Sustainable Wheat Based Crop Rotation System in Tropical

Abstract

Cropping systems in the Ethiopian highlands consist primarily of cereals in rotation with grain legume and oilseed crops. Bread Wheat (Triticumaestivum L.) is the dominant crop in wheat belt of Ethiopia and its production is mainly challenged by continuous wheat cropping year after year. Verification of wheat based crop rotation was conducted in Aris zone during 2014 and 2015 cropping seasons. The objective was to break down wheat monoculture and thereby enhance productivity and sustainability of wheat-based farming systems. Rotational crops included rapeseed (Brassica carinata L.), faba bean (Vicia faba L.) and continuous wheat. In second trail, the aforementioned three rotations were arranged with three levels of N fertilizer viz. recommended N, 75 and 50% of the recommended N in split plot design with three replications. Recommended rate of phosphorus fertilizer was applied for all treatments. Results indicated that faba bean and rapeseed wheat rotation increased wheat grain yield by 80% and 84 % cf. continuous wheat cropping, respectively. Rapeseed has been found better in controlling grass weed than faba bean. Demonstration of faba bean in the rotation enabled small-scale wheat farmers to use Rhizobium inoculants with appropriate inoculation techniques. Results of faba bean wheat rotation and fertilizer rate study indicated that there was no significant difference between wheat yields obtained from 100% and 75% recommended N fertilizer application. Hence, when faba bean wheat rotation is practiced 25% of the N fertilizer can be saved.