Effect of land use, season, and soil depth on soil and microbial biomass stoichiometry in northwestern Himalaya, India

Abstract The stoichiometry of soil and microbial biomass carbon, nitrogen and phosphorus are crucial for understanding the soil dynamic fluctuations and plays a major role in nutrient cycling of any terrestrial ecosystems. Land use significantly influences soil attributes and the impacts of climatic and edaphic conditions as well as land-use change on soil and microbial biomass properties are still unclear. However, the effects of land use, seasonal variation, and soil depth on soil physico-chemical characteristics and microbial biomass dynamics remain poorly understood in the north western Himalaya. This study investigated physico-chemical and microbial biomass properties of soil and their relation with several factors including soil depth, land use and seasonality. Composite soil samples at two different depths (0–15 and 15–30 cm) were sampled from three different land-use systems (mixed oak-pine forest, agricultural land and tea garden) in every season (summer, rainy and winter). Mixed oak-pine forest showed maximum values of soil properties in the rainy season followed by agricultural and tea garden. Principal Component Analysis (PCA) revealed a significant positive impact of different factors on soil and microbial biomass stoichiometry with eigen values of 8.6 and 2.0 respectively. Our results indicate that all these trends seem to be distinct to 3 different land use systems and may have an impact on the ecological functioning by promoting microbial diversity and soil fertility through the immobilization of nutrients in the Himalayan region.