Potentials of legumes rotation on yield and nitrogen uptake of subsequent wheat crop in northern Ethiopia

Nitrogen has becoming the most limiting nutrient in the northern highlands of Ethiopia due to continuous cropping with application of limited external inputs. To improve soil nutrient availability, farmers have been using legumes in crop rotation. However, the roles of various legumes on subsequent wheat (Triticum aestivum) crop are unknown in northern Ethiopia. The objective of this study was to investigate impacts of legumes on yield and N uptake of subsequent wheat crop. Experiment was conducted at farmer's field with faba bean (Vicia faba L.), 'dekeko' field pea (Pisum sativum var. abyssinicum), field pea (Pisum sativum), lentil (Lens culinaris) and wheat (Triticum spp.) in the first season and all plots were rotated by wheat in the second season. Yield of subsequent wheat crop was recorded and N uptake was analyzed. The result revealed that grain yield and dry biomass yields of subsequent wheat crop were significantly (p < 0.05) higher in the legume-wheat rotations than in the wheat-wheat rotation. The wheat yield is increased by 2196, 1616, 1254 and 1065 kg ha-1 and the N uptake is increased by 71.4%, 51.0%, 49.2% and 29.8% in the faba bean-wheat, 'dekeko'-wheat, field pea-wheat and lentil-wheat rotation plots compared to the wheat continuous cropping, respectively. The findings indicated that legumes improved yield and N uptake of the subsequent wheat crop. Thus, soil fertility management policy need to consider legume crop rotations as nutrient management option to improve sustainable soil fertility and yield.