Restauration des potentialités de sols dégradés à l'aide du zaï et du compost dans le Yatenga (Burkina Faso)

Abstract

Restoring soil potentialities using zaï and compost in Yatenga (Burkina Faso). Land degradation is a serious problem in the soudano-sahelian zone of Burkina Faso. Studies were carried out between 2002 and 2004 in two villages, Somyaga and Ziga in the Yatenga Province. The main objectives were to identify and characterize the soil potentialities and constraints applying the geomorphopedological approach and to assess the possibilities of restoring degraded soils by implementing the zaï technique and incorporating composted manure with natural phosphorus. Soil identification based on representative morpho-sequences has shown the prevalence of leached tropical ferruginous soils. These soils therefore present a weak potentiality and a poor fertility without fertilization and conservation practices. Experiments with the zaï technique and composted manure enriched with burkina phosphorus conducted over three years markedly improved the above mentioned soil parameters and sorghum yields. Carbon, nitrogen, phosphorus and pH increased in the compost treatment. The ANOVA analysis has shown significant differences between compost treatments and the untreated control plots. In general, the increased yields vary from 300 to 500 kg.ha-1 according to the village in our experiment. About 40 species of herbaceous plants and trees have been regenerated by the zaï system in degraded land. Future research is needed to identify vegetal material adapted to the zaï system and to assess the impact on the micro biomass.