When we talk about soil quality we talk about soil components. The chemical composition is an active part of the soil components because it has Nitrogen, Ca+, Oxygen and other molecules that affects the interaction among the soil and its environment. The living organisms interacts with the molecules in the soil changing constantly their concentrations that modify the pH and the soil quality. All of these changes accumulation tell us how the soil has changed through the time, also can give us information to predict how soil will change, this is known as history of the soil.
To summarize the chemical composition affects directly the soil quality, the history of the soil are all the changes that it has suffer in its composition through time so it define the actual soil quality and the living organisms interact with the chemical composition changing it constantly and giving new qualities to the soil.
