The history of development and classification of modern farming systems

In the 18th century, the first Russian agronomic scientists, A. T. Bolotov and I. M. Komov, attempted to provide a scientific definition and justification for farming systems. They classified farming systems according to the method of increasing soil fertility (virgin land, fallow, bare fallow, etc.). They considered the correct combination of arable farming and livestock breeding to be the main condition for increasing yield.

In his work "On Farming Systems" (1866), A. V. Sovetov provided the first definition of a farming system: "The various forms in which one or another method of land cultivation is expressed are customarily called farming systems."

Nowadays, a farming system is understood as a complex of interconnected agrotechnical, land reclamation, and organizational measures aimed at the effective use of land and other resources, the conservation and improvement of soil fertility, and the production of high and stable crop yields.

Farming systems have a rich history of development. They emerged and were replaced depending on the development of society's productive forces and scientific and technological progress. The role of socio-economic relations in the development of farming systems was especially emphasized by the first Doctor of Agricultural Sciences in Russia, A. V. Sovetov, while the prominent Russian scientist K. A. Timiryazev said that the culture of the field always went hand in hand with the culture of man.

Farming systems were previously subdivided according to the characteristics of the main measures aimed at increasing soil fertility, or they were named after the type of crop rotation, as it was on this that the most important organizational and agrotechnical measures depended. Farming systems changed with the development of agricultural production, and each corresponded to the levels of intensity of crop cultivation, by which systems are divided into four groups: primitive, extensive, transitional, and intensive.

Primitive farming systems are characterized by a very small area of land cultivated for crops (25% or less). The restoration of soil fertility in these systems relied entirely on the natural processes of nature. These include slash-and-burn, forest-field, virgin land, and fallow farming systems.

The slash-and-burn farming system emerged in the temperate forest zone during the primitive communal system. When reclaiming land overgrown with forest, humans used the force of fire. After burning the forest or tree remains, the soil was enriched with ash containing nutrients for plants, and excess acidity was neutralized, which contributed to an increase in its fertility. On such soils, a harvest (of cereals, flax) was obtained for 2-3 years. Fertility declined, the physical and chemical properties of the soil deteriorated, and microbiological processes faded. The plot was abandoned, and another area was burned. This was barbaric farming that destroyed forests. In the process, the forest litter and soil organic matter were burned. The slash-and-burn farming system persisted until the end of the 19th century.

The slash-and-burn farming system was gradually replaced by the forest-field system, which was based on the alternation of annual crop sowing with forest. Slash-and-burn and forest-field farming systems existed on the territory of Belarus. In steppe regions, where lands occupied by herbaceous vegetation with high natural fertility were reclaimed for arable land, virgin land and fallow farming systems were established.

Under the virgin land farming system, plots of virgin soil were ploughed for grain crops (wheat, barley, millet, etc.) and flax. They were cultivated continuously for 3—4 years. Repeated sowing in the same field and low-level agrotechnics led to weed infestation, one-sided depletion of soil nutrients, and a decrease in crop yield. After the harvest no longer met human needs, the ploughed plots were abandoned and new virgin lands were ploughed. Such a farming system was possible only with a vast area of untouched land and a very small population.

With population growth and the emergence of private land ownership, reserves of virgin lands decreased every year, and people were forced to resort to ploughing previously cultivated plots. This led to the transition of the virgin land system to the fallow system. It is based on the deliberate rotation of lands under crops with land temporarily left fallow to restore lost fertility. As with the virgin land system, under the fallow farming system, the restoration of soil fertility occurred naturally without human intervention. During this farming system, more advanced hoes and shovels appeared, and the wooden plough was replaced by a plough with an iron share and mouldboard. Instead of shallow non-mouldboard tillage, deep and mouldboard tillage began to appear. The development of the fallow farming system is attributed to the slave-owning and feudal systems. In some regions of Ukraine and Central Asia, it persisted until the 19th century.

Extensive farming systems (fallow and ley-farming) are characterized by the fact that all arable land, or a large part of it, is converted into cropland, with a significant portion allocated to fallows. These systems primarily involve the sowing of grain crops; forage and industrial crops are either not sown, or they occupy insignificant (historical review) 39 areas. Soil fertility is maintained by natural factors directed to a greater or lesser extent by humans (fallow tillage, sowing of grasses) and to a lesser extent by industrial means of production (machinery, fertilizers, etc.), as well as by land reclamation.

