摘要
采用水肥气一体化灌溉可改善土壤的通气状况,影响土壤碳氮循环过程,进而影响土壤N_2O的排放。为明确施氮、增氧和灌水对温室辣椒地土壤N_2O排放的影响,设置了施氮量(300、225 kg/hm^2)、溶氧量(40、5 mg/L)和灌水量(1. 0W、0. 6W,W为充分灌溉时的灌水量) 3因素2水平试验,采用静态箱-气相色谱法监测N_2O排放通量,系统研究了水肥气一体化灌溉对温室辣椒地土壤N_2O排放的影响,并通过结构方程模型分析各影响因子对N_2O排放的定量贡献。结果表明,增氧处理、施氮量和灌水量的增加可增加温室辣椒地土壤N_2O的排放通量峰值、排放总量和单产排放量。试验中增氧条件下N_2O排放总量较对照增加了31. 90%;充分灌溉较非充分灌溉增加了43. 22%;常量施氮较减量施氮增加了33. 01%。增氧处理和灌水量的增加可提高温室辣椒的氮素利用效率,而施氮量的增加降低了温室辣椒的氮素利用效率。综合考虑作物产量、氮素利用效率和单产N_2O排放量,减量施氮非充分灌溉增氧处理是推荐的水肥气管理方案。通过结构方程模型的路径分析,土壤温度、充水孔隙度和NO3--N含量可分别解释N_2O排放的42%、60%和58%,是影响水肥气一体化灌溉的主要影响因子。
Oxyfertigation delivers water,fertilizer and gas coupled mixture to crop root zone via subsurface drip irrigation system.This new technique changes the oxygen concentration and water distribution in soil and thus affecting the nitrogen cycling process,including nitrification and denitrification,and then affecting soil nitrous oxide(N2O)emissions.However,the influences of oxyfertigation on soil N2O emissions from greenhouse vegetable fields and its main influencing factors were both little known.To understand the influence of aeration,nitrogen application and irrigation on pepper soil N2O emission in greenhouse,totally eight combinations were tested,including two types of nitrogen application rates(300 kg/hm^2 and 225 kg/hm^2),two types of aeration levels(40 mg/L and 5 mg/L),and two types of irrigation amount(1.0 W and 0.6 W,W was full irrigation amount).Soil N2O emission flux was monitored via using static chamber-gas chromatograph technique.Soil temperature,water-filled pore space(WFPS),dissolved oxygen(DO),NO3^--N and NH4+-N content were also measured.Quantitative contribution of influential factors to N2O emission under oxyfertigation was analyzed by structural equation model(SEM).Results showed that aeration,the increase of nitrogen rate and water amount resulted in an increase of soil N2O emission peak,cumulative N2O emission and yield-scaled N2O emission under oxyfertigation.Compared with control,the cumulative N2O emission of aeration condition was averagely increased by 31.90%.The cumulative N2O emission under full irrigation was averagely increased by 43.22%compared with deficit irrigation.Similarly cumulative N2O emission under conventional nitrogen rate was averagely increased by 33.01%compared with the 75%conventional nitrogen rate treatment.Aeration and the increase of water amount resulted in an increase of crop nitrogen use efficiency.However,the increase of nitrogen rate caused a decrease of crop nitrogen use efficiency.Considering crop yield,nitrogen use efficiency and yield-scaled N2O emission,t
作者
雷宏军
刘欢
刘鑫
潘红卫
陈德立
LEI Hongjun;LIU Huan;LIU Xin;PAN Hongwei;CHEN Deli(School of Water Conservancy,North China University of Water Conservancy and Electric Power,Zhengzhou 450046,China;Faculty of Veterinary and Agricultural Sciences,University of Melbourne,Victoria 3010,Australia)
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2019年第3期262-270,共9页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家自然科学基金项目(U1504512
51779093)
河南省科技创新人才计划项目(174100510021)
华北水利水电大学研究生创新项目(YK2017-02)
中原科技创新领军人才项目(194200510008)
关键词
辣椒
水肥气一体化灌溉
N2O排放
增氧
结构方程模型
影响因子
pepper
oxyfertigation
nitrous oxide emission
aeration
structural equation model
influential factors
