asia demand for crop residues is higher where grazing land is poorer. And generally, no-till adoption is more common among small farmers in South America — where more plant matter is available as feed — than elsewhere. Understanding which farmers place the highest value on stubble as feed will help better target extension, and better design policies that improve access to alternative feed sources. . . .
‘Efforts to disseminate no-till and other technologies to small farmers in developing countries should therefore focus on identifying and alleviating the constraints that result in crop stubble being so valuable as feed to these farmers. Otherwise the cost of no-till adoption of no-till technology may simply be too high.
‘Nicholas Magnan recently joined the Department of Agricultural and Applied Economics at the University of Georgia, Athens. He was a research fellow at the International Food Policy Research Institute in Washington, DC studying various aspects of agricultural technology adoption. He is the co-author of “Stuck on Stubble? The Non-market Value of Agricultural Byproducts for Diversified Farmers in Morocco” in the American Journal of Agricultural Economics, which is available to read for a limited time. It examines the value of agricultural byproducts, such as crop stubble, to crop-livestock farmers who produce both cereal and crop residue, where the latter can be used as livestock feed. To properly assess the cost of introducing new technologies into such systems, one must value the implicit cost of byproducts.’
Read the whole article by Nicholas Magnan on the Oxford University Press Blog (OUPblog): Are small farmers in developing countries stuck on stubble?, 7 Aug 2012.
Read a recent science article on this subject by ILRI scientists Diego Valbuena, Alan Duncan, Bruno Gérard, Mariana Rufino, Nils Teufel and colleagues from other institutes in the CGIAR Systemwide Livestock Programme: Conservation agriculture in mixed crop–livestock systems: Scoping crop residue trade-offs in sub-Saharan Africa and South Asia, published in Field Crops Research 132: 175–184, in June 2012.