不同形态氮添加对毛竹林土壤N_(2)O排放的影响  

Effects of different forms of nitrogen addition on N_(2)O emissions from the soil of Moso bamboo(Phyllostachys edulis) forest

作　　者：蒋文婷 田立斌 朱高荻 唐荣贵 林永新 潘灵强 蔡延江 JIANG Wen-ting;TIAN Li-bin;ZHU Gao-di;TANG Rong-gui;LIN Yong-xin;Pan Ling-qiang;CAI Yan-jiang(State Key Laboratory of Subtropical Silviculture,Zhejiang A&F University,Hangzhou,Zhejiang 311300,China;College of Environmental and Resource Sciences,Zhejiang A&F University,Hangzhou,Zhejiang 311300,China;Anji County Lingfengsi Forest Farm,Anji,Zhejiang 313302,China;School of Geographical Sciences,Fujian Normal University,Fuzhou,Fujian 350007,China)

机构地区：[1]浙江农林大学省部共建亚热带森林培育国家重点实验室,浙江杭州311300 [2]浙江农林大学环境与资源学院,浙江杭州311300 [3]浙江省安吉县灵峰寺林场,浙江安吉313302 [4]福建师范大学地理科学学院,福建福州350007

出　　处：《植物营养与肥料学报》2022年第5期857-868,共12页Journal of Plant Nutrition and Fertilizers

基　　金：国家自然科学基金项目(41877088,41950410570);浙江农林大学校科研发展基金项目(2018FR005,2018FR006,2020KJ003)。

摘　　要：【目的】氧化亚氮(N_(2)O)排放是亚热带地区氮损失的主要途径,我们研究了不同形态含氮化合物对土壤N_(2)O排放的影响。【方法】以毛竹(Phyllostachys edulis)林土壤为研究对象进行了室内培养试验。设置土壤中添加KNO_(3)、NH_(4)NO_(3)、NH_(4)Cl、KCl处理,以去离子水作为对照(CK),在25oC黑暗条件下培养。在培养0.5 h,1、3、5、7、14、28、60天,测定土壤N_(2)O排放速率,铵态氮(NH_(4)^(+)-N)、硝态氮(NO_(3)^(−)-N)、可溶性有机碳(DOC)和水溶性氮(WSN)含量,采用荧光定量PCR技术测定了土壤氨氧化细菌(ammonia-oxidizing bacteria,AOB)、氨氧化古菌(ammonia-oxidizing archaea,AOA)、nirS、nirK、nosZⅠ、nosZⅡ基因丰度。【结果】培养第60天,氮添加与KCl添加处理均显著增加了土壤DOC含量,NH_(4)NO_(3)、NH_(4)Cl处理显著增加了WSN含量,但显著降低了土壤pH。氮添加及KCl添加处理均增加了土壤AOA、AOB、nirK基因丰度,降低了nosZⅠ、nosZⅡ基因丰度。氮添加处理N_(2)O排放速率均在培养第14天达到峰值,且相较于CK处理均增加了N_(2)O累积排放量,KNO_(3)、NH_(4)NO_(3)、NH_(4)Cl和KCl处理累积排放量的增幅分别为524.3%、771.1%、652.7%、98.6%。N_(2)O排放速率与NO_(3)^(−)、WSN、nirK基因丰度呈显著正相关,而与pH、nosZⅠ、nosZⅡ基因丰度呈显著负相关。【结论】铵态氮添加能显著促进毛竹林土壤N_(2)O的排放,其效果高于硝态氮,NH_(4)NO_(3)作为混合氮,外源性NH_(4)^(+)-N、NO_(3)^(−)-N同时输入对土壤N_(2)O排放的促进作用比单独添加NH_(4)^(+)-N、NO_(3)^(−)-N更显著,但并未出现叠加效应。【Objectives】Nitrous oxide(N_(2)O)emission is one of the main ways of nitrogen(N)loss in subtropical region,and the effects of different forms of nitrogen compounds on soil N_(2)O emission were investigated in this study.【Methods】A laboratory incubation experiment was conducted using soil from Moso bamboo(Phyllostachys edulis)forest.The N fertilizer treatments were addition of KNO_(3),NH_(4)NO_(3),and NH_(4)Cl with equal mole of N input,KCl was added for comparison of K+and Cl−,and no N addition was set as the control(CK).The soil N_(2)O emission rate,NH_(4)^(+)-N,NO_(3)^(−)-N,soluble organic carbon(DOC)and water-soluble N(WSN)concentrations were measured after 0.5 h,1 day(d),3 d,5 d,7 d,14 d,28 d and 60 d of incubation.On the 14th day of incubation,the gene abundance of ammonia oxidizing bacteria(AOB),ammonia oxidizing archaea(AOA),nirS,nirK,nosZⅠand nosZⅡwere detected by fluorescence quantitative PCR.【Results】The N fertilizers and KCl addition significantly increased soil DOC concentration,while NH_(4)NO_(3) and NH_(4)Cl addition significantly increased soil WSN concentration and decreased soil pH after 60 days of incubation.Both N and KCl additions increased soil AOA,AOB,and nirK gene abundance,but decreased nosZⅠand nosZⅡgene abundance.The N_(2)O emission in all the treatments reached peaks at the 14th day of incubation.Compared with CK,KNO_(3),NH_(4)NO_(3),NH_(4)Cl,and KCl increased cumulative N_(2)O emissions by 524.3%,771.1%,652.7%,and 98.6%,respectively.The N_(2)O emission rates were significantly and positively correlated with NO_(3)^(-),WSN,and nirK gene abundance and negatively correlated with pH and nosZⅠand nosZⅡgene abundance.【Conclusions】The addition of NH_(4)^(+)-N caused higher soil N_(2)O emission than NO_(3)^(-)-N in Moso bamboo forest.The simultaneous input of NH_(4)^(+)-N and NO_(3)^(-)-N,like NH_(4)NO_(3),promoted higher emission than their individual inputs,but less than that of the sum of KNO_(3) and NH_(4)Cl.

关 键 词：亚热带毛竹林 氮素形态 N_(2)O排放通量 水溶性氮 pH nirK基因丰度 nosZⅠ基因丰度 nosZⅡ基因丰度 

分 类 号：S714[农业科学—林学]