A review of earthworm impact on function and ecosystem …
from various land-use types under temperate climate conditions suggest that the amount of brought to the surface by earthworms annually as castings is about 40 t ha −1 year −1 (based on 19 studies), contributing about 0.4 cm (based on 13 studies) of topsoil per year. Under a temperate climate, earthworms can thus potentially ...