Soil as part of the Earth system

The idea that soil or the pedosphere is connected to the other terrestrial spheres dates back at least to 1880. Some 26 years later, the interdependency of the terrestrial spheres was established, but a fully integrative approach to addressing the interdependence of the biosphere, pedosphere, atmosphere, hydrosphere, geosphere, and toposphere did not emerge until the advent of Earth Systems Science during the 1980s. A significant development within the Earth Systems approach was a re-evaluation of the pedosphere’s role in the global system, the outcome of which is at least twofold: first, an appraisal of the pedosphere as a two-way interactor with the other terrestrial spheres, the study of which has given rise to some “new” pedologies—biopedology, geopedology, topopedology, hydropedology, and anthropopedology; and second, the pedosphere as a key component of what has become known as the Earth’s Critical Zone. The background, current status, and prospects of these hybrid pedologies and the extent to which they truly deal with interdependencies within the environment are the focus of this article.