The Worldwatch 'Nourishing the Planet' blog reports on a simple but ingenious means of tackling poor and degrading soil quality in Africa. The article quotes a report, “Agricultural success from Africa: the case of fertilizer tree systems in southern Africa (Malawi, Tanzania, Mozambique, Zambia and Zimbabwe),” from the International Journal of Agricultural Sustainability, which states that simple “Fertilizer Tree Systems” (FTS) can double maize production in soil that is low in nitrogen. A type of agroforestry, FTS incorporate nitrogen-fixing trees and shrubs into agricultural fields, usually inter-planted with food crops. These trees take in atmospheric nitrogen and return it to the soil, where it serves as a nutrient for plants.
The article goes on to say that soil analyses by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) and others in the 1980s revealed nitrogen to be a limiting factor in many African soils. In response, on-farm studies in the 1990s showed that FTS with the right species could increase crop yields with or without mineral fertilizers. FTS are much cheaper for farmers to implement than buying fertilizer inputs, and represent a more holistic approach to soil management. FTS scaling-up programs were broadly implemented about ten years ago, and in that time the number of small-holder farmers using these techniques has ballooned from a few hundred to more than 250,000 in Malawi, Tanzania, Mozambique, Zambia, and Zimbabwe.
Read the full article here.