中文摘要：

测定了浙江慈溪5个不同利用年限旱作农田土壤（50～700a）的微生物数量、生物量和酶活性,比较分析了农田土壤微生物学质量与利用年限的相关性,并测定了50a、100a和700a3个旱作土壤的微生物功能多样性.结果发现：农田土壤在旱作初期（〈100a）,除真菌数量（F）略有上升外,细菌数量（B）、B/F值、微生物生物量C、N及过氧化氢酶、转化酶、脲酶活性全部锐减;耕作100a之后,仅真菌数量随年限延长而显著降低,细菌数量、B/F值、微生物生物量C、N及过氧化氢酶、转化酶、脲酶活性则全部升高;在50～700a的整个旱作过程中,土壤微生物生物量C/N值始终随年限延长而显著升高.BIOLOG检测结果显示,旱作农田土壤微生物群落的Shannon、Simpson和McIntosh3种功能多样性指数在利用年限上的变化规律与细菌数量、微生物生物量及酶活性等完全一致.表明浙江慈溪旱作农田土壤微生物群落结构一直随利用年限的延长而变化,且土壤微生物学质量总体在持续利用100a左右止降回升.

英文摘要：

The microbial number, microbial biomass, and enzymatic activities m lave uplano soils under agricultural utilization for 50-700 years were determined, with the correlations between soil microbiological characteristics and agricultural utilization duration analyzed. In the meantime, the functional diversity of microbes in soils having been utilized for 50, 100, and 700 years were investigated. The results showed that at the early stage （ 〈 100 years） of agricultural utilization, the number of soil fungi （F） had a slight increase, while the bacterial number （B）, B/F ratio, microbial biomass C （Cmic ） , microbial biomass N （Nmic ）, and the activities of catalase, invertase and urease all decreased markedly. After utilized for more than 100 years, the F decreased significantly, while the B, B/F ratio, Cmic, Nmic, and the activities of test enzymes all tended to increase. During the whole utilization period from 50 to 700 years, the Cmic/Nmic ratio had a significant increase with year. The Shannon, Simpson, and McIntosh indices of soil microbial community had the same responses to the agricultural utilization duration as the bacterial number, microbial biomass, and enzymatic activities. All of these indicated that in the upland fields in Cixi of Zhejiang Province, shifts of soil microbial community occurred with increasing agricultural utilization duration, and soil microbiological quality had an overall increase after 100 years agricultural utilization.