Assessing sweetpotato-legume intensification for improved productivity and land use efficiency in Malawi

The integration of sweetpotato (Ipomoea batatas (L.) Lam) with legumes provides innovative cropping systems that enhance land use, crop yields, soil health, and climate change adaptation among farmers in Malawi. Declining soil fertility, crop yields, and shrinking productive land continue to affect agricultural productivity and food security. Sustainable intensification of sweetpotato production is therefore essential. This study assessed sweetpotato–pigeonpea intensification options for productivity and land use efficiency in Malawi. Experiments were conducted at Chitedze, Baka, and Chitala during the 2020/2021 and 2021/2022 cropping seasons. Five spatial arrangements—(i) sole sweetpotato, (ii) sole pigeonpea (Cajanus cajan (L.)), (iii) sweetpotato–pigeonpea (1:1), (iv) sweetpotato–pigeonpea (2:1), and (v) sweetpotato–pigeonpea within row (SP-PP_row)—were evaluated using a randomized complete block design in a split-plot arrangement with three replications. Analysis of variance was performed, and means were separated by LSD₀.₀₅. Land equivalent ratio (LER) and Absolute Mixture Effect (AME) were used to determine productivity. Cropping systems, locations, and seasons significantly influenced all measured parameters. Intercropping is more productive than sole cropping, with LERs exceeding one (LER > 1), indicating a yield advantage. The 1:1 and 2:1 arrangements showed the highest yield advantages of 3.57 and 2.55 tha⁻¹ above sole cropping, contributing 71% and 31% to total land productivity, respectively. Sweetpotato–pigeonpea intercropping enhanced land use efficiency, productivity, and pest and disease suppression, offering potential to improve food security, dietary diversity, and farmer incomes. The 1:1 and 2:1 arrangements are recommended for sustainable and productive farming systems in Malawi. Keywords: Sweetpotato - legume, intercropping, pigeonpea, productivity, yield, land use efficient