土壤微生物生物量在团聚体中的分布以及耕作影响

了解土壤微生物在土壤结构体内部的分布对于预测相关的土壤生物化学过程具有重要意义。由于气候、土壤以及耕作的影响，该领域的研究结果存在很大的空间和时间变异，因此有待进行更多的在不同气候和土壤类型下的研究。首次报道亚热带紫色水稻土中微生物生物量在长期不同耕作方式的土壤中不同水稳性团聚体中的分布特征。结果表明微生物生物量在紫色水稻土水稳定性团聚体中的分布模式决定于土壤结构本身，而耕作方式的影响不显著；微生物生物量碳在不同粒级土壤团聚体中无显著性差异，微生物生物量氮与可溶性有机碳在0．25～0．053mm微团聚体中含量最高；垄作免耕显著提高土壤团聚体中的微生物生物量及可溶性有机碳含量，而对微生物生物量及可溶性有机碳在土壤团聚体中的分布模式无显著影响。

Distribution of soil microbial biomass within soil water-stable aggregates and the effects of tillage

The distribution of soil microbes within soil aggregates is helpful to predict some essential soil biochemical processes. Results varied spatially and temporally because of factors such as climate, soil type, texture and dominant mineralogy as well. Therefore, further research under different climatic conditions and in different soil types needs to be carried out. The paper firstly reported the distribution pattern of microbial biomass in different sizes of water-stable aggregates under long-term different tillages in a subtropical purple paddy soil. Results showed that the distribution pattern of microbial biomass within water-stable aggregates depended on the structures of aggregates themselves, whereas tillage methods had no significant effect on it; Microbial biomass C had no significant differences among soil aggregates while microbial biomass N and water-soluble organic carbon are maximum in the 0.25-0.053mm microaggregates; Combing bridge and no-tillage remarkably increased the content of microbial biomass and water-soluble organic carbon, but had no significant effect on the distribution pattern of microbial biomass and water-soluble organic carbon in soil aggregates.