绿肥还田结合减量施氮对绿洲灌区麦田N_(2)O排放和小麦产量的影响  

Effects of green manure incorporation and nitrogen reduction on N_(2)O emissions and wheat yield in oasis irrigated areas

作　　者：张冬玲 于爱忠[1] 吕汉强 杨学慧 王玉珑 王鹏飞 尚永盼 尹波 刘亚龙 王凤 ZHANG Dong-Ling;YU Ai-Zhong;LYU Han-Qiang;YANG Xue-Hui;WANG Yu-Long;WANG Peng-Fei;SHANG Yong-Pan;YIN Bo;LIU Ya-Long;WANG Feng(College of Agronomy,Gansu Agricultural University/State Key Laboratory of Aridland Crop Science,Lanzhou 730070,Gansu,China)

机构地区：[1]甘肃农业大学农学院/干旱生境作物学国家重点实验室,甘肃兰州730070

出　　处：《作物学报》2025年第4期1005-1021,共17页Acta Agronomica Sinica

基　　金：国家重点研发计划项目(2022YFD1900200);国家自然科学基金项目(32160524);财政部和农业农村部国家现代农业产业技术体系建设专项(CARS-22-G-12);甘肃农业大学伏羲杰出人才培育计划项目(GAUfx-04J01);甘肃省自然科学基金项目(22JR5RA867)资助。

摘　　要：针对西北绿洲灌区长期施用化学氮肥造成农田氮损失、土壤肥力下降等问题,研究不同绿肥还田和施氮水平对作物产量和土壤N_(2)O排放的影响及机制具有重要意义。本研究基于甘肃河西走廊石羊河流域布设的田间试验于2019—2021年在春小麦收获后复种毛叶苕子,毛叶苕子开花期设置7500 kg hm^(-2)(G_(1))、15,000 kg hm^(-2)(G_(2))、22,500 kg hm^(-2)(G_(3))和30,000 kg hm^(-2)(G_(4))4个还田量。翌年春小麦播前设置2个施氮水平,分别为减氮15%(N153)和减氮30%(N126),以无绿肥传统施氮(G0N180)作为对照。结果表明,与G0N180相比,绿肥还田结合减量施氮显著提高了小麦籽粒产量,降低了麦田N_(2)O排放量和排放强度,其中以G_(4)N153处理产量最高,达9135.33~9250.42 kg hm^(-2)。同一还田量下,减氮30%较减氮15%处理显著降低了N_(2)O排放量;同一施氮水平下,G_(3)、G_(4)较G_(1)、G_(2)显著降低N_(2)O排放量。研究还发现,N_(2)O排放的消减主要发生在小麦拔节期以前,这主要归因于绿肥还田结合减量施氮处理显著降低了小麦播种期及苗期的土壤硝态氮、铵态氮含量和硝酸还原酶、亚硝酸还原酶活性。回归分析表明,小麦播种期及苗期的土壤速效氮含量和酶活性与N_(2)O排放量呈显著正相关(P<0.01)。在减氮15%水平下,G_(4)较G_(1)、G_(2)、G_(3)提高了小麦开花期和成熟期土壤速效氮含量,保障了小麦生育后期氮素吸收。综上所述,在河西绿洲灌区,绿肥还田结合减量施氮可显著提高小麦产量、降低土壤N_(2)O排放量和排放强度,其中绿肥还田量30,000 kg hm^(-2)结合减量施氮15%效果最佳。In the oasis irrigated regions of Northwest China,long-term use of chemical nitrogen fertilizers has resulted in significant problems,such as gaseous nitrogen losses and a decline in soil fertility.It is essential to study the effects of varying green manure incorporation rates and nitrogen application levels on crop yield and soil N_(2)O emissions.From 2019 to 2021,a field experiment was conducted in the Shiyang River Basin of the Hexi Corridor.After the harvest of spring wheat,hairy vetch was replanted,with four green manure incorporation levels established during its flowering stage:7500 kg hm^(-2)(G_(1)),15,000 kg hm-(G_(2)),22,500 kg hm^(-2)(G_(3)),and 30,000 kg hm^(-2)(G_(4)).In the following year,prior to spring wheat sowing,two nitrogen reduction levels were implemented:a 15%reduction(N153)and a 30%reduction(N126),with a traditional nitrogen application without green manure(G0N180)as the control.The results showed that,compared to G0N180,the combination of green manure incorporation and nitrogen reduction significantly increased wheat grain yield while reducing N_(2)O emissions and emission intensity.The yield of G_(4)N153 treatment was the highest,ranging from 9135.33 to 9250.42 kg hm^(-2).Within the same level of green manure incorporation,a 30%nitrogen reduction significantly lowered N_(2)O emissions compared to a 15%reduction.Similarly,for the same nitrogen level,G_(3)and G_(4)significantly reduced N_(2)O emissions compared to G_(1)and G_(2).The study also found,the reduction in N_(2)O emissions primarily occurred before the wheat jointing stage,which was attributed to a notable decrease in soil nitrate and ammonium content as well as the activities of nitrate and nitrite reductases during the wheat sowing and seedling stages under treatments combining green manure with nitrogen reduction treatments.Regression analysis revealed a significant positive correlation between soil available nitrogen content,enzyme activities during the wheat sowing and seedling stages,and N_(2)O emissions(P<0.01).Under a 15

关 键 词：绿肥还田量 施氮量 N_(2)O排放 土壤速效氮 土壤酶活性 

分 类 号：S51[农业科学—作物学]