中文摘要：

利用座落于江都市小纪镇良种场的FACE平台，研究了FACE条件下。不同氮素水平水稻土壤的生理生化指标及微生物区系特征。结果表明，高N水平下，FACE圈土壤微生物生物量碳、基础呼吸作用、脲酶活性、过氧化氢酶活性、氨化作用及放线菌数量都比对照高。而低N水平下，除真菌、放线菌数量以及氨化作用外，其他指标均比对照低。FACE条件下，高氮处理与低氮处理相比较，土壤微生物生物量碳、基础呼吸作用、脲酶活性、过氧化氢酶活性、氨化作用以及细菌数量分别提高610．57％、56．55％、24．32％、9．43％、1．09％和225％，供氮水平对FACE条件下水稻土生理生化指标以及微生物群落有调节作用。

英文摘要：

Over the past decade, free-air carbon dioxide enrichment（FACE） experiments have been conducted on many agricultural crops example for wheat, rice and perennial ryegrass etc.. But the studies on soil microbe were few. In order to explore the changes of soil enzyme and microbial populations in the condition of free-air carbon dioxide enrichment, some common soil biochemical indexes and microbial biomass were selected to express those changes. The results indicated that elevated CO2 increased soil microbial biomass carbon,basal respiration, urease activity, catalase activity, ammonification and the populations of actinomycetes under high N level, all these characteristics rised to 710.57%, 156.55%, 124.32%, 109,43%, 101.09% and 325% as compared with ambient respectively, whereas FACE decreased all the characteristics under low N level except for soil ammonification, the number of fungi and actinomycetes. The levels of nitrogenous fertilizer palyed the modulatory role under the free-air CO2 enrichment condition.