Is “slash and burn” – swidden agriculture – a good or a bad thing? That’s when farmers cut down an area of forest (though often leaving the larger trees standing), burn the cut vegetation, and plant their crops, often roots and tubers, in the resulting ashy soil for a few years. When the soil is exhausted, they move on to another patch of forest, leaving the first one to grow back, ideally for perhaps 20 years or more, before being used again. A recent article from a local newspaper in the Philippines makes this sound like something to be guarded against at all costs, but can a practice with a track record of sustainable management of agricultural biodiversity and other natural resources in various parts of the world stretching back thousands of years really be all that bad? Although there is always room for improvement, surely the problem does not rest with slash and burn itself so much as with what happens when the system goes wrong because of over-intensification and excessive shortening of fallows. That should have been explained in the article. I hope it was explained to the people who, according to the article, were forcibly prevented from carrying out their traditional agriculture. When forest conservation and farming livelihoods come into conflict in this heavy-handed way there can be no winners.
Cassava in Africa
Cassava has a big problem in Africa, and it is called brown streak virus. A virulent strain is spreading rapidly across eastern and southern Africa from a beachhead in Zanzibar, devastating the tubers but leaving the leaves looking healthy, which means farmers don’t realize anything is wrong until it is too late. Scientists from the International Institute for Tropical Agriculture (IITA) have been studying the virus and have developed resistant varieties, by conventional breeding, and these are finding their way to farmers.
There’s a short SciDev piece about brown streak virus which points to a longer, very readable New Scientist article. I know we’re talking about a very serious problem and a very nice solution based on the exploitation of agricultural biodiversity, but normally I wouldn’t blog about this sort of thing, simply because there are so many similar examples out there. But I was inspired to do so on this occasion because I also spotted an article in a Ugandan newspaper (via the wonderful allAfrica.com) which talks about the resistant varieties and efforts to get sufficient planting material of these cultivars into the hands of farmers in a particular district. It’s always nice to see “big” stories from international news sources reflected in the local media.
Cassava is an important constituent of Kinshasa’s urban gardens, whose role in providing nutrition, especially to children, is so well described in a Christian Science Monitor article today. Let’s hope brown streak virus doesn’t reach Kinshasa, but if it does the resistant varieties would find a ready means of dissemination through a project which “organized a team of local volunteers called “Mama Bongisa” (‘mom improver’) to teach mothers in some … impoverished neighborhoods about nutrition and farming.”
Livestock and carnivores
In many parts of Africa, carnivores such as lions and wild dogs still come into frequent conflict with pastoralist communities such as the Maasai because of their attacks on their cattle and goats. This naturally results in a tension between the aims – and indeed the practitioners – of wildlife conservation and of rural development that does no good to either camp. So it is interesting to read of a study which looked at how to foster co-existence between people, domesticated animals, and large predators. The paper identifies improvements to traditional livestock management, as well as other measures, that can contribute to wild carnivore conservation by minimizing the risk to livestock.
EU puts Trust in Sheep
A new Consortium to study heritage sheep breeds across Europe got off the ground recently with a meeting in Yorkshire, England. The meeting came at the end of a project set up by the European Union, although I confess I have found it very difficult to find out more. Help, if you can.
Heritage breeds are not necessarily rare, but they are often geographically isolated and that can put them at risk. After the most recent outbreak of foot and mouth disease in England man thousand Herdwicks were dead in England, and blue tongue threatened the Mergelland sheep of the Netherlands. The project will study threats and how to conserve and make use of sheep breeds. According to Amanda Carson, of the Sheep Trust, who is leading the new European consortium, “the information we gather will also inform policy-makers, nationally and at European level, about the best way to look after our farm animal genetic resourcesâ€.
Durum wheat erosion
If there’s a dominant meta-narrative in agricultural biodiversity circles it is that modern breeding programmes relentlessly decrease the genetic diversity of crops, increasing yields and quality but also, as new varieties displace landraces and older varieties in farmers’ fields, depleting the very resource on which they are dependent for continued success. But actually there’s not really that much in the way of hard figures on this process. So a recent paper on what breeding has done to diversity in Italian durum wheat is very much to be welcomed.
The researchers used molecular and biochemical markers to compare genetic diversity among five different groups of durum varieties, ranging from landraces from before 1915, to pure lines derived from landraces in the 30s, to genotypes selected from crosses between local material and CIMMYT lines in the 70s. In general, there was indeed a narrowing of the genetic diversity within these groups over time. In fact, the degree of narrowing was probably underestimated, because only a relatively few of the pre-1915 landraces were still available for analysis. Conserving what is left is all the more important.