Cowpea ( <i>Vigna unguiculata</i> (L.) Walp.)–maize ( <i>Zea mays</i> L.) intercrops grown with fertilizers enhanced cowpea grain yield and profitability in Guinea savannah of Ghana

Abstract

Abstract The low yield of cowpeas ( Vigna unguiculata (L.) Walp.) in sub‐Saharan Africa is credited to several limitations, including poor soil fertility and unsustainable cropping systems. Cereals like maize ( Zea mays L.) and legume crops like cowpea support smallholder farmers in sub‐Saharan Africa. Intercropping (more common than rotations) can boost productivity and food security if done right, but farmers often underutilize its benefits due to limited understanding. It improves resource capture (nutrients, light, and water), enhancing overall crop productivity. The research was conducted in Botanga and Golinga in the Northern Region of Ghana from March 2021 to October 2022 to evaluate the effects of maize–cowpea intercropping and fertilizer application on cowpea grain yield and profitability. In a factorial combination of 5 × 3, monocrops of maize and cowpea, one maize row and two cowpea rows and two maize rows and four cowpea rows were grown with no fertilizer (control), NPK fertilizer, and compost in a randomized complete block design with three replications. Analysis of variance was applied to the data through the GenStat statistical package, 13th edition, and averages were compared using least significant difference at 5% probability level. The interaction between maize–cowpea intercropping and fertilizer application significantly ( p &lt; 0.05) affected cowpea grain yield. Among the intercrops, two maize rows and four cowpea rows (2 M:4C) grown with NPK recorded the highest cowpea grain yields of 1905.00, 1909.00, 1868.00, and 1905.00 kg ha −1 at Golinga (2021), Golinga (2022), Botanga (2021), and Botanga (2022), correspondingly. The same row configuration treated with compost and NPK fertilizer had a benefit‐cost ratio of 8.65 and 8.39, respectively, for the two locations in both experimental years. In view of the findings of this research, farmers in the research locations can grow two maize rows and four cowpea rows as crop mixtures with either compost or NPK fertilizer to maximize cowpea grain yield and profitability.