The world’s most widespread cereal crop wheat is grown all over the world and ranks second after corn in terms of sown area. It serves as the main source of vegetable protein in the human diet and is considered a strategic food product in many countries. It’s much more nutritious than other popular crops – rice and corn. Except for protein, it contains fats and starch, vitamins B, PP, E, as well as carotene and ergosterol – precursors of vitamins A and D.
Types, Varieties and Characteristics of Wheat
Both spring and winter wheat are grown in Russia. Spring crops are sown from early spring to early summer and begin to be harvested in late June or early July, depending on the climatic conditions of a region. The period of winter wheat sowing is approximately from mid-August to the end of October. Harvesting starts next year in early June or later depending on the weather.
The winter wheat yield is higher, about 30 centners per hectare. What is more, spring varieties grow slower and are less weed-resistant. Therefore, winter varieties are most often cultivated in Russia. The most popular among them are the following:
- Moscow-39,
- Prestige,
- Lelya,
- Mironovskaya.
The most productive varieties of spring wheat include Munk, Toma, Koksa, and Rassvet.
Spring and winter varieties, in turn, are classified into durum and soft wheat. They differ in grain density and nutrient content. Durum varieties with elongated grains contain a high amount of protein (up to 24%) and gluten (up to 40%) and are used for the production of pasta and semolina. In soft varieties, the grain is round, and the content of protein and gluten is lower – up to 14 and 28%. Flour made from such wheat is good for baking bread and pastries.
In addition, starch, dextrin and food alcohol are made from wheat grains. Straw is used as fodder for farm animals, in paper and household production. Wheat bran is a popular raw material for the production of feed additives.
Winter Wheat Growing Features
Wheat is considered an easy to grow agricultural crop, preferring a temperate continental, fairly warm climate. In too hot regions, the yield will be low, since at a temperature of about 40 ˚С, wheat stomata begin to die off. Photoperiod is important, because with a lack of light, the plant becomes less endurant, suffers from diseases and insect pests. Spring varieties are more resistant to drought, while winter varieties are more tolerant to cold spells and sudden temperature changes. In the presence of snow cover, they withstand frosts down to -25 ˚С. If there is no snow, their sprouts may die at a temperature of -16–18 ˚С.
For good rooting, winter wheat seeds are sown in soil rich in micro and macro elements. With a lack of minerals, wheat yields suffer shortfalls. Chernozem, slightly podzolic and chestnut soils with a pH of 6.5–7 are best for growing winter wheat.
Requirements for Soil Condition and Precursor Crops
Wheat is quite demanding in terms of soil state and the crops that were previously grown in its fields. The best precursor crops for winter cereals are perennial and annual grasses, green manure, corn, legumes, buckwheat and rapeseed. These plants saturate the soil with nitrogen, resist weeds, contribute to the accumulation of easily digestible nutrients in the soil and reduce the likelihood of moist diseases. It is not recommended to sow wheat right after barley, as these plants are prone to one disease – root rot. Sorghum and sunflower dry up the soil to a critical depth leaving the field clear too late, so they are also not good precursors.
Preparation of the field for sowing winter wheat begins immediately after harvesting the previous crops. With the help of pre-sowing treatment, aeration is improved, weeds are exterminated and moisture is retained, the field and seed bed are levelled for further seeding. Harrowing and cultivation are the classic methods of preparation.
The best soil indicators for sowing winter wheat:
- dense subsowing layer,
- 2–3 mm soil particles,
- the height of the ridges after cultivation is less than 2 cm.
The type of pre-sowing treatment largely depends on weather conditions, precursor crops, the state of arable land, machinery and transport equipment available. For example, if the field was occupied with perennial grasses, disc plowing of the soil is carried out. Sometimes the grown culture is cut with a subsurface cultivator to a depth of 12 cm.
Seed Preparation
For sowing, winter wheat seeds from high-yielding plots are used. Such seed material has the best physical and biological characteristics. Before sowing, the biggest and healthiest seeds are treated using the following agricultural practices:
- Treatment with pesticides and agrochemicals approved for use in Russia.
- Encrusting – seed coating with a hydrophobic polymer substance with fungicides, fertilizers and growth stimulants.
Grain treatment provides protection against seed and soil infections and helps plants to survive winter. Encrusting protects grains against mold, mechanical damage and other negative environmental factors, and also improves the total germination capacity.
Sowing Winter Wheat
Seeding rate is on average 400-500 pieces per 1 m2. If sowing is carried out at a later date, this figure increases by 10-15%. For sowing winter wheat, one of three technologies is used:
- in-line, with row width 15 cm,
- narrow-row, with row width 7.5 cm;
- criss-cross.
