不同土地利用类型氨挥发氮同位素自然丰度特征  

Natural abundance of a volatile nitrogen isotope of ammonia under different land uses

作　　者：白潇 遆超普[1,3] 颜晓元 李淼[1,3] 陶莉敏 彭凌云[1,3] 周伟 BAI Xiao;TI Chaopu;YAN Xiaoyuan;LI Miao;TAO Limin;PENG Lingyun;ZHOU Wei(State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China;University of Chinese Academy of Sciences,Beijing 100049,China;Changshu Agro-ecological Experimental Station,Chinese Academy of Sciences,Changshu 215555,China)

机构地区：[1]土壤与农业可持续发展国家重点实验室,中国科学院南京土壤研究所,南京210008 [2]中国科学院大学,北京100049 [3]中国科学院常熟农业生态实验站,江苏常熟215555

出　　处：《农业环境科学学报》2022年第7期1590-1597,共8页Journal of Agro-Environment Science

基　　金：国家自然科学基金项目(42177313,42061124001)。

摘　　要：为了探讨不同土地利用类型下氨(NH_(3))挥发氮同位素自然丰度特征,采集3种土地利用类型(果园、菜地和林地)土壤,在可控条件下采用海绵吸收法开展了为期15 d的室内培养试验,测定了不同土地利用类型下土壤NH_(3)挥发全过程δ^(15)N值及其变化规律。培养期间,3种土地利用类型下的土壤NH_(4)^(+)-N浓度均呈现先上升后下降的趋势;果园和菜地土壤NO_(3)^(-)-N浓度均呈现出持续增加的趋势;土壤pH均呈现先升高后下降再升高的趋势,峰值出现在施入尿素后的第1天。菜地和果园土壤δ^(15)N-NH_(4)^(+)值随培养时间延长持续升高,林地土壤δ^(15)N-NH_(4)^(+)值呈现先降低后升高的趋势。果园、菜地和林地土壤NH_(3)挥发过程δ^(15)N值变化范围分别为-27.98‰--13.29‰、-29.26‰--18.52‰和-9.85‰-10.22‰。不同土地利用类型下土壤NH_(3)挥发过程δ^(15)N-NH_(3)均值水平表现为菜地<果园<林地。土壤pH、土壤NH_(4)^(+)-N浓度和土壤NH_(3)挥发累积量是影响上述结果的重要因素。果园和菜地的土壤pH、果园土壤NH_(4)^(+)-N浓度以及菜地和林地的土壤NH_(3)挥发累积量对土壤NH_(3)挥发δ^(15)N-NH_(3)值有显著影响;源解析模型显示,不同土壤NH_(3)挥发δ^(15)N-NH_(3)值会导致土壤NH_(3)挥发对大气NH_(3)的贡献存在较大的变化,进一步指出使用不同的土壤NH_(3)挥发δ^(15)N-NH_(3)值会导致溯源结果存在较大的差别。To explore the natural abundance of nitrogen isotopes volatilized from soil during ammonia(NH_(3))production from different land uses,we conducted a 15-day incubation experiment using the sponge absorption method under controllable conditions using vineyard,vegetable,and forest soils.Theδ^(15)N values were measured throughout the NH_(3) volatilization process.The results showed that the NH_(4)^(+)-N concentration in the three types of soil initially increased and then decreased.The NO_(3)^(-)-N concentrations of vineyard and vegetable soils continuously increased from the first day onward.The soil pH values peaked on the first day after urea application,and all soil pH values initially increased,decreased,then increased again.Theδ^(15)N-NH_(4)^(+) values of vegetable and vineyard soils increased during the incubation period,while theδ^(15)N-NH_(4)^(+) values of forest soil first decreased then increased.Theδ^(15)N-NH_(3) values of vineyard,vegetable,and forest soils ranged from-27.98‰--13.29‰,-29.26‰--18.52‰,and-9.85‰-10.22‰,respectively.The meanδ^(15)N-NH_(3) value was the lowest in the vegetable soil,followed by the vineyard and forest soil.Further analysis shows that soil pH,NH_(4)^(+) concentration,and cumulative NH_(3) loss significantly influencedδ^(15)N-NH_(3) values.A source trace model showed that differentδ^(15)N-NH_(3) values could result in large differences in the source contribution of NH_(3),revealing the importance of exploring source signatures under different soil conditions.

关 键 词：土地利用 氨挥发 氮同位素自然丰度 影响因素 源解析 

分 类 号：X144[环境科学与工程—环境科学] X71