Economic importance and technology of growing soybeans
Soy is a legume and one of the most popular crops. Its advantages include high nutritional value, good yield, and its ability to grow on almost any soil. This legume is in steady demand, despite its rather high cost compared to wheat. Therefore, a soybean farming business can bring good profits.
Contents:
- Characteristics and application of the crop.
- Growing conditions.
- Soybean producing countries and popular varieties.
- Best precursor crops.
- Soil preparation.
- Seed treatment.
- Sowing process.
- Soil fertilization.
- Main soybean growth stages.
- How to care for crops?
- Harvesting.
- Final processing and storage conditions.
Characteristics and Application of the Crop
Soy is an annual plant with a height of 20 to 150 cm, depending on the variety. It has a rough vertical root and a straight stem, thin or thick. Some varieties have twining stems. As a rule, the plant is covered with yellow or white pubescence: long, short, thick, or felty. Soybean fruits are yellow, red and light brown beans, 3-4 to 6-7 cm long. They contain a large amount of highly digestible high quality vegetable protein. Therefore, soy is one of the staple foods for those who do not consume food of animal origin.
This legume is used in various branches of food industry and agriculture:
- cooking vegetarian burgers, sausages, soups, and other dishes;
- production of soy milk;
- oil extraction and sauce production;
- production of flour used in soy meat production;
- as a highly nutritious feed for farm animals.
Soy dishes can also be cooked at home. The beans form the basis for tofu and yogurt, baked bread and cakes. Soy is added to salads, soups and side dishes.
Growing Conditions
Soy belongs to heat- and light-loving crops. Particularly, the plant needs warmth during flowering and fruit formation. At this time, the air temperature should be 21-22 °C never falling below 14 °C, otherwise the growth and development of the crop will stop. Only at the beginning and end of their growing season, soybeans tolerate frosts down to -3 °C relatively easily. The lack of light at any stage of development leads to the stem lengthening — this prevents the formation of side shoots and fruits, as a result, the yield decreases.
In addition to light and heat, soy needs enough water. At the initial growing stage, the seeds tolerate drought more easily, however, when the plant blooms, forms fruits and beans, moisture should be sufficient. At this time, soy needs intensive watering and moist air.
Soybean Producing Countries and Popular Varieties
In Russia, several regions are suitable for growing soybeans. The majority of areas under the crop (more than 80%) are located in the Krasnodar, Primorsky, Khabarovsk Krais, and the Amur Oblast. Popular soy varieties are cultivated here, including "Venus" and "Primorskaya". In the mid-Volga region, the "Sawyer" variety is grown. In Central Russia, early-ripening and midseason-ripening varieties, such as "Luchezarnaya", "Svetla" and "Belgorodskaya", are cultivated. The North Caucasus is the region with the most favorable conditions for this legume. Local yield index is 40-45 centners per hectare, while in Primorye and the central part of the country it is 20 centners. And in the Urals, no more than 15 centners can be taken from 1 hectare.
Best Precursor Crops
Soy is sowed on weed-free fields rich in nutrients and moisture. Its best precursor crops are spring and winter wheat, corn, potatoes, barley, and vegetables. It is not advisable to sow soybeans after sunflower, Sudan grass and legumes whose pests are harmful to soy.
Soil Preparation
Soy grows well on different soils, including chestnut, chernozem and sod-podzolic. The exceptions are swampy, heavy and acidic soils. The optimal pH for growing this crop is 6.0-7.0. The best soils for soy are textured, high-fertile and moisture-intensive, able to warm up well, rich in humus and mineral elements.
In the course of pre-sowing treatment, weeds are removed and the required amount of moisture is retained. In autumn, shallow plowing is carried out to a depth of 10 cm and fertilizers are applied. In early spring, harrowing is carried out using light, medium and heavy harrows at an angle or across the tillage line. If the field is overgrown with weeds, autumn preparations were not carried out, and the winter was long and cold, spring field cultivation at a depth of 6-8 cm, followed by soil compacting, is demanded. This helps to raise the temperature of the seed bed, which stimulates weed germination, and then the weed is removed. For pre-sowing cultivation, beet hoes or field sweep cultivators are used.
The field should be as flat as possible, so all earth balls are crushed. Rough surface makes harvesting difficult as mature soybeans grow too close to the soil surface. The height of the ridges and the depth of the furrows should not exceed 4 cm.
Seed Treatment
For sowing, even large seeds with high germinating power are selected. High-quality seed grains should be of equal size, free of pests, larvae or quarantine weeds. Before sowing, soybean seeds are pretreated and then treated with nodule bacteria rhizotorphin. Conventional treatment machines are not good to inoculate seeds. Some farmers use concrete mixers or truck bodies for treatment. Sowing material is loaded there, and liquid rhizotorphin is added at the rate of 70-80 liters per ton.
An alternative to rhizotorphin is ammonium nitrate, which is applied to the soil. This method increases the cost of production, but increases the yield, so it is used quite often.