How the evolution of farming systems protects the soil from depletion

The evolution of farming systems shows how a shortage of available land forces the optimization of crop rotation. Disruption of the balance between grains, fallows, and forage lands in the past led to a sharp drop in yields. Understanding these patterns helps the modern agronomist avoid soil depletion in their fields.

The fallow system replaced the shifting cultivation system when farms experienced a shortage of available land. The fallow rest periods were gradually reduced — from 15, 10, and 5 years to just one year. This one-year rest period (fallow) began to be actively managed: weeds were destroyed, soil moisture was accumulated, and nutrients in the soil were mobilized.

The introduction of bare fallows allowed for the expansion of areas for grain crops. At first, yields were maintained using manure, which was obtained in abundance from natural hayfields. During this period, three-field crop rotation (fallow — winter crops — spring crops) prevailed in the fields of Belarus, although two-field schemes were also used.

Later, with population growth, meadows and pastures began to be ploughed up for grain production. This sharply reduced the livestock population, caused a shortage of organic matter, and halted yield growth. Primitive tillage destroyed the soil structure and provoked severe weed infestation in crops. In Russia, the fallow system remained dominant until the 1930s.

In some regions, a grazing (ley-farming) system was formed based on the fallow structure. Half of the area here was allocated for perennial grasses for hay and grazing, while the remaining part was occupied by grains. In its pure form, the system did not spread in our country, but it included 40 cultivated plants. Later, in the non-chernozem zone, the fallow system was replaced by grain-grass systems, and in the chernozem zone — by fallow-row crop systems.

In the 1920s, based on the synthesis of predecessors' experience, a grassland farming system was developed. Its basic principle is that high soil fertility is provided only by a fine-crumb and water-stable soil structure. Such a state is created exclusively through the cultivation of a mixture of perennial grasses and leguminous grasses.

Within the framework of this concept, sustainable yields were associated only with a structured soil. The cultivation of annual plants was viewed as a factor of inevitable structure degradation and a decline in fertility. Maintaining the structure determined all agricultural practices, including tillage and land reclamation. Modern practice confirms the role of grasses in improving the quality of fields, but the solution to the problem is not limited to grass sowing alone.

Grass sowing was considered a key method for improving arable land due to the following factors:

• intensive enrichment of the soil with humus;
• restoration of a water-stable structure;
• natural disinfection of the topsoil;
• active accumulation of fixed nitrogen.

Practices for establishing grain-grass and fallow-row crop rotations

The grain-grass (improved grain) system was built on the introduction of perennial forage grasses with a two- to three-year usage period into rotation. Row crops and grain legumes were practically absent here or occupied minimal areas. Fertility was maintained through grasses, fallow tillage, and manure application. This system was actively used in the fields of Belarus.

• Share of grain crops — from one-half to 2/3 of the arable land
• Share of bare fallows — 15—20 %
• Share of perennial grasses — 20—30 %

An example of practical implementation was the eight-field grain-grass crop rotation. It differed from standard fallow-grain schemes by the presence of flax and perennial grasses. The crop rotation within it followed a strict sequence for restoring fertility.

1. Bare fallow
2. Winter crops with underseeding of clover and timothy
3. Clover with timothy, 1st year of use
4. Clover with timothy, 2nd year of use
5. Flax
6. Bare fallow
7. Winter crops
8. Spring grains

The introduction of row-crop fields (sugar beet, potato, sunflower, maize) into fallow-grain crop rotations led to the emergence of the fallow-row-crop system. Here, grain crops occupy 50—70% of the arable land, row crops, grain legumes, and pulse crops account for 15—25%, and bare fallow accounts for 15—25%. Soil fertility is maintained through intensive tillage in fallow and row-crop fields, application of fertilizer, and the implementation of measures for moisture accumulation and conservation. An example of a fallow-row-crop rotation: bare fallow; winter cereals; potato; spring cereals.

Currently, the fallow-row-crop farming system is widely used in the grain-producing regions of the south and southeast of the European part of Russia. It is most effective in these regions. Under modern conditions, it is rightfully classified as a group of intensive farming systems.

