Organic agriculture and the global food supply. Millennium Villages. What’s On My Food? :: Pesticides On Food. Soil retrogression and degradation. Soil retrogression and degradation are two regressive evolution processes associated with the loss of equilibrium of a stable soil. Retrogression is primarily due to erosion and corresponds to a phenomenon where succession reverts to pioneer conditions (such as bare ground). Degradation is an evolution, different from natural evolution, related to the local climate and vegetation. It is due to the replacement of primary plant communities(known as climax) by the secondary communities. This replacement modifies the humus composition and amount, and affects the formation of the soil. It is directly related to human activity. Soil degradation may also be viewed as any change or disturbance to the soil perceived to be deleterious or undesirable.[1] At the beginning of soil formation, the bare rock out crops is gradually colonized by pioneer species (lichens and mosses).
Ecological factors influencing soil formation[edit] Biorhexistasy theory[edit] Perturbations of the balance of a soil[edit]