Accepted 7th June, 2014
The present study was carried out to evaluate maize - soybean intercropping effect on yield components and yield of the intercrops and to identify the optimum population density and variety of soybean maximizing productivity of the system. Treatments were maize hybrid (BH540) at recommended population density and three soybean varieties (AFGAT, Awassa-95 and Crawford) in a factorial combination of three planting densities (25%, 50% and 75%) of the recommended population density of soybean with the respective sole of each variety of component crops were arranged in a randomized complete block design with three replications. Sole cropped maize grain yield (3189.80 kg ha-1) was non-significantly greater than intercropped (2753.70 kg ha-1) by means of 13.67%. However, maize intercropped with Awassa-95 at 50% planting density showed a yield advantage of 23.71% over sole cropped maize. A 100-seed weight (g) of soybean showed a significant difference due to varieties and cropping system. Soybean seed yield of 1993.61 and 747.48 kg ha-1 was obtained from sole and intercropped soybean, respectively. The intercropping system increased 100 - seed weight by 12.84% and reduced seed yield on average 62.51% compared to sole cropped. In all combinations, LER was greater than one justified that a yield advantage of (14-32%) and (6-28%) as depicted by LER 1.14-1.32 and 1.06 -1.28 due to varieties and planting densities, respectively. Generally, as LER was superior in all intercrops evaluating that the productivity of maize-soybean intercropping showed a higher relative yield advantage of 32% over sole cropping. Therefore, a variety Awassa-95 at 50% planting density was better in resources utilization attributed to yield under this additive intercropping system.
Keywords: Intercropping, land equivalent ratio, maize and soybean