Effects land-use types on soil microbial characteristics and carbon density in the loessial hilly-gully region
DONG Li-li1, ZHENG Fen-li2,3*
(1 College of Tourism and Environmental Sciences, Shaanxi Normal University, Xi′an 710062, Shaanxi, China; 2 College of Resources and Environment, Northwest A&F University, Yangling 712100, Shaanxi; 3 Institute of Soil and Water Conservation, Chinese Academy of Science and Ministry of Water Resource, Yangling 712100, Shaanxi, China)
Abstract:
Soil microbial biomass C(MBC), microbial biomass N(MBN) and microbial biomass P(MBP) under different land-use types in the loessial hilly-gully region were measured by the fumigation-extraction method. Soil organic carbon and bulk density were measured by the traditional method and soil organic carbon density(SOCD) was calculated. Results indicate that microbial C ranges from 84.14 to 512.78 mg/kg, microbial N from 4.29 to 41.83 mg/kg and microbial P from 3.40 to 12.39 mg/kg. The MBC/SOC ranges from 2.84% to 7.83%. And the soil respiration (SR) ranges from 55.43 to 140.37 mL/kg. Soil microbial biomass are markedly correlated with soil organic carbon and SR, which indicate that MBC is not only the sensitive index of SOC but also indicating soil microbial activities. The conversion of cropland into planted forest land and grass land resulted in a remarkable increase in the amounts of microbial biomass and soil organic carbon density, especially in the topsoil.
KeyWords:
land-use type; soil microbial biomass; soil organic carbon density; the loessial hilly-gully region
