Determination of Appropriate Time of Nitrogen Application to Improve Productivity of Sorghum Crops in Assosa Zone, Benishangul Gumuz Region

The research was conducted to determine the appropriate application time of nitrogen fertilizer on yield and yield components of sorghum in Benishangul gumuz region. Treatments consisted of eight application times of nitrogen: all recommended rate of N at planting (T1), ½ at planting + ½ at knee height (T2), Applying <sup>1</sup>/<sub>2</sub> at planting+<sup>1</sup>/<sub>2</sub> at near flowering (T3), Applying <sup>1</sup>/<sub>3</sub> at planting+<sup>1</sup>/<sub>3</sub> at knee height+<sup>1</sup>/<sub>3</sub> at near flowering (T4), Applying <sup>1</sup>/<sub>3</sub> at planting+<sup>2</sup>/<sub>3</sub> at knee height (T5), Applying <sup>1</sup>/<sub>3</sub> at planting+<sup>2</sup>/<sub>3</sub> at near flowering (T6), Applying <sup>2</sup>/<sub>3</sub> at planting+<sup>1</sup>/<sub>3</sub> knee height (T7), and Applying <sup>2</sup>/<sub>3</sub> at planting+<sup>1</sup>/<sub>3</sub> knee height (T8) Days to 50% maturity, plant height, and grain yield were the parameters significantly affected by treatment effect, while, days to heading, and thousand kernel weight showed non-significant. The maximum grain yield was 5658 kg ha<sup>-1</sup>, in two split applications (1/2 dose at sowing and 1/2 dose at knee height. The use of nitrogen in two split applications (1/2 dose at sowing and 1/2 dose at knee height stage) can be recommended for farmers for production of sorghum in the study area and other areas with similar agro ecological conditions.