Forage crop rotations solve the problem of providing large livestock farms with coarse and succulent fodder. Despite the fact that perennial and annual grasses and silage crops can be cultivated in field crop rotations, fodder production is insufficient to meet the needs of large livestock farms. In this regard, there is a need to use fodder crop rotations, which are the basis of fodder production.
Main crops of forage crop rotations
The main crops of forage crop rotations are:
- perennial leguminous grasses – alfalfa, clover, sainfoin, sweet clover, and Lotus;
- perennial grasses – meadow fescue, timothy, hedgehog, awnless brome, rootless couch grass, ryegrass, etc;
- annual grasses – chino-oat and vetch-oat mixtures, lupine, sorghum, Sudan grass, foxtail millet, etc.
Forage crop rotations may yield hay, baylage, green mass, and grass meal of high quality and high nutrient content. Winter rye, spring and winter vetch, oats, grass pea, peas, soybeans, rape, white mustard, etc. are often used for green mass.
A large variety of crops of forage crop rotations allows to provide the necessary assortment of forage for animal husbandry, but also to develop a crop rotation with an optimal structure of sown areas.
Principles of building forage crop rotations
The modern approach to the construction of forage crop rotations is based on a number of principles.
- Fodder crop rotations must comply with the structure of sown areas established in the farm and meet the needs of livestock in fodder by their quantity, assortment and quality.
- The choice of crops for forage crop rotations depends on specific soil and climatic conditions, which ensure the maximum yield of fodder from a unit area of arable land at its lowest cost and the possibility of using modern technologies of cultivation and use of forage.
- The choice of fodder crops should also be determined by their versatility, such as perennial grasses and others suitable for the production of green mass, silage, roughage or concentrated feed.
- The species composition of crops, the structure of sown areas, the timing of sowing, harvesting or pasturing should provide a continuous supply of green fodder (in the warm period of the year) for livestock under different methods of maintenance and feeding.
- In areas of sufficient moisture and under conditions of irrigated agriculture it is necessary to use intermediate crops.
- The selected fodder crops, the technology of their cultivation and preparation of fodder must ensure reproduction of soil fertility, protection from erosion and the environment.
The principles of forage crop rotations are close to the principles of field and special crop rotations.
Forage crop rotations are divided into:
- on-farm;
- hay-pasture;
- combined.
Combined forage crop rotation is a crop rotation which combines on-farm, hay-pasture, field or vegetable crop rotations.
If a forage crop rotation includes 1-2 fields of vegetable crops, such a rotation refers to forage-vegetable crop rotation. Some soil-protecting and soil-strengthening crop rotations introduced on plots subject to erosion can also be conventionally referred to forage crop rotations.
Forage crop rotations are evaluated according to the yield of fodder units, crude protein, especially valuable amino acids, vitamins and carotene from one hectare of arable land, with simultaneous evaluation of the prime cost of one fodder or fodder-protein unit.
If there are cereal, technical and other crops in forage crop rotations the total average return of production in monetary terms from 1 ha of arable area is evaluated at current prices. The economic assessment can be supplemented with the energy assessment of energy and technical resources inputs per unit production.
On-farm forage crop rotation
On-farm crop rotations are the most widespread among forage crop rotations. According to the structure of cropping areas they differ from field crop rotations by small share or complete absence of cereals, with a high share of row silage crops (sunflower, corn, fodder cabbage, etc.), fodder root crops (fodder beet, rutabaga, carrot, turnip, etc.), potatoes. In some crop rotations fodder watermelon, pumpkin and zucchini are used as forage crops. Corn, oats, barley, peas, lathyrus, fodder lupine, sorghum, chumiza (Setaria italica), etc. are used for fodder grains.
On-farm crop rotations are located near livestock farms, on fertile fields. Crops of little fitness for transportation, such as silage or root crops, occupy large areas in such crop rotations.
Composition of on-farm crop rotations
In on-farm rotations, as well as in field rotations, perennial grasses are sown with one leguminous grass, such as alfalfa, clover, or a simple legume-grass mixture, such as a mixture of clover and timothy or alfalfa with bromegrass (Bromus erectus).
