Soil is the upper fertile layer of the earth, created as a result of permanent interaction of soil-forming factors. Until the 80-ies of XIX century soil was regarded as a geological formation. The essential characteristics of the soil is its fertility, meaning that it supplies plants with water, nutrients and warmth. Soil is the primary means of agricultural production. Soils are treated as a three-state system of solids, liquids, and gases. In different soils, and in different layers of the same soil, the number and the ratio of these components are different. Solids have more minerals, formed as a result of differential depletion. The depletion takes place under the climate influence and has different intenseness in different landscape areas. Chemical depletion is more characteristic to humid subtropical and tropical soil. In high mountains and deserts mechanical depletion prevails. The fertility greatly depends on the solid phase of the soil. It determines its absorption capacity. Black soil and red soil rich in colloids, are characterized by the highest absorption capacity. The solid phase of the soil also contains an organic matter consisting of humus matter. Organic part also contains compounds of plant, animal and microbial origin. Soil protection is an important issue for Georgia. This is a state problem for Georgia, where soil losses from pollution, erosion, re-wetting and excessive salinity, open way extraction of minerals and construction materials, and disordered housekeeping are very high.
Soil degradation is an issue in Georgia. Overgrazing, deforestation and irregular land development under urban construction are key factors leading to degradation. Soil erosion, which is a natural process, is often exacerbated by unsustainable land use by people. The soil fertility also depends on salinity level. These processes ae caused by depletion of formations under the influence of less mineralized ground-waters etc. Soil fertility decreases due to excessive soil acidity. Besides, soil is contaminated from unsustainable use of fertilizers (organic and mineral) and pesticides, from heavy metals and household and industrial waste. Soil degradation can be reduced/mitigated by adoption of efficient land policy on national, regional and local levels.