Unlike primitive, extensive, and transitional systems, intensive farming systems are based on the application of production factors affecting soil fertility. In these systems, all arable lands must be used for sowing valuable food, industrial, and forage crops, and natural forage lands must be converted into cultivated, high-productivity hayfields and pastures. Soil fertility under these systems is increased by applying increasing amounts of organic and mineral fertilizers, proper tillage, the introduction of the most high-yielding cultivars of cultivated plants, the use of agrotechnical, chemical, and biological measures for controlling weeds, plant diseases, and pests, as well as necessary land reclamation measures. The set of crops and their ratio are determined depending on the specialization of the farm and natural-economic conditions.

Intensive farming systems include: crop rotation (fodder-grain), grain-row-crop, and row-crop systems.

Among them, the crop rotation system is the most common. It emerged with the transition from the feudal system to the capitalist one, which created new conditions in social life and requirements for agriculture. It first appeared in Belgium, Holland, France, and Germany in the XVI—XVII centuries, but it gained development in England in the second half of the XVIII century. The structure of sown areas in this system included 50% cereals, 25% row crops, and 25% legumes. An example of this crop rotation is the 4-course rotation first introduced in England in Norfolk County with the following crop sequence: red clover; winter cereals; row crops; spring cereals with clover undersowing. Grain crops here alternate with row crops and legumes; bare fallow is replaced by green manure/catch crops. In this crop rotation, the natural scientific principles of crop sequence are fully realized. The crop rotation system made it possible to significantly increase crop yield and improve land use in Western European countries. This system is characterized by the fact that purely grain-based farming gave way to farming with developed livestock production and the cultivation of row crops and legumes.

Restoration and improvement of soil fertility in this system are primarily provided for through machinery, fertilizers, more sophisticated tillage, and proper crop sequencing in the rotation. In pre-revolutionary Russia and Belarus, the crop rotation farming system did not find wide application in landed and peasant farms due to their weakness and technical backwardness. Currently, in our republic, it is successfully used in farms of various orientations.

The grain-row-crop system is feasible in regions with good moisture supply and under irrigation conditions. Grain crops account for 60—70% of the area, and the remaining area is allocated to row crops and other non-grain crops; here, grain crops are grown in repeat sowings.

A row-crop (industrial-scale) farming system can be defined as one in which the majority of arable land is used for row crops. It belongs to the most intensive systems. It is used on farms growing high-productivity forage and industrial crops (maize, soy, fodder carrot, sugar beet, cotton, sunflower, etc.), as well as in specialized potato farms. Repeat sowings of row crops and intermediate crops are widely used here. There is no bare fallow in this system.

To improve soil fertility in the row-crop system, intensive tillage, high rates of organic and mineral fertilizers, timely weed control, drainage of excessively wet lands, irrigation in arid regions, and soil erosion control, especially water erosion, are of great importance.

At present, the following farming systems prevail in the Republic of Belarus: grain-grass, grain-row-crop, row-crop, crop rotation, green manure (sideral), and soil-protective grain-forage systems.

The grain-grass system is used in farms focusing on grain-livestock production. Its basis is a grain-grass crop rotation containing two groups of crops — grain crops and perennial grasses. When

in Belarus 43 including row crops in such crop rotations, this system can transition into a more intensive crop-rotation farming system.

Grain-row crop system, like the grain-grass system, is used in farms focusing on grain-livestock production. It is based on grain-row crop rotations, in which 60—70% of the area is occupied by grain crops and 30—40% by row crops and other non-grain crops.

Row crop farming system is more common in suburban vegetable-growing and specialized potato farms. It is the most intensive of all systems. In its crop rotations, a large part of the arable land is allocated to row crops.

The crop-rotation system is the most widespread. It is used in farms with a diverse range of crops (forage, grain, potatoes, vegetables, etc.). The crop rotations here do not include bare fallow. About half of their area is occupied by grain crops, and the rest by grain legumes and row crops. This allows for the implementation of the crop rotation principle within them. In farms sowing flax, crop-rotation systems of the flax-forage type are developed.

The green manure system is common in farms located on sandy soils. In its crop rotations, green manure crops are widely used:

• lupine
• serradella
• sweet clover
• field pea, etc.

The soil-protective grain-forage system is found on drained peat-bog soils. To protect and rationally use peat soils, special crop rotations are introduced on them, where 60—70% of the area is allocated to perennial grasses and 30—40% to solid-seeded grain crops. Soil-protective agrotechnical (tillage, sowing) and other measures are widely implemented (agromechanical forest reclamation, construction of hydraulic engineering structures).

