In the “final frontier” of soils, the vast diversity of living things is less well known than above ground. A teaspoonful of soil holds more kinds of microbes than there are people in the world. Who-eats-what can hold secrets and surprises.
Plants, rooted in soils, are the primary producers of food that sustains almost all life on Earth. By using the energy of sunlight to transform carbon dioxide from the air into energy-rich organic chemical compounds, plants set in motion soil food chains and intricate soil food webs.
Soils teem with life, yet myriads of organisms living in soil are intimately involved with death. Decomposers feed on the remains or waste by-products of other organisms. These living recyclers put the mineral nutrients bound in dead organisms back into soils. Plants and animals must have these nutrients to grow.