南京市郊区集约化大棚蔬菜地N2O的排放

采用静态暗箱-气相色谱法，研究了南京市郊区集约化生产管理下，芹菜-空心菜-小白菜-苋菜轮作菜地与休闲裸地的N2O排放通量的动态变化，及其与土壤温度、湿度以及NO3--N和NH4+-N含量的关系.结果表明： 轮作菜地的N2O累积排放量达1372 kg N·hm-2，显著大于休闲裸地(29.2 kg N·hm-2)；轮作菜地生态系统N2O-N的排放系数高达46%.4种蔬菜地中，空心菜地对轮作菜地的周年累积排放量贡献最大，为53.5%，小白菜地次之，为31.9%，芹菜地和苋菜地最小，分别为4.5%和4.8%.轮作菜地的N2O排放通量与土壤温度呈显著正相关，Q10为2.80；土壤湿度以及NO3--N和NH4+-N含量与轮作菜地的N2O排放通量之间的相关性不显著.

N2O emission from an intensively managed greenhouse vegetable field in Nanjing suburb,Jiangsu Province of East China.

By using static opaque chamber and gas chromatography, this paper studied the dynamic changes of N2O fluxes and their relationships with soil temperature, soil moisture content, and soil nitrate and ammonium contents in an intensively managed greenhouse celery-
Tung choy-Bok choy-amaranth rotation field and in a bare fallow land in Nanjing suburb. The cumulative N2O emission from the rotation vegetable field was as high as 137.2 kg N·hm-2, being significantly higher than that from the bare fallow land (29.2 kg N·hm-2), and the N2O-N emission factor of the rotation vegetable field ecosystem was up to 4.6%. In the rotation field, the planting of Tung choy had the greatest contribution to the annual cumulative N2O emission, occupying 53.5% of the total, followed by the planting of Bok choy (31.9%), celery field (4.5%), and amaranth (4.8%). The N2O flux of the rotation field had significant positive correlation with soil temperature, the Q10 being 2.80, but no significant correlations with soil moisture content and soil nitrate and ammonium contents.