How to Grow Soybeans: Detailed Guide to Planting Techniques and Precautions

Soybeans are an extremely common food ingredient. The main ingredient of the soy sauce we eat so often is soybeans; the soybean oil used for stir-frying is pressed from them; and in our breakfast pairing, the soy milk in soy milk and fried dough sticks is made from them; the soybean paste used for stir-frying and mixing noodles is made from them; half of the bean sprout world is made from them too; even all kinds of tofu products use them as the main ingredient. But how do you grow this common food ingredient?

How to Grow Soybeans

Spread a layer of moist soil from the field, and after one day, use a hoe to dig a small hole, put in two soybean seeds, and cover with fine sand.

Soybean Planting Techniques and Precautions

I. Planting Techniques

1. Seed selection and treatment: it is best to choose a variety with a growth period about 5 days longer than the local one. The seeds are required to have a purity higher than 98%, a cleanliness higher than 97%, a germination rate higher than 95%, and a moisture content lower than 13%. All seeds should be coated before sowing. Before sowing, all seeds should be treated with 35% Duokefu seed coating agent, and soybeans should be mixed with the agent at a medicine-to-seed ratio of 1.75.

2. Site selection and land preparation: choose relatively flat highland or flat land, and wheat stubble or corn stubble with loose soil, good soil quality and good drainage are all acceptable. There should be fewer than 5 clods larger than 5 cm per sq m, the plowing depth should be 2-15 cm, and the subsoiling depth should be more than 25 cm, reaching a ready-to-sow state.

3. Scientific fertilization: apply 15 tons of organic fertilizer (organic matter content above 80%) per hectare, applied all at once as base fertilizer combined with land preparation. Apply 175 kg of chemical fertilizer per hectare, including 125 kg of diammonium phosphate, 25 kg of urea, and 25 kg of potassium sulfate fertilizer. Implement separate deep application or side deep application of seed fertilizer, with the side deep application at a distance of 6-8 cm from the seeds.

4. Precision sowing: sowing can begin when the local temperature steadily passes 7-8°C. With a row spacing of 75 cm and a seedling spacing of 3 cm under alternate-row film mulching, use special film-mulching machinery for precision sowing, completing fertilization, compaction and film mulching in one pass. Keep 220,000-250,000 seedlings per hectare. The sowing rate is about 70 kg per hectare. Ensure uniform sowing with no breaks, a sowing rate error of ±3%, a sowing depth of 5 cm, a row spacing error of ±1 cm, and uniform film mulching. Agricultural film with a thickness of 0.008 mm and a width of 1 m should be selected, with a film consumption of about 50 kg per hectare.

5. Chemical weeding: soil sealing treatment can be carried out 3 days after sowing, using 800-1000 ml of 90% acetochlor + 150-300 g of 70% Saike wettable powder, diluted with 125-150 kg of water, and sprayed onto the soil.

II. Precautions

1. Temperature: because it originated in tropical regions and likes high-temperature and high-humidity environments, it has strict temperature requirements for winter and cannot overwinter safely in areas where frost occurs.

2. Light: it is not strict about light, likes sufficient sunlight, and also tolerates semi-shade.

3. Fertilizer and water: for potted plants, in addition to adding organic fertilizer when potting, proper fertilizer and water management should also be carried out during routine care.

Soybean Fertilizer and Water Management

1. Soybeans need large amounts of phosphorus and potassium fertilizer, and applying phosphorus and potassium fertilizer has a significant yield-increasing effect on edamame. Phosphorus and potassium fertilizer is generally mainly used as base fertilizer, with topdressing as a supplement.

2. The amount of base fertilizer should be determined according to soil fertility. Generally, 25 kg of nitrogen-phosphorus-potassium compound fertilizer per mu is applied as base fertilizer, and topdressing can be applied at the appropriate time during the growth period according to growth conditions. At the seedling stage, when rhizobia have not yet formed, 10% human manure and urine or 10 kg of ternary compound fertilizer can be applied once.

3. Spray mepiquat chloride twice before flowering and during the flowering period to inhibit excessive soybean growth, make the stems thicker and the plant type more compact, promote the transfer of nutrients to the pods, and increase the pod number and plumpness rate of soybeans, generally increasing yield by 10-20%.

Common Soybean Disease Control Measures

1. Soybean root rot can occur throughout the entire growth period of soybeans and cause damage, with yield reductions ranging from 25% to 75% or more. The protein content of affected seeds is significantly reduced. The main symptom is dark brown lesions at the stem base. For chemical control, mainly use 58% metalaxyl-mancozeb or 72% Curzate wettable powder, both at 0.3%-0.4% of seed weight for seed dressing.

2. Soybean sclerotinia stem rot mainly infects the stems and begins to occur in late July. In the early stage of infection, there are brown lesions on the stems; later, white cotton-like mycelium and white granules appear on the lesions, which then turn into black granules (sclerotia). For chemical control, spray with 1000-fold dilution of 50% procymidone wettable powder, or 1000-fold dilution of 40% Hejunjing, or 500-fold dilution of 50% thiophanate-methyl.

3. Soybean gray leaf spot, also called speckled disease, generally begins to occur on leaves in early to mid-June and enters the peak incidence period in mid-July. Pods begin to be affected from the tender pod stage, and the peak incidence period is the seed-filling stage. In July-August, years with high temperature and abundant rain have more severe incidence. Chemical control: besides dressing seeds with 70% dexon wettable powder or 50% thiram wettable powder at 0.3% of seed weight when sowing, during the flowering and pod stage of soybeans, use 1.5 kg of 40% carbendazim suspension concentrate per hectare, diluted with 450 kg of water for spraying.

Soybeans are an extremely common food in daily life. Because of their high nutritional value and diverse processing methods, soybeans are widely loved by growers. Moreover, after a series of difficult transformations, soybeans are made into all kinds of food ingredients, and in three meals a day, it is hard not to encounter them.