粒径对冻融过程中加氮灌溉土壤N_2O排放的影响  

Effects of particle sizes on the N_2O emission of soil irrigated with nitrogen in freezing and thawing process

作　　者：王风[1] 白丽静[1] 张克强[1] 黄治平[1] 杨鹏[1] 

机构地区：[1]农业部环境保护科研监测所,天津300191

出　　处：《农业工程学报》2009年第9期69-73,共5页Transactions of the Chinese Society of Agricultural Engineering

基　　金："十一五"国家科技支撑项目(2006BAD17B02);中央级公益性科研院所基本科研业务专项(农业部环境保护科研监测所)

摘　　要：通过室内模拟的方法,研究了冻融过程潮土两种粒径(1cm和0.25mm)在加氮灌溉条件下N2O的排放通量,并且分析比较了3种氮素形态(铵态氮、硝态氮和酰胺态氮)和3种浓度(40、200和800mg/L)对土壤N2O的排放通量的影响。结果表明:冻结前,除硝态氮浓度在大于200mg/L时,细土N2O排放通量小于粗粒径土壤,其他氮素形态和浓度得到相反结果;冻结过程细土达到N2O稳定排放通量的时间要早于粗粒径土壤;融化后细土比粗粒径土壤早出现N2O排放峰,并且该峰值总体比粗粒径土壤小;随氮素浓度增加,粗粒径土壤3种氮素形态平均N2O累积排放量分别比细粒径土壤多45.46%、7.81%和46.87%。建议土壤在加氮灌溉时应尽量避免施加硝态氮肥,铵态氮肥的施用应尽量考虑降低浓度,并建议在灌溉越冬水且土壤冻结后耙碎大土块以减少N2O排放。Through simulated experiments in fridge,the effects of soil particle sizes （1cm and 0.25mm） irrigated with three kinds of nitrogen forms （ammonium,nitrate and amide-N） and three concentrations （40,200 and 800 mg/L） on the fluvio-aquatic soil N2O emission flux in freezing and thawing process were conducted.The results showed that：before soil freezing,the N2O emission fluxes of coarse soil were smaller than those of the fine particle with the exception of nitrate concentration of more than 200 mg/L.And fine soil could reach stable N2O emission flux earlier than coarse soil in the freezing stage. The fine soils could also reach N2O emission peaks earlier than coarse soils in the thawing stage, but the peak values of N2O emission were mostly smaller than those of the coarse soil. With nitrogen concentration increasing, the coarse soils of the average cumulative soil N2O emissions （three kinds of nitrogen forms） increased by 45.46%, 7.81% and 46.87% compared with the fine soils, respectively. The paper proposed irrigation with nitrogen in winter should try to avoid nitrate fertilizer, reduce the ammonium nitrogen fertilizer concentration, and break the coarse particle size of soil after irrigation with nitrogen in winter in order to reduce N2O emissions.

关 键 词：冻融 铵态氮 硝态氮 排放控制 酰胺态氮 N2O 

分 类 号：S154[农业科学—土壤学]