Effects of soybean precursor crop and nitrogen rates on subsequent maize grain yield and nitrogen use efficiency at Bako, West Ethiopia

Maintaining soil fertility using legumes precursor crop and minimum nitrogen, is ofparamount importance for of sustaining maize production. A study was carried out atBako Agricultural Research Center to assess the effects of soybean precursor crop andnitrogen rates on subsequent maize grain yield and nitrogen use efficiency. Maizevarieties planted were significantly varied following soybean precursor crop.Significantly higher mean grain yield and dry biomass of maize were harvested fromBH-661 varieties planted following soybean precursor crop indicating variations ofmaize varieties in yielding potential following soybean. Application of nitrogenfertilizer following soybean precursor crop was significantly affected mean grain yieldof maize. Significantly higher mean grain yield of maize was produced from maizeplanted with application of half and full recommended rate of nitrogen fertilizerfollowing soybean precursor crop showing importance of nitrogen application incropping sequence. Higher mean grain yield of 7870 kg ha -1 was obtained from BH-661maize varieties planted following soybean without rhizobium application. Higher meangrain yield of maize varieties was obtained from maize planted following soybean withrhizobium application. Therefore planting of maize following soybean precursor cropwith rhizobium with half recommended nitrogen fertilizer application or soybeanprecursor crop without rhizobium with full recommended nitrogen fertilizer applicationwas recommended for sustainable maize production. Agronomic efficiency, plant Nuptake efficiency, nitrogen use efficiency and fertilizer N (recovery) use efficiency wereincreased with lower rates of nitrogen fertilizer. Production of BH-661 and BH-543maize varieties following soybean precursor crop with half recommended (55 kg N ha -1 )application improved mean grain yield and recommended for maize in mid altitudeareas of western Ethiopia.