A field experiment was conducted to evaluate the effects of intercropping and planting densities on the growth and yield of maize (Zea mays) and soybeans (Glycine max). A 1 ha plot located at the Institute of Agricultural Research for Development (IRAD), Ekona, South West Region of Cameroon was used. There were two blocks: block 1 which was fertilized with 60 kg/ha NPK (20:10:10) and top dressed with urea at 50 kg N and block 2 which was unfertilized. The experimental design was a randomized complete block design with three replications and a total of 15 treatments. Treatments were intercropped combinations of maize (53,320, 40,000 and 26,666 plants/ha) and soybeans (200,000, 160,000 and 100,000 plants/ha) and six sole-cropped treatments. Intercropping affected grain yields for both soybeans and maize; however, the effect on maize was not significant (P ≥ 0.05). Maize at 53,320 plants/ha intercropped with soybeans at 200,000 plants/ha produced the maximum mean number of pods (34.67), pod weight (13.09 g), number of grains (69.6) and grain weight (8.66 g) per pod. The productivity of the intercropping system indicated yield advantage of 25 to 80% in the unfertilized block and 33 to 96% in the fertilized block as depicted by the land equivalent ratio of 1.25 to 1.8 and 1.33 to 1.96, respectively. All the intercropped combinations had relative value total above unity (1.32 and 1.29) in both unfertilized and fertilized blocks, respectively, meaning a high profitability of this system as compared to monocropping. Maize at a population density of 53,320 plants/ha intercropped with soybean at a plant density of 200,000 plants/ha showed the highest profitability and overall, was the best intercropping combination in this study.
Key words: Intercropping, soybean, maize performance, yield.