中国农田土壤N_2O排放通量分布格局研究  

The distribution pattern of N_2O emission from agricultural soil in China

作　　者：王效科[1] 庄亚辉[1] 李长生 

机构地区：[1]中国科学院生态环境研究中心系统生态室,北京100085 [2]CSRC University of New Hampshire

出　　处：《生态学报》2001年第8期1225-1232,共8页Acta Ecologica Sinica

基　　金：国家自然科学重大基金 (4 98992 70和 3 9790 1 0 0 )资助项目

摘　　要：中国作为世界上一个重要农业大国 ,对全球大气中 N2 O浓度的影响正在引起人们的普遍关注。该研究采用针对农业土壤痕量气体排放估算建立的、基于 N2 O的产生、传输和消耗机理的反硝化分解 (DNDC)模型 ,在建立了有关中国气候、农业土壤和农业生产的分县数据库基础上 ,估计了我国各县农业土壤 N2 O的排放通量 ,发现我国农田土壤 N2 O排放通量有较明显的地区差异 ,西北地区较低 ,东南地区较高。还发现无论温度升高 ,还是施肥量变化 ,对我国农田土壤 N2 O排放通量的影响 ,都存在区域差异 ,表现为东南地区的变化幅度较西北地区大 。As a large country, the impact of China's agricultural practice on atmospheric N 2O would be highly significant. Field measurements of N 2O emission from agricultural land have been carried out. However, it is still difficult to estimate the total soil emission of N 2O in China from these field measurement because of the diversity of climate and cultivation practices that control soil N 2O emission. In this study, in order to estimate N 2O emission more accurately, a process oriented model DNDC (Denitrification and decomposition) was employed. DNDC model has been developed to predict soil carbon and nitrogen biogeochemistry, including N 2O and other trace gas emissions. DNDC was constructed with two components that reflect the two levels of driving force which control geochemical and/or soil biochemical processes related to trace gas emissions. The first component, consisting of soil conditions, crop growth and decomposition sub models, predicts soil temperature, moisture, pH, redox potential (Eh) and substrate concentration profiles based on ecological drivers (e.g., climate, soil, vegetation and anthropogenic activity). The second component, consisting of the nitrification, denitrification and fermentation sub models, predicts NO, N 2O, CH 4 and NH 3 fluxes based on soil environmental variables. Classical laws of physics, chemistry or biology, or empirical equations generated by previous studies were used in the model to parameterize each specific reaction. The entire model forms a bridge between basic ecological drivers and trace gas emissions. DNDC model has been tested against a number of field measurements worldwide. Most of the tests showed that DNDC was able to capture general patterns and magnitudes of N 2O emissions observed in field. To run DNDC using data files of climate, soil and farm management compiled in University of New Hampshire, we validated DNDC against 6 site studies in Nuancheng, Hebei Province, Shenyang, Liaoning Province, Agricutural experiment station and Changqiao V

关 键 词：农田土壤 排放模型 一氧化二氮排放 分布格局 排放通量 

分 类 号：S152[农业科学—土壤学]