A field experiment was conducted for two consecutive cropping seasons (2013-2014) on farmers’ fields in Dendi district of Oromiya Regional State. The objective of this study was to evaluate the effect of organic and inorganic fertilizers on growth and yield of tef and soil chemical properties. The treatments included eleven selected combinations of organic and inorganic nutrient sources (Farm yard manure, vermicompost, Compost, Nitrogen and Phosphorus). The design was randomized complete block with three replications. Results showed that tef yield, some yield components and soil chemical properties are significantly affected by the application of organic and inorganic fertilizer sources. The highest tef grain yield (3144.8kg ha-1) and biomass yield (12562.5kg ha-1) were obtained from the applications of half doses of vermicompost (4.8t ha-1) which is based on recommended N equivalent and half doses of the recommended nitrogen and phosphorus fertilizers (34.5kg ha-1N and 30kg ha-1P that half dose contains) followed by 2846 kg ha-1and 11833.3 kg ha-1for grain yield and biomass yield, respectively, due to the application of the full recommended N and Prates (69kgN ha-1and 60kg P ha-1). Application of the different organic fertilizers improves the organic matter, Total N, available P and pH of the soil in the study area. The result also showed that the highest marginal rate of return was obtained from application of 3.2t ha-1vermicompost + 2.37t ha-1 conventional compost + 1.37t ha-1 farmyard manure (based on equivalent N rate, which is economically the most feasible alternative on vertisols of central Ethiopian highlands.