On-farm crop rotations generally do not have bare fallows. More often they belong to row crop rotations, grass-row, cereal-grass-row, and cereal-row crop rotations.
On-farm crop rotations consist of grass and row crop rotations:
- 1-2 – perennial grasses, 3 – row crops;
- 1-2 – perennial grasses – winter intermediate crops for fodder; 3 – row crops;
- 1 – annual grasses with undersowing of perennial grasses; 2-3 – perennial grasses;
- 1 – row crops, 2 – spring grain forage;
- 1 – row crops (corn for silage), 2 – row crops (forage root crops and potatoes).
On-farm crop rotations are characterized by short rotations of 3 to 5-6 years and are located near farms on fertilized fertile soils. The latter circumstance is due to the high saturation of the crop rotation with row crops, often in repeated crops. These crops (corn for silage and green fodder, forage root crops) are very demanding to soil fertility and show high productivity of up to 10 thousand fodder units from 1 ha of arable land against the background of high doses of fertilizers and irrigation.
According to the research of the Moscow Agricultural Academy named after K.A. Timiryazev, saturation from 25 to 100% of the four-field farm rotation with row crops without irrigation in conditions of sod-podzolic loamy soils near Moscow with a simultaneous increase in fertility increased the productivity of the crop rotation more than 2 times.
Table. Productivity of on-farm crop rotations at different saturation with row crops (according to Vorobyov)
When using perennial grasses it is important to choose the right cover crop for their seeding. On fertile fields, overseeding perennial grasses into cereal crops, which usually give large yields, is associated with the possibility of complete fallout or severe thinning of perennial grasses.
Therefore, in on-farm fodder crop rotations, perennial grasses are sown under the cover of crops harvested early from the field, such as annuals for green fodder (vetch-oat mixture) or winter intermediate crops (winter rye for green fodder). According to the recommendations of the All-Russian Research Institute of Fodder, alfalfa is sown into corn for green fodder after one or two cultivations between the rows.
In grass-row on-farm crop rotations it is important to use perennial grasses as a predecessor for row crops. Optimal placement after perennial grasses is the sowing of corn or other silage crops that are good consumers of nitrogen accumulated by legume predecessors, as well as forage crops from the cabbage family – turnip, rape, fodder cabbage, rutabaga, etc. One year after perennial grasses in the crop rotation, potatoes or fodder root crops are placed.
Grass period of on-farm grass-row crop rotation is used for temporary pastures. For this purpose, the period of perennial grasses use is increased up to 3-4 years, starting pasturing from the second half of the second year of use.
For a longer use of perennial grasses, non-rotation (withdrawal) fields or the number of fields up to 3-4 are used. Then it is possible to build an alternating grass-row crop rotation with an extended grass period: 1 – annual forage grasses with undersowing of complex mixtures of perennial grasses, 2-5 – perennial grasses, 6 – corn for silage, 7 – fodder root crops. Such crop rotations are often used in dairy cattle farms under stall-and-pasture conditions.
On pig farms, crop rotations with intermediate crops are used to organize a green conveyor and to obtain grass meal:
- 1 – annual grasses with undersowing of perennial grasses; 2-5 – perennial grasses; 6 – winter rye forage with two mowing periods + post-mowing annual grasses; 7 – annual ryegrass with different mowing periods;
- 1 – annual grasses with undersowing of perennial grasses; 2-5 – perennial grasses; 6 – winter rye for green fodder + post-mowing sowing of annual sauerkraut; 7 – annual grasses + undersowing of annual ryegrass.
