不同施肥处理对水稻土微生物生态特性的影响

Effect of different fertilizer treatments on ecological characteristics of microorganism in paddy soil

采用室内恒温培养研究不同施肥处理水稻土微生物生物量C、微生物数量、群落结构的变化特征.发现施秸杆(RS)和施厩肥(PM)处理的微生物生物量C明显高于不施肥(CK)和施化肥(CF)处理(P<0.05).不同处理微生物生物量C在培养期内都呈现出先上升后下降的趋势,但达到峰值时间不同.施用有机肥后土壤中细菌、真菌数量明显增加,放线菌数量略有减少.应用磷脂脂肪酸(PLFA)法分析微生物群落结构,发现不同施肥处理条件下,各个单体磷脂脂肪酸的相对百分含量有明显差别,其PLFA谱图差异很大.表征细菌、真菌、放线菌的磷脂脂肪酸相对含量在各个施肥处理中有明显的不同.CK和CF处理的G+/G-值显著高于RS和PM处理(P<0.05).主成分分析结果也表明微生物群落结构发生了很大改变,施肥对水稻土微生物生态特征产生了明显的影响.

The effect of fertilization on ecological characteristic of soil microorganism was studied in thermostatic culture.The results showed that microbial biomass carbon were significantly higher in RS and PM treatment compared to the CF or CK（P〈0.05）.During the 14 to 42 days incubation,the microbial biomass carbon reached their maximum values in the four treatments separately and then started to decline.Plate counts also supported that there were more microorganisms in organic treatments than that in CF and CK.The relative amounts of PLFAs obviously were different among the four treatments and fertilization may increases the PLFA biomarkers for bacteria and fungi,while reduced actinomycetes.The ratio of G^＋/G^- was significantly higher in CK and CF compared to the RS and PM（P〈0.05）.The results of principal component analyses（PCA）indicated that the composition of microbial community were also altered by different fertilization treatment.All of the results illuminated that the fertilization had impact on the microor ganism community structure and the ecological characteristics in paddy soils.