Forage crops
Forage crops — a group of agricultural crops grown to feed farm animals and poultry.
Most field crops can to varying degrees be classified as forage crops, since their by-products are suitable for feeding to animals. Thus, winter grain crops (rye, wheat, triticale, barley) are used in the green conveyor system. Domestic and foreign breeders have developed special varieties to obtain high yields of green mass of cereals.
Many grain legumes are also grown not for food but for feed purposes. More than 60% of the grain produced and its processing waste (bran, chaff) goes to animal feed. Potatoes, sugar beet and their processed products are used in large quantities for feed. Oil cakes and meals, which are distinguished by high feed indicators and are obtained in the production of vegetable oil from the seeds of oilseed and fiber crops.
In modern agricultural production, a number of crops are cultivated whose green mass or root crops are used mainly as feed for animals and poultry in fresh or processed form (hay, haylage, silage). For silage preparation, maize, sunflower, and mixtures of annual grasses are mainly used. For succulent feed preparation, perennial grasses, fodder cabbage, and wild mixed grasses are used.
In 1970-1980, in the USSR forage crops occupied from 40 to 70 million ha, or one third of all sown areas. In many regions, especially in the Non-Chernozem Zone, forage crop sowings accounted for up to 50% of areas. In 2001-2005, 26.2 million ha, or 26.8% of all areas, were occupied by forage crops.
Thanks to field forage production, 70-80% of all feed in Russia is procured.
In the structure of sown areas occupied by forage crops, 64% is accounted for by perennial grasses, 22% by annual grasses, 9% by maize for silage and green feed, and 5% by others.
One of the main problems of modern forage production in our country is the low protein content. According to zootechnical standards, 1 feed unit should contain 100-110 g of digestible protein, but the actual content is 75-80 g, which leads to a 1.5-fold overconsumption of feed per unit of livestock product, its higher cost, and reduced quality.
At present, agricultural enterprises face the task of producing high-quality feed with low expenditure of energy, labor, and financial resources, for which it is necessary to expand sowings of perennial legumes, silage crops, grain legumes, and small-seeded crops, and to improve the soil tillage system.
The range of forage crops is gradually expanding as a result of introducing new and little-distributed plants into production. New crops are taken from wild flora and are distinguished by valuable economic and biological qualities, primarily productivity and protein content.
Many species of new crops are perennial and capable of producing high yields for 10-15 years. These include:
- hogweeds (Heracleum) — Sosnowsky's (Heracleum sosnowskyi) (now considered a pernicious invasive weed plant), Lehmann's (Heracleum lehmannianum), downy (Heracleum pubescens), Pontic (Heracleum ponticum);
- knotweeds (Polygonum) — Weyrich's (Polygonum weyrichii), Transbaikal;
- goat's rue eastern (Galega orientalis), or eastern galega;
- cup plant (Silphium perfoliatum);
- maral root (Rhaponticum carthamoides), or safflower-like rhaponticum;
- rough comfrey (Symphytum asperum), or prickly comfrey.
Among annual plants, the following have found use: oilseed radish, perko, curled mallow, and whorled mallow.
Despite the fact that many crops were introduced into agricultural production long ago, some of them have not become widespread, for example, oilseed radish, fodder cabbage, kohlrabi.
With a high level of agronomic practices, these crops can be cultivated in many regions of the country and, with sufficient moisture supply, produce high yields of green mass. For example, the yield of annual species is 25-40 t/ha, and of perennial species 50-150 t/ha. Many of them are highly cold-resistant, perennial species are also winter-hardy, and most of them are characterized by aftermath regrowth.
Plants recently taken from wild flora also have disadvantages that, with further work, can be significantly weakened or eliminated. However, the introduction of new crops also requires careful study of possible ecological and biological consequences and their impact on natural phytocenoses. For example, insufficient study of the consequences of using Sosnowsky's hogweed, which was considered a promising forage crop and was introduced in Tver Oblast (Experimental Production Farm "Pobeda"), Stavropol Krai, and Odesa Oblast of Ukraine, caused the mass spread of this plant across many oblasts of Russia. Sosnowsky's hogweed turned out to be a persistent invasive species, and so far it has not been possible to cope with its spread by agronomic, chemical, and biological methods.
Perennial grasses
Perennial grasses — a group of agricultural crops grown for green feed for farm animals or for harvesting hay, haylage, and grass meal.
Perennial grasses account for 19 million ha, which is 15% of the area occupied by all forage crops. The yield of perennial grasses is up to 5 t/ha of hay, and under irrigation up to 10 t/ha.
Perennial grasses are divided into perennial legumes and perennial cereal grasses. In modern forage production, mixtures of them are usually used.
