摘要
【目的】基于高标准农田建设改善了旱地麦田灌溉条件,但小麦季通常仅能进行一次灌溉的生产实际,探索返青后补灌与氮肥互作对旱地小麦生产力、水氮利用以及土壤硝态氮残留的影响,为旱地小麦高产高效和环境友好生产提供理论依据和技术支撑。【方法】于2019—2022年,在黄土高原与黄淮海平原交汇处的典型旱地小麦种植区,设置两因素裂区试验,灌溉水平为主处理,分别为全生育期不灌溉(I0)和返青后补灌(I1,小麦返青后0—40 cm土层首次出现土壤含水量低于田间持水量的60%时,补灌至田间持水量的85%,全生育期仅灌溉一次)。施氮量为副处理,分别为0(N0)、120(N120)、180(N180)和240 kg N·hm^(-2)(N240)。分析小麦产量及其构成因素、水分利用效率、氮素吸收利用特征以及0—200 cm土层硝态氮残留量。【结果】与I0相比,I1优化了小麦产量构成要素,增加了氮素吸收能力,籽粒产量和水分利用效率3年平均分别显著提高55.8%和34.7%,0—200 cm土层硝态氮残留显著降低11.6%。随着施氮量增加,I0水平下小麦产量、穗数、穗粒数和水分利用效率均呈现先升高后下降的趋势,以N180处理最高;而I1水平下表现为先增加后保持稳定,N180和N240处理均保持较高水平。两种灌溉水平下,增加施氮量均显著降低了氮素利用效率、氮肥吸收效率和氮肥偏生产力,但N180处理下氮肥农学效率和氮肥表观利用率与N120相比无显著降低(2021—2022年度I1除外)。无论灌溉与否,增加施氮量均提高了成熟期麦田土壤硝态氮残留量,I0水平下各施氮处理硝态氮主要富集在0—60 cm土层,且N180和N240处理在0—200 cm土层出现逐年累积效应;而I1较I0显著降低了0—60 cm土层硝态氮残留量,0—200 cm土层仅在N240处理下出现硝态氮累积。从互作效应看,3年试验中,I1N180和I1N240组合均具有较高的籽粒产量和水分利用效率,但I1N180较I1N240降低了生育期耗水量和土壤硝态氮残留量,并提高了氮效率。【结论】小麦返青后补灌配施氮肥180 kg N·hm^(-2)可以优化产量构成要素,提高植株氮素积累量及积累强度,不仅在提高小麦产量的同时获得最优氮效率,还能降低0—200 cm土层硝态氮残留量,是旱地小麦在灌溉条件改善后兼顾小麦高产高效和环境友好生产的水肥组合。
【Objective】The project of high standard farmland construction in China has improved the irrigation conditions in dryland,however,there is usually only once limited irrigation that could be carried out in wheat growing season.In this study,the effects of supplemental irrigation after regreening and nitrogen(N)fertilizer rates on productivity,water and N utilization in dryland wheat and nitrate residue in soil were investigated,so as to provide the theoretical basis and technical support for high-yield,high-efficiency and environment-friendly production in dryland wheat.【Method】The two-factor split-plot field experiment was conducted in the typical dryland of the intersection between Loess Plateau and Huang-Huai-Hai Plain from 2019 to 2022,where the irrigation conditions of no-irrigation during whole growth period(I0)and supplemental irrigation after regreening(I1,supplemental irrigation to 85%of field capacity when the soil water content in the 0-40 cm soil layer after wheat regreening was lower than 60%of field capacity at the first time)were assigned to the main plots,and the nitrogen application rates of 0(N0),120 kg N·hm^(-2)(N120),180 kg N·hm^(-2)(N180)and 240 kg N·hm^(-2)(N240)were assigned to the subplots.The grain yield and yield components,water use efficiency,N absorption and utilization in wheat were tested,as well as the nitrate residue in the 0-200 cm soil layer in dryland.【Result】Compared with I0,I1 could optimize wheat yield components and increase N absorption capacity,for the 3-year average grain yield and water use efficiency significantly increased by 55.8%and 34.7%,respectively,however,it decreased soil nitrate residue by 11.6%in the 0-200 cm soil layer.With the increase of N application rate,the grain yield,spike number,kernels per spike and water use efficiency initially increased and then decreased,and reached the maximum under the N180 treatment with I0 level,but there were initially increased and then remained stable,and reached the higher level both in the N180 and N240 treatments under I1 level.With the increase of N application rate,the N use efficiency,N uptake efficiency and N partial factor productivity were significantly decreased under the both two irrigation conditions,but the N agronomy efficiency and N apparent efficiency under N180 treatment was not significantly decreased compared with N120 treatment(except I1 level in 2021-2022).Regardless of irrigation,with the increase of N application rate,the soil nitrate residue at harvest were significantly increased.Soil nitrate accumulated largely in the 0-60 cm soil layer under each N application rates with I0 level,and the obvious accumulated effects of soil nitrate residue in the 0-200 cm soil layer were found under N180 and N240 treatments;meanwhile,the soil nitrate residue under I1 level in the 0-60 cm soil layer was significantly lower than that under I0,and there were only accumulated effects of soil nitrate residue was found in the 0-200 cm soil layer under N240 treatment.In general,both the I1N180 and I1N240 could obtain the higher grain yield and water use efficiency.I1N180 treatment reduced water consumption during growth period and soil nitrate residue in the 0–200 cm soil layer,and improved the N efficiency,compared with I1N240 treatment.【Conclusion】Supplemental irrigation after regreening combined with 180 kg N·hm^(-2)N fertilizer could optimize the yield components,shoot N accumulation and N accumulative rate,thus it could not only improve the grain yield and N absorption and utilization efficiency in wheat,but also reduce the soil nitrate residue in 0-200 cm soil layer.Therefore,I1N180 treatment was an optimal model for realizing the collaborative target of high-yield,high-efficiency and environment-friendly in dryland wheat production system.
作者
赵凯男
吴金芝
黄明
李友军
汪洪涛
黄修利
吴姗薇
张军
赵志明
赵雯馨
李淑靖
李爽
李文娜
ZHAO KaiNan;WU JinZhi;HUANG Ming;LI YouJun;WANG HongTao;HUANG XiuLi;WU ShanWei;ZHANG Jun;ZHAO ZhiMing;ZHAO WenXin;LI ShuJing;LI Shuang;LI WenNa(College of Agriculture,Henan University of Science and Technology,Luoyang 471023,Henan)
出处
《中国农业科学》
CAS
CSCD
北大核心
2023年第17期3383-3398,共16页
Scientia Agricultura Sinica
基金
国家重点研发计划(2016YFD0300404,2018YFD0300700)
河南科技大学博士科研启动基金(13480082)。
关键词
返青后补灌
氮肥用量
旱地
小麦
产量
水分利用效率
硝态氮残留
supplemental irrigation after regreening
N fertilizer application rate
dryland
wheat
yield
water use efficiency
nitrate residue
