Effect of plant density of hybrid maize and common bean varieties on their productivity and economic benefit under intercropping system at jimma, south west Ethiopia

Abstract

Limited farmland size owned by smallholding farmer is one of the challenges to increase crop production and productivity at Jimma area in particular and in the country at large. Accordingly, famers have a long standing traditional knowledge of growing multiple crops in different cropping patterns. Intercropping is one of the crop combination systems practiced by resource poor farmers to increase crop production per unit area of land per year and reduce the risks to food and cash sources. However, research information is scanty on optimum intercropping technology options for irrigated agriculture. Hence, this study was conducted at the Jimma Agricultural Research Center in 2014 with the objectives to determine the effects of component density of maize and common bean varieties on growth, yield and yield components of the associated crops and on their productivity, To identify the best performed common bean variety with component population density that maximizes productivity of maize and common bean under Jimma conditions; and To identify economically suitable maize-bean intercropping system under Jimma conditions, southwest Ethiopia. The experiment was conducted in factorial experiment arranged in a Randomized Complete Block Design of three replications. The treatment combinations included six component densities (100% * 17.7%, 100% * 26.7%, 100% * 53.3%, 75% * 17.7%, 75% * 26.7%, 75% * 53.3%) of hybrid maize and common bean respectively, and two common bean varieties (Nasir and Local Asendabo) along with sole maize and common bean varieties. Data on some soil chemical properties, phenology, growth, yield and yield components of the two crops as well as system productivity and economic benefits were recorded and analyzed. The analysis of variance showed that the interaction effects of bean varieties and component population densities as well as the main effects were comparable on the phenology of maize and common beans, except the main effects of varieties indicated significant variation on days to 50% emergency of common bean. All yield and yield components showed significant effect due to the main effect of common bean variety, component density and interaction effects of the main effects on maize and common bean. Conversely, harvest index of maize showed significant effect only due to component density. In general, the yield obtained from the mean intercropped maize 4990 kg/ha was greater than the mean yield obtained from sole cropped maize 4790 kg/ha. However, the yield obtained from the mean intercrop common bean 697 kg/ha was less than the yield obtained from sole crop 2,177kgt/ha. Moreover, Land Equivalent Ratio (LER), Gross Monetary Value (GMV) and Monetary Advantage (MV) showed significant variation due to the main effects of common bean varieties, component density and the interaction of them. The highest LER (1.90) and Monetary Advantage (MV) (3710.73 Birr) were obtained when 100% maize population density intercropped with 26.7% Nasir common bean population density. The results showed that intercropping maize with common beans was advantageous than sole cropping of either of each crop; particularly during the summer season when production during main season is running out and shortage of food supply occurred. Generally, the findings clearly depicted that intercropping of hybrid maize and common beans had more yield and monetary benefits. In general maize 100% population density intercropped with 26.7% population density of Nasir common bean variety; and as an alternative: - Maize with 75% population density intercropped with 53.3% population density of both varieties of common beans make farmers benefited from the system. Nonetheless, further investigations are required to generate reliable technologies and draw recommendations on irrigated maize-beans production systems.