中文摘要：

通过温室盆栽试验，研究种植水稻对长江三角洲绰墩山遗址的古水稻土与现代水稻土的微生物功能多样性和氨氧化细菌数量的影响。在60d的试验期内观察发现，现代水稻土含有0．416～1、235MPN mg^-1的氨氧化细菌，古水稻土在温室培养后也检测到0．013—0、055MPN mg^-1的氨氧化细菌，但数量远远低于现代水稻土；在不施氮的条件下种植水稻会降低古水稻土与现代水稻土中氨氧化细菌的数量，但施加硫酸铵在种植水稻30d时增加了其数量，而施加硝酸钠对其数量没有显著影响。现代水稻土的碳底物利用能力明显弱于古水稻土，微生物群落的Shannon指数、Simpson指数和McIntosh指数也不同程度的低于古水稻土；种植水稻60d后，现代水稻土中微生物群落的整体活性显著提高，三种多样性指数也达到与古水稻土相同的水平，但施加氮肥又减缓了种植水稻对微生物整体活性的增强作用。种植水稻和施用氮肥对古水稻土微生物群落的三种多样性指数均没有显著影响，而且3320a古水稻土和6280a古水稻土的微生物功能多样性也没有显著差异。

英文摘要：

According to the latest archaeological discoveries in the low Yangtze River Delta of China, in history rice cultivation can trace back to B.C. 4 000 in China. A mini-pot-culture experiment was carried out to evaluate effects of rice cultivation on microbial functional diversity and ammonia-oxidizing bacterial number in ancient paddy soils that have been buried underground for thousands of years, and in present paddy soil as well. A huge population of ammonia-oxidizing bacteria （AOB）, about 0.416- 1.235 MPN mg^-1 dry soil, was observed in the present paddy soil, while only a limited number of AOB, about 0.013 - 0.055 MPN mg^- 1 dry soil, was detected in the ancient paddy soils after incubation for one or two months in greenhouse. Rice cultivation without N fertilization decreased the number of soil AOB significantly, while rice cultivation with ammonium sulfate fertilization increased its number within a short period of time, but sodium nitrate fertilization did not show any significant effect on soil AOB. The present paddy soil was much lower than the ancient paddy soils in carbon-source utilization capability, and in Shannon index, Simpson index and McIntosh index of microbial community to a varying extent. Rice cultivation, however,significantly increased carbon-souree utilization capability of the microbial community as a whole in the present paddy soil, and raised the three indices therein up to the level of the ancient soils. The increase was slowed down by N fertilization. Rice cultivation and N fertilization did not significantly affect these functional diversity indices of the microbial community in the ancient paddy soils, and no significant difference was observed between the 3 320 a and 6 280 a ancient paddy soils.