Earthworms are sensitive soil-dwelling organisms that thrive in moist soils. They only live in damp environments because the moisture helps them maintain mucus secretions on their skin, through which they breathe. Without moisture, the worms will lose up to 20% in body weight each day until they dry up and die. Although earthworms don’t have eyes or ears, they are sensitive to vibrations and have light-sensing tissues on their heads that allow them to detect light.
If you have earthworms on your farm, it’s a good sign that your soil is suitable for plant growth. Earthworms like balanced soil that is not too dry, wet, hot, cold, acid, or alkaline. Places like paddy fields with pools of water are unlikely to have earthworms.
To keep a healthy earthworm community on your farm, you should:
- Make sure there is enough dead or decaying plant matter on or in the soil for the worms to feed on. This can be done through mulching or just letting plants drop their leaves to decompose on the soil.
- Reduce the use of acidic fertilisers and fungicides such as ammonium sulfate.
- Avoid constant human, animal, and vehicular traffic in areas where earthworm communities live. The soil will get too compacted for earthworms to move.
- Reduce heavy tilling. Digging up the soil with heavy machinery can drive earthworms away.
- Make sure that the soil has a continuous supply of calcium.
In undisturbed soils, which are free from heavy tilling and synthetic chemical fertilisers and pesticides, earthworm populations can grow very quickly into large numbers.