Perennial legumes
Main page: Perennial legumes
Perennial cereal grasses
Main page: Perennial cereal grasses
Importance
Advantages of perennial grasses:
- The possibility of obtaining feed for animals from early spring to late autumn. All perennial grasses cultivated in field crop rotations begin growth when the average daily air temperature reaches 5 °C, or approximately two weeks after snow cover melts, and continue until the onset of autumn frosts; the long growing period allows them to be used for the production of haylage, silage, hay, briquettes, and pellets, or as pasture crops. The average hay yield is 1.6 t/ha.
- The green mass and hay of perennial grasses are distinguished by high feed qualities. For example, clover hay has a high content of digestible protein, and the nutritional value of 1 kg is 0.52 feed units. Pellets and briquettes made from the green mass of perennial grasses are not inferior in nutritional value to oats grain.
- Perennial grasses serve as an effective means of protecting soils from water and wind erosion. Thus, in Kazakhstan, on soils subjected to strong wind erosion, crop rotations have been introduced in which the share of perennial grasses is more than 50%. For example, soil loss over 4 rainstorms on a slope of 8-9° sown with winter wheat was 28.8 m3/ha, on a slope of 4-6° sown with sugar beet — 28.6 m3/ha, whereas on a slope of 8-9° sown with alfalfa (2nd year) — 0 (Ukrainian RIA).
- Perennial grasses retard the leaching (infiltration) of nutrients beyond the root zone. For example, nitrogen and potassium leaching under grasses is 6-7 times less than in winter wheat sowings or on autumn-plowed land (Department of Crop Production, MAA named after K. A. Timiryazev).
- Perennial grasses promote the accumulation of organic matter in the soil, contributing to the reproduction of fertility. In particular, with an increase in humus content in the soil, thermal conductivity and heat capacity improve, which is especially important in a continental climate as a way of mitigating the effect of negative temperatures on winter crops in winter.
Perennial grasses can ensure a positive balance of organic matter in the soil provided there are high yields of green mass. Conversely, with low yields they do not justify their purpose.
Perennial grasses of the Legume family, as a result of their ability for nitrogen fixation, enrich the soil with nitrogen. For example, clover is capable of leaving up to 100-150 kg/ha of nitrogen in the soil, and alfalfa up to 300 kg/ha. This property accounts for the higher yields of crops sown after the sod layer of perennial grasses than when sown on old arable lands. The aftereffect of perennial grasses persists for three years, which must be taken into account when designing crop rotations.
In crop rotation, perennial grasses can serve as a good forecrop for winter wheat, winter rye, spring wheat, flax, millet, cotton and other crops.
When perennial grasses are sown in early spring without a cover crop, by autumn they form a small yield of green mass, and the year of life and the year of use coincide. If sowing is carried out in early spring under a cover crop or in summer without a cover, then the grasses are used starting the next year. The second sowing method has become the most widespread.
Grasses in the first year of use correspond to the second year of life; in grasses in the second year of use, to the third year of life, and so on.
Features
A distinctive feature of perennial grasses is their ability for vegetative renewal, which determines their perennial life cycle. Thus, lateral shoots of cereal grasses are formed each year from the tillering node, while in legumes during the growing season they are formed from buds of the root collar and main stem.
Depending on the soil and climatic conditions of the zones, different grasses are grown. For example, in the Non-Chernozem Zone, red clover and hybrid clover, timothy, meadow fescue, cocksfoot are cultivated, whereas in the southern regions, alfalfa, sainfoin, crested wheatgrass, beardless wheatgrass, smooth brome, tall oatgrass are cultivated.
In each specific locality and farm, the set of perennial grasses is determined taking into account biological characteristics and natural conditions.
In field and near-farm crop rotations, grasses may be sown in pure stands, for example, one legume crop or, less often, a cereal grass.
Mixtures of perennial grasses are often used. Mixtures are divided into simple and complex. Simple grass mixtures include one legume and one cereal grass crop. Complex ones include three or more grass species. Simple grass mixtures are usually used in field and near-farm crop rotations, complex ones in hayfield-pasture and soil-protective rotations, as well as for creating cultivated pastures.
The period of use of perennial grasses varies from 2-3 years (red clover) to 6-10 years (cereal grasses).
Annual grasses
Main page: Annual grasses
List of sources
- Vavilov P. P., Gritsenko V. V., Kuznetsov V. S., et al. (1986). Crop Production. Edited by Vavilov P. P. 5th ed., revised and enlarged. Moscow: Agropromizdat.
- Kolomeichenko V. V. (2007). Crop Production/Textbook. Moscow: Agrobiznescentr.
- Niklyaev V. S. (2000). Fundamentals of Agricultural Production Technology. Farming and Crop Production. Moscow: "Bylina".
