Does rise in temperature adversely affect soil fertility, carbon fractions, microbial biomass and enzyme activities under different land uses?

摘要

We studied the variable dynamic response of different soil properties under the exposure of three elevated temperature treatments on six land-use systems. After one month of incubation, the associated changes were measured in terms of soil fertility, carbon, microbial biomass and soil enzymes. Our results confirmed the significant increase (P 0.05) in soil available nitrogen content (by 1.85-49.32%) with the subsequent rise in incubation temperature for soils collected from orchards and agriculture land uses. We observed a steady decrease in total organic carbon (TOC) levels with increase in incubation temperature varying between 4.1% and 31.4% (P 0.05) across different soil types and land-use systems, resulting in a significant rising trend for microbial biomass carbon and labile carbon : TOC ratio up to 3 degrees C elevation from maximum temperature. Among the soil enzymes, dehydrogenase, fluorescein diacetate hydrolase and beta-glucosidase activity increased significantly with increase in incubation temperature from the ambient temperature, while acid phosphomonoesterase and arylsulphatase activity decreased. Our current research findings will provide new insights regarding temperature control on soil C dynamics and nutrient availability in terms of modified soil enzyme activity that will be useful to model the dynamics of soil organic matter and associated nutrient availability in acid soils.