摘要
采用静态箱-气相色谱法对保护性耕作和常规耕作小麦田的CH4排放进行了原位测量,同时测量了土壤温度、水分、无机氮等相关影响因子,以研究保护性耕作农田CH4排放通量及相关因素的影响.结果表明:保护性耕作及常规耕作麦田CH4的排放具有明显的季节性变化规律,且变化趋势一致;保护性耕作与常规耕作各处理的CH4平均吸收通量、季节吸收量差异显著(P<0.05).在小麦生长季内,各处理农田均表现为CH4的吸收汇.各处理CH4季节吸收通量表现为:常规耕作无秸秆还田>常规耕作秸秆还田>深松秸秆还田>耙耕秸秆还田>旋耕秸秆还田>免耕秸秆还田,与常规耕作相比,保护性耕作CH4吸收通量减少.保护性耕作CH4吸收通量与温度呈正相关,与水分呈负相关,常规耕作CH4吸收通量与两因子相关不显著;各处理CH4吸收通量与NH4+-N含量呈显著负相关.
In order to understand the relationships between CH4 fluxes and its affecting factors in a wheat field with conservation tillage, the CH4 fluxes in two wheat fields, one with conservation tillage and the another with conventional tillage, were measured in situ by static chamber-GC method, with soil temperature and soil moisture and inorganic nitrogen contents determined at the same time. The results showed that these two fields had an obvious and similar seasonal variation pattern of CH4 fluxes, but the average and seasonal CH4 absorption fluxes differed significantly. In the growth peri- od of wheat, the fields were the sink of CH4, and the CH4 absorption fluxes was in the order of conventional tillage with no straw returning （CN） 〉 conventional tillage with straw returning （CS） 〉 subsoiling with straw returning （PS） 〉 harrowing with straw returning （HS） 〉 rotary tillage with straw returning （RS） 〉 no tillage with straw covered （NS）. Comparing with conventional tillage, conservation tillage reduced the CH4 absorption fluxes. In conservation tillage, the CH4 absorption fluxes was positively correlated with soil temperature but negatively correlated with soil moisture content; while in conventional tillage, the CH4 absorption fluxes had no significant correlations with the two factors. In all treatments, there was a significant negative correlation between CH4 absorption fluxes and soil NH4^＋ -N content.
出处
《应用生态学报》
CAS
CSCD
北大核心
2008年第11期2490-2496,共7页
Chinese Journal of Applied Ecology
基金
国家粮食丰产工程项目(2004BA520A14C10)
国家科技支撑计划资助项目(2006BAD15B07)
关键词
保护性耕作
小麦
CH4吸收
影响因素
conservation tillage
wheat
CH4 absorption fluxes
impact factors
