Earthworms are important for soil fertility and sustaining agriculture. They play an imporatnt role in the creation of healthy, productive soils. Bascially, earthworms feeding and burrowing activities incorporate organic residue and amendments into the soil, enhancing decomposition, humus formation, nutrient cycling, and soil structure development. Earthworm burrows persist as macropores, which provides low resistence channels for root growth, water inflitration, and gas exchange.
These incredible earthworms are a vital component in the living biosystem that is healthy, "living" soil. Studies found that the introduction of earthworms to areas not previously populated has led to improvements of soil quality and productivity in New Zealand grasslands, on drained Dutch polders, in heathlands in Ireland, and in mining spoils in US.
Studies also show that worms hatched in an new environment are able to better adapt than transporting and releasing worms. Thus, using cocoons is an effective and efficient way to increase the worm population in your farm or garden.