Productivity of Phosphorus Fertilization in Cowpea-Maize Strip Intercropping under Rainfed Conditions

Crop yields are declined due to low soil fertility, insufficient soil water availability and poorly managed cropping systems in Limpopo province of South Africa. Phosphorus (P) is a major essential nutrient element required by crops for enhanced growth and development. Interactions between different rates of P fertilization and strip intercropping system have not been studied in detail under rainfed conditions in semi-arid region of Limpopo province. Therefore, this study was conducted to assess the performance of four cowpea varieties at four levels (0, 15, 30, 45 kg P ha-1) of P fertilization in a cowpea-maize intercropping system in a split-split plot design during two seasons. Significant interactions were obtained between variety and phosphorus application as well as variety and cropping system for 90% physiological maturity, root mass and grain yield in both seasons. P levels significantly influenced and enhanced grain yield, land equivalent ratio, profit and benefit cost ratio achieved. PAN311 and TVu13464 matured earlier across P levels and they were selected promising cowpea varieties based on their early maturity and high yield. Land equivalent ratio values were greater than 1.0, which indicated performance and advantage of an intercropping system over monocropping system in land utilisation. The optimum P level for cowpea-maize strip intercropping was at 30 kg P ha-1 based on yield and financial return. The results showed that P application enhanced the productivity of the cowpea varieties in cowpea-maize strip intercropping in the semi-arid environment of Limpopo province. © 2021 Friends Science Publishers