Patterns of changes in soil properties in the southeast of the central black earth region under the influence of anthropogenic impact. Geographical patterns of distribution of humic substances in soils The main pattern of changes in soil fertility

Soil classification is the grouping of soils into groups according to their most important properties, origin and fertility characteristics. Soil classification groups
ecological-genetic (Dokuchaev, Sibirtsev, Afanasiev),
factor-genetic (Glinka, Vysotsky, Zakharov),
morpho-genetic (Kossovich, Glinka, Gedroits),
evolutionary-genetic (Kossovich, Polynov, Kovda),
historical-genetic (Williams, Gerasimov),
agrogeological (Mayer, Knop, Fallu),
physical (Payer, Schubler),
soil-mineralogical (Ramani, Zsigmond, Streme, Kubieka,
Duchafour and others),
genetic and geographical (Marbut, Kellat, Thorne, etc.).

Principles of modern classification

Soil classification should be based on basic
soil properties and take into account processes and conditions
soil formation, i.e. must be genetic.
Be based on a strictly scientific system
taxonomic units.
Classification must take into account the characteristics and
properties acquired by soils as a result
human economic activity.
Must disclose production features
soils and promote their rational
use in agriculture and forestry.

General laws of soil geography

Law of horizontal (latitudinal) soil
zonality (Dokuchaev). The most important
soil formers (climate, vegetation
and fauna) naturally change in
latitudinal direction from north to south, then
main (zonal) soil types should
successively replace each other,
located on the earth's surface
latitudinal bands (zones).

Law of vertical soil zonation:

In mountainous terrain, natural
successive changes in climate, vegetation and soils in
connection with changes in the absolute altitude of the area. Changes
manifest themselves in the formation of vertical plant-climatic and soil belts (vertical zones).
The successive change of zones is similar to their change on the plains
spaces when moving from south to north.

The soil-climatic zone is a set of latitudinal soil zones and mountain (vertical) soil provinces, united

The soil-climatic zone is a set of
latitudinal soil zones and mountain (vertical) soil zones
provinces united by similar factors and conditions
soil formation. (polar, boreal, subboreal,
subtropical, tropical).
Soil-bioclimatic regions are characterized by soils
similar in moisture regime and vegetation types.
Combination of zonal and intrazonal soil types.
The soil zone is an area of ​​soil combinations, in
the composition of which includes zonal and intrazonal soils.
Soil facies are parts of a zone that differ from each other
according to the temperature regime and the nature of humidification.
Soil province

The soil type develops under similar biological, climatic and hydrological conditions and is characterized by bright manifestations.

The soil type develops in the same way as associated biological ones,
climatic and hydrological conditions and is characterized by bright
manifestation of the main process of soil formation with possible
combination with other processes (chernozems, gray forest soils, chestnut soils, etc.)
The characteristic features of the soil type are as follows:
- Uniform supply of organic substances and
processes of their transformation and decomposition.
- Same type complex destruction process
mineral mass and synthesis of minerals
formations.
- Same type of migration and accumulation
substances.
- Same type of soil profile structure.
- Same type of activities for
increasing and maintaining soil fertility.

Taxonomic units

Soil subtypes are distinguished within a type - this is a group of soils
qualitatively different in the manifestation of the main and
overlapping soil formation processes and are
transitional stages between types. When identifying subtypes
processes related to both zonal and
facies change of natural conditions. Events for
increasing and maintaining fertility for each subtype
more homogeneous compared to type. For example, black soil
leached, ordinary, southern.
Soil genera (generic groups) are distinguished within the subtype.
Their qualitative genetic characteristics are determined
influence of a complex of local conditions, composition
soil-forming substrate acquired in the process
previous phases of weathering and soil formation
(relict horizons and signs of ancient soil formations).
For example, ordinary carbonate chernozem.

Taxonomic units

Soil types are distinguished within the genus and differ in
degree of development of soil-forming processes.
For example, the degree of podzolicity, depth and degree
humid content, degree of salinity, etc.) and their
mutual conjugation.
Soil varieties are determined by mechanical
composition of the upper soil horizons and
soil-forming rocks.
Soil category is determined by genetic properties
soil-forming rocks (dense, moraine,
alluvial, cover, etc.).

The established names of soils in accordance with their properties and classification position are called soil nomenclature.

Dokuchaev V.V. used Russian scientific
names based on the natural color of the upper
soil horizons. Genetic Type Terms:
chernozem, podzol, red soil, chestnut soil, gray soil, yellow soil,
brown soils.
Features of the composition and properties of soils (salt marsh,
solonetz – sodium salts; malt – spilled soil; peat-gley
the soil).
Brief landscape geographical characteristics. Brown
forest soils and brown desert soils.
The nomenclature names of some types are entirely similar to
names of landscapes or areas. For example, swamp, meadow, arctic
soil.

Nomenclature of soil subtypes

In each genetic type there is a central subtype with
the term is typical. The subtype is transitional, connecting the given
soil type with the neighboring one. To designate these subtypes of steel
use terms.
Characterizing additional processes (gley-podzolic soils, leached chernozem, chernozem
podzolized).
Indicating a change in color compared to the main one
subtype (light gray, dark gray, etc.).
Indicating the position of the subtype within the soil zone
(southern chernozems).
Indicating the relative difference in their thermal regime
(warm, moderately warm, cold, deep-freezing),
or features associated with the hydrothermal regime
(mycellar-carbonate, powdery-carbonate).

The following terms are used for the nomenclature of soil genera

Determining characteristic properties of soils: solonetzic,
saline, solodized.
Indicating relict features remaining from
previous phase of soil formation: residual solonetzic, residual podzolic.
To quantitatively characterize the composition, properties of soils and
severity of soil processes, 3 categories are used
terms.
1. Terms indicating content: little, medium and a lot
humus; carbonate, etc.
2. Terms indicating the thickness of individual soils
horizons and the entire profile: small, medium, heavy-duty.
3. Terms characterizing the severity of phenomena: weak,
medium, strongly podzolic; unsalted.

SOIL NAME

begins with the name of the type, then subtype, genus,
type, variety.
For example, chernozem (type), ordinary (subtype),
solonetzic (genus), medium humus,
medium-power (species terms),
heavy loamy (difference).

Soil diagnostics is a set of morphological characteristics, composition indicators, properties and regimes that characterize the soil of any taxonomy

Soil diagnostics - a set of morphological characteristics,
indicators of composition, properties and regimes characterizing the soil
any taxonomic level and allowing to objectively give
it has a specific name.
Diagnostics based on morphological characteristics - structure
profile, color of individual horizons, their thickness, structure,
neoplasms.
Main diagnostic indicators: composition indicators –
content and composition of humus, gross composition of the mineral part,
content of carbonates, easily soluble salts; indicators
properties - reaction, cation exchange capacity and composition of exchangeable
cations, biological activity; physical properties.

Posted on /

MINISTRY OF EDUCATION AND SCIENCE

RUSSIAN FEDERATION

FEDERAL EDUCATION AGENCY

Federal State Educational Institution

Higher professional education

“Chuvash State University named after I.N. Ulyanov"

Faculty of History and Geography

Department of Environmental Management and Geoecology

COURSE WORK

Soil fertility

Completed by: Lisova N.

Checked by: Ph.D. Vasyukov S.V.

Cheboksary 2010

Introduction

1. Humus content

2. Soil fertility

2.1 Types of soil fertility

2.2 Factors limiting soil fertility

2.3 Reproduction of soil fertility

2.4 Methods for studying soil fertility

3. Assessment of dynamic properties of soils using space methods

4. Dynamics of soil fertility in Chuvashia

Conclusion

Bibliography

Application

Introduction

In my work I would like to talk about soil fertility. Soil fertility is the most important property of the soil, without which the soil can be considered unsuitable and useless. Therefore, I consider it appropriate to consider this topic in more detail.

The purpose of my work: to determine the importance of soil fertility for plants and for agriculture.

Study of types of soil fertility;

Determination of factors limiting fertility;

The role of humus for soil fertility;

Studying soil fertility using space methods;

Studying the dynamics of the properties of the Chuvash Republic.

Since ancient times, when using land, people have assessed it primarily from the point of view of its ability to produce crops. Therefore, the concept of soil fertility was known even before the establishment of soil science as a science and expressed the most essential property of land as a means of production.

Soil science is the science of soils, their formation (genesis), structure, composition and properties; about the patterns of their geographical distribution; about the process of interaction with the external environment that determines the formation and development of the most important property of soils - fertility; about ways of rational use of soils in agriculture and national economy and about changes in soil cover in agricultural conditions.

Soil science as a scientific discipline took shape in our country at the end of the 19th century thanks to the works of outstanding Russian scientists V.V. Dokuchaeva, P.A. Kostycheva, N.M. Sibirtseva.

