中文摘要：

研究不同施肥处理与季节更替条件下黑土微生物群落结构与活力,揭示影响黑土肥力质量的重要因素.以未施肥耕作（CK）与休闲（fallow）处理为对照,研究不同季节有机肥（MCK）处理与氮磷钾肥配施（NPK）处理对土壤微生物群落数量与结构影响,测定微生物量碳（氮）（Cmic或Nmic）及不同菌群磷脂脂肪酸（PLFA）含量.结果表明,有机肥处理显著提高土壤养分、Cmic及各菌群PLFA含量;休闲处理真菌PLFA（均值8.40 nmol.g^-1）、Cmic（均值322.5 mg.kg^-1）和Nmic（均值57.9 mg.kg^-1）等含量显著高于CK（分别为5.4 nmol.g^-1、152.6 mg.kg^-1、32.1 mg.kg^-1）或NPK（分别为3.5 nmol.g^-1、144.3 mg.kg^-1、30.7 mg.kg^-1）处理;NPK处理Cmic、Nmic及各菌群PLFA低于CK处理.相关分析表明,土壤各养分含量与Cmic、各菌群PLFA含量、G-/总细菌显著正相关,与G＋/G-显著负相关（p〈0.05）.PLFA的主成分分析表明,各季节不同施肥处理微生物群落结构显著不同.土壤基本理化性质显著受季节更替影响,耕作土壤与休闲处理微生物群落结构各自严格依取样时间而变化;Cmic于仲春最高（295.6mg.kg^-1）,而Nmic（49.3 mg.kg^-1）与各菌群PLFA含量则在夏季最高,Cmic（184.2 mg.kg^-1）、Nmic（30.63 mg.kg^-1）与各菌群PLFA含量在春季较低.施肥与季节更替显著影响农田黑土肥力质量及微生物群落结构、活力.

英文摘要：

Fertilization and seasonal variation play very important roles in affecting microbial structure and activity, as a result, leading to the significant evolution of soil fertility. The effect of manure （MCK） and combined application of chemical fertilizers （NPK） on soil microbial biomass and structure were studied by measuring soil microbial biomass carbon （nitrogen） and phospholipid fatty acid （PLFA） in different microbial communities ,with the nil-fertilization （CK） and fallow as controls. Results show the manure application significantly improves the soil nutrient contents and the amounts of Cmic and PLFA of different microbial communities. The amounts of fungal PLFA （8.40 nmol·g^- 1 ） and Cmic （322.5 mg·kg^-1） and Nmic（57.9 mg·kg^-1） are significantly higher than those of CK （5.4 nmol·g^-1, 152.6 mg·kg^-1, 32.1 mg·kg^-1, respectively） or NPK （3.5 nmol·g^-1, 144.3 mg· kg^-1, 30.7 mg·kg^-1, respectively）. And the contents of Cmic, Nmic and PLFA of different microbial groups in NPK are lower than those in CK. Correlation analyses show the soil nutrient contents are significantly positively correlated with Cmic, different microbial PLFA contents and G^-/total bacteria ratios, while negatively correlated with G^＋/G^- bacteria ratio （p 〈 0.05 ）. The principle component analysis of PLFA shows the microbial structures in different treatments and sampling dates are significantly different. Seasonal changes arc also found to cause great fluctuations in soil basic properties, and microbial community structure in arable soils and fallow respectively cluster strictly together by sampling dates. The amount of Cmic is highest on April 11 （295.6 mg· kg^-1 ）, while Nmic （49.3 mg· kg^ - 1 ） and PLFA contents are highest in summer （July- August ） ; the lowest amounts of Cmic （ 184.2 mg· kg^ - 1 ）, Nmic （ 30.63 mg· kg^ - 1 ） and PLFA exist on May 31. Fertilization and seasonal variations significantly affect soil fertility, microbial structure and act