Soil Microbial Biomass in Degenerated and Recovered Vegetation on Sloping-land with Purple Soils in Hengyang of Hunan Province,China

Soil microbial biomass was not only usually looked as transforming factors and pool of resource of nutritional elements needed by plants, but also a main index of development status and biochemical capacity of soils. In order to study the properties of soil microbial biomass in degenerated vegetation and recovered vegetation on sloping-land with purple soils in Hengyang of Hunan Province, China. Taking degenerated plant community(Ass. Setaria viridis) and recovered plant community(Ass. Liquidamdar formosana+Melia azedarach-Robinia pseudoacacia+Vitex negundo var. cannabifoloa-Chrysanthemum indicum+ Prunella vulgaris) in the region as test objects, soil samples from depths of 0~10 cm, 10~20 cm, 20~30 cm, 30~40 cm and 40~50 cm were collected to study the properties of soil microbial biomass through the combination of sample investigation and experimental analysis. The results showed that:(1) With the increase of soil depth, the total soil microbial biomass, bacteria and filamentous microbial biomass were followed the order as 0~10 cm soil layer10~20 cm soil layer20~30 cm soil layer30~40 cm soil layer40~50 cm soil layer(P0.05);(2) The soil microbial biomass in recovered vegetation was significantly higher than that in degenerated vegetation(P0.05);(3) The soil microbial biomass was significantly and very significantly correlated with SWC(Soil water content), SBD(Soil bulk density), SOM(Soil organic matter) and SMB(Soil microbial biomass)(P0.05 or P0.01). All the results indicated that recovered vegetation was beneficial to the increase of soil microbial biomass and improvement of soil quality.