Effect of different vegetation restoration models on soil microbial characters in the gully region of Loess Plateau

【Objective】 The study was to find the effect of different vegetation restoration models on soil microbial characters and to provide scientific basis for assessing the ecological effects of Grain for Green.【Method】 Soil physiochemical properties,microbial biomass enzyme activities in the soil under Platycladus orientalis,Vitex negundo,Robinia pseudoacacia,Medicago sativa L were studied,compared with the wheat land in Ranjiagou Catchment at the Qianyang county of Shaanxi province in China.【Result】 Soil physiochemical properties,microbial biomass enzyme activities increased apparently compared with the farmland.After different vegetation recoveries,soil microbial biomass C,N,P(SMBC,SMBN,SMBP) respectively increased by 254.78%-35.72%,112.67%-6.8% and 115.03%-5.3% as compared with the farmland.Soil enzyme activities also increased.The activity of soil Catalase,Alkaline phosphatase,Ureases and invertase all increased along with the vegetation rehabilitation ages by 95.84%-18.94%,119.51%-20.36%,229%-20% and 250%-73% as compared with the farmland.The change of soil microbial characters bettered the soil physiochemical properties.Soil microbial biomass C,N,enzyme activities were positively related to soil organic carbon,total nitrogen,suggesting that soil microbial biomass,enzyme were closely correlated with soil fertility and plant restoration could indirectly influence soil microbial characters.【Conclusion】 Different vegetation restorations had different effects on soil microbial biomass and enzyme activities,they were critical for the improvement of soil physiochemical properties and microbial properties,the eco-effect of Robinia pseudoacacia was the best.