The first scientific definition of soil was given by V.V. Dokuchaev: “Soil should be called the “day” or outer horizons of rocks (no matter what), naturally changed by the combined influence of water, air and various kinds of organisms, living and dead.” He established that all soils on the earth's surface are formed through "an extremely complex interaction of local climate, vegetation and animals, the composition and structure of parent rocks, the terrain and, finally, the age of the country." These ideas of V.V. Dokuchaev were further developed in the concept of soil as a biomineral (“bio-inert”) dynamic system, in constant material and energetic interaction with the external environment and partially closed through the biological cycle.

The development of the doctrine of soil fertility is associated with the name of V.R. Williams. He studied in detail the formation and development of soil fertility during natural soil formation, examined the conditions for the manifestation of fertility depending on a number of soil properties, and also formulated the basic principles on the general principles of increasing soil fertility when used in agricultural production.

1. Humus content

The most important characteristic of soils is the humus content in it. Humus is a collection of organic compounds found in the soil, but not part of living organisms or their remains that retain their anatomical structure. Humus makes up 85-90% of soil organic matter and is an important criterion in assessing its fertility. Humus imparts certain chemical and physical properties to the soil. Soil humus accumulates energy assimilated in plants during photosynthesis. Humic acids, acting on primary and secondary soil minerals, cause their decomposition and contribute to the formation of organomineral substances. Thanks to humus compounds, individual parts of the soil stick together into structural aggregates.

The amount and nature of above-ground and underground residues, the direction of humus formation and the properties of humic substances largely depend on the type of vegetation and the hydrothermal conditions of its growth. Thus, the highest biomass is characteristic of forest vegetation (up to 4000-5000 c/ha). In savannas, steppes and shrub tundras the value is in the range of 250-260 c/ha. The minimum total biomass is observed in polar and tropical deserts - less than 50 c/ha.

From all of the above, we can draw a small conclusion: the highest fertility is characteristic of the forest zone, and the lowest - in polar and tropical deserts. fertility soil humus

2. Soil fertility

Soil fertility is the ability of the soil to satisfy the needs of plants for nutrients, water, to provide their root systems with sufficient air, heat and a favorable physical and chemical environment for normal activity. It is this most important quality of soil, which distinguishes it from rock, that V.R. emphasized. Williams defines soil as "the surface horizon of the earth's land capable of producing a crop of plants." The concept of soil and its fertility are inseparable. Soil fertility is the result of the development of the natural soil-forming process, and in agricultural use, also the process of cultivation.

The development of soils and soil cover, as well as the formation of their fertility, is closely related to the specific combination of natural factors of soil formation, the diverse influence of human society, the development of its productive forces, economic and social conditions.

A special role in soil formation belongs to living organisms, primarily green plants and microorganisms. Thanks to their influence, the most important processes of transformation of rock into soil and the formation of its fertility are carried out: the concentration of elements of ash and nitrogen nutrition of plants, the synthesis and destruction of organic matter, the interaction of waste products of plants and microorganisms with mineral compounds of the rock, etc. in the knowledge of the biological essence of soil formation, a special contribution was made by V.R. Williams and V.I. Vernadsky.

Being in a state of continuous exchange of matter and energy with the atmosphere, biosphere, hydrosphere and lithosphere, the soil cover acts as an indispensable condition for maintaining the existing balance on Earth between all its spheres, which is so necessary for the development and existence of life on our planet in all its diverse forms.

At the same time, having the property of fertility, soil acts as the main means of production in agriculture. Using soil as a means of production, a person significantly changes soil formation, influencing both directly the properties of the soil, its regimes and fertility, and the natural factors that determine soil formation. Planting and cutting down forests and cultivating crops change the appearance of natural vegetation; drainage and irrigation change the humidification regime, etc. no less dramatic effects on the soil are caused by methods of its cultivation, the use of fertilizers and chemical reclamation agents (liming, gypsum).

An important condition for soil fertility is the absence in the soil of excess amounts of easily soluble salts, mainly sodium chlorides and sulfates and partly magnesium, calcium and other cations.

To eliminate excess salts, soil leaching is used and to prevent salt accumulation - correct irrigation regime, drainage, etc. Soil fertility is greatly reduced when harmful chemical compounds accumulate in it (acidified iron compounds, mobile aluminum compounds), which usually accumulate under conditions of stagnant waterlogging. Regulation of moisture reserves in the soil is achieved with the help of damp-technical and hydraulic measures (autumn plowing, snow retention, early spring harrowing, inter-row cultivation of crops, irrigation, drainage, etc.).

The highest and most effective soil fertility is characterized by soils that, along with a sufficient amount of moisture, have good aeration. And also, with proper use of soils, their fertility not only does not decrease, but also constantly increases.

2.1 Types of soil fertility

The following types of fertility are distinguished: natural (natural), artificial, potential, effective and economic.

Natural (natural) fertility is the fertility that the soil (landscape) has in its natural state. It is characterized by the productivity of natural phytocenoses.

Artificial fertility (natural-anthropogenic, according to V.D. Mukha) is the fertility that the soil (agrolandscape) has as a result of human economic activity. In many respects it inherits the natural. In its pure form, it is typical for greenhouse soils and reclaimed (bulk) soils.

The soil has certain reserves of nutrients (reserve fund), which are sold when creating a plant crop through partial consumption (exchange fund). From this idea follows the concept of potential fertility.

Potential fertility is the ability of soils (landscapes and agricultural landscapes) to provide a certain yield or productivity of natural cenoses. This ability is not always realized, which may be due to weather conditions and economic activities. Potential fertility is characterized by the composition, properties and regimes of soils. For example, chernozem soils have high potential fertility, podzolic soils have low potential fertility, but in dry years, crop yields on chernozems may be lower than on podzolic soils.

Effective fertility is part of the potential, realized in the crop yield under certain climatic (weather) and agrotechnical conditions. Effective fertility is measured by the yield and depends both on the properties of the soil, landscape, and on human economic activity, the type and variety of crops grown.

Economic fertility is the effective fertility measured in economic terms that take into account the value of the crop and the costs of its production.

2.2 Factors limiting soil fertility

Factors limiting soil fertility include indicators of the composition, properties and regimes of soils that reduce the yield of cultivated plants and the bioproductivity of natural phytocenoses. To a first approximation, they can be designated as deviations from optimal indicators. The degree of deviation characterizes the level of the limiting factor and the degree of yield reduction. The theoretical basis for research into factors limiting soil fertility is the laws of the limiting factor and the cumulative action and optimal combination of plant life factors.

It is necessary to distinguish between planetary limiting factors, characteristic of soils in all natural zones, intrazonal (regional), characteristic of certain zones and regions, and local, characteristic of small areas.

General planetary ones include: insufficient supply of nutrients, increased density, unsatisfactory structure, reduced content of easily decomposed organic matter.

Intrazonal (regional) - increased acidity, increased alkalinity, lack and excess of moisture, eroded and deflated soils, stony content, salinity, solonetzity, etc.

Local factors limiting soil fertility include local soil contamination with radionuclides and heavy metals, oil products, soil disturbance by mining, etc.

For a number of soil properties and regimes, critical levels of indicators have been determined at which other agronomically important soil properties and regimes sharply deteriorate and plant yield or its quality sharply decrease.

In soils with low natural fertility, developed, cultivated and cultivated varieties are distinguished. Developed soils are formed under conditions of low agricultural technology, with irregular application of low doses of organic and mineral fertilizers. Cultivated and cultural - are formed with high agricultural technology, regular application of organic and mineral fertilizers and carrying out the necessary reclamation measures (drainage, irrigation, liming, application of high doses of peat, sanding of clay soils, claying of sandy soils, etc.). As a result of measures aimed at eliminating limiting factors, the fertility of cultivated soils is significantly higher compared to developed analogues.

The process opposite to cultivation is proposed to be called plowing. Plowing is a decrease in the level of fertility of arable soils, deterioration of agronomic properties (decrease in humus content, destructuring, overcompaction, soil fatigue) as a result of their use with a low level of humus sources (organic fertilizers and post-harvest residues) for a number of years. Scientific research is currently underway to quantify the degree of plowing. Both cultivated soils and cultivated soils to varying degrees can be plowed. In plowed soils, soil fatigue and soil phytotoxicity most often manifest themselves, sharply reducing plant yields.

Soil fatigue is a multifactorial phenomenon that manifests itself in agrocenoses, especially in monoculture conditions. A.M. Grodzinsky (1965), V.T. Lobkov (1964) identifies the following, the most significant causes of soil fatigue:

one-sided removal of nutrients, disruption of balanced plant nutrition;

changes in the physicochemical properties of soils, pH shift;

deterioration of the structure and water-physical properties of soils;

violation of the biological regime, development of pathogenic microflora (fungi Fusarium, Penicillium, etc., bacteria Pseudomonas, some actinomycetes);

accumulation of phytotoxic substances (colins) - derivatives of phenols, quinones and naphthyzine, causing soil toxicity;

proliferation of pests and harmful weeds.

Soil fatigue is considered as a result of a violation of the ecological balance in the soil-plant system due to the unilateral impact of cultivated plants on the soil.

