Nitrogen Uptake and Use Efficiency of Irrigated Bread Wheat (Triticum aestivum L.) as Influenced by Seed and Nitrogen Fertilizer Rates at Werer, Afar National Regional State, Ethiopia

An offseason field experiment was conducted in 2015-2016 at Werer Agricultural Research Center Middle Awash, Afar regional state to determine N-uptake and use efficiency of irrigated bread wheat (Triticum aestivum L.) as influenced by seed and nitrogen fertilizer rates. The experiment was laid down in a randomized complete block design (RCBD) with three replications. The treatments were factorial combination of five nitrogen levels (0, 23, 46, 69, and 92 kgNha-1) with four seed rates (75, 100, 125, and 150 kgha-1). The results of the study showed that both main and interaction effect of nitrogen and seed rates significantly affect N concentrations of the grain and straw, Nuptake, apparent nitrogen recovery, agronomic and physiological efficiencies, nitrogen use efficiency, grain protein content, and N harvest index. The apparent recovery, agronomic and physiological efficiencies and nitrogen use efficiencies decreased with increasing N-rate. Concentration of N and total nitrogen uptake in straw and grain, grain protein and NHI were increased as the N rate increased, while decreased with the increment of seed rate. In conclusion, rate of nitrogen fertilizer applied and seed rate affect the N-uptake and N-use efficiencies.