EFFECTS OF VERMICOMPOST AND NITROGEN FERTILIZER ON SELECTED SOIL PROPERTIES,YIELD AND YIELD COMPONENTS OF BREAD WHEAT (Triticum asetivum L.) IN TIYO DISTRICT, ARSI ZONE, SOUTHEASTERN ETHIO

Soil fertility depletion is one of the major impediments to sustained agricultural productivity in Ethiopia. Soil fertility maintenance requires a balanced application of inorganic and organic nutrient sources. Therefore, this study was conducted to evaluate the effect of vermicompost (VC), nitrogen fertilizer and their interaction in improving soil fertility and increasing wheat productivity at Kulumsa Agricultural Research Center, southeastern Ethiopia during the main cropping season of 2022. The experimental treatments consisted of four rates of VC (0, 2.5, 5, and 7.5 t ha-1 ) and four rates of nitrogen (0, 50, 100 and 150 kg N ha-1 ) which were arranged in factorial combinations in a randomized complete block design in three replications. Representative composite soil samples were taken at a depth of 0-20 cm before the application of treatments and after harvesting. Data on phenological development, growth, yield and yield components of the wheat crop were also collected. The data were analyzed using SAS computer software version 9.0. The results revealed that the main effect of VC significantly increased the values of selected soil physical parameters were improved at 5% level of significance. Soil chemical parameters, such as organic matter, available phosphorous, exchangeable calcium, magnesium, potassium, and cation exchange capacity were positively influenced by the main effects of VC. The interaction effects VC and Urea affected the yieid and yield components of wheat. Similarly the interaction effects of VC and Urea positively influenced some of the soil chemical parameters (soil pH and total nitrogen) and yield parameters (spike length, grain per spike, thousand grain weight, straw yield, and grain yield). The combined application of vermicompost at 5 t ha-1 and mineral nitrogen fertilizer at 100 kg ha-1 resulted in the highest grain yield of the wheat crop better than the other treatments. Therefore, to keep the sustainability of soil fertility and high wheat production, integrated application of 100 kg N ha-1 and 5 t ha-1 VC was recommended for the study area and other areas having similar agro-ecology as it had the highest net benefit and positive marginal rate of return.