The Effect of Earthworms on Soil

Earthworms are beneficial to gardens.

Earthworms are very beneficial to the soil, and boost plant production by improving the fertility and structure of the soil. An active earthworm population stimulates the growth and development of beneficial organisms, which reduces the parasitic nematodes in soil.

Feeding on Soil

Earthworms tunnel into the earth, and feed while they do it. The worms swallow debris such as leaf and grass matter that if left alone could damage the soil.

Tunneling

Earthworms will pull organic matter deep into a garden's soil.

Earthworms create many tunnels, which allow air and water to penetrate into the soil.

Speeding Up the Breakdown

Earthworms also pull organic matter from the surface deep into the soil. This action speeds up the breakdown and rotting of plant material, which speeds up the rate at which nutrients are supplied to the plants.

Kitchen Waste

Earthworms will also finish off kitchen waste such as vegetables, fruit and coffee grounds that are tilled into the soil or compost pile.

Fertilizer

Castings are excretions left behind by the worms. The castings are high in plant nutrients and organic matter and serve as a rich fertilizer.

References

• Michigan Department of Agriculture
• Colorado State University

Resources

• University of Wisconsin Urban Horticultural website.