In Kurgan region the rocks which make soils basement in Kurgan region, are horizontally lying stratas of the Paleogene, the Neogene and the Quaternary ages.

Pre-Quaternary rocks are mainly clays and heavy loams of different colors. Concretions of gypsum, siderite, marcasite, lime and other salts can be often found in the rocks. The salinity of these rocks cause the formation of saliniferous and subsaline soils.

The rocks of the Quaternary age have more monotonous coloring. On such rocks chernozem soils are formed with high contents of humus and big depth of humus layer. They cover more than one third of the regional surface.





There are several types of chernozems:

• Leached chermozem. The humus horizon is 45-20 cm. These are the most fertile soils of Kurgan region. Most frequently the boiling up is found out at 60-90 cm, in light soils it is located at the depth of 120-140 cm. From north to south the humus horizon decreases.
• Ordinary chernozems do not form solid massifs. They are found in combination with subsaline chernozems, saline soils. They are widespread in the southern districts of the region. In such soil the humus horizon varies from 15 to 25 cm, the boiling up starts from 30 to 50 cm.
• Subsaline chernozems. Subsaline chernozems can be found on territory to the east from the Tobol. They are also can be found as dissemination in other parts of the region.
  
  

The humus horizon is thin – from 15 to 20 cm. The depth of boiling up is 30-40 cm. Subsaline chernozems are fertile, but because of its consistence they badly emit water and dry out slowly.

Subsaline soils.
They are located in the lowlands. Subsaline soils are formed on heavy loams and clays. Mother rocks are rich in carbonates. Calcium carbonate is located on the depth of 20-30 cm, sometimes in the upper humus horizon. Subsaline soils are very massive.

Solonetzes (alkali soils)
They are spread on flat interfluve areas between the Tobol and the Ishim, the Iset and the Miass, and the Tobol. Their mother rocks are re-salinized clays and loams of the Quaternary age.

The humus horizon is 6-12 sm. It is usually columnar, solid, has a nut structure in the lower profile. In spring and after rain there is a water stagnation on the surface. In dry time deep fissures appear on the alkali soils.

Saline soils
They contain in the upper layer a significant amount of chloride, sulfate and carbon combinations of natrium, calcium and magnesium. If they are not covered with vegetation, they have white - gray saline crust on the surface. In Kurgan region saline soils are located on beds of dried up lakes and rivers, near a swamp and by lake reductions, river tributaries, etc.

Saline soils are located in relief reductions and they are salinizated by the Paleogene and the Neogene mother rocks.
Typical saline soils have a thin gray humus horizon. Its depth is 15-25 sm. On the depth of 1-1.5 meters groundwaters are frequently bedded. The soils emit water and air badly. They are used as meadow lands and are not ploughed up.

Grey wood soils.
They are located in the areas of alluvial and aeolian sands and sandy loams of ancient river terraces. The humus horizon is thin. Its depth is about 15 cm. Dark gray wood humus horizon is up to 40 cm.

On gray wood soils naturally grow pine forests. Pine root system grasp firmly to the soils. To preserve gray wood soils it is necessary to guard pine forests from felling.

Thus, the territory of Kurgan region is characterized by a combination of soils, different in genesis, fertility and economic use.