The term earthworm is used to refer to any of the larger species included in 16 families under the subclass of animals known as Oligochaeta. The smaller species in the same subclass are generally referred to simply as worms or as microdriles, whereas earthworms are classified as megadriles. Earthworms are also known by several colloquial names, such as night crawlers, dew worms, rain worms and angleworms.
All life benefits from earthworms in one way or another. Some of those benefits are as follows:
- Earthworms aerate the soil, keeping it soft, lush and with adequate drainage. Golf courses add worms to the soil to provide for an optimal playing surface.
- Earthworms distribute nutrients throughout the soil, making the nutrient content of deeper soil homogenous with the soil near the surface. Studies show that soil rich in earthworm excretions, or casts, have five times more nitrogen and seven times more phosphates than soil without casts. In one year, a single earthworm may produce as much as 10 pounds of casts.
- Earthworms not only distribute nutrients, but they help nutrients to form by aiding in the decomposition process. The faster plant material decomposes, the faster the nutrients get into the soil.
The Earthworm Market
Earthworms are big business in the gardening and organic farming industries. Many species are used in composting and in soil preparation. Earthworms are also farmed and bred for use as fishing bait. Some earthworm species are so desirable that a market has sprung up for earthworms that are only used for breeding purposes. In addition, earthworms are used in many types of animal feed to increase protein content. Many earthworms are shipped out of Canada, but they are also farmed in the United States and around the world.