Effect of maize (zea mays l.) and cowpea (vigna unguiculata l.) intercropping on agronomic performance, yield and nutritional values of maize and cowpea under supplementary irrigation

A field experiment was conducted to evaluate the effect of maize (Zea mays L.) and cowpea (Vigna Unguiculata L.) intercropping on agronomic performance, yield, and nutritional values at Arba Minch University. Treatments were only maize crop (T₁), only cowpea (T₂), intercrop (maize and cowpea) in a 1:1 ratio (T₃) and alternative rows of 2:2 (T4) as treatments. Treatments were arranged in a randomized complete block design (RCBD). Data on plant morphology, yield, nutritional composition, and economic return were recorded. The height of the plant (145.5 cm) of maize was significantly (P < 0.001) higher at 1:1 intercropping than the height of the sole while the height of the cowpea was higher at the sole cropping. Higher number of branches (P < 0.05) per plant (5.28) of cowpea was recorded in pure stands of cowpea than intercropping. The grain yield of maize (6.9 t/ha) and cowpea (4.2 t/ha) was significantly (P < 0.05) higher in sole cropping than in intercropping. A higher dry matter yield of 9.06 t/ha of maize was obtained in a 1:1 maize-cowpea intercropping ratio than sole maize. Significantly (P < 0.001) highest dry matter cowpea yield of 5.77 t/ha was obtained at sole cultivation than intercropping. The intercropping of maize with cowpea had an advantage of resource utilization in terms of land equivalent ratio (LER) 41.7 %-62.5 %. The marginal rate of return (MRR) of intercropping in the ratio of 1:1 was as high as 48.23 % in intercropping maize-cowpea, which was much better than sole cropping. Therefore, it could be recommended that the ratio of 1:1 maize-cowpea intercropping for land resource use and economic food and feed production in Arba Minch and similar agro-ecology zones.