The most valuable preceding crops in on-farm crop rotations are perennial grasses and row crops, therefore it is advisable to use their aftereffect to obtain high yields of grain forage and other cereal crops. For this purpose, the structure of sown areas is changed, and grass-row crop rotations are transformed into cereal-grass-row crop rotations with prolongation of rotation up to 8 years:
- 1-2 – perennial grasses, 3 – winter cereals, 4 – corn for silage, 5 – spring cereals, 6 – fodder root crops and potatoes, 7 – spring cereals, 8 – annual forage grasses with undersowing of perennial grasses;
- 1-2 – perennial grasses; 3 – corn for silage; 4 – fodder root crops and potatoes; 5 – spring cereals; 6 – corn for silage; 7 – spring cereals; 8 – annual grasses for forage with undersowing of perennial grasses.
Cereal-row on-farm forage crop rotations, as a rule, have a short rotation, in which row crops and cereals occupy approximately equal areas, replacing each other. For example: 1 – corn for silage, 2 – cereals, 3 – potatoes and forage root crops, 4 – cereals. Cereal-row crop rotations have no perennial grasses, but annual grasses or leguminous plants are possible as predecessors of winter cereals: 1 – annual grasses or leguminous crops, 2 – winter cereals, 3-4 – silage corn, 5 – spring cereals, 6 – fodder root crops and potatoes.
Examples of on-farm crop rotations (for Russian)
Examples of on-farm crop rotations:
- 1 – winter or spring cereals with undersowing of perennial grasses, 2-3 – perennial grasses of 1-2 years of use, 4 – forage root crops and potatoes, 5 – corn for silage;
- 1 – annual grasses with undersowing of perennial grasses, 2-3 – perennial grasses of the 1-2nd year of use, 4 – silage, 5 – forage root crops;
- 1 – spring cereals with undersowing of perennial grasses, 2-3 – perennial grasses of the 1-2nd year of use, 4 – silage crops, 5 – forage root crops, 6 – corn for green fodder and silage, 7 – forage root crops;
- 1 – silage crops, 2 – forage root crops and silage, 3 – legume-mint mixtures for green fodder and silage, 4 – winter wheat;
- 1 – annual grasses for green fodder, 2 – winter cereals, 3 – forage roots and potatoes, 4 – silage crops;
- 1 – annual grasses; 2 – winter crops for green forage with post-mowing sowing of forage sprouts or with planting of potatoes; 3 – forage root crops and potatoes; 4 – corn for green forage and silage; 5 – forage root crops and silage crops;
- 1 – annual grasses or rape (winter, spring), 2 – forage root crops, 3 – corn for silage (non-rotation field), 4 – late potatoes, 5 – sunflower for forage, 6 – early potatoes;
- 1 – annual grasses with undersowing of clover, 2-3 – clover of the 1st and 2nd years of use, 4-5 – corn for silage, 6 – forage root crops, 7 – potatoes.
Non-Black Soil Zone
In the central regions of the Non-Black Soil Zone, 3-4-5-field on-farm row crop rotations are used on cohesive soils:
- 1 – corn for silage, 2 – forage root crops, 3 – silage early crops, 4 – winter cereals;
1-2 – corn, 3 – forage root crops; - 1 – annual grasses with undersowing of clover, 2 – clover, 3 – potatoes, 4 – forage root crops, 5 – corn for silage.
The following rotation is used on light soils: 1 – corn for silage or green fodder + winter intermediate crops for green fodder, 2 – lupine for green fodder, 3 – potatoes and forage root crops, 4 – forage crops.
On some specialized farms crop rotation is effective: 1-2 – perennial grasses of 1-2 years of use, 3 – silage crops, 4 – forage root crops, 5 – vetch-oat mixture, 6 – winter crops for green fodder with undersowing of perennial grasses. Under the condition of high level of agrotechnics, perennial grasses and vetch-oat mixture show higher yield of green mass.
Silage crops and forage root crops coming immediately and one year after perennial grasses, as well as winter crops cultivated after vetch-oat mixture give high yields of green mass and succulent fodder.
In on-farm crop rotations specializing in row crops, their specific weight can be more than 50%.
Forest-steppe and steppe zones
In areas of sufficient moisture and irrigated lands of the forest-steppe and steppe zones of Russia as on-farm crop rotations are used grass-row species of crop rotations, with approximately equal areas occupied by crops of row crops and perennial and annual grasses.
