Influence of cowpea and soybean intercropping pattern and time of planting on yield and gross monetary value of sorghum

The form of agriculture and cropping system found throughout the world are the results of variation in local climate, soil type, and a range of socio-economic and biological factor that are the main determinants of the physical ability of crops to grow and cropping system to exist. Field experiment was conducted at Mechara Agricultural Research Center during 2013; to determine the effect of cowpea and soybean intercropping pattern on Land Equivalent Ratio (LER) and Gross Monetary Value (GMV) on system productivity. The treatments included two legume crops (soybean and cowpea), their planting time (simultaneously and at first weeding of sorghum),three planting patterns of legumes (double alternate plants within sorghum plants, two rows in between two rows of sorghum and both double alternate plants and two rows in between two rows of sorghum) along with sole crops (sorghum, soybean and cowpea). The experiment was conducted in randomized complete block design with three replications. Intercropping of cowpea in sorghum depressed sorghum yield. There was a variable response yield of soybean and cowpea due to legume planting time, planting pattern and their interaction. However, grain yields of both the legumes were significantly (p<0.05) influenced by time of planting and planting pattern. Simultaneously planting proved significantly better than planting at first weeding of sorghum, while combination of double alternate plants within sorghum plants with two rows in between sorghum rows proved significantly better in enhancing the yield in case of both the legumes. Partial and total LER (1.55) was significantly higher in sorghum/soybean intercropping. Highest gross monetary benefit (20561Ethiopian birr) was accrued from planting two rows of cowpea with the first weeding of sorghum in between the two rows of sorghum however, it was at par with simultaneous planting of cowpea in double alternate plants within sorghum plants along with two rows of cowpea in between sorghum rows and two rows of soybean planted in between two rows of sorghum with first weeding in sorghum.Keywords: Cowpea, Gross Monetary Value, Intercropping, Land Equivalent Ratio Planting pattern, Sorghum, System productivit