Nitrogen cycling in agroforestry systems of sub-humid Zimbabwe: closing the loop.

This thesis focuses on nitrogen: its acquisition in cropping systems through biological N2- fixation and subsoil capture, its release by legume prunings and litter, its use by maize and its loss through leaching and as nitrous oxide gas. The context of the study is improved fallows using leguminous trees/shrubs on a sandy clay loam soil under sub-humid conditions in Zimbabwe...