Steppe soils: common types and their main properties, humus content

The zone of Russian steppes extends from the Black Sea to Altai and the Caucasus Mountains. Partly it is located on the East European, partly on the West Siberian Plain. Consider the location, climate, main types of steppe soils, characteristic properties, what processes form them, how steppe lands are used in human economic activity.

Geographic location and types of steppes in Russia

The steppe of Eurasia is located in the temperate zone and subtropics, stretching from west to east for thousands of kilometers. These are flat territories with dense herbaceous and shrubby vegetation, there are almost no trees, most often they are found along river banks.In the north, the steppe borders on the forest-steppe, in the south - on semi-desert lands and deserts.

Steppe soils are highly fertile, most of the zone is plowed up for use in agriculture. It is here that chernozems are found, which, however, differ in terms of humus content. In ordinary chernozems, the percentage of humus reaches 6-10%, in southern ones it does not exceed 6%, in chestnut soils it is even lower - 4-5%. Steppe soils have excellent physical properties and contain many nutrients sufficient for growing plants.

Steppe climate

The climate of the steppe zone can be temperate continental and continental. The average winter temperature of the East European Plain reaches -5 °C, and along the edges of the West European Plain it can drop to -30 °C. In winter there is little snow, frequent winds. In spring, the snow melts quickly, with little rainfall.

In summer, on average, the temperature reaches +25 °C, most of the days are sunny. The predominant amount of precipitation falls in spring and summer, but, nevertheless, aridity is inherent in the steppe climate. Dry winds can blow in summer. Autumn is moderately warm until November.

The climate of the southern steppes is milder due to southerly winds that bring moisture in summer and warmth in winter. In the western steppes, severe frosts are not uncommon in winter, the ground freezes deeply, and the snow cover is shallow. Summer is short and frosts come early.

Plant and animal life

The main steppe vegetation is herbs belonging to the cereal family, wormwood and feather grass. They have powerful roots that allow plants to draw moisture from the lower layers of the soil and tolerate drought and heat well. Most vegetation has dark green and narrow leaves that help reduce evaporation. Steppe vegetation includes honey plants: motherwort, alfalfa, sweet clover, phacelia, buckwheat.

The fauna of the steppe is not very diverse. There are few large animals, these are saigas, antelopes. For the most part, ground squirrels, hedgehogs, hamsters, jerboas, marmots are common in the steppe.Foxes, ferrets, wolves feed on them. There are also birds of prey - hawks, owls, buzzards. Of non-predatory species, there are cranes, ducks, herons and bustards. Amphibians include lizards, snakes, toads and frogs.

Main species

Typical chernozems are widespread in the steppe, most of their territories are plowed up, and agricultural products are grown on them. The arid zone is characterized by leaching of sodium, calcium and magnesium s alts from the fertile layer and erosion processes.

Chestnut

In the zone where they are common, flat or wavy relief prevails. Soil-forming soils are carbonate loams, clays, loesses, weathered sandstones, limestones and others. The earth has a characteristic brown hue.

Steppe chestnut soils are formed under low-growing plants in an arid climate, each subzone has its own composition of vegetation. Dark chestnut trees are formed under small-grained grasses, feather grasses, forbs.Chestnut trees are formed from the remains of cereals and ephemeral plants, such as irises, bulbous bluegrass, tulips and xerophytic shrubs. On chestnut soils of light composition, richer vegetation is formed, consisting of couch grass, feather grass and forbs.

Brown

Formed under the influence of the humid climate of the subtropics, under xerophytic shrubs and meadow-steppe forbs. They are characterized by a non-flushing water regime, which causes claying of the middle horizon, saturation with s alts and calcium, the content of which in the upper layer reaches 90%.

Brown soils have a pronounced structure, mostly heavy in texture, neutral acidity. The humus horizon is thick, up to 1 m, therefore, for the most part, brown steppe soils are fertile.

S alt licks and solonchaks

Steppe solonetzes are formed at a low occurrence of soil water, they can be found on chernozems, brown and chestnut soils.Despite the fact that the water lies deep, steppe vegetation pulls it out with long roots. Along with the water, s alts also rise, which remain on the surface after the water evaporates. The composition of s alts contains not only useful, but also those that harm plants.

For the formation of solonetzes, the combination of solonetz and sod processes is characteristic. The accumulation of s alts increases in the steppe zone from north to south, while the intensity of the sod process, on the contrary, decreases. Solonetsity is more typical for soils that have a heavy mechanical composition, that is, for clay soils.

Soil formation

Steppe soils are formed in conditions of unstable and insufficient moisture. Vegetation every year gives, though small, but constant litter. The decomposition of plant residues proceeds in the warm season and stops in the cold season. The lack of moisture leads to weak wetting of the earth, therefore, only easily soluble s alts are washed out from the layer where the roots are located, while calcium and magnesium s alts move down slightly.

Application

Steppe soils are great for growing cereals, corn, sunflowers, gourds and vegetables, and for the development of animal husbandry. Grass is an excellent fodder base for farm animals. Cows, pigs, sheep, poultry are bred in the steppe zone.

The advantage of steppe soils is high fertility, but there are also disadvantages: unfavorable water regime, they dry out quickly and require constant moisture. Steppe land, especially light composition, is prone to wind erosion, which requires anti-erosion measures.

Steppe soils are formed mainly on loams, under the influence of moderate humidity, evaporation prevailing over moisture, perennial grass vegetation.More often these are fertile chernozems or brown soils with good physical properties. They are most suitable for use in agriculture, for growing plants and as a base for grazing livestock. To obtain a crop, they require the use of agricultural technology, which includes mandatory irrigation and loosening of the soil, fertilization, and protection from weathering.