Population dynamics of earthworms during crop rotation under rainfed agriculture in Central Himalayas, India

Abstract

The density and seasonal distribution patterns of three to five earthworm species was observed in relation to crop rotations during a period of 2 years in three localities ((a) Sun temple site; (b) Small tank site; (c) Dak bunglow site) in the rainfed upland agricultural system of central Himalayan district of Almora, India. Earthworm species composition at Sun tample site was different from the Dak bunglow site and Small tank site. Drawida sp. was dominant at the Sun tample site whereas Lennogaster yeicus and Metaphire holutii were dominant at the Dak bunglow site. Maximum earthworm density (200 m^-2) was recorded in the late rainy season in the rice crop mixture and in Eleusine coracana (finger millet) crop mixture (335 m^-2) sown following the harvest of winter wheat crop. Ploughing, harrowing and cult-discing the soils in the agricultural system during crop rotation had adverse effect on earthworm species populations. Ploughing back of crop byproducts along with the addition of the organic manure encouraged increase in the earthworm populations.