Spring brings a sense of renewal and new life. Farmers are in the fields planting, people are buying flowers for their garden, and earthworms are working to keep soil quality top notch.
Earthworms are not necessary to have in soil, but if they are present, it is a good indication that the soil they inhabit is healthy and nutrient-filled. There are over 7,000 species of earthworms, but they are separated into three varieties: Litter, Topsoil, and Subsoil dwellers. Litter dwellers live in crops or forest litter, and usually not in agricultural fields. Topsoil dwellers live, as stated, in the topsoil, surviving on materials decomposing within. Subsoil dwellers have permanent burrows 5 to 6 feet deep. They will go to the surface for food sources, but return below the soil.
These beneficial creatures are major decomposers of organic matter. In farm fields, they feed off of crop residue, bacteria, and fungi in the soil. The materials are digested and excreted in casts. Casts are the feces of earthworms; they show up on the soil surface in little piles. Casts are nutrient-rich, containing high nitrogen, phosphorus, and other mineral levels. The earthworms’ digestive process also gives casts healthy microbes and a neutral PH.
Not only to they improve soil quality, but they help to aerate it by creating paths and burrows to move around. Aerating the soil reduces compaction, and allows areas for water to drain more effectively. Earthworms can shred, mix, and move the soil around very effectively. They can turn over the top 6 inches of soil in 10 to 20 years.
“Earthworms.” PennState Extension
Edward, Clive. “The Living Soil: Earthworms.” USDA