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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
List of used literature
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 found that all soils on earth's surface are formed through “an extremely complex interaction of local climate, vegetation and animal life, the composition and structure of the parent rocks, the topography of the area 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 that are characteristic of soils of all natural areas, 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 an 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 represents 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, using remote methods, not only at a qualitative, but also at a quantitative level, a fairly large amount of research has been carried out on such soil properties as humus content, salinity, moisture content, erosion, as well as their contamination. 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 Alatyrsky, 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. etc.
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.
List of used literature
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.
Kravtsova, V.I. Space methods for soil research/V.I. Kravtsova - M.: Aspect Press, 2005. - 190 p.
Appendix 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, and biological. Soil conservation treatment. Basic laws of agriculture. The importance of 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 organic fertilizers. Liming of acidic soils. Natural and energy efficiency of the fertilizer application system. Use of fertilizers when their quantity is limited.
Ministry agriculture and food 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.
>>Patterns of soil distribution
§ 27. Patterns of soil distribution
The main types of soils in Russia. Modern soil cover of Russia- the result of a long and complex development of nature as a whole. Depending on the conditions of soil formation in our country, the following types of soils are distinguished: arctic, tundra-gley, podzolic, soddy-podzolic, gray forest, chernozem, chestnut, etc.
Analyze the soil map and catch it. What soils are there in our country?
Match the fig. 48 with the venerable atlas map and determine which soils predominate in the forest zone and which in the steppe.
In the European part of Russia, various podzolic soils predominate, and in Siberia, taiga and mountain taiga soils predominate. Large areas in the north of the country are occupied by tundra soil mi. In the south there are chernozem and chestnut soils.
The phenomenon of latitudinal zoning in our country, especially in the European part of Russia, is more pronounced than in other countries of the world. This is due not only to its significant length from north to south, but also to the predominance of flat land. relief and in conditions of a temperate continental climate.
If we take an imaginary journey along the Russian Plain from north to south on the map, we will see how soils of different types replace each other, differing in structure, color, composition, and fertility. Arctic soils are thin (1-5 cm) and form only isolated spots. In the tundra, tundra-gley and swamp soils are formed. Podzolic soils are formed in intensively leached soils of northern forests. To the south - with a decrease in precipitation and an increase in the thickness of the humus horizon - soddy-podzolic soils. In deciduous forests and under forested areas of forest-steppe there are gray forest soils. The most fertile soils - chernozems - are formed in the steppes. Abundant grass vegetation in this area contributes to an increase in the amount of humus. Here is the most powerful humus layer. When moving south and east climate it becomes drier and warmer, the grass cover is thinner: the soils lighten and turn into chestnut under dry steppes, into brown in semi-deserts, into gray-brown and gray (gray soils) in deserts. As soils become lighter, their salinity increases. In the southern regions of the country (in the Caspian lowland) salt marshes are common.
Rice. 49. Relationship between soil types and climate and vegetation
In mountainous regions, soils, following vertical zonation, also change with climate and vegetation changes. A common property of these soils is gravelly and rough mechanical composition.
Questions and tasks
1. Name the main types of soils in Russia.
2. Using the soil map, determine what types of soils predominate in our country. Explain why.
3. What kind of soils are there in your area?
Geography of Russia: Nature. Population. Farming. 8th grade : textbook for 8th grade. general education institutions / V. P. Dronov, I. I. Barinova, V. Ya. Rom, A. A. Lobzhanidze; edited by V. P. Dronova. - 10th ed., stereotype. - M.: Bustard, 2009. - 271 p. : ill., map.
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Soil classification
Soil classification is usually called the grouping of soils into groups according to their most important properties, origin and characteristics of fertility.
V.V. Dokuchaev and N.M. Siberians adopted a view of soil as a special natural organo-mineral body that develops in close interaction with the environment. They created the doctrine of genetic soil types. Their classification approach was called genetic.
Ecological-genetic classifications of soils, which are based on Dokuchaev’s doctrine of genetic types of soils, were developed by Dokuchaev, Sibirtsev, Afanasyev, Glinka, Zakharov. In these classifications, the connection between genetic types of soils was established not only by their properties, but also by the characteristics of their occurrence and geographic distribution. Ecological-genetic classifications reflect real natural patterns: soil properties and their relationship with the natural environment. For this reason, they provide answers to many questions of agricultural practice and are widely used in qualitative accounting of land resources.
Morphogenetic classifications are based on the most important properties soils, but also include analysis of soil formation conditions.
Principles of constructing a modern soil classification The development of modern soil classification is based on the following basic principles.
1. The classification of soils should be based on the basic properties and regimes of soils and must take into account the processes that create them and the conditions of soil formation, i.e., it should be genetic in the broad sense of the word, combining ecological, morphological and evolutionary approaches.
2. The classification must be based on a strictly scientific system of taxonomic units.
3. In classification, it is extremely important to take into account the characteristics and properties acquired by soils as a result of economic activities.
4. The classification should reveal the production characteristics of soils and promote their rational use in agriculture and forestry.
Modern soil classifications, compared to previous ones, more fully take into account the morphological and micromorphological structure of the soil profile, the composition and properties of soils, the main processes and regimes of soil formation, as well as environmental conditions. The qualitative composition of organic matter, the peculiarities of the biological cycle of substances, intrasoil weathering and issues of the energy of soil formation are also taken into account. All this allows us to better understand the main genetic characteristics of soils, give agronomic characteristics and conduct a comparative assessment of their fertility (grading).
The manual “Classification and Diagnostics of Soils of the USSR” (1977) provides a detailed classification and diagnosis of about 80 soil types in the country, excluding the soils of the Far North and frozen regions of Siberia. Main soil types in Russia(except arctic, tundra and alluvial), grouped by zonal-ecological groups and moisture series.
