Agroecology in Madagascar

Most of the historical farming in Madagascar has been conducted by indigenous peoples. The French colonial period disturbed a very small percentage of land area, and even included some useful experiments in sustainable forestry. Slash-and-burn techniques, a component of some shifting cultivation systems have been practised by the inhabitants of Madagascar for centuries. As of 2006 some of the major agricultural products from slash-and-burn methods are wood, charcoal and grass for Zebu grazing. These practises have taken perhaps the greatest toll on land fertility since the end of French rule, mainly due to overpopulation pressures.

The Madagascar dry deciduous forests have been preserved generally better than the eastern rainforests or the high central plateau, presumably due to historically less population density and scarcity of water; moreover, the present day lack of road access further limits human access. There has been some slash-and-burn activity in the western dry forests, reducing forest cover and the soil nutrient content. Slash-and-burn is a method sometimes used by shifting cultivators to create short term yields from marginal soils. When practiced repeatedly, or without intervening fallow periods, the nutrient poor soils may be exhausted or eroded to an unproductive state. Further protection of Madagascar's forests would assist in preservation of these diverse ecosystems, which have a very high ratio of endemic organisms to total species. A switch to slash-and-char would considerably advance preservation, while the ensuing biochar would also greatly benefit the soil if returned to it while mixed with compostable biomass such as crop residues. This would lead to the creation of terra preta, a soil among the richest on the planet and the only one known to regenerate itself (although how this happens exactly is still a mystery). The nascent carbon trading market may further bring direct economical benefits for the operators, since charcoal is a prime sequester of carbon and burying it spread in small pieces, as terra preta requires, is a most efficient guarantee that it will remain harmless for many thousands of years.

See also

• Agroecology