2.3 Reproduction of soil fertility

Along with the concept of “soil fertility,” the term “soil cultivation” is widely used in agronomy. Cultivation refers to the improvement of the natural properties of the soil through the use of agro-reclamation measures. Along with this, the concept of “field cultivation” is distinguished, associated with the cultural and technical impact on arable land, increasing the size of the field contours, leveling, removing stones, etc. in order to create favorable conditions for the operation of agricultural machinery.

In modern agriculture, the concept of “soil cultivation” is applicable to newly developed soils with very low natural fertility (podzolic soils, solonetzes, etc.), heavily washed away soils when an infertile subsoil horizon is involved in the arable layer. In these cases, essentially, it is necessary not to reproduce, but to create fertility. The same problem arises when restoring soil in mining or peat areas. Since these landscapes previously contained cultivated fertile soils, their restoration is called reclamation. As the properties inherent in the cultivated soils acquire, the fertility of cultivated and reclaimed soils is subsequently reproduced.

With agricultural use of soil, its fertility decreases, since organic matter and mineral nutrition elements are consumed for the production of crop products, water-air conditions, phytosanitary conditions, microbiological activity, etc. deteriorate. therefore, there is a need to manage soil fertility in intensive farming. It is based on a regulatory and technological basis. This means determining the optimal parameters of soil fertility indicators in specific production conditions and technologies for reproducing optimal levels of fertility.

Reproduction of soil fertility can be simple or extensive. The return of soil fertility to its original state means simple reproduction. Creating soil fertility above the initial level is expanded reproduction of fertility. Simple reproduction is applicable for soils with optimal fertility levels. Expanded reproduction is implemented for soils with a low natural level of fertility, which is not capable of ensuring sufficient efficiency of agricultural intensification factors. Expanded reproduction of the fertility of soddy-podzolic soils is a prerequisite for expanded reproduction of agricultural products in general.

Soil fertility management in modern agriculture should be carried out on the basis of appropriate models. The soil fertility model is a combination of experimentally established fertility indicators that are closely correlated with the size of the crop. A fertility model is developed for specific soil, climatic and production conditions for growing crops.

Reproduction of soil fertility in modern agriculture is carried out in two ways: material and technological. The first involves the use of fertilizers, ameliorants, pesticides, etc., the second - crop rotation, intercrops, various soil cultivation methods and sowing methods, etc. These paths are aimed at achieving a single goal, although their mechanism of action is different.

Material reproduction factors have the strongest and most diverse impact on soil fertility. Technological impact is not able to compensate for material losses of soil fertility; its effect is based on the mobilization of material resources of the soil and is short-term. Ultimately, this leads to a decrease in permanent sources of soil fertility, although it provides short-term success in increasing crop yields.

The natural basis of the theory of reproduction of soil fertility is the law of return - a particular manifestation of the general law of conservation of matter and energy. Reproduction of soil fertility begins with determining the optimal parameters of the fertility model. Fertility models are strictly differentiated depending on the natural conditions of the economy, the specialization of agriculture, and the economic level of production.

Experimental substantiation of the fertility parameters of specific agricultural regions allows us to give an objective agronomic assessment of the soil. This means that each soil fertility model must ensure the effective use of fertilizers, specialized crop rotations, modern resource-saving technologies for soil cultivation, land reclamation, and plant protection products.

2.4 Methods for studying soil fertility

To quantify soil fertility, indicators that are correlated with yield are used. These indicators are combined into three groups: agrophysical, biological and agrochemical.

Agrophysical indicators of soil fertility are represented by granulometric and mineralogical composition, structure, density, porosity, air capacity and thickness of the arable layer. Biological indicators include the content, reserves and composition of soil organic matter, the activity of soil biota, and the phytosanitary condition of the soil. The group of agrochemical indicators of fertility consists of nutrient content, the reaction of the soil environment and the absorption properties of the soil.

Fertility indicators are in most cases interrelated. Some of them can be considered fundamental, which determine the state of all soil processes. These include particle size and mineralogical composition, organic matter and phytosanitary condition of the soil. Other indicators of fertility, such as the activity of soil biota, agrophysical and agrochemical, are largely derived from the above.

3. Assessment of dynamic properties of soils using space methods

The assessment of properties changing over time using the remote method, which is one of the important tasks of monitoring the state of soils, especially in connection with economic impact, is still exploratory and experimental in nature. At the same time, to date, a fairly large amount of research on such soil properties as humus content, salinity, moisture content, erosion, as well as their contamination has been carried out using remote methods not only at a qualitative, but also at a quantitative level. These parameters of soils and soil cover are characterized by significant changes in space and time and are most important in economic development.

The most important characteristic of soils is the humus content in it. Humus content determines soil fertility. Unreasonable use of arable land, long-term plowing without observing soil-protective crop rotations, and the development of water and wind erosion processes lead to the loss of humus. Therefore, control over its content in the soil is required.

Such control is most reliable when using direct observations, laboratory tests, and soil samples, which is only possible for individual points or small areas of the area. To monitor vast areas, remote methods are used, aerospace images are used. Their application is based on the study of spectral imaging ability and taking into account the spectral properties of soils.

It is known from experimental work that the humus content of the soil is related to its spectral brightness. With an increase in humus in the soil, the spectral brightness coefficient decreases (Appendix 1).

4. Dynamics of soil fertility in Chuvashia

In the Chuvash Republic, for the first time, a large-scale study and mapping of soils on all farms of the republic was carried out in 1961-1967. soil party of the Chuvash Agricultural Institute under the leadership of Professor S.I. Andreev. By the end of the 60s, material on assessing the state of soil fertility and soil erosion was summarized.

In soil surveys, exceptional attention was paid to the scale of soil erosion, as one of the main limiting factors in the development of agriculture in the republic. It turned out that the Krasnochetaisky, Poretsky, Shumerlinsky and Alatyrsky districts had the least erosion. And the largest scale of soil loss was identified in the Marposadsky, Cheboksary, Kozlovsky and Alikovsky districts.

And by 1985, soil surveys showed that the area of ​​eroded land had increased. By the end of the 60s, the state of soil fertility was characterized by the following indicators: humus constituted a low and very low supply of mobile phosphorus. The soils were poorest in exchangeable potassium. About 25% of the arable land needed liming. Large areas of acidic soils were distributed in the territories of Alatyr, Poretsky, Shumerlinsky, Cheboksary, Marposadsky and Ibresinsky districts.

Large-scale soil surveys 1961-1967. showed the high erodibility of the lands of Chuvashia, the average level of potential and low level of effective fertility of arable land. The materials from such a study of the state of soils subsequently provided great assistance in improving and improving both individual elements and the agricultural system of the Chuvash Republic as a whole.

The completion of this great work coincided with the beginning of the intensification of agriculture through chemicalization, land reclamation and mechanization, which continued to increase until the end of the 80s. The widespread use of mineral fertilizers, liming, phosphorite treatment and increased use of organic fertilizers had a significant impact on the level of soil fertility throughout the republic. In the 80s, the republic reached the level of a positive balance of nutrients in agriculture. As effective soil fertility increased due to intensification factors, agricultural yields gradually increased.

Since 1994, for well-known reasons, the country has sharply reduced the use of mineral fertilizers, the volume of chemical reclamation of arable land = liming, phosphorite treatment and other measures. Therefore, since this year there has been a stable negative balance of macroelements and, since 1996, of organic matter in the soil.

In general, the state of soil fertility in Chuvashia in terms of agrochemical indicators by the end of the 20th century can be considered quite satisfactory. However, in the agriculture of the republic it is necessary to take into account the increasing negative balance of organic matter and mineral nutrition elements in the soil.

Research conducted in the last 10 years by the departments of general agriculture, soil science and agrochemistry show that among the limiting reasons, agrophysical and biological indicators of soil fertility come first: structure, density, water permeability, biological activity of the soil, mesofauna, etc. Therefore, the main direction expanded reproduction of soil fertility, along with maintaining agrochemical indicators, should be considered a significant improvement in water-physical properties and biologization of intensification processes in the soil and agrocenoses.

Conclusion

So, we tried to understand the significance of soil fertility in general, its significance for the economy, plants, etc. and so on.

As was said in the chapter on soil fertility, soil fertility is the ability of the soil to satisfy the needs of plants for nutrients, water, to provide their root systems with sufficient air, heat and a favorable physical and chemical environment for normal activity. It follows that soil fertility is the most important property of the soil, without which the normal development of plants would be impossible, without soil fertility agricultural activity would be impossible, it directly affects the development of agriculture.

Consequently, the soil is not only the subject of human labor, but to a certain extent also the product of this labor. Thus, soil science studies soil as a special natural body, as a means of production, as an object of application and accumulation of human labor, and also, to a certain extent, as a product of this labor.

As the main means of production in agriculture, soil is characterized by the following important features: irreplaceability, limitation, immobility and fertility. These features emphasize the need for exceptionally careful treatment of soil resources and constant concern for increasing soil fertility.

Bibliography

Gennadiev, A.N. Geography of soils with basics of soil science/A.N. Gennadiev, M.A. Glazovskaya - M.: Higher School, 2008. - 462 p.

