Impact of Land Use Types and Seasonal Variations on Soil Physico-chemical Properties and Microbial Biomass Dynamics in a Tropical Climate, Ghana

Abstract

Land use conversion significantly impact on sensitive soil quality parameters such as microbial biomass and soil microbial quotient. Therefore, soil microbial biomass and physicochemical properties were compared under three different land use systems namely agricultural land, degraded mine land and an adjacent natural forest in the Newmont Gold Ghana Limited concessional areas, Kenyasi, Ghana. In our field experimentation, an area of 300 m2 was demarcated in each land use type for soil sampling. In each of the land use type, we collected soil 5 samples at a depth of 0-15 cm in both the dry and wet seasons respectively. Parameters we measured included soil bulk density, pH, particle size distribution, organic carbon, total nitrogen, available phosphorus, microbial biomass carbon and nitrogen, and moisture content. Our results revealed that land use type significantly impacted on soil microbial biomass and physicochemical properties. Microbial biomass carbon and nitrogen was higher in the forested land compared to the agricultural land and degraded mine land, which was due to relatively higher amounts of litter inputs. Microbial biomass carbon decreased between 20.23 - 88.36% when land use changed from forested land to other land uses. Significant positive correlation was observed between soil microbial biomass and water content, soil organic carbon, phosphorus, clay, nitrogen. Generally, seasonal variation in our study area did not influence soil physical and chemical properties, however, it significantly affected microbial biomass indices. Findings of our study further revealed the importance of forested area in the maintenance of soil quality parameters.