Determination of Optimum Phosphorus Rate for Tef (<i>Eragrostis tef/Zucc./Trotter</i>) Under Balanced Fertilization in Vertisol, East Shoa Zone, Oromia Riginal State, Ethiopia

The fertilizer requirement of tef varies from agro-ecology to and soil soil. Therefore, the objective this study was refine optimum phosphorus rate for under balanced fertilization. experiment conducted on-farm during main cropping season two consecutive years (2015-2016) in Vertisol at Ada’a District. had 8 treatments (six rates each with fixed amount N, K2O, S, Zn B, negative control (without fertilizer), recommended NP (60 N+10 P) kg ha-1). Phosphorus applied 0, 23, 46, 69, 92 115 P2O5 ha-1 using TSP (triple super phosphate) as a source it. Nitrogen, B were 92, 90, 30, 2 1 urea, potassium chloride, calcium sulfate, zinc sulfate borax penta hydrate fertilizers, respectively. laid out randomized complete block design (RCBD) triple replication treatment. ANOVA revealed that plant height number tillers highly significantly affected (P<0.05) application rates. above ground biomass (AGB), grain yield (GY) straw (SY) which received strongly (P<0.001) over control. maximum recorded 69 ha-1 (30 P ha-1) following by 46 (20 ha-1) results found being 1719 1607 ha-1, Similarly, net benefits (30 then amounts 56035.1 54744.4 ETB However, marginal return MRR 1329.5% 306.8%, could be site areas having similar area.