Organisms which live in the soil are its very important component; both the bigger ones – earthworms and insects, and the smaller ones – nematodes, fungi and bacteria. This organisms are usually microscopic but they live in thousands (or even millions) per one cubic meter of soil. Those creatures greatly influence the conditions of their habitat (chemical composition of soil, its structure, as well as the amount of air and water in the soil). Numerous interactions between these organisms ensure good living conditions for plants and other components of the ecosystem.

Many of the organisms living in the soil die due to intense agricultural manipulations. The biggest changes in soil environment are introduced by plowing. When the external layer of soil is pushed deep inside the earth, all processes are interrupted. The organisms from the environment rich in oxygen are pushed into anaerobic conditions where they die. Natural balance in the soil is returned after a couple of months. The more often such intrusions take place, the less stable the group of cooperating organisms is.

Such changes in the soil are invisible for us at the beginning, however dramatic decrease in number of plant and animal species we can observe is a result of serious disturbance in the balance of soil life.

Moreover, industrial waste introduces serious changes in the soil. Poisonous substances or heavy metal ions kill some organisms inhabiting the soil, as well as change its acidity (pH), the structure and the content of air and water in the soil.

Production (plants produce organic matter using the energy from the light, carbon dioxide and simple mineral compounds) and consumption (animals consume plants and out of this food build their own organic matter, which later serves as food for other animals) takes place mostly in above the surface of the earth. However, under the ground in the soil another important process invisible for us occurs – constant, complex and multileveled recycling of dead organic matter which results in creating energy, water, carbon, nitrogen and other elements. Without this continous activity of huge number of microscopic organisms inhabiting the soil, within days plants would lack substances necessary for them to survive, therefore leading to a total pause of production and shortly afterwards of consumption.