南方红壤丘陵区不同土地利用方式土壤N_(2)O排放系数研究  

Differences in soil N_(2)O emission coefficients of different land use types in red soil hilly areas in southern China

作　　者：王芝麟 邹彬 张涵 郭季璞 韩林蓉 王逗 李玲玲 秦红灵[4] 郭家骅 WANG Zhi-lin;ZOU Bin;ZHANG Han;GUO Ji-pu;HAN Lin-rong;WANG Dou;LI Ling-ling;Qin Hong-ling;GUO Jia-hua(State Gird Shaanxi Electric Power Company,Xi’an 710048,China;State Gird Shaanxi Electric Power Research Institute,Xi’an 710100,China;College of Urban and Environmental Sciences,Northwest University/Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity,Xi’an 710127,China;Institute of Subtropical Agriculture,Chinese Academy of Sciences/Key Laboratory of Agro-ecological Processes in Subtropical Region,Changsha 410125,China;Agronomy College,Gansu Agriculture University/Gansu Provincial Key Laboratory of Arid Land Crop Science,Lanzhou 730070,China)

机构地区：[1]国网陕西省电力公司,西安710048 [2]国网陕西省电力公司电力科学研究院,西安710100 [3]西北大学城市与环境学院/陕西省地表系统与环境承载力重点实验室,西安710127 [4]中国科学院亚热带农业生态研究所/亚热带农业生态过程重点实验室,长沙410125 [5]甘肃农业大学农学院/甘肃省干旱生境作物学重点实验室,兰州730070

出　　处：《南方农业学报》2021年第8期2193-2201,共9页Journal of Southern Agriculture

基　　金：国家自然科学基金面上项目(41771335);湖南省自然科学基金面上项目(2020JJ4654)。

摘　　要：【目的】明确不同土地利用方式土壤氧化亚氮(N_(2)O)排放系数的差异并评估区域N_(2)O排放,为评估南方红壤丘陵区N_(2)O排放清单提供基础数据和参考依据。【方法】选择南方红壤丘陵区4种常见的土地利用方式(油茶林、旱地农田、稻田和松林),通过分析土壤不施肥与施氮肥时N_(2)O排放速率和排放量的差异,计算排放系数,并用^(15)N同位素标记方法探究硝化作用和反硝化作用对土壤排放N_(2)O的相对贡献。【结果】不同土地利用方式土壤理化性质差异明显,稻田全氮含量最高(2.22 g/kg),显著高于其他3种土地利用方式土壤(P<0.05,下同)。土壤不施肥时,N_(2)O排放速率在0~227.80μg/(kg·h),施氮量为200 kg N/ha时,N_(2)O排放速率在0~4213.27μg/(kg·h)。4种土地利用方式的土壤N_(2)O排放系数均随土壤孔隙含水量(WPFS)增加而增加,WPFS为75%时,稻田、旱地农田、油茶林和松林土壤N_(2)O排放系数分别为2.47%、0.39%、2.31%和0.91%。4种土地利用方式土壤N_(2)O排放系数主要受全氮含量影响,N_(2)O累积排放量均与潜在反硝化潜势呈显著正相关,除稻田外,其他3种土地利用方式土壤N_(2)O累积排放量也与潜在硝化势呈显著正相关,以NO_(3)^(-)-N为底物的反硝化作用对N_(2)O排放的相对贡献平均大于90.00%,远高于硝化作用。【结论】南方红壤丘陵区土壤以NO_(3)^(-)-N为底物的反硝化作用主导N_(2)O排放,施用氨基氮肥可能有效减少氮肥N_(2)O排放损失,为国家执行碳中和政策提供理论依据。【Objective】To clarify the differences in soil N_(2)O emission coefficients of different land use methods and assess regional N_(2)O emissions,to provide basic data and basis for evaluating the N_(2)O emission inventory of red soil hilly areas in southern China.【Method】This paper selected four common land use methods(Camellia oleifera forest,dry farmland,rice field and pine forest)in the red soil hilly region of southern China,and calculated the emission coefficient by analyzing the difference in the N_(2)O emission rate and amount when the soil was not fertilized and when nitrogen was applied,and ^(15)N isotope was used.The labeling method explored the relative contribution of nitrification and denitrification to soil N_(2)O emissions.【Result】There weregreat differences in soil physical and chemical properties among different land use methods,and the total nitrogen content of paddy fields was the highest(2.22 g/kg),which was significantly higher than others(P<0.05,the same below).When the soil was not fertilized,the N_(2)O emission rate was 0-227.80μg/(kg·h),and when the nitrogen application rate was 200 kg?N/ha,the N_(2)O emission rate was 0-4213.27μg/(kg·h).The soil N_(2)O emission coefficients of the four land use methods all increased with the increase of water content of soil porosity(WPFS).When the WPFS was 75%,the soil N_(2)O emission coefficients of paddy field,dry farmland,C.oleifera forest and pine forest were 2.47%,0.39%,2.31%,0.91%,respectively.The N_(2)O emission coefficients of the four land use methods were mainly affected by total nitrogen content,and accumulated N_(2)O emissions were significantly positively related with potential denitrification potential,except paddy fields,N_(2)O cumulative emission of the other three land use methods was significantly positively related with potential nitrification potential.The relative contribution of denitrification with NO_(3)^(-)-N as the substrate to N_(2)O emissions was more than 90%on average,which was much higher than nitrification.�

关 键 词：氧化亚氮(N_(2)O) 排放系数 硝化和反硝化 土地利用方式 红壤 

分 类 号：S154.1[农业科学—土壤学]