Biodiversity of soil arthropods with emphasis on oribatid mites in three different tea agro-ecosystem with three different agronomical practices in Assam, India

Soil represents an important reservoir of biodiversity consisting of various forms of life and role in promoting soil health and fertility. The present study was undertaken to explore the diversity and seasonal occurrence of soil arthropod mesofauna with emphasis on oribatid mites in three different tea agro-practicing gardens viz., conventional, organic and biorational approaches located in Assam. Periodical survey was carried out for a period of two years (August 2016–July 2018) and the soil arthropods were extracted, preserved, counted and identified. Oribatid mites were recognized as the most numerically dominant group of arthropod mesofauna in tea soils. A total of 40 species of oribatid mites belonging to 19 families were recorded in the present work. Population of oribatid mites exhibited a fluctuating trend being higher in post-monsoon period (October–November), slightly declined in monsoon (June –September), then in winter (December–February) and was sharply declined during summer (March–May). The Shannon diversity index (H) was found to be appreciably high in organic tea garden (3.08) followed by biorational tea garden (2.8) and conventional tea garden (2.72).