Belobrov, V.P. Geography of soils with fundamentals of soil science/V.P. Belobrov, I.V. Zamotaev, S.V. Ovechkin - M.: Publishing center "Academy", 2004. - 352 p.

Motuzova, G.V. Compound of microelements in soils: systemic organization, environmental significance, monitoring/G.V. Motuzova - M.: Editorial UPSS, 1999. - 166 p.

TSB, volume 20 – editor-in-chief A.M. Prokhorov - M.: from "Soviet Encyclopedia", 1975. - 608 p.

Soil fertility is the basis of highly efficient agriculture (materials of the interregional scientific and practical conference dedicated to the 100th anniversary of the birth of Professor S.I. Andreev, June 22-23, 2000) - Cheboksary: ​​from the ChGSHA, 2000. - 181 p. .

Problems of soil evolution (materials of the IV All-Russian Conference of the Russian Academy of Sciences, Institute of Chemical and Biological Soil Science. Dokuchaevsky Society of Soil Scientists. - Pushchino, 2003. - 261 p.

Ganzhara, N.F. Soil Science/N.F. Ganzhara - M.: Agroconsult, 2001. - 392 p.

Kaurichev, I.S. Soil Science/I.S. Kaurichev, N.P. Panov, N.N. Rozov et al. - M.: Agropromizdat, 1989. - 719 p.

Bazdyrev, G.I. Agriculture/G.I. Bazdyrev, V.G. Loshakov, A.I. Puponin et al - M.: KolosS, 2004. - 552 p.

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Annex 1

Table 1. The relationship between the reflectance coefficient and the humus content in sandy soils of Belarus (according to Zborischuk, 1994)

Posted onBasic laws of agriculture

The role of humus in soil fertility. Existing methods of weed control are agrotechnical, mechanical, biological. Soil conservation treatment. Basic laws of agriculture. The importance of the combined use of organic and mineral fertilizers.

Interaction of humic substances with the mineral part of the soil. Aerobic anaerobic processes in soil. Their role in the fertility and life of plants. Agronomic features of podzolic soils and their cultivation. Use of swamps and peat in agriculture.

Characteristics of JSC Plemzavod "Semenovsky". Production and use of organic fertilizers. Liming of acidic soils. Natural and energy efficiency of the fertilizer application system. Use of fertilizers when their quantity is limited.

Ministry of Agriculture and Food of the Russian Federation Don State Agrarian University Department of Agrochemistry, Soil Chemistry and Plant Protection.

Chernozem is a type of soil that forms under steppe and forest-steppe vegetation of the subreal zone, hypotheses of its origin. Gradation of chernozem by type, thickness and content of the humus layer. Its properties, areas of distribution and application.

Features of soil fertility in Bashkortostan. Optimal parameters of the composition and properties of the soil. Factors limiting soil fertility. Factors of productivity of phytocenoses and crop yields. Methods for studying soil fertility.

The essence of soil reclamation. Objectives of reclamation works. Phytomelioration as a set of measures to improve the conditions of the natural environment through the cultivation or maintenance of natural plant communities. Phytomeliorative methods for soil restoration.

The influence of the mechanical, mineralogical and chemical composition of soil-forming rocks on the agrochemical properties of the developing soil. Chernozems of the forest-steppe and steppe zones, their characteristics, use. Measures to increase and preserve fertility.

Agricultural land. Land as an active means of production. The task of the land user. Identification of factors influencing the efficiency of land use and ways to improve it. System of economic efficiency indicators.

The land with its soil cover, waters and vegetation and its role in agriculture. Land as a sphere of application of labor and spatial basis. Fertility management is the key to increasing land productivity. Artificial and natural fertility.

Description of the agricultural production properties of the Primanych depression. Results of monitoring the reaction of the soil environment in the region: loss of humus from erosion processes, deterioration of the nutritional regime of arable land. Ways to increase the productivity of land in the Stavropol Territory.

The most important prerequisite and natural basis for the creation of material wealth is land resources. The role of the earth is truly enormous and diverse. The importance of rational use of land resources in the economics of agriculture and the country as a whole.

Zonal types of land - for agriculture, livestock raising, forestry. Land suitability categories. Economic fertility. Capital investments in agriculture. Cost of agricultural products. Concept, types of structure by cost elements.

Soil-forming rocks. Chernozems of the forest-steppe and steppe zones, their characteristics, use. Measures to increase and maintain fertility. The importance of perennial grasses in crop rotations. Characteristics of mineral fertilizers. Fertilizer systems in crop rotation.

Completed by: 2nd year student, group 1493 Larionov Alexander the Great Novgorod, 2003. Ministry of Education of the Russian Federation Novgorod State University

Academy of Agriculture and Natural Resources Department of Soil Science and Agriculture COURSE WORK "Soil cover of part of the territory of the Yartsevo state farm" Lyubytinsky district, Novgorod region

The concept of soil as a habitat for various microorganisms, its essence, classification and properties. Main types, characteristics of vital activity and methods for determining the composition of soil microorganisms, as well as their role in the formation of soils and their fertility.

The formation (genesis) of any soil is the result of a complex interaction of soil-forming factors. Since certain patterns are observed in the distribution of factors on the earth's surface, they are naturally reflected in the distribution of soils. The main patterns in soil geography are expressed by the following laws: the law of horizontal (latitudinal) soil zonation, the law of vertical soil zonation, the law of soil facies, the law of similar topographic series.

Law of horizontal (latitudinal) soil zonation. Formulated by V.V. Dokuchaev. Its essence lies in the fact that since the most important soil formers (climate, vegetation and fauna) naturally change in the latitudinal direction from north to south, then the main (zonal) types of soils should successively replace each other, located on the earth’s surface in latitudinal stripes (zones) ). This law reflected the main position of Dokuchaev’s genetic soil science that soil as a special natural formation is a consequence of a certain combination of soil-forming factors, and at the same time was the result of a generalization of the extensive geographical research of V.V. Dokuchaev on the study of soils of the Russian Plain.

The law of latitudinal soil zonation is reflected in the following two main manifestations. The first is the presence on the land surface of the globe of successively replacing each other soil-bioclimatic (thermal) zones, characterized by similar natural conditions and soil cover, due to the commonality of radiation and thermal indicators (see Table 5). When moving from north to south within the Northern Hemisphere, five zones are distinguished: polar, boreal, subboreal, subtropical and tropical. Similar belts can be identified in the Southern Hemisphere.

The second manifestation of the law of horizontal soil zonation is expressed in the division of soil-bioclimatic zones according to the totality of soil formation conditions and general features of the soil cover into soil zones - latitudinal bands in connection with the natural pattern of not only thermal conditions, but also moisture (see Table 6) and, as a result, vegetation.

The most clearly latitudinal soil zones are isolated in vast flat areas within continents (Russian Plain, Western Siberia, etc.). Thus, the subboreal zone within Central Eurasia is divided into the following zones: forest-steppe (gray forest soils, podzolized, leached and typical chernozems) - steppe (common and southern chernozems) - dry steppe (chestnut soils) - semi-desert (brown semi-desert soils) - desert (gray-brown desert, takyr, takyr-like and desert sandy soils). On the territory of continents adjacent to oceanic and sea basins, this sequence in the change of latitudinal soil zones is disrupted due to the complicating influence of moist air masses flowing from vast expanses of water on changes in soil formation conditions (climate, vegetation and soils).

Law of vertical soil zonation. It states that in mountainous terrain, natural, consistent changes in climate, vegetation and soil occur due to changes in the absolute altitude of the area. As you rise from the foot of the mountains to their peaks, the air temperature decreases by an average of 0.5 ° C for every 100 m of absolute height, which entails a change in the amount of precipitation and, as a consequence, changes in vegetation and soils. These changes are manifested in the formation of vertical plant-climatic and soil belts (vertical zones). In general, the successive change of zones is similar to their change in flat areas when moving from south to north. For example, if the lower zone is represented by chernozems, then as the absolute height increases, gray forest soils can be located, then soddy-podzolic soils, etc.

This general pattern of sequential change of vertical soil zones can be complicated and disrupted due to the characteristics of the mountainous terrain (sharp changes in absolute heights, steepness and exposure of slopes, types of macrorelief - plateau, intermountain depressions, diversity of slopes, etc.) and frequent changes of soil-forming rocks .

The specific composition of soil vertical zones is determined by the position of a mountainous country in the system of latitudinal zones and the absolute heights of its relief.

Law of soil facies. The point is that the soil cover in certain meridional parts of thermal belts and zones can change noticeably due to climate change under the influence of thermodynamic atmospheric processes. These changes are due to the proximity or distance of specific parts of the belt or zone from sea and ocean basins, as well as the influence of mountain systems, etc. They manifest themselves in the form of an increase or decrease in atmospheric moisture and continental climate.

Such changes affect vegetation and the manifestation of soil-forming processes. Facies features of the soil cover are often expressed in the differentiation of soils by temperature regime (warm, moderate, cold, non-freezing, freezing, long-freezing soils, etc.), in the emerging differences in the structure of the profile (thickness of humus horizons, etc.) and the properties of the zonal soil type or subtype, and sometimes in the emergence of new types in a given facies.

