Vol. 3, Issue 2, Part A (2021)

Field experiments were conducted at Omonada woreda for two consecutive years 2019 and 2020 main growing seasons at farmer's fields. Three sorghum varieties (Bonsa, Abamelko and Dagem) and Five nitrogen treatments at four levels (0, 23, 46, 69 and 92 kg N ha-1) were applied. Fifteen treatments were arranged in a randomized complete block design (RCBD) with three replications. Across season data analysis most parameters were not significantly affected by sorghum varieties. The number of spikelets per head was significantly affected by nitrogen rates and stem diameter was affected by both nitrogen fertilizer application and sorghum varieties. The highest and statistically significant (16.87 t ha^-1) above-ground biomass yield was recorded from Abamelko. The tallest plant height 216.14 cm was recorded from the variety Abamelko and in contrast, the shortest 126.30 plant height was recorded from the variety Dagem. The highest grain yield was 2.61 t/ha obtained from Ababmelko and 2.53 t/ha from no application of nitrogen fertilizer. While the lowest from 2. 18 t/ha was obtained from Bonsa and it was statistically non-significant. The total nitrogen in the soil before planting analysis showed medium for crop growth and development. Based on the current results, those sorghum varieties were not responded to nitrogen fertilizer, unless the soil is degraded or if the preceding crop nitrogen residue was not available. So, applying 23 kg/ha nitrogen fertilizer for sorghum in the Omonada area was recommended when no nutrient residual effect and the crop was deficiency was observed during growth and development.