Understanding cropping systems in the semi-arid environments of Zimbabwe: options for soil fertility management .

African smallholder farmers face perennial food shortages due to low crop yields. The major cause of poor crop yields is soil fertility decline. The diversity of sites and soils between African farming systems is great, therefore strategies to solve soil fertility problems should suit the opportunities and problems encountered in the different climatic regions. This thesis characterizes the semi-arid regions of south-western Zimbabwe and explores some of the strategies that can be used to provide farmers with more options for soil fertility improvement...