As an example of the manifestation of the law of facies, we can cite the territory of the boreal belt on the Eurasian continent. Here, moving from west to east, wetter and warmer climate conditions are gradually replaced by increasing continentality and coldness in Eastern Europe and further in Western and Eastern Siberia. In the Far Eastern Primorye, humid oceanic climate conditions again dominate. In connection with this change in hydrothermal conditions, there is a consistent change from sod-podzolic moderately warm short-term freezing soils to moderate freezing soils (the center of the European part of the belt) and then to moderately cold long-term freezing soils (southern part of taiga Siberia), then the emergence of specific types of permafrost-taiga soils (Eastern Siberia) and brown-taiga soils (Primorye).

Regularities in soil geography, manifested in the form of laws of latitudinal and vertical zonality and the law of soil facies, are a consequence of the pattern of changes in bioclimatic conditions over vast territories in connection with their latitudinal and meridional position on the continents.

Law of analogous topographic series. Reflects a similar regular change of soils along the elements of meso- and microrelief in all zones. The essence of this law is that in any zone the distribution of soils on relief elements is of a similar nature: elevated elements contain soils that are genetically independent (automorphic), which are characterized by the removal of mobile soil-forming products and the accumulation of sedentary ones; on lowered relief elements (slope trails, bottoms of lowlands and depressions, lakeside depressions, floodplain terraces, etc.) there are genetically subordinate soils (semihydromorphic and hydromorphic) with the accumulation of mobile soil formation products brought with surface and intrasoil runoff from watersheds and slopes ; on slope elements of the relief there are transitional soils, in which, as they approach negative forms of relief, the accumulation of mobile substances increases.

SOIL COVER STRUCTURE

The territory of any farm, often a separate field and even a small plot, is characterized by a combination of several soils.

The entire set of soils in a particular territory is called its soil cover (SC). We can talk about the soil cover of the Earth, individual continents, countries, farms, their individual land plots, etc.

In his practical work, an agronomist always deals not with just one soil, but with all their diversity, which characterizes the soil cover of a particular territory. For the rational use of the soil cover of a particular territory, it is important to take into account not only the properties and level of fertility of each soil in the area, but also to know how many contours, what size and shape each soil is represented in this territory, i.e. what PP pattern is formed by all soils, its components, how close or different (contrasting) these soils are in relation to each other in terms of their agronomic qualities, which determine the conditions and timing of field work, the range of cultivated crops, the use of fertilizers, etc.

An idea of ​​this is given by knowledge of the soil cover structure (SCS). The doctrine of soil cover structure is based on the concept of elementary soil area (ESA). An elementary soil area is a section of territory occupied by one specific soil of the lowest taxonomic level (category), limited on all sides by other ESA or non-soil formations (quarry, reservoir, etc.). The characteristics of the ESA are determined by the name of the soil, the size and shape of the contour, as well as the dissection of its boundaries. Small-contour EPAs are distinguished by size (<1га), среднеконтурные (1-20 га), крупноконтурные (>20 hectares).

Elementary soil areas, replacing each other, form soil combinations (SC), which characterize the SSP of a particular territory.

The most important characteristics of PCs are their component composition, the size of the EPAs included in them and the degree of agronomic differences (contrast) between them.

There are six (classes) of soil combinations (Table 37).

37. Classification of soil combinations

PC by size	PC classes		Advantageous factor
	contrasting	low-contrast	PC formation
Microcombinations	Complexes	Spotting	Microrelief
Mesocombinations	Combinations	Variations	Mesorelief
Meso- and macrocombinations			Change of rocks (mosaics); change of rocks and vegetation (tachets)

The larger the ESA areas in the soil combination, the more homogeneous they are in agronomic properties, the more agronomically favorable the SPP. And, conversely, the more (more contrasting) in combination one soil differs from another, the smaller the ESA area, the more unfavorable the SSP in agronomic terms. In patchiness, the small sizes of EPAs do not play a noticeable negative role, since the soil components of the patchiness are similar (non-contrasting) in their agronomic properties. Karmanov distinguishes three groups of SPP according to their agronomic qualities: agronomically homogeneous, agronomically heterogeneous compatible, agronomically heterogeneous incompatible.

Agronomically homogeneous SSPs make it possible to apply the same set of agrotechnical and reclamation measures on plots (crop rotation fields, etc.), carry out sowing and harvesting at the same optimal times and obtain similar crop yields. Agronomically homogeneous SSPs can always be included in one field of crop rotation. Agronomically homogeneous SSPs are represented by spots, variations and tachets. For example, SSP of a crop rotation field with a combination of patches (fine-contour patches) of medium-deep and thick chernozems or variations of soddy-weak- and medium-podzolic loamy soils.

Agronomically heterogeneous compatible SSPs include territories that require, when using soils from an array of small differences in the systems of agrotechnical and reclamation measures, with their overall uniformity. At the same time, the timing of field work on the contours of the soils of this structure is close, although the yields may vary noticeably. Such WBS can be included in one field. In this case, it is necessary to implement methods for leveling the fertility of the soils that make up the SSP of the site. An example of agronomically heterogeneous compatible SSPs can be combinations of unwashed and slightly washed away soils.

Agronomically incompatible SSPs require qualitatively different measures and do not allow basic field work to be carried out within the same time frame. As a rule, they are not included in one field. In some cases, they can be included in one field of specialized crop rotations (forage, soil protection). In this case, it is necessary to take into account the ratio of agronomically incompatible soils in the composition of the SSP, the area of ​​their contours, the nature of the boundaries, relative location, etc. As an example of the agronomic incompatibility of SSP, one can cite the combination of sod-podzolic soils of uplands and gentle slopes with highly gleyed soils of hollows and depressions, a combination of uninhabited and highly saline soils.

There are special methods for quantitative assessment of the complexity (variegation), contrast and heterogeneity of SPP, developed for soils in different zones. At a qualitative level, such an assessment can be made based on the comparative characteristics of soils of various agricultural production groups (see Chapter 37). The study of SPP is based on soil cover mapping.

SOIL-GEOGRAPHICAL AND NATURAL-AGRICULTURAL ZONING

To divide the territory into separate parts based on the commonality of their soil cover and the natural conditions of its formation, two types of zoning are carried out: soil-geographical and natural-agricultural.

Soil-geographic zoning is a method of analyzing and identifying the main features of the soil cover and identifying on this basis territories that are homogeneous in their zonal-provincial characteristics, structure and possibilities for agricultural use.

The main unit of soil-geographical zoning is the soil zone - an area of ​​one or several zonal soil types in combination with other accompanying (intrazonal, intrazonal) soils.

The soil zone is united into larger taxonomic units - the soil region and further into the soil-biocymatic (thermal) belt. Based on the characteristics of the soil cover, in connection with the differentiation within the zone of conditions of heat supply, moisture and continentality, the zone is divided into subzones (not always) and soil provinces. The latter, in turn, are divided into soil districts, and the district into soil regions.

A soil district is a part of a soil province characterized by a certain type of soil combinations determined by the characteristics of the topography and soil-forming rocks.

A soil region is a more homogeneous part of the territory of a soil district, characterized by one type of soil mesostructure. Typically, soil regions within a district differ in the quantitative ratio of rows, species and varieties characteristic of the district.

For mountainous territories, they use their own taxonomy of soil-geographical zoning, below the soil-bioclimatic region: mountain province (a set of vertical zones of a specific mountain territory), vertical soil zone, mountain soil district, mountain soil region.

Natural and agricultural zoning involves dividing a territory into separate parts based on an assessment of the entire complex of physical and geographical conditions (climate, topography, soils, etc.) and their compliance with the requirements of agricultural production. It is based on materials of soil-geographical zoning, but provides for a more in-depth and versatile analysis of them, taking into account the requirements of agricultural production. Therefore, it serves as a natural scientific basis for the placement of agricultural production, the development, starting from the scale of the country and ending with the territories of individual farms and land users, of rational systems for its management (determination of specialization, farming systems with all links, etc.).

There is the following system of taxonomic units of natural-agricultural zoning: natural-agricultural zone (the highest level of zoning) and then for lowland territories - natural-agricultural zone, province, for mountainous - natural-agricultural mountain regions, mountain provinces and mountain districts.

Each taxonomic unit is characterized by a combination of certain natural conditions and associated features of agricultural production.

The natural-agricultural zone is distinguished by the sum of active temperatures (>10°C). The following natural and agricultural belts are distinguished.

Cold tundra-taiga (∑t > 10 °C to 1600 °C). It is characterized by low heat supply, limiting field farming (it is strictly selective). The main areas of use of natural biological resources are reindeer husbandry, fur farming, hunting and fishing.

Temperate zone (∑t > 10 °C 1600-4000 °C) - intensive farming and livestock farming (forest, forest-steppe and steppe zones), selective farming and pasture livestock farming (semi-desert and desert zones), crops with moderate heat requirements.

