The soils are formed from the surface down to the deeper layers of the parent rock. For hard rocks, like granite or limestone, this process is slow, much faster when the rocks are loose, like sand, loess or glacial clay. The first plants, which inhabit the rocks, there are lichens. As the airing process progresses, taller plants appear, whose roots grow into the crevices of the rock. Humus forms from the remains of dead plants. The airing process continues. Plants have better and better growth conditions and develop better and better. In conditions of high humidity or in the event of improper soil cultivation, clay or humus colloids turn into salts and are washed into the soil.. This causes too much compaction of the lower layers of the newly formed soil, which inhibits root growth downwards. Water collects above the condensed levels, as a result, space is reduced, in which roots can grow, and plants die. Soils can develop, but also degenerate through leaching, compaction and accumulation of water. In the long-term process of soil formation, its successive levels develop. These levels form a characteristic system known as the soil profile. The drawing is an attempt to schematically explain this process. From the variety of factors involved in soil formation, like bedrock, climate, ground water, plants, the variety of soil types is derived. In mountainous areas and on slopes, we find shallow soils, on carbonate rocks referred to as rendzinas, and on massive scales as rankers (stadium 2).
In areas protected against erosion, brown soils are formed (stadium 3). In bigger ones, flat and dry basins and in the lowlands, especially on the loess substrate in eastern Europe, deep, humus chernozems. In the Central European area, loess was deposited on vast plains or to the east of the hills; in a humid climate, these loess were used to create leached brown soils (stadium 4) or on the sands, np. poor podzolic soils developed on the moors in northern Germany (podsole), which are dark brown under the washed layer of sand, broken level. In both types of soil, they can become compact (piled up) layers, with a tendency to retain water (top-glued soils - stage 5 i 6).
In conditions of excessive humidity, Ground-glued soils develop in field depressions and in river valleys, which may develop further into marshy soils.
In the areas of occurrence of clay parent rocks, where soil development is very slow, clay soils are formed (clay). The gardener's job is to increase the fertility of the soil. There is no one-size-fits-all solution for this. The effect of some fertilization treatment will be different on sandy soil in warm climates, and another on clay soil with a high level of groundwater.