接种蚯蚓对加入不同植物残体土壤微生物特性的影响

通过室内试验,研究不同类型土壤和植物残体施用下接种蚯蚓对土壤微生物群落组成及活性的影响,为将蚯蚓引入农田及水土流失区提供理论依据。供试土壤为黏粒含量较低的灰潮土和黏粒含量较高的典型红壤,供试植物残体为高碳氮比的玉米秸秆和低碳氮比的三叶草,供试蚯蚓为体型较大的威廉腔环蚓(Metaphire guillelmi)。结果表明:接种蚯蚓对微生物量碳(MBC)无显著影响;不同土壤无论是否施用植物残体,接种蚯蚓均使土壤基础呼吸(BR)显著增大,尤其是不施用植物残体时;两种土壤中不施用植物残体和施用三叶草时,接种蚯蚓均使代谢熵(qCO2)增大,而施用玉米秸秆接种蚯蚓使qCO2有下降趋势。Biolog孔平均颜色变化(AWCD)在接种蚯蚓时均增大,基质利用丰富度(S)和多样性指数(H)也增大,且未施用秸秆时的变化较为明显;主成分分析(PCA)表明接种蚯蚓后土壤微生物群落组成与结构发生了明显变化。土壤微生物群落特性变化受蚯蚓、土壤及植物残体间交互作用的影响。

Earthworm effects on microbial characteristics in different soils under different plant debris inputs

An experiment was conducted to investigate the effects of earthworm activity on soil microbial community structure and activity under different plant debris inputs in different soils, the soil macro-aggregate were destroyed completely before the start of experiment. A soil with high-silt content and a soil with high-clay content were chosen to be tested. The debris was maize straw with high carbon to nitrogen ratio and white clover debris with low carbon to nitrogen ratio while the earthworm used was Metaphire guillelmi for test. The results indicated that earthworm had no significant effect on soil microbial biomass carbon. Earthworm increased soil basil respiration (BR) significantly under different plant debris inputs in different soils, especially under no plant debris input. The qCO2 were increased at the presence of earthworm under no debris or white clover debris input, while the qCO2 were decreased at the presence of earthworm under maize straw input. The AWCD (average well color development) and substrate richness (S) and biodiversity index (H) were increased at the presence of earthworm, and the change was more obvious under no debris input. Soil microbial community structure changed significantly at the presence of earthworm. Earthworm had interactive effects on soil microbial characteristics with soil and plant debris types.