Effects of different irrigation and nitrogen application levels on the yield and water and nitrogen use efficiency of spring maize

Abstract

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 (9580% fy, and 65% the 6f was the field soil-water holding capacity, and was designated as FI, 1)11 , and DI2) and N application rates (0, 70, 140 kg • hm 2 and 210 kg • hm designated as NO, 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 NO treatment, respectively, but there was no significant difference between N140 and N210 treatments under 1)11 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 which resulted in a yield of 23.68 t • hm 2, and the net benefit was 25 390 yuan • hm.