In the early seventies, there was little research funding for such esoteric pursuits as studying the apparently uneconomically-important organisms that live in the soil. Consequently, I had to broaden my interests, in this case to include insects and ecological approaches to farming. In most parts of the world there is more life beneath the surface of the soil than above it. Nearly all groups of animals that are not exclusively marine have representatives in the soil. My particular favourites are the mites, which in most soils are the most abundant group of arthropods.
Most mites are beneficial, feeding on microorganisms or on other small animals.
In a few shovelfuls of forest soil there may be as many as 100 different types of mites and all together more than 1,000 different types of organisms. The number of individuals of each type can also be impressive. In a square metre there can be more than 10 million nematodes and protozoa, one million mites and springtails and thousands of other invertebrates, including several hundred earthworms. Even in a teaspoon of soil there can be as many as 10 million bacteria and two kilometres of fungal filaments. The soil is indeed a living, breathing firmament in which the primary action taking place is the breakdown of organic matter and the release of plant nutrients.