Monthly Variation in the Density of Drawida willsi (Michaelsen) in Relation to some Climatic and Edaphic Factors

Fluctuation of population density of the earthworm Drawida willsi (Michaelsen) in relation to some climatic and edaphic factors was assessed from a tropical cropland agroecosystem site at Ranchi for a period of eighteen months. The total density ranged between 75 ± 25.49 (April 2010) to 2115 ± 189.87 m^-2 (August 2010). Of the various factors studied rainfall, relative humidity, soil moisture, organic carbon and nitrogen content of the soil showed a significant positive correlation with the total earthworm density. Moisture content of the soil was considered to be the most important single factor responsible for the population fluctuation of the earthworm.