Warm subtropical zone (∑t > 10 °C over 4000 °C) - irrigated and rain-fed subtropical agriculture, transhumance and livestock farming, heat-loving crops with a long growing season.

The main unit of natural and agricultural zoning is the natural and agricultural zone. In terms of the complex of conditions (climate, soil, etc.) it basically corresponds to the soil-climatic zone, however, taking into account the special demands of agricultural crops on moisture and heat supply conditions, the taiga-forest soil zone is divided into several independent natural-agricultural zones zones The following zones are distinguished: polar-tundra, forest-tundra, northern taiga, middle taiga, southern taiga, forest-steppe, steppe, dry steppe, semi-desert and desert.

A natural-agricultural province is a part of a zone characterized by facies characteristics of the soil cover associated with changes in the continentality of the climate, the severity and snowiness of winter, and indicators of heat and moisture availability during the growing season.

These features of the soil and climatic conditions of the province determine important features of agricultural production - the main set of crops, the general nature of agricultural technology, the level of efficiency of fertilizers, etc.

The natural and agricultural district is distinguished as part of the territory of the province with more homogeneous geomorphological and hydrological features, soil cover, macro- and microclimate. Its identification provides the basis for more differentiated and specific agricultural production within the province (a more limited set of crops and varieties adapted to local conditions is established, agricultural techniques and land ratios are specified in accordance with the soil-geomorphological characteristics of the district territory, crop rotations are specified and etc.).

Natural-agricultural and soil-geographical zoning makes it possible to have fairly complete information about the quantity and quality of soil resources and, on the basis of this information, to carry out their most rational use.

SOIL CLASSIFICATION

Successful study and correct use of the extremely large variety of soils is impossible without their strictly scientific classification. Soil classification is the grouping of soils into groups according to their characteristics, properties and fertility characteristics.

The basis for constructing modern classifications is the genetic principle, according to which the characteristics and properties of soils should be considered as a consequence of soil-forming processes that arise and develop under the conditions of a specific combination of soil-forming factors.

The fundamental ideas of genetic classification were developed by V.V. Dokuchaev and N.M. Sibirtsev.

In the first schemes of genetic classifications they constructed, soils were united into large groups (genetic types), characterized by a common profile structure and some properties (humus content, presence of salts, etc.), which are a consequence of the commonality of soil-forming factors in their main features.

For example, for the type of chernozem soils (chernozems), the common features are the presence of a dark (dark gray, black) layer well stained with humus, which has a distinct lumpy-grained structure, gradually turning into a slightly modified soil-forming rock, their confinement over large areas to territories with a moderately warm climate with some lack of atmospheric moisture, with meadow-steppe or steppe herbaceous vegetation.

A common feature of the structure of the soil profile of the podzolic type is the separation of a whitish (podzolic) horizon under the forest litter layer. They form under taiga-type forests in a moderately cold, humid climate. V.V. Dokuchaev and N.M. Sibirtsev noticed that such a combination of climate, vegetation and soils is characteristic of the vast latitudinal strips of flat spaces in Russia.

Such territories are called natural zones, and the corresponding soil types are called zonal soils. These included tundra, podzolic, chernozems, gray forest and some other soils. Within the zones, individual soil types, in addition to the zonal ones, could be formed under conditions that differed in the combination of factors from the typical zonal ones. For example, persistently excessive moisture in depressions of the relief, highly saline soil-forming rocks, atypical for those dominant in the zone, the manifestation of intense geological processes (deposition of alluvium in river floodplains), etc. The soils formed under these conditions differed in profile structure and properties. For example, excessive moisture contributed to the formation of swamp soils, saline rocks - solonchaks and solonetzes, and alluvial sediments - alluvial soils. Such soils, in contrast to zonal ones, were called azonal and intrazonal by V.V. Dokuchaev and N.M. Sibirtsev.

In the genetic classifications of V.V. Dokuchaev and N.M. Sibirtsev, some soil types were divided into smaller groups - subtypes, which was explained by the need for a more detailed division of soil types.

The genetic principle of classification turned out to be successful. It received wide recognition and subsequent development. In Russian soil science, a number of classification schemes were developed that reflected the general genetic principle of their construction, but differed depending on the role of a particular factor or soil formation process. When constructing schemes, some authors gave primacy to rocks (lithogenic schemes), others - to climate (climatogenic schemes), others - to vegetation and climate (bioclimatic), and fourth - to soil formation processes (actually genetic, etc.).

In all schemes, the genetic type of soil was taken as the basic unit of classification.

As soil science developed, the classification of soils developed and improved. At the same time, the concept of soil type was clarified and deepened, a system of subordinate taxonomic units was developed, which makes it possible to divide the large variety of soils united into a single genetic type into its smaller groups, as well as to combine types at a higher taxonomic level (series, groups).

The need to divide soil types into smaller groups is obvious, since within a type there are soils of different granulometric compositions, formed on different rocks, having different horizon thicknesses, different humus contents and heterogeneity in other indicators. Naturally, these differences differentiated soils within the type and according to the characteristics of their fertility.

Currently, the following system of taxonomic units is adopted in the domestic classification of soils: type - subtype - genus - species - variety - category.

Genetic type is a large group of soils, distinguished by the common structure of their profile, due to the uniformity of the supply and transformation of organic substances and the complex of processes of decomposition and synthesis of mineral compounds, the uniformity of the processes of migration and accumulation of substances and the uniformity of measures to increase and maintain soil fertility.

Soil types are divided into subtypes.

Subtypes are groups of soils within a type that differ qualitatively in the manifestation of the main process or acquire characteristic features in the structure of the profile and properties in connection with the manifestation of the overlapping process.

Zonal soil types are divided into subtypes taking into account the properties and characteristics determined by both subzonal and facial features of the natural conditions of their formation. The criteria for identifying subzonal subtypes are the structural features of the profile in connection with the manifestation of the main and overlapping processes (the thickness of the horizons and the nature of their expression, etc.). Facies subtypes are distinguished by the characteristics of their temperature regime - by the sum of temperatures at a depth of 20 cm and the duration of the period of negative temperatures at the same depth (duration of freezing).

The identification of facial subtypes is important for assessing temperature conditions during the selection and cultivation of crops.

Genera are distinguished within a subtype according to the qualitative characteristics of soils (properties, profile structure, regimes) that arise in soils of the subtype under the influence of local conditions - rock composition, groundwater chemistry, characteristics inherited from previous stages of soil formation (relict), etc.

Soil types are distinguished within the genus according to the degree of development of soil-forming processes (thickness of individual horizons, degree of humus content, salinity, etc.).

Soil varieties are distinguished by the granulometric composition of their upper horizon.

Soil categories are determined by the genetic properties of soil-forming rocks (moraine, alluvial, fluvioglacial, marine, etc.) with an indication of their granulometric composition. The division of soils at any taxonomic level (combination into types, subtypes, genera, species, etc.) is carried out according to the properties and characteristics of soils, determined both by the manifestation of a natural process and acquired as a result of economic activity during their use.

Soil types are combined at a higher taxonomic level. For example, combining types into series according to the generality of the moisture regime: automorphic, semi-hydromorphic and hydromorphic, as well as according to the generality of some indicators of their composition and properties (bio-physico-chemical series - according to humus composition, reaction, the presence of carbonates, salinity and other indicators). Other soil groups are also known.

Here is a systematic list of the main soil types by zone.

Soil types
Tundra gley
Podzolic	Taiga-forest
Permafrost-taiga non-gleyed
» gleyed
» » fawn
Sod-podzolic
Swamp-podzolic
Sod-carbonate	Taiga-forest, etc.
Sod-gley
Peat bog riding	Tundra, taiga-forest
» » lowland	Taiga-forest, etc.
Gray forest	Forest-steppe
Brown forest soils (burozems)	Broad-leaved forest
Podzolic-brown earth
Chernozems	Forest-steppe and steppe
Meadow-chernozem
Chestnut	Dry-steppe
Meadow-chestnut
Brown semi-desert	Semi-desert
Gray-brown desert	Desert
Taupe	Subtropical steppes, xerophytic forests and shrubs
Brown
Serozems	Subtropical desert steppes
Meadow-gray earth
Zheltozems	Humid subtropics
Krasnozems
	Forest-steppe, steppe, dry steppes and semi-deserts
Automorphic solonetzes
» semihydromorphic
» hydromorphic
Salt marshes
Alluvial turf	In all zones
» meadow

The components of soil classification are nomenclature and diagnostics.

The nomenclature (name) of soils for large taxonomic units (type, subtype) was formed historically based on the following three provisions: based on the traditional color characteristics of the soil profile and, above all, their upper horizons, which often coincided with the folk names of soils (chernozems, podzols, red soils, etc.); the name of a soil type by color is not only a simple reflection of the typical color of its surface and upper horizon, but in this term generalizes the entire set of properties inherent in a given soil and the level of its fertility, determined by a certain direction of the soil-forming process; landscape terms are also used to name types, characterizing the general features of the conditions for the formation of a soil type - tundra soils, meadow soils, etc.

