Land and Agricultural Systems in West African Small Watershed

在热带非洲，传统的农业体系以高地作物为主，破坏了高地森林，低地尚未得到广泛利用。热带非洲以水稻为基础的低地农业的总潜力超过2000万公顷。在低地中，内陆山谷对萨瓦人的发展尤为重要。由于地质施肥，即土壤、养分和水流在流域从高地到低地的作用，低地沙瓦系统的可持续生产力是高地种植系统的十倍以上。正因为如此，如果这2000万公顷的潜在土地在今后50年到100年内变成萨瓦田，不仅可以为5亿到10亿人提供食物，还可以防止2亿多公顷的森林被砍伐，最终为恢复森林铺平道路。在三年的研究基础上，提出了基于生态技术的西非低地沙漠化防治策略和实践参与式方法。恢复森林每年固定的碳量约为每公顷2.5-5吨，今后50-100年将达到每年5亿至10亿吨。

In tropical Africa, agriculture is mostly upland crops by traditional system, which destroys upland forests, and lowlands have not been yet widely used. Tropical Africa's total potential for lowland sawah, paddy, based farming is more than 20 million hectares. Among the lowlands, inland valleys are especially important for sawah development. The sustainable productivity of lowland sawah systems is over ten times as high as that in upland cropping systems because of Geological fertilization, i.e., soil, nutrients and water flow, from upland to lowland in a watershed. Because of this, if these 20 million ha of potential land were turned into sawah fields in 50 to 100 years from now, that would not only bring about food for 500 million to one billion people but also prevent deforestation of more than 200 million ha, which would ultimately pave the way to restore forest. Based on the three years of research, we proposed the ecotechnology based strategy and practical and participatory approached for the reforestation and the checking desertification through lowland sawah development in West Africa. The carbon to be fixed by restored forests will reach about 2.5-5 tons per ha per year and will total to 500 million to one billion tons a year in 50-100 years from now.