Beneficial organisms take part in many physical and chemical reactions that improve soil structure , break down organic matter and cycle nutrients. Others, however such as the tiny nematode, a worm,less than 0.1 mm long can cost farmers billions of dollars, every year, in lost production. In their search for food and nest building, these animals dig and burrow, bringing tons of subsoil to the surface. A valuable tilling service if it isn't your lawn or golf fairway. The most important members of our soil macroflora group are the living plants or more importantly below-ground portion or the roots.
Vegetation is an important factor in soil formation .
We often forget that plants have underground root mass that can be equal or exceed the amount of material that we see above ground. The grassland soils of Saskatchewan have root masses greater 4000 kg per hectare in the top 120cm of soil. The roots of certain grasses can grow to depths of ten feet or more and trees can extend their roots to several hundred feet. For a few millimetres around the active roots is a special zone called the rhizosphere. As seen in the image, root exudates create a rich environment for the growth of microorganisms.