Impact of Land Uses on Microbial Biomass C, N, and P and Microbial Populations in Indian Himalaya

Abstract

Changes in land use affect microbial biomass carbon (MBC), nitrogen (MBN), and phosphorus (MBP), and microbial populations, important parameters to sustain ecological systems. MBC, MBN, MBP, and microbial populations vary markedly among land uses and with conversion of one land use to another. A literature survey suggests that forest lands have favourable influence on MBC, MBN, MBP, and microbial populations, followed by agroforestry, silvipasture, and agriculture, respectively. Microbial quotients also vary with land use and have strong positive correlations with MBC, MBN, and MBP. It is well established that population pressure is causing the conversion of forest lands to non-forest purposes. This conversion of forest land to agriculture and other uses affects the quantity of MBC, MBN, MBP, and microbial populations. The ratio of MBC to soil organic carbon (SOC), MBN to total N, and MBP to total P varies significantly. The soil microbial biomass (SMB) is lively and active in regulating the transformation of soil organic matter (SOM). These activities are vital for the cycling of nutrients in the soil. In general, the increased level of microbial biomass in the soil is beneficial and a decreased level is seen as harmful, provided it should improve or decrease the functional biology of the soil. Interpretation of soil microbial biomass parameters is very difficult. Here, we have tried to explain the importance of microbial biomass, its role and measurement, including examples from Indian Himalaya.