Its magma core breaks the surface to form volcanos and fluid still allows some shift in its tectonic plates, we record as earthquakes. Much of the land mass, about a third of the earth's surface, is either desert waste or too mountainous to permit significant vegetation, so man builds on the relatively few accessible surfaces. How he administers these crucial areas defines his lifestyle and will determine his survival. Earth's crust available to vegetation is relatively thin, broken here and there by core rock projecting through the surface. Soil, that surface rock already pulverized by sea and river, the tug of freeze and thaw, the split of vegetation's roots, is precious.
Biologists estimate it takes a million years to produce one inch.
The forest floor is a living, breathing factory of life and death. The outreaching roots of a great tree seek from that chemical stew we call soil, not only moisture but all those elements it needs, while its solar panels, or leaves, exchanging both carbon dioxide and oxygen, assemble the molecular pieces. Years later, when this aged giant has completed its cycle and falls, crashing to earth, those very organisms and creatures which sustained it in life will gradually disassemble its biomass, returning to the soil those molecules which the next generation of seedlings, already sprouting, eagerly await. Primitive man learned early on he could not take season after season the grains, fruits and other crops from land he tilled unless he gave back some of the building blocks from which his harvest was constructed. From trial and error he learned to rotate crops, to plow under certain plantings and add the droppings of animals and birds as he worked the soil.