| In order to explore the optimal efficient combination of water and nitrogen (N) for the high\|yield of spring maize in Hexi through field experiments, the different irrigation levels (95%θf, 80%θf, and 65%θf, the θf was the field soil\|water holding capacity, and was designated as FI, DI1, and DI2) and N application rates (0, 70, 140 kg·hm-2 and 210 kg·hm-2, designated as N0, N70, N140, and N210) on spring corn yield, water and N use efficiency, and economic benefits were studied. The results showed that, both irrigation and N application increased the yield of spring maize. Under FI and DI2 irrigation conditions, spring maize yield significantly increased with increasing N application rate, the grain yield of N210 treatment was 21.8% and 18.8% higher than that of N0 treatment, respectively, but there was no significant difference between N140 and N210 treatments under DI1 irrigation. The average yield of DI1 was 5.5% and 8.3% higher than that of FI and DI2, respectively. Adding N fertilizer increased the water use efficiency of spring corn, but the amount of N should not exceed N70, otherwise the water use efficiency would be reduced. Under the same irrigation level, the partial productivity of N fertilizer obviously decreased with increasing N application, N70, N140, and N210 treatments were 262.59, 141.52, and 97.31 kg·kg-1, respectivley. Taking the yield, economic benefits and environmental factors into consideration, DI1×N140 was recommended as the most suitable water and N combination for spring corn in Hexi region of China, which resulted in a yield of 23.68 t·hm-2, and the net benefit was 25 390 yuan·hm-2. |