The name of the subtypes is determined by their geographical location (for example, southern chernozems), the color characteristics of the humus layer (light gray, gray, dark gray forest, dark chestnut, chestnut, light chestnut, etc.).

The names of the genera are associated with the characteristics of properties caused by the corresponding process (gleyic, solodized, solonetzic, etc.) superimposed on the main one, or the presence of relict characteristics and properties (soils with a second humus horizon, residually saline, etc.).

The species name reflects the quantitative expression of a particular property or characteristic - low-humus, low-power, weakly podzolic, weakly, moderately, strongly solonetzic, etc.

The name of the variety is determined by the granulometric composition of the upper horizon - sandy, sandy loam, light loamy, etc.

The genetic name of the rock characterizes the soil type (for example, soils on carbonate loamy moraine, on alluvial sands, etc.).

Soil diagnostics is a set of morphological characteristics, composition indicators, properties and regimes that characterize soil of any taxonomic level and allow one to objectively give it a specific name. Diagnostics are distinguished by morphological characteristics - profile structure, color of individual horizons, their thickness, structure, neoplasms, etc., as well as by micromorphological features.

The main analytical diagnostic indicators are: composition indicators - the content and composition of humus, the gross composition of the mineral part, the content of carbonates, readily soluble salts, mobile forms of nutrients, etc.; property indicators - reaction, cation exchange capacity and composition of exchangeable cations, biological activity; physical properties (density, structure), etc.

Indicators of regime observations (temperature, water, salt, redox, etc.) are also used for soil diagnostics. Diagnostics allows not only to establish (identify) the main features of the genesis of the soil and its belonging to any taxonomic level, but also to give an applied assessment of the soil according to the degree of suitability for a particular type of use (in agriculture and forestry, road construction, etc.) and determine the need to carry out specific measures to improve the soil (reclamation assessment, use of fertilizers, etc.). For example, a pH value indicating a strongly acidic reaction indicates the need for liming of such soil; gleyization indicates the need to regulate the water-air regime. Diagnostic indicators of soil for an agronomist are the initial data for managing its fertility.

Along with the genetic (basic) classification, there are applied classifications (groupings) of soils. They represent the combination of soils into groups according to their suitability for practical use: in agriculture, in its individual types (field cultivation, fruit growing, vegetable growing, pasture use of soils, etc.), in forestry, in sanitary affairs, etc. This grouping is carried out on the basis of an assessment of those genetic indicators that determine the suitability of the soil for its specific practical use.

From the above it follows that when choosing the practical use of soils, the basis is their initial genetic indicators. The most important importance of genetic classification lies in solving practical problems of rational use of soils. At the same time, the agronomist is required to know the specific properties of the soil, the indicators of its composition in the formation of effective fertility. Only then will he be able to correctly use soil genetic diagnostic indicators.

Test questions and assignments

1. In the form of what laws do the main patterns in soil geography appear? Describe them. 2. What is soil structure? Give the concept of elementary soil area and soil combinations. How to take them into account in agronomic practice? 3. Give the concept of taxonomic units of soil-geographical and natural-agricultural zoning. 4. Name the soil zone and soil districts of your region. 5. Name the taxonomic units of soil classification and describe them. 6. What are the main morphological and analytical indicators of soil diagnostics?

Soil fertility ensures the development of soil biota

(higher plants, microorganisms). Fertility is affected by the processes of transformation and transfer of substances and energy. These changes may be different for the development of fertility. For example, accumulating nutrients and improving structure increases fertility. The removal of elements and deterioration of the structure reduces fertility. The creation of soil fertility at the initial level is called reproduction.

Reproduction of soil fertility is an objective law of soil formation. Under natural conditions, it occurs in an incomplete, simple or extended type.

In farming conditions, fertility reproduction occurs under the influence of natural factors and various methods of human influence on the soil. In this case, natural vegetation is replaced by cultivated agrocenoses. Soil formation processes are affected by soil cultivation, the use of fertilizers and other chemicals, and various land reclamation techniques. The development of the anthropogenic soil-forming process under conditions of reasonable activity helps to improve soils and increase fertility. Violation of the principle can lead to loss of soil fertility (development of erosion, salinization, loss of humus, destruction of structure).

Test questions and assignments

Topic 6. Fertility

Give the concept of fertility and its types

Name the groups of soil properties that determine fertility

Describe the conditions of soil fertility.

What are the features of fertility reproduction?

5. Give examples characterizing fertility as a result of the interaction of the composition, properties and regimes of soils.

Topic 7 Main types of soils in Russia

Lesson objectives:

Give the concept of classification and patterns of soil distribution on the territory of Russia.

Familiarize yourself with the concepts: soil zones, soil types and the main features of their formation.

Have an idea of ​​the soils of different natural zones of the Russian territory.

7.1 Main patterns of soil distribution

Any soil is formed as a result of the interaction of soil-forming factors. The distribution of factors on the earth's surface is regular, therefore soils are also distributed regularly, which can be expressed by laws.

Law of horizontal (latitudinal) soil zonation. Formulated by V.V. Dokuchaev. The essence of this law is that soil formers (climate, flora and fauna) naturally change in the latitudinal direction from north to south, therefore the main types of soils must successively replace each other and be located in latitudinal stripes.

On the landmass of the globe, soil and climate zones have similarities when moving from north to south within the Northern Hemisphere. There are five zones: polar, boreal, subboreal, subtropical, tropical. Similar belts can be identified in the Southern Hemisphere. Horizontal soil zonation also appears in accordance with moisture conditions. The most clearly defined latitudinal soil zones are found on the plains within continents.

Law of vertical soil zonation. In mountainous terrain, there is a natural, consistent change in climate, vegetation, and soil due to changes in the absolute altitude of the area. As you rise from the foot of the mountains to their peaks, the air temperature decreases by an average of 0.5 o C for every 100 m of height. Rainfall and vegetation also change. Vertical plant-climatic and soil belts are formed. In general, the sequence of zone changes is similar to their change on the plains when moving from south to north.

Law of soil facies. The soil cover changes in the meridional parts of thermal belts and zones. Soil zones can be located in different ways from sea basins or mountain systems. Therefore, the influence of a humid or continental climate and temperature regime leads to differences in the structure of the soil profile. For example, at one latitude of the territory of Russia, in the center of the European part there are soddy-podzolic soils that are moderately warm and freeze for a short time, and in Primorye there are brown taiga soils.

Law of analogous topographic series. The essence of the law is that in any zone the distribution of soils on relief elements is similar. Genetically independent soils lie on the elevated elements, from which mobile products are carried out. On lower relief elements there are genetically subordinate soils. They accumulate mobile soil formation products brought by runoff. Transitional soils occur on the slopes.

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Changes in the main indicators of soil fertility on different relief elements have been studied. It has been shown that the relief largely determines the distribution of humus, mobile phosphorus and exchangeable potassium content in the arable soil layer, as well as the depth of the arable layer. The smallest depth is noted on the upper parts of the slopes and the greatest depth of the arable layer is on the lower parts of all slopes. There is a general pattern of increasing humus content in the soil as one moves from the upper part of the slope to the lower part. The change in phosphorus content in different parts of different slope exposures is multidirectional. The phosphorus content is highest in the upper part of the northern slope and lowest on the southern slope. In the middle and lower parts of the southern slope, on the contrary, the phosphorus content in the soil is highest. The change in the content of exchangeable potassium in the arable soil layer on different elements of the relief is less clearly expressed than the content of humus and phosphorus. The highest potassium content was noted in the middle part of the southern slope and the lowest content in the middle part of the northern slope. The difference in potassium content in different parts of the northern, western and eastern slopes is relatively small. The variability of soil fertility on different elements of the relief is due to natural factors and anthropogenic impact. The need to take into account the variability of soil fertility in fields with complex terrain when placing and developing technology for cultivating field crops is pointed out.

fertility

1. Abdulvaleev R.R., Ismagilov R.R. Relief as a factor of agroclimate // Materials of the All-Russian Scientific and Practical Conference within the framework of the XIX International Specialized Exhibition “Agrocomplex-2009”. – Ufa, 2009. – pp. 73-75.

3. Ismagilov R.R., Abdulvaleev R.R., Ismagilov K.R. Features of the natural conditions of the Belebeevskaya Upland and measures for their rational use // Collection of articles of the All-Russian Scientific and Practical Conference. – Ufa, 2014. – P. 318-323.

4. Ismagilov R.R. How to “link” basic technology to the conditions of a specific field // Agriculture. – 2000. – No. 4. – P. 26-27.

5. Kashtanov A.N., Yavtushenko V.E. Agroecology of slope soils. – M.: Kolos, 1997. – P. 88-107.

6. Sibirtsev, N.M. Selected works. T. 1. Soil science. – M.: State Publishing House of Agricultural Literature, 1951. – 472 p.

7. Chuyan G.A., Ermakov V.V., Chuyan S.I. Agrochemical properties of typical chernozem depending on slope exposure // Soil Science. – 1987. - No. 12. –S. 39-46.

