中亚热带丘陵区茶园和林地土壤春季N_2O排放及其影响因素  

Nitrous oxide emission and its impact factors in tea garden and woodland soils in subtropical hilly region of China during spring season

作　　者：何志龙[1] 周维[1] 田亚男[1] Muhammad Shaaban 林杉[1] 

机构地区：[1]华中农业大学资源与环境学院/农业部长江中下游耕地保育重点实验室,武汉430070

出　　处：《农业环境科学学报》2016年第6期1210-1217,共8页Journal of Agro-Environment Science

基　　金：国家自然科学基金项目(41201255;41171212);教育部创新团队课题(IRT1247);河南省农业科学院自主创新专项基金

摘　　要：中亚热带地区春季降雨频繁,茶园施肥量大,该季节茶园土壤氧化亚氮(N_2O)排放量较高,研究春季茶园土壤N_2O排放及其影响因子有一定意义。以中亚热带丘陵区土壤为对象,采用静态箱-气相色谱法,研究了两种植茶年限茶园和林地土壤春季N_2O排放特征及其影响因子。结果表明:茶园N_2O排放量明显高于林地,50年茶园N_2O排放量明显高于20年茶园,林地N_2O的排放量最少;50年茶园、20年茶园和林地土壤春季N_2O累积排放量分别为2.07、1.39、0.22 kg·hm-2。两种植茶年限茶园土壤N_2O排放通量均与土壤NO_3^--N含量呈显著正相关(P<0.05),林地土壤N_2O排放通量则与土壤NH_4^+-N含量呈极显著正相关关系(P<0.01);茶园和林地土壤N_2O排放通量均与5 d累积降雨量之间存在显著的相关性。多元逐步回归分析显示,茶园土壤N_2O排放通量受土壤温度和NO_3^--N含量影响,共同解释其48%~49%的变化;林地土壤N_2O排放通量受土壤温度和NH_4^+-N含量影响,共同解释其55%的变化。这项研究显示施肥对春季茶园N_2O排放的促进作用与降雨有关。In the central subtropical region of China, more rain events and higher fertilization rates make tea field soil become a larger source of N2O emissions in the spring season. Therefore, it is necessary to investigate soil N2O fluxes and related influencing factors under tea field in spring. This study measured the N2O emission characteristics and environmental factors of soils from tea fields with two plantation ages in a hilly region, using static chamber and gas chromatography technique. At the same time, N2O emissions in woodland were also measured.Results showed that the highest cumulative N2O emission（2.07 kg N2O-N·hm-2）was observed in the tea field of 50 years of plantation during the experimental period（spring）, followed by the tea field（1.39 kg N2O-N·hm^（-2））of 20 years of plantation. The lowest cumulative N2O emission（0.22 kg N2O-N·hm2）was found in the woodland. Soil N2O flux had a significant positive correlation with soil NO3^--N concentration under tea field of two plantation ages（P〈0.05）, whereas soil N2O flux was significantly correlated with soil NH4~＋-N concentration in woodland（P0.01）. The cumulative precipitation during the previous five days was found to be significantly correlated with soil N2O fluxes under both tea field and woodland（P〈0.05）. Stepwise regression analysis showed that 48%~ 49% of the variability in the N2O flux from tea fieldsoil could be explained by NO3^--N concentration and soil temperature, while 55% of the variability in the N2O flux from woodland soil could be explained by the concentration of NH4~＋-N and soil temperature. These results indicate that fertilizer induced N2O fluxes from tea field soils is related with rain events during the spring period.

关 键 词：茶园 氧化亚氮排放 矿质态氮 温度 降雨量 

分 类 号：X511[环境科学与工程—环境工程]