Soil fertility decline and erratic rainfall are major constraints to crop productivity on smallholder farms in southern Africa. The objective of this thesis was to identify appropriate crop production intensification options that are suitable to selected maize-based smallholder farming systems in southern Africa.
Conservation agriculture is not suitable as it requires legume rotations and large nitrogen inputs which are out of reach of most farmers. Intercropping maize with pigeonpea or cowpea increased total crop productivity. The residual benefits of maize-pigeonpea intercropping were large (5.6 t ha-1) whereas continuous maize (0.7 t ha-1) was severely infested by striga (Striga asiatica). In mixed crop-livestock systems, combined manure and fertiliser are required to increase crop yield although effectiveness is limited by quantities and quality of manure obtained. Livestock owners have no scope of retaining maize residues in the field for soil fertility as that leads to severe losses in animal productivity due to shortage of cattle feed in the dry season. This study revealed that crop production intensification options developed without considering the biophysical conditions as well as socio-economic circumstances of farmers are nuisances.