中文摘要：

对中国科学院红壤生态实验站长期定位试验中不同施肥处理红壤水稻土磷脂脂肪酸（PLFA）特性及酶活性进行了分析．结果表明：不同施肥处理的土壤酶活性、养分、微生物生物量及微生物群落多样性差异较大；施肥处理增加了PLFA的种类和微生物量；施肥土壤的真菌PLFA量大于不施肥土壤，细菌PLFA量小于不施肥土壤，说明真菌较细菌更能适应养分贫瘠的条件．NPK平衡施肥和施有机肥处理的PLFA总量均高于施无机氮肥和未施肥处理，两者分别比未施肥处理高222％和79％，表明NPK平衡施肥和施有机肥更有利于作物生长．施肥还可增加土壤酶活性，其中，土壤脲酶和磷酸酶活性可以作为衡量土壤肥力水平的指标．

英文摘要：

Soil samples were collected from the paddy fields at the Ecological Experimental Station of Red Soil, Chinese Academy of Sciences under different treatments of long-term fertilization, and their phospholipid fatty acids （PLFAs） and enzyme activities were determined. The results showed that soil enzyme activities, nutrient contents, microbial biomass, and PLFAs varied greatly with different fertilizations. Fertilization increased the kinds and amount of soil PLFAs. Compared with fertilized soil, unfertilized soil had more fungal PLFAs but less bacterial PLFAs, indicating that fungus was more adaptable to infertile soils than bacteria. Soils applied with NPK and organic fertilizer had higher amount of total PLFAs, which was 3.22 and 1.79 times higher than that under N fertilization and no fertilization. It was indicated that balanced fertilization with NPK or applying organic fertilizer was more beneficial to the growth of plants. Fertilization could also increase soil enzyme activities, and soil urease and phosphatase activities could be used as the indicators of soil fertility.