in green areas where broad-leaved species are grown, produced gray forest soils.The natural area of their location - the territory of the temperate continental climate.These are the areas where there is a large number of sunny days and no rainfall.
Distribution
Gray forest soils are located in the vast territories of Russia.Vast territories they occupy in Canada and the United States.This steppe zone bordering to the north with the taiga, and in the south - from the steppe region.
gray forest soils on the territory of Russia, is a continuous band in the European part of the country.They are found in a vast area from the Ukrainian border to the Ural Mountains.Grab gray forest soils and the area situated somewhat to the east, to the Altai.This is the area of the West Siberian Plain.The area of gray soil - is 3.5% of the total area of the Russian Federation.Below is a look at what are the gray forest soils.Characteristics of Russia's land and their primary use in the agricultural sector will also be covered in this article.
Relief
the whole character of the landscape in the area of finding the gray soils is plain.In the European part of the forest-steppe plain is steeply sloping and undulating.In Asian, moreover, even with the planar areas.In the forest there is a network of gullies and ravines.Such relief is also influenced by the characteristic of the gray soil, because thanks to him, there is a natural drainage area.
Terms formation
How are gray forest soils?Formation conditions are optimal for them only in the continental climate.This is the average annual temperature from plus seven degrees in the western regions to minus four and a half to the east.Also, the formation of the land affects a certain amount of shortfall in rainfall during the year.In the territories west of the Ural mountains is 500-600 mm, and to the east of these ridges - 300 mm.At the same time there is an equal ratio of precipitation and evaporation.On the whole territory where gray forest soils are formed, observed the same average temperature of July.They make up 19-20 degrees.
Gray forest soils are formed under the vegetation represented grassy deciduous forests.To the west of the Dnieper, they are oak and hornbeam composition.To the east, to the Urals, the forests grow limes and oaks.Sometimes there is an ash.To the east of the Ural Mountains is dominated by aspen and birch forests.Further, to the Trans-Baikal region, there is a larch.
Due to the high weight of the deciduous trees litter certain properties have gray forest soils.Characterization of the composition shows a high content of calcium and ash constituents.All of these substances enter the soil with litter, the mass of which, according to scientists, is from 70 to 90 quintals per hectare.
on the territory forest-steppe soil-forming rocks are represented by loams.This carbonate deposits.
in terms of herbaceous broadleaf forests in the land of the two main process going on.Without them there would be able to form gray forest soils.Feature-forming layer is directly related to these processes.The first of these takes place under the influence of the downward flow of water from falling on the ground precipitation.The result of this process is the issuance of products of soil formation and weathering of rocks in the lower horizons.Sometimes all these substances move into the layers of loam.
second, equally important process, due to the fact that the gray forest soils formed under deciduous trees and grasses.Dead vegetation, rich in minerals, is deposited in the upper horizon in the form of organic residues.In the surface layers of the soil humus is formed.This layer is rich in organic and mineral substances associated with calcium.To a small extent in the forest passes and podzol process.It enriches the topsoil sesquioxides and oxides of magnesium, calcium and many other elements.
structure
gray forest soils (see below photo) presented five layers.
The top one has a thickness of 3 cm. This litter, consisting of neperegnivshey dead grass and mortality.Next is a more powerful grainy gray layer whose thickness - 12 cm. It is formed from humus and has a loose structure.The depth of the third layer - 12 cm. The soil is painted in walnut or light gray color.This layer has inclusions of silica and humus.Subsequently, the soil becomes brown hue.In this layer, where the accumulated organic-ferrous compounds are common glossy blotches.The following is the source rock of yellow-brown color.
the type of gray soils allocate such subtypes:
- light gray;
- gray;
- dark gray.
This classification depends on the nature of the processes occurring in the earth Podzolization.
Chemical characterization gray soils
composition and number of micro and macro elements, depending on the conditions of formation of all the layers of the horizon.What are the chemical properties of gray forest soils?Characteristics obtained in the investigation of an aqueous solution, allows to speak about the slightly acidic and acidic reaction.In addition, the results of laboratory analysis suggests low saturation of the soil and reduced number of bases in the first two horizons of silt particles.
a chemical studies can accurately point out to any subtype are certain gray forest soils.Characteristics of different.So, dark gray forest soils have accumulated a large amount of humus.They found the prevalence of humic acids on fulfokislotami.What else is different dark gray forest soil?Characteristic given as a result of chemical analysis confirmed accumulation of calcium in it.This element is located in the upper layer.
Feature gray forest soil resulting from a chemical research points to the poverty of its upper horizons sesquioxides and significant enrichment in silica.This part of the process for confirming podzolization.This is most clearly expressed in a light gray soil subtype.Less - dark gray.Depending on the subtype of the soil and have different chemical properties.For example, light gray have an acidic reaction.In this they are no different base saturation.
Feature gray forest soils indicate that this subtype also has an acidic reaction.At the same time there is some unsaturated bases.However, it appears less than that of light gray subtype.
third type of soil has the most favorable chemical properties.Dark gray soils are slightly acidic reaction and a large base saturation.Furthermore, their structure observed high humus phosphorus, calcium and nitrogen.
plays an important role for those who are studying the gray forest soils characteristic.
table, in which all properties of the different subtypes, would better remember all the data obtained by researchers.
