Effect of nitrogen fertilization on growth and yield of summer maize under mulched drip irrigation in Southern Xinjiang

ZUO Shunli; LI Fengxiu; LIU Zelong; ZHAO Qiao; XU Yuan

doi:10.13522/j.cnki.ggps.2024029

Abstract：[Objective]Mulched drip irrigation is a widely used technique in Northwestern China.This paper investigates the combined effects of mulched drip irrigation and nitrogen fertilization on the growth and yield of summer maize.[Method]The experiment was conducted in a maize field in Southern Xinjiang and included a mulched drip irrigation(MD)treatment and a conventional drip irrigation treatment without mulching(LD).Each irrigation treatment had five nitrogen applications:0 kg/hm2(N0),224.6 kg/hm2(N1),278.4 kg/hm2(N2),368.9 kg/hm2(N3),and 464.0 kg/hm2(N4).The control was flood irrigation with a nitrogen application of 278.4 kg/hm2.For each treatment,we measured growth traits and grain yield of the maize.[Result]① With increasing nitrogen application,the SPAD value,leaf area index(LAI),and aboveground dry biomass initially increased before plateauing;these metrics were 18.67％,10.39％,and 10.41％higher in the MD treatment compared to the LD treatment,respectively.② The relationship between dry matter accumulation and nitrogen application fit a logistic model,with the accumulation plateauing when the nitrogen application was 368.9 kg/hm2.Compared to LD,MD prolonged the period of rapid growth by 7-18 days and delayed its onset by 1-6 days.③ The yield in the MD treatment was 1 027.52-2 023.04 kg/hm2 higher than that in LD;nitrogen application increased grain yield by 29.41％-84.46％.The combination of MD and nitrogen application increased yield by 52.17％-106.61％.Nonlinear regression indicated an asymptotic increase in maize yield with nitrogen application.The grain yield in MD and LD plateaued to 362.75 kg/hm2 and 364.14 kg/hm2,when their associated nitrogen application exceeded 267.69 kg/hm2 and 274.11 kg/hm2,respectively.④ In both irrigation treatments,applying 278.4 kg/hm2 of nitrogen fertilizer produced yields comparable to the control,while saving 256.5 mm of water.[Conclusion]Mulched drip irrigation combined with a nitrogen application of 278.4 kg/hm2 is optimal for promoting the growth and yield of summer maize in Southern Xinjiang.