Incorporating groundnut into the maize-based smallholder farming systems in semi-arid Limpopo province, RSA.

Incorporation of grain legumes into existing predominantly maize-based monoculture smallholder farming system may improve the productivity and sustainability of the system. This paper presents the results of a study conducted on-farm with the aim of evaluating the best groundnut cultivar for incorporation into the existing predominantly continuous maize cropping system. Treatments consisted of three groundnut (Arachis hypogaea) cultivars (Kwarts, Akwa and Kangwana red) and four phosphorus fertilizer rates (0, 15, 30 and 60 kg P/ha applied as superphosphate at planting) arranged in a completely randomized block design with three replications. Dry matter was measured at regular intervals and grain yield determined at maturity. The APSIM model was used to simulate growth and grain yield. Cultivar and P application had no effect on grain yield. Grain yield ranged from 554 to 649 and 1254 to 1503 kg/ha, in 2007/8 and 2008/9 seasons, respectively. A strong relationship (R=0.83) was recorded between observed and simulated grain yield. Long-term simulation with non-limiting P indicated that 50% of the seasons yielded >506 kg/ha grain. Low rainfall coupled with prolonged drought periods during growing season may have limited the potential response to P application.