In the Republic of Belarus, the structure of sown areas for most regions has developed historically. The following crop structure is scientifically justified:

Such a structure allows for an optimal crop rotation or a system of crop rotations with correct crop succession. In this case, an 8-field crop rotation is used, in which there are four fields of grain crops, one field of row crops, one field of any industrial crop, two fields of clover for one-year use, or one field of clover and one of annual grasses and corn. Such a crop rotation will allow for increasing the gross harvest of crop production by 15—20%, will contribute to the reproduction of soil fertility, improvement of the phytosanitary situation of crops and soil, and protection against weeds, diseases, and pests. 44 cultivated plants

The border between the Eurasian dark-coniferous forest zone and the European broad-leaved forest zone passes through the Republic of Belarus. Three subzones are distinguished within them: the northern one — spruce-broad-leaved forests; the central one — spruce-hornbeam oak forests; the southern one — broad-leaved-pine forests. Within these three subzones, districts are also distinguished: West Dvina, Oshmyany-Minsk, Orsha-Mogilev, Berezina-Predpolesye, Neman-Predpolesye, Bug-Polesye, and Polesye-Dnieper.

The southern limit of the distribution of dark-coniferous forests approximately coincides with the border of the agroclimatic zone with a sum of active temperatures greater than 2200 °С and less than this value, respectively. The northern limit of the distribution of broad-leaved-pine forests roughly corresponds to the line separating territories with a duration of the air temperature period above 10 °С of more than 150 days per year and less than this period. The natural-economic zones of Belarus differ due to these

Fig. 3. Geobotanical zones of Belarus: subzones: А — oak-dark-coniferous forests; Б — hornbeam-oak-dark-coniferous forests; В — broad-leaved-pine forests; districts: 1 – West Dvina; 2 — Oshmyany-Minsk; 3 —

Orsha-Mogilev; 4 — Neman-Predpolesye; 5 —

Berezina-Predpolesye; 6 — Bug-Polesye; 7 — Polesye-Dnieper

Fig. 4. Changes in the borders of agroclimatic regions of Belarus: а — borders of agroclimatic regions according to A. Kh. Shklyar (1973); б — borders of agroclimatic regions according to V. I. Melnik for the period 1989—2005; agroclimatic regions: I — Northern; II — Central; III — Southern; IV — New 46 cultivated plants natural-climatic parameters, as well as due to the nature of the terrain relief, soil structure, vegetation type, hydroecological conditions, climatic, transport, and other features. Sometimes significant differences are discovered between individual farm entities or even within a single farm.

Even the ancient Romans selected species and cultivars of agricultural plants that corresponded to the specific natural features of regions and individual latifundia, taking into account soil differences, slope lighting by sunlight, the prevailing directions and force of the wind (causing, primarily, soil drying), moisture availability, and the nature of runoff, etc.

In accordance with the basic hereditarily determined adaptations of plants to growing conditions and the existing soil-climatic resources, certain patterns of distribution and the association of cultivated species with specific natural zones and subzones are observed in the territory of Belarus. The country's territory is divided into three agricultural zones, within which similar natural conditions are observed and specific features for agricultural production are created, which serves as the basis for the zoning of agricultural crop cultivars.

Global climate warming is also making adjustments to the traditional agro-climatic zones of Belarus, which is reflected in the emergence of a fourth zone in the south of the republic, previously characteristic of Ukraine. Time will test the stability of this new agro-climatic zoning.

In the theory of high yields, an important role belongs to the laws of agriculture. The laws of agriculture are a specific expression of the laws of nature manifesting themselves in the agricultural process. They reveal the regular connections between a developing plant and the conditions of its external environment.

The law of autotrophy in green plants states that green plants, using solar energy and absorbing carbon dioxide from the air, as well as minerals and water from the soil, synthesize all the organic substances they need. This law united two theories: photosynthesis and plant mineral nutrition.

The law of plant autotrophy states that photosynthesis is the fundamental process that actually creates the harvest. Any agricultural practice that increases yield ultimately acts to enhance the use of solar radiation energy, i.e., to intensify photosynthesis. The formation of the harvest depends not only on the leaf area but also on the duration of their functioning.