The most important purpose of soil cultivation for the lawn is to give it a certain porosity. As you know, porosity depends on the mechanical composition of the soil. If it is possible to bring the correct proportion of the basic soil fractions, this is the way to ensure the most durable porosity. So talc for light soils, sandy, with high permeability it is necessary to add 10-30% clay and mixing it to the depth 20 cm. This corresponds to adding this material in the thickness layer 2-6 cm. Such an additive after mixing with loose sandy soil does not change the height of the soil surface, because it only fills the gaps between the sand grains.
However, for heavy soils, clayey, having low permeability and porosity, it is advisable to add loosening materials, at least to the depth 15 cm, but not deeper than up to 30 cm. Effective loosening of the soil structure can be achieved by adding coarse sand or fine gravel. The amount of these materials may vary, limits 20-90% the volume of the release layer, zależnie od typu gleby.
In case of loosening the layer up to 15 cm, you need to spread the added materials in a layer of thickness 3-13,5 cm.
The added materials must be mixed with the substrate using a cultivator or a rotary tiller.
Please note, that adding sand and gravel to clay soil increases its volume, and thus an increase in the soil surface. These changes should be taken into account in height projects.
The soil can be porous by loosening it during cultivation. Then, the loosening of mineral and organic soil particles takes place. After some time, however, the loosening disappears as a result of various factors, such as e.g.. the effect of the weight of the soil, which is favored by strong hydration, load when moving on the soil surface of people and vehicles, decomposition of organic loosening materials, etc..