南疆覆膜滴灌夏玉米生长特性及产量对施氮量的响应研究

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

【目的】探究南疆干旱区夏玉米在覆膜滴灌(MD)与裸地滴灌(LD)条件下的生长表现及不同施氮水平对产量的影响。【方法】设计MD处理和LD处理夏玉米滴灌试验,5个施氮梯度(N0:0 kg/hm^(2)、N1:224.6 kg/hm^(2)、N2:278.4 kg/hm^(2)、N3:368.9 kg/hm^(2)、N4:464.0 kg/hm^(2)),以2个漫灌处理(MCK、LCK,施氮量均为278.4 kg/hm^(2))为对照(CK),共计12个处理。【结果】(1)随着施氮量的增加,夏玉米的生长指标(SPAD值、LAI值、地上部干物质量)逐渐增大后趋于稳定,呈先升后缓趋势。全生育期内,MD处理夏玉米的SPAD值、LAI值和干物质量分别较LD处理显著提高18.67%、10.39%、10.41%。(2)干物质量Logistic拟合方程表明,当施氮量超过368.9kg/hm^(2)后,干物质量不再增加;与LD处理相比,MD处理配合施氮能够延长夏玉米生长旺盛时间7~18d,推迟群体最大生长率出现时间1~6d。(3)MD处理产量较LD处理高1027.52~2023.04kg/hm^(2),施氮处理的产量较不施氮处理高29.41%~84.46%,而MD处理配合施氮可使产量显著增加52.17%~106.61%。非线性拟合分析表明,玉米产量与施氮量之间整体呈“S”型曲线关系,当施氮量超过267.69kg/hm^(2)和274.11 kg/hm^(2)后,MD处理和LD处理的产量逐渐放缓,分别达到362.75kg/hm^(2)和364.14kg/hm^(2)后几乎无增长。(4)MD处理和LD处理下,N2处理下夏玉米的生长指标和产量与CK无显著差异,但灌水量却比CK少256.5 mm。【结论】MD处理结合278.4 kg/hm^(2)的施氮量能显著促进夏玉米生长并提高产量,可以实现较优的栽培效果。

【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/hm^(2)(N0),224.6 kg/hm^(2)(N1),278.4 kg/hm^(2)(N2),368.9 kg/hm^(2)(N3),and 464.0 kg/hm^(2)(N4).The control was flood irrigation with a nitrogen application of 278.4 kg/hm^(2).For each treatment,we measured growth traits and grain yield of the maize.【Result】①With 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.②The relationship between dry matter accumulation and nitrogen application fit a logistic model,with the accumulation plateauing when the nitrogen application was 368.9 kg/hm^(2).Compared to LD,MD prolonged the period of rapid growth by 7-18 days and delayed its onset by 1-6 days.③The yield in the MD treatment was 1027.52-2023.04 kg/hm^(2) 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/hm^(2) and 364.14 kg/hm^(2),when their associated nitrogen application exceeded 267.69 kg/hm^(2) and 274.11 kg/hm^(2),respectively.④In both irrigation treatments,applying 278.4 kg/hm^(2) 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/hm^(2) is optimal for promoting the growth and yield of summer maize in Southern Xinjiang.