Evaluation of Fertilizer and Seed Rate Effect on Yield and Yield Component of Tef [Eragrostis tef (Zucc.) Trotter] on Vertisols in Central high-lands of Ethiopia

Tef [Eragrostis tef (Zucc.) Trotter] is among the major cereals of Ethiopia and occupies the largest cultivated land more than any other cereals. The need for its production as a staple food is increasing from year to year; however, its productivity is almost stagnant. Nutrient depletion is one of the major causes that contribute to declining in soil productivity in the highlands of Ethiopia. This experiment was conducted from 2012-2014 during the main cropping season to determine the optimum fertilizer and seeding rates for optimum grain yield of tef on high land vertisols. Factorial combination of 6 levels of tef seed rate (5, 10, 15, 20,25 & 30 kg ha-1) and 3 levels of fertilizer rates (34.5kg N/ha with 30kg P2O5/ha, 69 kg N/ha with 60kg P2O5/ha, & 103.5kg N/ha with 90 kg P2O5/ha) were compared in Randomized Complete Block with three replication. Results indicated that fertilizer rate significantly (P< 0.01) affects tef grain yield, biomass yield, plant height and number of fertile tiller per plant. Seed rate significantly (P< 0.01) affects the biomass yield of tef, panicle length and number of fertile tiller per plant but not significantly affects the tef grain yield and plant height. The interaction effect of seed rate and fertilizer rate was significantly (P< 0.01) affects the grain yield and biomass yield of tef but not significantly affects plant height, panicle length and number of fertile tiller per plant. The optimum tef grain yield (2239.1kgha-1) was obtained using 20kg/ha tef seeding rate and 69kg N/ha with 60kg P2O5/ha fertilizer rate. Taking into account productivity and economic analysis, 20kg ha-1 tef seed rate and 69kg N/ha with 60kg P2O5/ha fertilizer rate on heavy black soil is recommended for main cropping season for tef production. Keywords: fertilizer and seed rate, grain yield, marginal rate of return, tef, vertiso