Each zonal-ecological group is characterized type of vegetation(taiga-forest, forest-steppe, steppe, etc. .), the sum of soil temperatures at a depth of 20 cm from the surface, the duration of soil freezing at the same depth in months and the moisture coefficient. Within zonal-ecological groups, soils are subdivided according to biophysical and chemical properties (humus composition, soil reaction, carbonate content, salinity, salinity, etc.), as well as according to moisture conditions (automorphic, semi-hydromorphic, hydromorphic).
The basic taxonomic unit of modern soil classification is genetic soil type , established by Dokuchaev.
The basis for determining the genetic type of soils was the views of L.I. Prasolov, who believed that soil types are characterized by “unity of origin, migration and accumulation of substances”. In accordance with this, one genetic type includes soils that develop in the same type-associated biological, climatic and hydrological conditions, on a certain group of soil-forming rocks.
Each soil type develops “in the same type of associated biological, climatic and hydrological conditions and is characterized by a clear manifestation of the main process of soil formation with a possible combination with other processes.”
Characteristics soil type is determined by:
The uniformity of the supply of organic substances and the processes of their transformation and decomposition;
A similar complex of processes of decomposition of the mineral mass and synthesis of mineral and organo-mineral new formations;
The same type of migration and accumulation of substances;
Same type of soil profile;
The same type of activities to increase and maintain soil fertility.
Below the soil type, the following taxonomic units are provided: subtypes, genera, species, varieties and soil categories. This descending branch of soil classification (below soil type) is often called soil taxonomy.
Subtypes soils are distinguished within a type; they are transitional steps between types. When identifying subtypes, processes associated with both subzonal and facies changes in natural conditions are taken into account. The division into facies subtypes is carried out taking into account the sum of active soil temperatures (> 10 °C) at a depth of 20 cm and the duration of the period of negative soil temperatures at the same depth (in months) (warm, cold, deep-freezing, etc.). d.).
Childbirth soils are distinguished within a subtype, their qualitative genetic characteristics are determined by the influence of a complex of local conditions: the composition of soil-forming rocks, the chemistry of groundwater, etc.
Soil types are distinguished within the genus and differ in the degree of development of soil-forming processes (degree of podzolicity, salinity, depth and degree of humus content, etc.) and their mutual conjugation.
Varieties soils are determined by the granulometric composition of the upper soil horizons and soil-forming rocks.
Rank soils are determined by the genetic properties of soil-forming rocks (dense rocks, alluvial, cover, etc.).
The full name of the soil begins with the name of the type, followed by subtype, genus, species, variety, category.
Example.
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Chernozem(type), ordinary (subtype), solonetzic (genus), medium-humus, medium-dense (species terms - species), heavy loam (variety), on loess-like heavy loam (category).
Soil diagnostics- a set of soil characteristics by which they are identified and assigned to one or another classification division. To diagnose soils, first of all, signs that are easily established during soil surveys, morphological studies of the soil profile and simple analyzes are used.
The main patterns of soil geography. 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 is essentially that since the most important soil-forming agents (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 . First- the presence on the landmass of the globe of successively replacing each other soil-bioclimatic (thermal) zones, characterized by the similarity of natural conditions and soil cover, due to the commonality of radiation and thermal indicators. 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.
Second The 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 stripes in connection with the natural pattern of not only thermal conditions, but also moisture and, as a consequence, vegetation.
The most clearly latitudinal soil zones are isolated in vast flat areas within continents (Russian Plain, Western Siberia etc.). Thus, the subboreal belt within Central Eurasia is divided into the following zones: forest-steppe(gray forest soils, podzolized, leached and typical chernozems) - steppe(ordinary 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 climate changes occur in 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 ° 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 view the successive change of zones is similar to their change in flat areas when moving from south to north.
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 according to temperature conditions(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 type or subtype of soils, and sometimes in the emergence of new types in this 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 the Territory of 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 essentially 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 lower 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 usually 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 one particular soil, but with all their diversity, which characterizes the soil cover of a particular territory. For the rational use of the soil cover of any 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 in this territory is represented, i.e. what kind of soil plots form 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 structure of the soil cover (SPP). At the root of the study of soil cover structure is the concept of the elementary soil area (ESA). Elementary soil area - a section of territory occupied by one specific soil of the lowest taxonomic level (category), limited on all sides by others EPA or non-soil formations (quarry, pond, etc.). The characteristics of the EPA 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 (<1 га), среднеконтурные (1-20 га), крупноконтурные (>20 hectares).
Elementary soil areas, replacing each other, form soil combinations (PC), which characterize the SPP 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. The larger the ESA areas in the soil combination, the more homogeneous they are in agronomic properties, the more agronomically favorable the SPP. And, on the contrary, 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 spotting, the small sizes of EPAs do not play a noticeable negative role, since the soils that make up the spotting are similar (non-contrasting) in their agronomic properties . There are three groups of SPP according to their agronomic qualities: agronomically homogeneous, agronomically heterogeneous compatible, agronomically heterogeneous incompatible.
Agronomically homogeneous SSP
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.
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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, SPP 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.
Towards agronomically heterogeneous compatible SPPs These include territories that require, when using soils of an array, small differences in the systems of agrotechnical and reclamation measures, although they are generally of the same type. 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. At the same time, it is extremely important 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 SPPs require qualitatively different activities and do not allow basic field work to be carried out within the same time frame. Οʜᴎ, as a rule, are not included in one field. In some cases, they are included in one field of specialized crop rotations (forage, soil protection). In this case, it is extremely important 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 position, 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 non-saline and highly saline soils.
Basic patterns of soil distribution - concept and types. Classification and features of the category "Basic patterns of soil distribution" 2017, 2018.
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 as they move 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 altitude. 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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