Earthworm Casting Activities Under Bamboo Plantations of West Tripura, India and their Impact on Soil Physicochemical Properties

Earthworm casting activities under five species of bamboo plantations of West Tripura, India and their physicochemical relationship with the surrounding soil were studied for two successive years (2016 and 2017). Annual cast production in the bamboo plantations of West Tripura was 42,620 kg ha^–1 year^–1. Maximum casting activity occurs in summer followed by monsoon which is statistically higher than (P < 0.05) in winter. The amount of cast production and its monthly variation strongly correlated (r = 0.60, P = 0.008) and coincided with the amount and pattern of rainfall in West Tripura. The optimum temperature range for maximum casting was between 26°C and 27°C. Amount of cast produced had strong positive correlation with soil moisture (r = 0.56, P = 0.003) and negative correlation with soil temperature (r = –0.55, P = 0.004). Casts in general were significantly richer (P < 0.05) in different physicochemical parameters (moisture, pH, available N, P, K, etc.) than the surrounding soils.