Productivity of pigeon pea, cowpea and maize under sole cropping, legume–legume and legume–cereal intercrops on Alfisols in Central Malawi

A study was conducted in Lilongwe and Dowa districts of central Malawi to assess the performance and productivity of pigeon pea (PP), cowpea (CP) and maize (MZ) when grown as sole crops, legume–legume and legume–cereal intercrops. The experiment was arranged in a randomized complete block design (RCBD). Analysis of variance for yields was carried out on a per plant basis and the productivity was assessed by using various competition indices including the land equivalent ratio (LER), relative dry matter yield (RDY), relative nutrient yields and the monetary advantage index (MAI). Results showed significantly higher ( P < 0.05) grain yield per plant for the sole cropped PP and CP than their intercrops, but only slight differences were observed for MZ, at both study sites. However, for overall productivity, results showed higher productivity in terms of yields (LER > 1) and monetary gains (positive MAI values) in all the intercropping systems than sole cropping, at both study sites. Furthermore, the PP + MZ intercrop was the most productive system in terms of yields and monetary gains as it produced the highest LER and MAI values. From this study it is noted that prudent implementation of legume-based diversified intercropping systems including pigeon pea–cowpea and pigeon pea–maize intercrops can play a crucial role in sustaining the intensification of agriculture in smallholder dominated systems.