8. Shirinyan M.Kh., Kildyushkin V.M., Lesovaya G.M. The influence of agricultural landscape relief on soil fertility and fertilizer efficiency // Problems of agrochemistry and ecology. – 2009. – No. 2. – P. 14-17.

9. Shpedt A.A., Purlaur V.K. Assessment of the influence of relief on soil fertility and grain yield // Siberian Bulletin of Agricultural Science. – 2008. – No. 10. – P. 5-1.

Terrain and soil fertility are closely interrelated. The famous Russian soil scientist Nikolai Mikhailovich Sibirtsev considered relief to be one of the main factors of soil formation. He wrote: “... if the soil changes, then it certainly changes for some reason: the parent rock has changed, the relief has changed, the action of atmospheric water has changed due to the relief, the accumulation of moisture has changed, the vegetation cover has changed - the soil has changed accordingly.” Further research showed that relief has a multifaceted effect on soil fertility. The intensity of water soil erosion primarily depends on the structure of the relief. The relief determines the agrochemical properties of the soil, the content of macro- and microelements in it. Hydrological features, radiation and heat balance, the intensity of biological, chemical and physical processes in the soil, determined by the structure of the relief, create diversity in soil fertility even within a small area. The upper and lower parts of the slope and its exposure with a slight steepness (1-3º) have a significant influence on soil fertility indicators, winter wheat yield and fertilizer efficiency. The soil of the southern slope, compared to the soil of the plateau, has a reduced content of humus carbon, mobile humic substances (1.2-1.3 times), water-soluble humus (1.2-1.3 times) and labile organic matter (2. 1 time). Taking into account changes in soil fertility depending on the topography is a necessary condition for adapting the technology of cultivating field crops.

The Republic of Bashkortostan is a unique physical and geographical region where diverse landscapes meet - from dry steppe to mountain tundra. Their soil cover is represented by complex combinations and mosaics of various types, subtypes, types and varieties of soils - the predominance of gray forest (27.9%), chernozems (31.7%), mountain (25%) and alluvial (6%). The territory of the Republic of Bashkortostan is characterized by complex terrain and dissected arable lands. More than 70% of arable land is located on slopes with a steepness of more than 1°. At the same time, in the regional aspect, patterns of changes in soil fertility depending on the topography of the field remain poorly studied and poorly covered in the scientific literature.

Purpose of the study. The purpose of the research was to study soil fertility and its spatial variability on different relief elements.

Materials and methods of research. The research was carried out in 2003-2014 at the Educational and Scientific Center of the Aksenovsky Agricultural College of the Republic of Bashkortostan.

To characterize the study area of ​​the fields of the Aksenovsky Agricultural College, a topographic survey of the fields was carried out using a ThorsonGTS-236N tacheometer on a scale of 1:2000 with a relief cross-sectional height of 1.0 m. The survey of the area was carried out in a polar way: from survey justification points by setting pickets along characteristic areas of the relief. The distances from the electronic total station to the pickets and the horizontal position (L) from the survey justification point to the pickets were measured with a laser rangefinder. The heights of the pickets Нп were calculated automatically. The measurement results were entered into the memory of the electronic tacheometer, and an outline was simultaneously drawn at each station. According to the survey results, 5 fields out of 6 included in the crop rotation had a slope from 2 to 4°, one field did not have a pronounced slope (less than 0.3°). Agrochemical analysis of soil for the content of humus, nitrogen, phosphorus and potassium was carried out at the Laboratory of Biochemical Analysis and Biotechnology of the Bashkir State Agrarian University.

Research results and discussion. Soil fertility determines the productivity and efficiency of crop cultivation. There are potential (natural and artificial) and effective (economic) soil fertility. Potential soil fertility is determined by the supply of humus, nutrients and other living conditions in the soil, being the main means of agricultural production. The manifestation of potential fertility in production activities, characterized by the ability of plants to use nutrients to create crops, is expressed in effective soil fertility. The optimal level of fertility of a particular soil is determined by such a combination of its basic properties and indicators that all vital factors for plants can be most fully used and the capabilities of the cultivated crops can be realized. Based on a synthesis of numerous scientific studies, the main groups of soil fertility indicators include agrochemical, agrophysical and biological.

Research has shown that soil fertility is subject to significant variability within the same field, due to topography. One of the indicators of soil fertility is the depth of the arable layer. Fertile soils are characterized by a deep arable layer. The depth of the arable layer (A 1) on different relief elements differs significantly (table).

Soil fertility depending on the field relief element (UC ASHT, field No. 1)

Part of the slope	Slope exposure
	northern	western	eastern
Depth of arable layer (A 1), cm
Middle
Middle
Middle
Middle

We noted the smallest depth of the arable layer on the upper parts of the slopes and amounted to 16-21 cm, in the middle of the slopes the depth increases to 20-29 cm, and the greatest depth was noted on the lower parts of all slopes (26-41 cm). This difference in the depth of the arable layer is probably caused by both the heterogeneity of the parent rock and erosion processes during the period of agricultural use. Soil from elevated areas of the field is washed away into lower areas, which leads to an increase in the depth of the arable layer.

Humus content is the main indicator of soil fertility. The same pattern of changes in humus content is observed as the depth of the arable layer depending on the relief element. There is a general pattern of increasing humus content in the soil as one moves from the upper part of the slope to the lower part. Thus, in the upper part of the southern slope the humus content was 7.81%, in the middle part - 8.07% and in the lower part - 8.77%. This is also explained by the movement of soil masses by the force of gravity of flowing water into relatively low relief elements. The role of relief increases with increasing difference in relative heights. When comparing different exposures, the highest humus content is observed in the soil of the northern slope (9.5-10.1%), and the lowest content is in the lower part of the western slope. In order of decreasing humus content, the slopes can be arranged in the following row: northern, western, eastern and southern (table).

Nitrogen is one of the main elements of plant mineral nutrition. With a lack of nitrogen, the intensity of growth processes decreases. There is a higher content of easily hydrolyzed nitrogen in both the arable (8%) and subarable layer (26%) of the soil on the northern slope compared to the southern slope. The content of easily hydrolyzed nitrogen in the middle part of the southern slope decreases compared to the upper part, and when moving to the lower part it increases again. A.A. Shpedt also points out that the highest content of humic substances, as a rule, is characteristic of the soil of the hollow. The soil of the northern and southern slopes with a steepness of more than 5° is poorer in nitrate nitrogen compared to the soil of the plateau. In spring, 1.8 times more ammonium nitrogen accumulates in the soil of the northern slope than in the soil of the southern slope.

Phosphorus and potassium are essential macroelements for plant growth and development. The content of available phosphorus in the arable soil layer increases as one moves from the upper part of the slope to the lower part (table). For example, in the upper part of the southern slope the phosphorus content was 69 mg/kg, in the middle part - 126 and in the lower part of the slope - 135 mg/kg. This pattern is observed on slopes of all exposures. At the same time, the change in phosphorus content in different parts of different slope exposures is multidirectional. Thus, the phosphorus content in the soil is highest in the upper part of the northern slope compared to other slopes of the relief. In the middle and lower parts of the southern slope, on the contrary, the phosphorus content in the soil is highest compared to other slope exposures.

The change in the content of exchangeable potassium in the arable soil layer on different elements of the relief is less clearly expressed than the content of humus, nitrogen and phosphorus. The highest potassium content was noted in the middle part of the southern slope and the lowest content in the middle part of the northern slope (table). The difference in potassium content in different parts of the northern, western and eastern slopes is relatively small. On the southern slope, the highest potassium content is in the middle part of the slope, somewhat less in the lower part and significantly less in the upper part of the slope. At the same time, there are experimental data indicating the active removal of exchangeable potassium from the soil on the southern slope.

Conclusions. Relief is a significant factor influencing the content of humus, easily hydrolyzed nitrogen, mobile phosphorus and exchangeable potassium in the arable soil layer, as well as the depth of the arable layer (A 1). The variability of soil fertility on different elements of the relief is due to the natural conditions of soil formation and anthropogenic impact. The heterogeneity of soil fertility should be taken into account when placing and cultivating field crops on relief elements.

Reviewers:

Akbirov R.A., Doctor of Agricultural Sciences, Professor, Professor of the Department of Soil Science, Agrochemistry and Agriculture of the Federal State Budgetary Educational Institution of Higher Education "Bashkir State Agrarian University" of the Ministry of Agriculture of the Russian Federation, Ufa;

Yukhin I.P., Doctor of Agricultural Sciences, Professor, Professor of the Department of Soil Science, Agrochemistry and Agriculture of the Federal State Budgetary Educational Institution of Higher Education "Bashkir State Agrarian University" of the Ministry of Agriculture of the Russian Federation, Ufa.

Bibliographic link

Ismagilov R.R., Abdulvaleev R.R. SPATIAL VARIABILITY OF SOIL FERTILITY ON RELIEF // Modern problems of science and education. – 2015. – No. 1-2.;
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