植物营养与肥料学报2026，Vol.32Issue(8)：1645-1662,18.DOI:10.11674/zwyf.2025503
施氮对旱作农田土壤剖面温室气体排放影响的Meta分析
Effects of nitrogen fertilization on soil profile greenhouse gas emissions in rainfed croplands:A meta-analysis
摘要
Abstract
[Objectives]Nitrogen(N)fertilization leads to greenhouse gas(GHG)emissions from croplands,and the emission intensity is jointly mediated by fertilizer type,N application rate,and soil physicochemical properties.However,previous studies have primarily focused on surface soils,with limited efforts devoted to a systematic synthesis of GHG fluxes across soil profiles in rainfed croplands,particularly regarding deep-soil processes and their controlling factors.This study aimed to quantify the effects of nitrogen fertilization on soil-profile emissions of CO2,CH4,and N2O in rainfed croplands worldwide,identify the major driving factors,and improve understanding of the underlying carbon and nitrogen cycling mechanisms in agroecosystems.[Methods]Relevant peer-reviewed studies were retrieved from Chinese and international databases,including CNKI and Web of Science,by using keywords related to nitrogen fertilization,greenhouse gases,soil profiles,and deep soil.Only field experiments that included both control and nitrogen treatment groups and reported soil-profile GHG fluxes with extractable statistical information were considered.In total,32 studies conducted at 11 global sites between 1997 and 2020 were included,providing 643 paired observations.To ensure comparability among studies,soil profiles were standardized into five depth intervals:0-10,10-20,20-40,40-60,and>60 cm.A meta-analysis was conducted to evaluate the effects of nitrogen fertilization on soil-profile GHG fluxes and to identify the major regulating factors.[Results]N fertilization exerted pronounced depth-dependent effects on GHG fluxes in rainfed croplands.Compared with the no-nitrogen treatment,moderate nitrogen input(<200 kg N/hm2)increased CO2 fluxes by 2％-22％,whereas excessive nitrogen application(>400 kg N/hm2)decreased CO2 emissions by 2％-14％,likely because of suppressed microbial activity.The stimulatory effect of nitrogen on CO2 emissions was more evident in soils with higher soil organic carbon content(>5.12 g/kg)or near-neutral pH.N2O emissions increased exponentially with nitrogen input,indicating a clear threshold response.Rainfed croplands generally acted as a sink for atmospheric CH4,but the effect of nitrogen fertilization on CH4 fluxes was bidirectional,CH4 uptake was inhibited in soil layers above 60 cm but enhanced below 60 cm.This pattern suggests that nitrogen fertilization may reshape the deep-soil CH4 sink by altering oxygen diffusion along the profile and methanotrophic activity.Nitrogen fertilization also significantly increased global warming potential,with N2O contributing the largest share.In addition,combined application of organic and inorganic fertilizers reduced GHG emission intensity,with the strongest mitigation effect observed in neutral soils of arid regions.[Conclusions]Nitrogen fertilization significantly increases CO2 emissions in surface soil and N2O emissions across the 0-60 cm profile,and reduces the CH4 sink effect in the soil profile above 60 cm.Heavy nitrogen application exaggerates the greenhouse gas emission effect.The contribution of deep soil to sustained N2O release and to shifts in CH4 sink function suggests the importance of controlling nitrogen fertilizer rate for achieving the dual goals of crop productivity and GHG mitigation.关键词
氮添加/农田土壤/温室气体/meta分析Key words
nitrogen fertilization/farmland soil/greenhouse gas/meta-analysis引用本文复制引用
刘瑾,马鸿泽,闫伟明,衣学慧,王小鸽,胡小赢,刘冰琦,上官周平..施氮对旱作农田土壤剖面温室气体排放影响的Meta分析[J].植物营养与肥料学报,2026,32(8):1645-1662,18.基金项目
国家自然科学基金青年科学基金项目(32401447) （32401447）
陕西省教育厅一般专项科学研究计划项目(24JK0735) （24JK0735）
2025年度陕西高校优秀青年人才支持计划 （）
中国现代林业职教集团林业科学研究项目(LZJB2025KY002) （LZJB2025KY002）
杨凌职业技术学院国家自然科学基金培育项目(GZ2024-003). （GZ2024-003）
