Bulb Yield and Economic Return of Onion (Allium cepa L.) as Influenced by the Application of Integrated Nutrient Management at Selekleka, Northwestern Zone of Tigray, North Ethiopia

Onion is an important crop as a condiment and income generation for smallholder farmers in northwestern Zone of Tigray. However, Continuous use of inorganic fertilizers and inappropriate soil fertility management practices are among the major factors limiting onion productivity in the North Western Tigray. Therefore, a field experiment was undertaken in selekleka district from October 2015 to June 2016 to assess the effects of integrated nutrient management on bulb yield and economic return of onion (Allium cepa L.). The treatments consisted of combinations of two rates of farmyard manure (FYM) (10 and 20 t ha-1) and two rates of vermicompost (VC) (2.5 and 5 t ha-1) each combined with three rates of nitrogen (25, 50 and 75) of recommended N fertilizers, RDF. In addition, 100% RDF N (69 kg N ha-1), 100% (5 t ha-1) of VC, 100% (20 t ha-1) FYM and zero rates (unfertilized treatment) were used for comparison. The experiment was laid out in a randomized complete block design with three replications. (ANOVA) revealed that combined application of 5 t ha-1 VC+50% inorganic N fertilizers recorded the highest bulb yield (35.13 t ha-1) and economic return (246,354 Birr ha-1). On the other hand, the lowest bulb yield (18.48 t ha-1) and economic net return (143,018 Birr ha-1) were obtained from the control. It could, thus, be concluded that, based on the partial budget analysis and bulb yield result the application of 5 t ha-1 vermicompost and 50 % recommended inorganic nitrogen was the appropriate combination for better onion production and economic return in the study area.