Yield evaluation of maize-bean intercropping in a semi-arid region of South Africa

Information on the effect of row orientation on land productivity of intercropping systems, especially in a semi-arid environment is limited. Field trials were, therefore, carried out under full irrigation and rainfed conditions in a semi-arid region of South Africa (Bloemfontein, Free State) during 1998-2002. The trials evaluated the intercrop yield advantage in terms of land equivalent ratio (LER), energy value (EV) and monetary value (MV). Treatments included three cropping systems (sole maize, sole bean, and the intercrop) and two cultural practices, namely, row orientation (north-south row vs east-west row) and sowing date (November/December and January). Intercropping showed a higher yield advantage in terms of LER and EV compared to sole cropping. Therefore, intercropping has potential for increasing yields in the semi-arid regions of South Africa. Monetary value is influenced by fluctuations of the price ratio of crops, so it is not always a useful factor for evaluating the yield advantage.