Economic significance and prospects of soybean cultivation in the agro-industrial complex

Soy combines the properties of a valuable food, forage, and industrial crop. Its cultivation allows farms to obtain two highly liquid products simultaneously: vegetable oil and high-protein flour. The value of soy is due to its unique chemical composition, which makes it a leader in many processing industries.

• Protein content in seed — 45–50 %
• Carbohydrate content — about 20 %
• Lipid content — up to 30 %
• Soy's share in global vegetable oil production — 40 %
• Protein content in soybean meal — 40 %

Nutritional value, forage, and industrial application

Soy protein is characterized by high digestibility, water solubility, and a balanced amino acid profile, which surpasses the protein of other crops. The main protein of soy seed, glycinin, is capable of curdling when acidified. Soy milk obtained from beans, like animal milk, contains casein and is used both in human nutrition and for industrial purposes. Due to its low carbohydrate content and abundance of easily digestible phosphorus compounds, as well as vitamins A, B1, and B2, soy products are in demand for dietary and diabetic rations.

In livestock farming, soy is used both as green forage and for ensiling in mixtures with corn, as well as for grain. Processing by-products—oilcake, meal, and soy flour—have high nutritional value. Soybean meal contains about 40 % protein, 1.4 % fat, and up to 30 % nitrogen-free substances, which makes it an indispensable component of balanced compound feed.

In the technical industry, soy serves as a raw material for the production of plastics, glue, varnishes, paints, and artificial wool fabrics. Adding soybean oil to white enamel paints prevents them from yellowing and adds shine to the coating. In the global production of edible vegetable oil, soy ranks first with a 40 % share, whereas sunflower accounts for only 17 %. Soybean oil is used to produce margarine and lecithin, which is applied in medicine and the confectionery industry as a substitute for egg yolks.

Geography of cultivation and potential of modern cultivars

Soy ranks first in the world in terms of sowing area among grain legumes. In 2003, global areas exceeded 83.7 million hectares across 40 states, and the gross harvest totaled more than 150 million tons with an average yield of 22.5 c/ha. The leaders in production are the USA (about 25 million hectares) and China (8 million hectares); large areas are also occupied in Argentina, Brazil, and India. Only 1.5 % of the global harvest is produced in Europe.

In the Russian Federation, about 90 % of soy crops are traditionally concentrated in the Far East: in the Primorsky and Khabarovsk Territories and the Amur Region. At the same time, modern cultivars are successfully cultivated in other regions of the country as well. For example, in the Central Non-Black Earth Region, the northern ecotype cultivar Mageva consistently provides a seed yield of 20–25 c/ha. In Belarus, in 2007, about 1 thousand hectares were occupied by soy with an average yield of 15.4 c/ha.

According to the duration of the growing season and the sum of active temperatures, soy cultivars are divided into 9 groups. The most promising for cultivation in temperate latitudes are the ultra-early, early, and mid-early ripening groups. Proper selection of the ripening group allows the agronomist to guarantee a mature harvest under specific climatic conditions.

Northeast Asia is considered the homeland of soy: it was cultivated in China as early as 6 thousand years BC. From China, the crop spread to the Russian Far East, where it was known under the names "Manchurian," "oil-bearing," or "coffee beans." Botanists note the close relationship between cultivated soy and wild Ussuri soy, common in Primorye and China. Manchuria, the surrounding areas of Northeast China, and Korea are considered the center of genetic diversity for this crop.

In European botanical gardens, soy was sown starting in 1709, but for a long time, it remained a decorative novelty. Practical interest in it arose only after the publication of the scientific papers of a Viennese professor in 1875, which proved the nutritional superiority of soy. Since 1890, experimental stations in the USA launched large-scale work on the acclimatization and breeding of the crop, which allowed soy to take leading positions in the global agribusiness within one hundred years.

Biological characteristics and requirements for conditions

Soybean (Glycine hispida (Moench.) Maxim., synonym — Glycine max [L.] Merr.) belongs to the Fabaceae family and is included in the Soja Benth. section of the Glycine L. genus. The crop possesses enormous genetic diversity — there are more than 500 varieties of soybean in the world, which are divided into 6 subspecies. Wide-scale cultivation of soybean in our country began in 1930, when the sowing area increased to 800 thousand hectares. The breeding base was created on the basis of an extensive global collection, gathered from 15 countries and including more than 7 thousand seed samples.

The plant forms a solid, lodging-resistant stem 60–100 cm high. All above-ground organs — stems, branches, leaves, and pods — are densely covered with stiff hairs of white or brown color. Soybean is a self-pollinator. Most cultivars completely drop yellowing leaves along with petioles before harvesting, facilitating the work of the combine. In forage crops, the leaves dry out but remain on the stems.

• Sum of active temperatures — 1700–2700 °C
• Soil temperature for sowing — 9–10 °C
• Optimal germination temperature — 15–20 °C
• Seed vernalization parameters — 20–25 °C (10–15 days)
• Humidity during vernalization — 75 %
• Growing season — 75–140 days and more

Soybean is sensitive to day length. Under short-day conditions, plants branch more actively and flower faster, but the filling and ripening of pods are delayed. A long day slows down the onset of flowering but accelerates the yellowing and shedding of leaves, stimulating harvest ripening. Flowering begins with the appearance of 5–6 true leaves or at the start of branching (in late cultivars — upon vigorous development of lateral shoots) and lasts from 15 to 40 days.

Agrotechnics, application rates, and protection system

The best predecessors for soybean are winter and spring cereal crops, crops on fallow land, and virgin lands. In turn, soybean itself serves as an excellent predecessor for corn and spring cereals. Field preparation begins with autumn ploughing, which should be preceded by stubble harrowing after cereals. The crop is extremely responsive to deep tillage.

When sowing, corn or beet seeders are used. Mineral nutrition is calculated based on the planned yield and soil fertility. Organic fertilizers for soybean are applied only on poor soils after cereal predecessors; on cultivated fields, it is more effective to apply manure for the preceding crop. Pre-sowing seed treatment or soil application of nitragin provides a high agronomic effect.

Protection of crops from weeds is based on a combination of autumn and spring herbicide treatments. To control pathogens and pests, fungicidal and insecticidal spraying is applied during the growing season. The system of protective measures includes the following sequential steps:

1. In autumn on stubble: application of Roundup after harvesting the cereal predecessor against perennial grasses and broad-leaved weeds.
2. Before sowing (with incorporation) or before soybean emergence: use of soil herbicides Gesagard, Harness, Frontier, or Pivot against annual grasses and broad-leaved weeds.
3. In the 1–3 true leaf stage of the crop: treatment with Basagran herbicide to destroy annual broad-leaved weeds.
4. In the 4–5 leaf stage of the crop: use of Fusilade-Super herbicide to control couch grass.

Upon detection of the first signs of Septoria, olive spot, or bacteriosis, crops are treated with the fungicide Fundazol. Spraying is repeated 2–3 times at intervals of 7–10 days. If there is a threat of damage by the soybean pod borer, meadow moth, or leaf beetle, treatment with insecticides, for example, the preparation Almethrin, is carried out.

During germination, cotyledons are brought to the soil surface, and therefore seeds should not be sown deeply. When tending soybean crops, inter-row loosening is used — after emergence and upon the formation of true leaves. In solid-seeded crops, early harrowing of seedlings is useful — for crust breaking and weeding.

Signs of soybean maturity include yellowing and falling leaves, browning of stems and pods, and the rattling sound of beans within the pods when shaken. Once the pods are fully mature, soybean harvesting is carried out by direct combining. If the upper pods have not yet ripened, the crop is mown, dried, and then harvested using a two-stage method.