Soil Is the Skin of the Planet Earth

Abstract

We have mentioned earlier in the introductory chapter that recent soil scientists like to say in their scientific jargon that the soil is a sort of skin to our planet Earth. When we have now more space and the reader has more time, we can afford the luxury of going into some details. First, this comparison is not exact because we mammals are born with skin, have it at the beginning of our existence, and continue to have skin throughout our lives even if it is not in perfect condition upon death. Hearing the parable about Earth’s skin, others may deduce that soil and the Earth were created simultaneously. Such a conclusion is not valid. The soil, or the Earth’s skin as we used to say, started its existence when macroscopic life was moving from oceans to the mainland, to the surface of continents and islands. This migration was happening roughly 500 million years ago – maybe even a little bit earlier. It was the time of Earth’s adolescence and certainly not immediately after the birth of our planet. During this period, various kinds of proto-soils gradually began to uniquely develop and slowly appear at diverse locations. Before this time, only weathering fragments and remnants from rocks – stones, gravels, sands, and even clays – scattered across continental surfaces, completely void of any action by living macroorganisms. Without the contributing actions of these organisms, a soil cannot exist. Although some microorganisms, mainly bacteria, were thriving at that time, their contribution to the transformation of the weathered inorganic rocky material was negligible and has not been documented. As our initially skinless planet aged, an outer jacket of soil eventually became a reality owing to the essential actions of macroscopic life. Real soil does not exist without such a living community.