Physical characteristics
Properties land steppe zone is largely dependent on the content of humus.In the physical characteristics of the gray soils affects the texture of primary source rocks.
upper horizons of these areas are characterized by high porosity of up to 60%.As we move down the profile of soil density increases.This is associated with a decrease in concentration of humus.The data of physical properties are some differences depending on the subtype of these soils.Thus, in the dark gray rock density is even lower horizons of the smallest.This is due to high humus content and more pronounced structuring.
One of the physical characteristics of a density of illuvial horizons.All subtypes of gray soils it is quite high.Its value reaches from 1.5 to 1.65 grams per cubic centimeter.As for the total porosity, it is in the range of from 50 to 60%.In the upper levels - from 40 to 45%.Characteristics of porosity in light gray subtype tends to capillary type.This feature reduces soil permeability.
Regarding charcoal subtype, its physical properties are more favorable.This soil layer is distinguished by high moisture capacity, which allows the entire plant world to receive the much-needed water for him.Gray and light gray subtypes land steppe zone have a rather discouraging physical characteristics.This low humus content, and a small percentage of silt and the large amount of silt fractions.All of these qualities contribute obesstrukturirovaniyu upper layers after plowing horizon.Such lands swim fast, but on the surface crust formation.
microstructures of different subtypes of gray soils different from each other and water stability.For example, light gray appearance after plowing quickly sealed.This is due to the fact that this subtype is observed the presence of water-soil aggregates that are larger than 0.25 mm.
biological characteristics
Humus gray soils accumulates in the upper horizons, and it is a whole group of high-molecular-related compounds.It is a biological component - the main organic substance of the first layer of the profile.It has a lot of phosphorus, nitrogen and other elements.Education comes from humus and plant deciduous downturns, as well as dead roots of the plants with the active participation of microorganisms.
Heat mode
This figure gray forest soils properties are quite favorable.For a long period, which lasts from April to December, around them there is a positive temperature profile.Freezing occurs with the onset of winter, and sometimes in January.By April, the layer depth of 50 to 70 cm already completely thawed.
In the central and western zone of forest-steppe soils belong to facies subtype of heat supply.Here you can observe the periodic freezing and thawing of the upper layer throughout the winter period.
Sometimes the thermal regime of soil characteristic of Western Siberia.It takes a long period of freezing layers horizon.In addition, with the advent of spring soil thaw slowly.This is due to the severe frosts and low snow.Field work in these areas begin to be carried out only in May.However, at this time at the lower levels still remain negative temperatures.
Air mode
This feature is a collection of a large number of phenomena.And all of them are associated with the arrival of the air into the soil, its further movement along it, as well as costs.This is also the phenomenon of gas exchange that occurs between the layers of the horizon and the surrounding atmosphere.
soil air with the arrival of the season undergoing some changes in its composition.And in the upper layers of this process is much more intense.
Water regime
Gray forest soils characteristic of the type of periodic washing of the indicator.Typically, dropping heavy rainfall in the autumn moistened the ground only 50 cm. More moisture can penetrate deeply at the spring thaw.In this regard, the thickness of the wetting of the soil depends on the capacity of the winter cover and meltwater runoff.
certain characteristics of the water regime is observed in areas with rugged terrain.Here, the maximum flow of water in the summer can be 20% and cover layer of soil having a meter thick.
completely different water regime of the soil are located in forest areas.Here in the winter is a big accumulation of snow.In connection with this spring the soil is moistened much more intense.Subsequently, however, it uses a deep root system of trees.It dries up the soil to a depth of 4 to 5 meters.
nutrient regime
most favorable properties for this indicator have a dark gray forest soils.They have a high natural fertility due to the large amount of them are located in humus, phosphorus and nitrogen.
nutrient status of the soil depends on its cultivation and application of fertilizer.In such cases, the upper layers of the horizon will contain more nutrients.
on nutrient status of soil affects the content of hydrolyzable nitrogen.This element is particularly poor light gray soil.One of the indicators of soil fertility is the presence in them of available phosphorus.The maximum amount of this element is in the residual-calcareous soils.
Summertime helps to activate the chemical, biological and other processes that occur in arable soils.In the middle of the warm season there is an increase hydrolytic and exchangeable acidity.In this connection, it reduced soil base saturation.
Use
economic activity in the agricultural sector of the country is widely involved area in which there are gray forest soils.The fertility of the land allows people to successfully grow them different crops.In addition, gray forest soils take their place in the structure of pastures and pastures and hayfields.
in the development of agriculture for the forest-steppe zones of cultivated spring and winter wheat, corn and sugar beet, flax, potatoes and so on.. In the European part of forest-steppe widespread gardening.
in economic turnover includes all subtypes gray soils.This person tends to increase their fertility by applying a range of activities.Powerful fertile topsoil is created by fertilization and grass cultivation.This improves the physical properties of soils and nutrition, as well as reduces the ability to form a crust on the surface layer.In addition, land with high acidity to improve their performance subjected to liming.
process of domestication of forest gray, and light gray soils and possible deepening of the plow layer.The event is accompanied by fertilization.If necessary, carry out and liming lands.
fertility of dark gray soils enhance the systematic application of fertilizers.And to eliminate their increased hydrolytic acidity of phosphorite flour.
Agricultural use of gray soil erosion control measures should be accompanied.This is especially true of the European territory of the forest-steppe zone.For such measures to cultivate the soil across the slope, arrange earthen ridges and so on. D.
