| Efficient utilization of water and fertilizer is the basis of high and stable yield of crops. The aim of this study was to determine the response of maize yield and WUE to different long-term fertilization measures in dryland, and to provide a scientific basis for improving WUE with rational fertilization in dryland.In the semi-humid arid region of Shouyang, Shanxi Province, a 30-year long-term experiment was carried out on the application of nitrogen and phosphorus fertilizer, organic fertilizer alone, and nitrogen and phosphorus fertilizer combined with organic fertilizer. Including four different nitrogen and phosphorus dosages (N1P1M0, N2P2M0, N3P3M0 and N4P4M0), single application of organic fertilizer (N0P0M6), nitrogen and phosphate fertilizer and combined application of organic fertilizer (N2P1M1, N4P2M2 and N3P2M3), with no fertilization (N0P0M0) as the control, The maize yield, water storage capacity of 2 m soil, water consumption during growth of maize, and water use efficiency (WUE) of maize were analyzed in the last three years (2019-2021).The results showed that fertilization increased maize yield and water use efficiency. Nitrogen and phosphorus fertilizer combined with organic fertilizer had the highest yield and the best stable yield. Yield increased by 32.7% on average, yield variation coefficient decreased by 6.1%, and WUE increased by 33.0% compared with single N/P. In the four treatments with nitrogen and phosphorus fertilizer, maize yield and water use efficiency were the highest in N2P2M0 treatment. Long-term single application of organic fertilizer (N0P0M6) improved soil fertility, organic matter content in which was about 2 times of those treatments with nitrogen and phosphorus fertilizer, and its yield and water use efficiency were general higher than those treatments with nitrogen and phosphorus fertilizer. There was a significant positive correlation between WUE and soil organic matter content. Compared with nitrogen and phosphorus fertilizer, the soil yield contribution rate of WUE was decreased by applying organic fertilizer. However, the application of organic fertilizer can maintain high and stable yield, indicating that soil fertility improvement is of great significance for dryland. Therefore, long-term application of organic fertilizer to improve soil fertility is also an effective measure to improve high and stable yield and WUE in dryland. |