Yield and Economic Assessments of Five Cowpea Varieties in Cowpea-Maize Strip Intercropping in Limpopo Province, South Africa

Abstract

Farmers’ traditional cropping practice in Limpopo Province is to mix and broadcast crops at planting without definite row arrangement. Although this practice is very easy and cost-saving, it leads to low plant density, hinders farm input application, and results in low crop yields and poor return on investment. Strip intercropping, where crops are planted with definite row arrangement, reduces inter-species competition, optimises plant population, and increases crop yield. Five cowpea varieties i.e. ‘TVu 13464’, ‘IT86D-1010’, ‘Glenda’, ‘IT82E-16’ and ‘IT87K-499-35’ and maize was grown under strip intercropping, monocropping, and mixed intercropping as a control during two seasons. During both years, significant interactions were obtained between the cowpea varieties and the cropping systems in most of the variables measured. Cowpea sown in the strip intercropping performed better compared those sown in mixed intercropping. Cowpea varieties ‘IT86D-1010’, ‘IT82E-16’ and ‘IT87K-499-35’ harvested more grain yield under monocropping and strip intercropping than under mixed intercropping. The land equivalent ratio (LER) of strip intercropping during the two seasons ranged between 1.25 and 2.29 and was higher compared to mixed intercropping, which ranged between 0.50 and 1.32. In conclusion, cowpea varieties ‘IT86D-1010’, ‘IT82E-16’ and ‘IT87K-499-35’ sown with maize as strip intercropping resulted more profits under intercropping systems and were recommended for cultivation by farmers in the Limpopo region with low rainfall. Moreover, grain yield, LER, and net profit achieved by strip intercropping was three-fold more than mixed intercropping.