Crops in these rotations are grouped in such a way that two rotation periods are formed – row and grasses. For example:
- 1 – annual grasses for fodder with undersowing of perennial grasses, 2-3 – perennial grasses, 4 – corn for silage, 5 – forage root crops, 6 – corn for silage;
- 1 – annual grasses for fodder with undersowing with perennial grasses, 2-3 – perennial grasses, 4 – corn for silage, 5 – forage root crops and potatoes, 6 – annual grasses for green fodder + intermediate crops for fodder.
Southern regions
In the southern regions of Russia, perennial grasses are often cultivated in the non-rotation fields. For example, the following crop rotation for a dairy farm was introduced in Belorechensk district of Krasnodar Krai: 1 – winter rye mixed with winter vetch for green fodder and post-mowing Sudanese grass, 2 – vetch-oat mixture for green fodder and post-mowing corn for green fodder, 3 – fodder beets + fodder gourds, 4 – Sudanese grass, 5 – corn with soybean for green fodder or silage, 6 – lucerne in the non-rotation field with 4-5 years of use. This set of crops provides dairy cattle with green fodder from spring to late autumn.
In the Kuban regions, alfalfa is cultivated in the non-rotation field during 4-5 years of use, which significantly increases the average green mass yield per unit area.
In arid areas, annual grasses give greater yields than perennial grasses, so more fields with annual grasses, for example, melilot, which give good yields in these conditions, prevail in on-farm crop rotations. An example of a crop rotation: 1 – corn and sorghum for silage, 2 – annual grasses for green top dressing, 3 – winter rye for early top dressing with sowing after its harvest of annual grasses for late green top dressing with seeding of melilot, 4 – melilot of the 1st year of use for green top dressing, 5 – melilot of the 2nd year of use for green top dressing and for silage, 6 – fodder melons (fodder pumpkin, watermelon), 7 – annual grasses.
Hay and pasture forage crop rotation
The main purpose of a hay and pasture forage rotation is the production of hay and green pasture fodder. It is based on crops of perennial grasses with a long period of use, dominating in the structure of sown areas of grass-field or multi-field-grass crop rotation.
The share of low-transportable crops such as root crops, melons or silage crops is small or absent altogether. The simplest example of a hay and pasture crop rotation: 1-7 are perennial grasses, 8 are annual grasses with undersowing of perennial grasses.
These crop rotations, as a rule, are placed on remote massifs, low-yielding natural forage lands, meadows, floodplains of rivers, drained bogs, on lower parts of arable land slopes during creation of cultivated pastures and meadows.
They differ from the on-farm ones in the composition of forage crops and their ratio. Complex grass mixtures consisting of 2-3 or more perennial grasses and 2-3 or more perennial leguminous grasses are used in hay and pasture crop rotations. For example, meadow clover, hybrid clover, creeping clover, meadow timothy, meadow fescue, meadow bluegrass, white bentgrass.
The effectiveness and duration of perennial grasses in hay and pasture forage crop rotations depend on soil, hydrological, agrotechnical conditions and methods of their use.
On dense soils with stagnant water for perennial grasses there are anaerobic conditions, the negative impact of which on the growth and development of perennial grasses increases every year. As a result, the composition of herbage changes, yields and quality of forages decrease. On such plots the duration of perennial grasses use does not exceed 7 years.
On the contrary, well-drained soils with the application of fertilizers, irrigation, periodic undersowing of perennial grasses and proper management can increase the period of their use up to 20-30 years, creating on such plots long-term cultivated pastures and hayfields with high productivity.
In some areas of Russia, different types of grass mixtures are sown, adapted to the conditions of the soil and climatic zone, taking into account the requirements of the specialization of the farm. Thus, hay and pasture rotations complement the on-farm forage crop rotations.
Multicomponent mixtures of perennial leguminous and cereal grasses, which include up to 4-5 and more species, are effective for long-term use. Multicomponent mixtures are more resistant to multiple mowing and pasturing as well as to unfavorable conditions of overwintering or violation of water regime during warm periods, to mechanical effect of machinery or trampling by cattle.
