施肥和土壤管理对土壤微生物生物量碳、氮和群落结构的影响

以中国科学院沈阳生态试验站的长期定位试验为平台,研究了不同施肥和土壤管理对潮棕壤微生物生物量碳、氮和群落结构的影响。结果表明,裸地和农田处理的微生物生物量碳、氮较低,但是农田处理下施肥增加了微生物生物量,其中NPK+M效果最明显。DGGE图谱显示,处理间细菌条带分布较相似,其中裸地的细菌多样性最高;长期施肥和土壤管理改变了土壤真菌群落结构,施肥增加了真菌多样性,且有机肥的影响大于化肥;不同处理间氨氧化细菌群落结构差异显著,NPK+M显著增加了氨氧化细菌多样性,且无机肥和有机肥对氨氧化细菌群落影响不同。施肥和土壤管理对细菌影响较小,但显著改变了真菌和氨氧化细菌的群落结构。聚类分析结果显示,土壤管理措施较施肥对细菌、真菌和氨氧化细菌群落的影响更为显著。

Effects of fertilization and soil management on microbial biomass and community BI Mingli1,2, YU Wantai1,*, JIANG Zishao1, ZHOU Hua1, SHEN Shanmin1

Based on a field study of the aquic brown soil in the suburbs of Shenyang City in Northeast China over a consecutive 19 years, the effects of fertilization and soil management on the microbial biomass (C and N) and communities were investigated. The results showed that microbial biomass of the bare land and farmland was low. Fertilization increased the microbial biomass, especially when mineral fertilizers and pig manure (NPK+M) were applied. DGGE fingerprinting indicated a high similarity in the distribution of most bacterial bands among all treatments, and the bacterial diversity of the bare land was the highest. There were significant variations of fungal community structure among different treatments. Long-term fertilization increased fungal diversity and manure was more effective than mineral fertilizer to increase fungal diversity. Long-tem fertilization and soil management had a large effect on the ammonia-oxidizing bacteria structure in soil. Moreover, manure and mineral fertilizer influenced the ammonia-oxidizing bacterial communities in different ways. When applied together NPK+M increased the diversity most significantly. On the contrary, fertilization and soil management had less effect on the bacterial communities. Cluster analysis suggested that soil management practice had a larger effect on the community structures of bacteria, fungi and ammonia-oxidizing bacteria than fertilization.