摘要
用静态暗箱-气相色谱法测定了川中丘陵地区典型冬水田(RF)及冬水田转稻麦轮作处理(RW)在小麦生长季的温室气体排放通量,并同步测定了土壤温度、水分和可溶态碳氮含量.结果表明,RW在小麦生长季的CH4、生态系统呼吸CO2和N2O平均排放通量分别为0.05、117.01 mg·m-2·h-1(以C计)和77.19μg·m-2·h-1(以N计),而RF相应通量分别为1.43、7.85 mg·m-2·h-1和-0.61μg·m-2·h-1.RW施氮肥后出现N2O的排放峰,其N2O直接排放系数为1.28%.土壤可溶态有机碳含量与CO2通量之间呈显著正相关关系(r=0.342,p<0.01),与CH4、N2O的相关关系不显著;硝态氮、可溶态总氮含量与N2O通量的关系为显著正相关,但与CH4通量呈显著负相关.RF的综合增温潜势(以CO2-eq计,下同)为3.03 Mg·hm-2,大于RW(-1.66 Mg·hm-2),暗示冬水田转稻麦轮作会降低生态系统的综合增温效应.
Field experiment were conducted in the hilly area of Central Sichuan to investigate the effects of altering rice-flooded-fallow(RF) to rice-wheat rotation(RW) on the emissions of CH4,CO2 and N2O.Gas fluxes were analyzed by static opaque chamber and gas chromatography techniques.Soil samples were collected to determine dissolved organic carbon and nitrogen concentrations.Soil temperature and moisture were measured at the same time of gas sampling.Results showed that average CH4,CO2(ecosystem respiration) and N2 O fluxes for RW treatment were 0.05,117.01 mg·m-2·h-1and77.19 μg·m-2·h-1,respectively,and were 1.43,7.85 mg·m-2·h-1and-0.61 μg·m-2·h-1,respectively,for RF treatment.N2 O flux peak was observed after nitrogen fertilizer application from RW,and the N2 O direct emission factor for RW was 1.28%.Soil dissolved organic carbon content was significantly correlated with CO2flux(r = 0.342,p < 0.01).Nitrate and dissolved total nitrogen was positively correlated with N2 O flux while negatively with CH4 flux.Global warming potentials of three greenhouse gases were 3.03 Mg·hm-2for RF,which was higher than that for RW(-1.66 Mg·hm-2).Result of this study proved that converting RF to RW decreased global warming impact of the ecosystem.
出处
《环境科学学报》
CAS
CSCD
北大核心
2014年第10期2675-2683,共9页
Acta Scientiae Circumstantiae
基金
国家重点基础研究发展计划(No.2012CB417100)
国家自然科学基金项目(No.41171212)~~
关键词
冬水田
稻麦轮作
减排
综合增温潜势
温室气体
影响因子
直接排放系数
winter flooded paddy field
rice-wheat rotation
global warming potential
greenhouse gases
impact factors
direct emission factor
