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土壤微生物群落被认为是土壤生态系统变化的预警及敏感指标,指示着土壤质量的变化。本研究利用3年定位试验,通过测定磷脂脂肪酸(PLFAs)的含量,分析了连年绿肥和化肥配施对植烟土壤微生物群落结构的影响。研究结果表明:施肥明显地提高了土壤中PLFAs的种类和总量;在绿肥和化肥配施处理中,当翻压15 000 kg/hm2绿肥的基础上施用大于85%常规化肥时,明显提高了土壤中细菌、AM真菌及微生物总的PLFAs含量;而当化肥的施用量减至常规施肥70%时,对土壤细菌、真菌及微生物总PLFAs含量的积累产生不利影响。从不同处理的主成分分析和聚类分析的结果可知,不同绿肥和化肥配施比例对土壤微生物群落结构变化有明显影响。经相关性分析表明,PLFA分析方法和氯仿熏蒸法之间具有很好的一致性,且土壤速效钾和速效磷含量与革兰氏阴性菌的PLFAs含量呈显著相关,而与土壤真菌PLFAs含量则无明显的相关性。
Soil microbial community is considered as an early warning and sensitive indicator of soil ecosystem changes, indicating the change of soil quality. In this study, the effects of green manure and chemical fertilizers on the microbial community structure of tobacco were analyzed by measuring the content of phospholipid fatty acids (PLFAs) by using 3-year experiment. The results showed that: fertilization significantly increased the types and total amount of PLFAs in soil; when green manure and chemical fertilizer were applied, the application of more than 85% conventional fertilizers significantly increased when the green manure of 15 000 kg / hm2 was turned over The total PLFAs content of bacteria, AM fungi and microorganisms in soil, while when the application rate of fertilizer reduced to 70% of the conventional fertilization, the accumulation of total PLFAs in soil bacteria, fungi and microorganisms was adversely affected. From the results of principal component analysis and cluster analysis of different treatments, we can see that the proportion of different green manures and chemical fertilizers have a significant impact on the changes of soil microbial community structure. Correlation analysis showed that there was a good consistency between PLFA analysis method and chloroform fumigation method, and the contents of available potassium and available phosphorus in soil were significantly correlated with the PLFAs contents of Gram-negative bacteria. However, No obvious correlation.