Sowing Process
The best time for sowing soy is the second half of April or the first or second decade of May, when the soil warms up to 10-15 °C. First, late-ripening varieties are sown, and early-ripening ones come next. Seeds are laid at a depth of 45-70 cm, with a distance of 40-60 cm between rows. Seeding rate depends on the soybean variety, sowing technology and weed control method. The average density is 35-40 seeds per meter.
Soil Fertilization
After sowing, before seedling emergence, the field is treated with herbicides using harrowing to a depth of 3 cm. Star-wheeled rollers can be used, since they increase the effectiveness of nitrogen-fixing bacteria. If rhizomatous or rootstock weeds have appeared on the field, pre-sowing treatment is not carried out. In this case, it is necessary to wait until the leek germinates by 10-15 cm, and then sow. After 3-4 days, until soy sprouts emerge, the field is fertilized with Roundup non-selective herbicide. The standard rate of fertilizer input per hectare is 10-20 kg for nitrogen, 15-30 kg for phosphorus, and 25-60 kg for potassium.
Main Soybean Growth Stages
The soy development process consists of several stages: from seeds swelling and the emergence of seedlings, to the full maturation of the beans. The first stage is the emergence of seedlings. First, cotyledonary leaves appear on the soil surface, and then primordial leaves open at the top of the plant. The germination stage lasts from 5 to 20 days depending on humidity, soil temperature and seeding depth. This period is considered critical, since the plant is easily affected by fusarium, bacteriosis and other diseases that reduce yields.
The branching stage begins with the opening of the first or second ternate leaf and ends with the emergence of flowers. Until this stage, the root system is actively formed in the plant, and nutrients accumulate in the leaves. Branching usually begins 5-20 days after emergence of seedlings.
The next stage of soy development is flowering. Depending on the variety, flowers show up between the first and the third or the fifth and the seventh internodes. The flowering process is not distinguished from fruit formation. During this period, the plant accumulates a large amount of assimilates, which are spent on the formation of flowers and seed maturation. At this time, nitrogen-phosphorus top dressing will be very effective.
The fruiting stage occurs when flowering is not yet complete. The first beans appear at the bottom of the plant. As the number of ripe fruits increases, leaves turn yellow and die. The stage ends with the development of beans in the upper internodes. The duration of the fruiting period depends on the humidity and environmental temperature.
How to Care for Crops?
After sowing and during the growing season, the field is regularly cleared of weeds, and the topsoil is loosened. With such care, enough moisture and nutrients remain in the soil, and plants have enough air and light. Depending on weather conditions and weediness of the field, the following agricultural practices are used:
- On weed-free soil, in case of row sowing, only pre-emergence and post-emergence harrowing is performed in combination with soil and auxiliary herbicides.
- In case of wide-row sowing without herbicides, 1-2 harrowings are done before germination, and then another 1-2 after their seedling emergence, 2-3 cultivations of inter-row spacings is performed.
- With a large number of weeds, mechanical and chemical methods are used: inter-row cultivation, harrowing, pre- and post-emergence application of herbicides.
Harrowing is carried out across the rows at a plant height of 10-12 cm, with equipment moving at no more than 4-5 km/h. Treatment is best done in sunny weather in the afternoon, when soybean stalks break less and weeds are easily removed.
Harvesting
Product quantity and quality largely depend on timely and high-quality harvesting. Harvesting begins when the leaves and stems of the plant turn yellow or brown. Mature beans, when shaken, make a slight noise, acquire the shape and color characteristic of their variety.
Harvesting is carried out by combining. Soy is very sensitive to the air humidity and easily dries out while standing, which must be taken into account when harvesting. Wet seeds spoil quickly, so dry weather is good for harvesting.
In the soybean production process, defoliants are often used – these are chemical compounds that speed up bean ripening. Chemical defoliation is carried out several times. First, crops are treated on the green bean growth stage, then, on the yellow bean stage and after complete browning. As a result, soybean maturation is accelerated without yield reduction.
The optimal duration of harvesting is no more than 15 days. Agricultural machinery that is used for harvesting must meet the following requirements:
- cutting plants at a maximum height of 5-7 cm from the soil surface,
- pick out grain among a heap of soybeans,
- ensure harvesting within 12-16% at varying grain moisture,
- inflict minimum damage to the beans during threshing.
The average soybean yield is 10 centners per hectare. With good irrigation and other favorable conditions, it increases to 25 centners. However, experienced suppliers know that growing a good crop is only half the work. It's much harder to pick the beans before they shatter and fall to the ground.
Final Processing and Storage Conditions
Before threshing, soybeans are laid out in the sun. Under the rays, the fruits open and shell out, after which they are blown through and bagged.
Harvest soy is stored in simple Quonsets. Humidity should not exceed 15%; 12% is considered the best. Too wet beans are dried with special equipment before storage. However, drying is a very costly process that increases production costs being unprofitable for manufacturers.