Most often, the usual in-line method is used. To get uniform shoots, you need to choose the right seeding depth. For heavy soils, this figure is 1-2 cm, for wet and cultivated soils 3-4 cm, for light soils 6-8 cm.
Growth Stages
Winter wheat has the following growth stages: germination, tillering, stalking, heading, flowering, and ripening. Under normal conditions, the first stage takes 15 to 25 days. Even sprouts are observed at a temperature of 12–17 ˚С, and intensive growth occurs at 20–25 ˚С. The tillering stage of winter wheat begins after 3–4 leaves develop. The plant develops nodal roots and lateral shoots. The process begins in spring or autumn at a temperature of 6–10 ˚С, when wheat growth slows down. Tillering enhances when nitrogen fertilizers are added to the soil.
The booting stage occurs about 30 days after the start of spring growth. At this stage, the first stem node is formed at a height of 3–5 cm from the soil surface. After another 30 days, the heading stage begins when an ear emerges. The intensity of this stage depends on the amount of moisture and nutrients in the soil. The earing period is considered the most favorable for the treatment of crops with fungicides.
Flowering of winter wheat begins 2–3 days after the ear appears and usually lasts a week. At the maturation stage, grains are forming and filling. The duration of this stage depends on the weather conditions: during a drought, the process accelerates, and during rains it slows down.
Crop Tending
Usually, tending includes 3 procedures: packing, harrowing and protection. Post-sowing packing with soil compaction improves seed-to-soil contact, reduces moisture loss and ensures more even sprouting. This method is not used during rain and for clay soils. Early spring harrowing is used to loosen the soil, which improves aeration and prevents weed germination. Seed protection means treatment with industrial compounds: herbicides, fungicides, top dressings.
Fertilizers
Winter wheat fertilizing is an obligatory stage of care. Herbicides are used to control weeds, pests are destroyed with insecticides. Fungicides, if necessary, treat bacterial diseases.
To feed this crop, mineral nitrogen and phosphate fertilizers are usually used. Organic compounds are used when the content of humus in the soil is less than 2%. Almost all phosphate fertilizers are applied to the soil before sowing. The fields are treated with granulated superphosphate, and a small amount of this compound is added in autumn or early spring.
Nitrogen fertilizers are used:
- during pre-sowing cultivation (30 kg/ha),
- on the tillering stage of winter wheat,
- at the beginning of booting (60–70 kg/ha),
- during heading and flowering.
On poor soils, nitrogen fertilizers should be applied in the ammonium form, since in this case fertilizers are washed out less.
Irrigation Rules
Low soil moisture reduces the yield of winter wheat. Soil moistening is especially important in the early stages of crop development, when the root system is set. In autumn, plants receive rain moisture from the topsoil. The same thing happens in the spring when snow melts. Subsequently, when air temperature rises, the soil begins to dry out, which is why wheat has to extract water at a depth of up to 1 m using a well-developed root system. However, in very dry weather, moisture can sink even deeper, so arable land in arid regions requires regular watering.
Irrigation of winter crops is necessary during the autumn growing season if there is not enough rainfall. As a rule, a cultivated land is watered once, but very plentifully. Fields are also irrigated in spring, provided that less than 2 m of the topsoil are saturated with water. In summer, wheat is watered only during drought. This is done at least twice – at the heading stage and at the initial stage of grain maturation.
Harvesting
The timing and methods of harvesting are chosen taking into account weather conditions, the height and density of stalks, weed infestation and the tendency to shed. Harvesting winter wheat with a combine begins in the phase of full seed maturity, when its moisture content is 14–17%. Harvesting is carried out in a one or two stages. The first option is preferable because it allows to save most of the crop. A two-stage method is used for harvesting tall and dense varieties, in case of unevenly ripening and high weed infestation.
Storage and Transportation
Wheat production is a complex industrial process. It is not enough to collect a good harvest of this crop; it is also important to preserve it without loss. For grain storage, elevators – specially equipped warehouse complexes – are used. First, wheat is weighed, then cleaned using separators and dried, after which it is sent to silos.
Grain preservation depends on several factors:
- humidity and ambient temperature,
- intensity of biochemical processes inside the wheat,
- presence or absence of harmful microorganisms and insects.
Therefore, grains are pre-dried and stored at 10–12 ˚C in silos, some of which are equipped with ventilation and disinfection units. Periodically, the temperature of the product is measured using multipoint temperature transmitters installed at various heights.
Each elevator has a shipping compartment with a hopper system. Here, grains are loaded into motor vehicles or rail transport for further transportation.