The interactions between crops, the soil, and the living organisms play important roles in sustaining our farms. Regarding the living organisms, earthworms are among the most visible and essential.
Earthworms play a fundamental role in maintaining the productivity of the soil. Their activities can help improve various soil properties and increase yield. It’s therefore important that your management practices favor, rather than hurt, these important organisms.
Here are some practices that can help stimulate earthworm populations in your field:
A larger population of earthworms is present in no-till fields compared to clean-tilled ones. Soil tillage brings the organisms to the surface where predators can get them. The practice also buries crop residue and manure and stimulates fluctuations in soil temperature. No-till farming allows earthworms to stay underneath the surface and continue nurturing the soil by providing adequate aeration.
Retaining crop residue
Earthworms will lose their food source if you always remove crop residue. It’s a good management practice to leave a cover crop in the field or at least leave a part of the commercial crop to feed earthworms. The process also yields a potent natural fertilizer.
Some plants produce minimal crop residue. In addition, crop residues from plant species, such as legumes, are more palatable to earthworms than crop residues from mature grasses and grains. Crop rotation involves plating a different type of crop after every production cycle. This practice provides soil organisms with a diverse diet, as well a supply a variety of nutrients to the soil that will benefit the plants.
Manure application and organic practices
Manure, sludge, and compost are good food sources for soil organisms. Manure also makes some crop residue more palatable to earthworms. Accordingly, earthworm populations usually increase after manure application and other organic practices.
As earthworms burrow and feed on organic matter, they improve soil quality for increased agricultural production. They promote better water infiltration, soil aeration, soil compaction, soil tilt, and soil PH. Earthworms can help create a favorable environment for beneficial microbes in the soil, as well as control nematodes.