In the first two years of life, perennial grasses are not dense enough turf, and as a result, there is a risk of trampling by cattle. Therefore, in the first years after sowing, grass is used for making hay, haylage, grass meal, and from the third year – for pasturing livestock. For these purposes, in hay-pasture forage crop rotations several fields are allocated annually, used as variable pastures of short term use – from 2 to 5 years.
Thus, the total time of use of perennial grasses is 4-7 years. During this time, perennial grasses form a strong turf, which improves the structure and fertility indicators of the soil, contributes to the accumulation of organic matter in the soil. But anaerobic conditions caused by soil compaction, as well as physiological aging of grasses leads to thinning of crops and deterioration of herbage composition, the number of weeds accumulates. This is the reason for the 4-7-year period of using perennial grasses, after which the field is ploughed and annual crops are cultivated on it for several years.
Thus, the rotation of hay and pasture forage crop rotation can be divided into two periods – meadow and field. During the meadow period the fields are occupied by perennial grasses, during the field period – annual crops. The duration of the meadow period is 3-7 years, while the field period is 2-4 years.
Field, technical and forage crops are cultivated as annual crops, for example, in the fields adjacent to farms – corn for silage, annual grass and forage root crops, annual grasses, in remote fields – fiber flax, cereals, annual grasses. In the first case there may be the following crop rotation: 1-7 – perennial grasses, 8 – corn for silage, 9 – forage root crops, 10 – annual grasses with undersowing of perennial grasses. For remote areas and on soils subject to erosion the variant of meadow-pasture crop rotation is suitable: 1-7 – perennial grasses, 8 – winter cereals, 9 – fiber flax and spring cereals, 10 – annual grasses with undersowing of perennial grasses.
Examples of hay and pasture crop rotations
Depending on the specialization of farms and soil conditions the general schemes of hay and pasture crop rotations may be as follows:
- 1 – annual grasses with undersowing of perennial grasses, 2-5 – perennial grasses of the 1st-4th year of use, 6 – spring grain forage;
- 1-2 – perennial grasses 1-2 years of use for hay, 3-4 – perennial grasses 3-4 years of use for pasturing, 5 – annual grasses, 6 – winter cereals for green fodder with post-mowing sowing of fodder crops (annual grasses, fodder cabbage, turnip), 7 – spring grain-fodder crops with undersowing of perennial grasses;
- 1-2 – perennial grasses of the 1-2nd year for hay, 3-4 – perennial grasses of the 3-4rd year for pasturing, 5 – perennial grasses of the 5th year for pasturing, winter cereals, 6 – winter, silage or forage root crops.
Ramensky district of the Moscow Region uses the following scheme of rotation: 1-4 – perennial grasses of the 1-4-th year of use, 5 – mixed vetch-oat, 6 – corn, 7 – forage root crops, 8 – oats with undersowing of perennial grasses. Perennial grasses account for half of the area, silage and root crops – 25%, vetch-oat mixture and oats – 25%.
Five- and six-field hay and pasture crop rotations are recommended in the Belgorod region: 1-3 – perennial grasses of the 1st-3rd year of use, 4 – winter cereals, 5 – oats with undersowing of perennial grasses.
In Vurnarskiy district of Chuvashia Republic hay and pasture crop rotation was introduced: 1-4 – perennial grasses of 1-4 years of use for hay, 5 – spring wheat, 6 – oats with undersowing of perennial grasses. In this crop rotation 2/3 of sown areas are occupied by perennial grasses and 1/3 by cereals. The third and fourth year of perennial grasses is economically justified where old-age mixtures do not reduce yields and serve as good pastures for livestock.
Sources
Farming. Textbook for universities / G.I. Bazdyrev, V.G. Loshakov, A.I. Puponin et al. – Moscow: Publishing House “Kolos”, 2000. – 551 с.
Fundamentals of agricultural production technology. Farming and crop production. Edited by V.S. Niklyaev. – Moscow: Bylina, 2000. – 555 с.