Earthworms and farmed worms The best medium for growing healthy
plants is a rich, loose, and fertile soil. Earthworms make a
significant contribution by loosening the soil and providing
plant nutrients in their droppings. When they burrow, worms
aerate the soil to provide essential oxygen for bacteria, fungi,
and other micro-organisms required for soil fertility. An
earthworm can digest approximately half its own bodyweight of
soil each day. Given that average populations number hundreds of
worms per square metre, the combined effect will be the
processing and movement of large volumes of earth each year.
Earthworms concentrate essential nutrients and minerals from
soil as it passes through their digestive tract. Their expelled
waste, also known as cast, contains many times the nitrogen,
phosphorus, and potassium that is normally available from soil.
Additionally, these casts will contain higher concentrations of
minor elements such as calcium, magnesium, and zinc. All of
these nutrients and minerals are prov