Effect of nitrogen on water use efficiency of rain, nitrogen agronomic efficiency and soil moisture depletion under rainfed wheat

In order to study the effects of rate and application time of nitrogen on grain yield of rainfed wheat, water use efficiency of rain (WUE), nitrogen agronomic efficiency (NAE) and soil moisture depletion (SMD), one experimental farm was carried out in Kurdistan province during 2012-2014. Tratments were five rates of nitrogen (N0, N30, N60, N90 and N120) kg.ha-1 as Urea with three application times, consist of T1 (Total in the fall), T2 (2/3 in the fall� in the spring), T3 (1/2 in the fall퟽ in the spring) with three replications as split plot arrangments, based on randomized complete block design. Annual precipitations were 256.1 and 294 mm respectively. Soil moisture measured in 0-20, 20-40 and 40-60 cm depths in five growth stages of wheat. Results shown interaction effects of timing and nitrogen rates on grain yield was significantly.The effect of nitrogen rates were significantly on WUE, NAE and SMD at (P