Efficient utilization of water and nitrogen for spring wheat high-yield in Hetao Irrigation Region

The effect of nitrogen-application amount on yield formation,water use and nitrogen use were studied under water-saving irrigation model and conventional sufficient irrigation model in Shahaoqu experimental station of Hetao irrigation region,Inner Mongolia.Of water-saving irrigation model,wheat was irrigated at jointing and heading stage;while of conventional sufficient irrigation,wheat was irrigated at tillering,jointing,heading and grain-filling stage.The results showed that there were no significant difference of wheat yield and yield component between water-saving irrigation model and conventional sufficient irrigation model.But of water use efficiency(WUE) the former was higher than the latter by 7.8%.In the range of lower nitrogen-application amount,wheat yield,water consumption amount and WUE increased with the increasing of nitrogen-application amount.However,wheat yield and WUE would decrease when the nitrogen-application amount reached some level.Nitrogen-application could promote the nitrogen absorbing of plant and decrease nitrogen use efficiency(NUE) obviously under both two model.Comparing with conventional sufficient irrigation model,wheat WUE of water-saving model was increased significantly.It was conic section between Wheat economic yield,WUE and NUE and total nitrogen-application amount.The suitable nitrogen-application amount of spring wheat for water-saving,fertilizer-saving and high yield was about 8-10 kg N/667m2 in Hetao irrigation region.