The soil as an ecosystem

In: Biology and Fertility of Soils, 2015, 51(6), pp.645-648. Can soil be considered as just a component of terrestrial ecosystems and agroecosystems or is it an ecosystem in itself? The present piece of opinion suggests that we should refer to the original definition of the ecosystem given by Tansley and apply it to the soil viewed as a multi-scale assemblage of ecological systems.