Detailed Explanation of Key Technical Points for Soybean Sowing

1. What key techniques should be mastered for soybean sowing?

1. Land selection. Soybean land should not be planted continuously, otherwise it is prone to pests and diseases. After the land is selected, it should be harrowed until broken up, achieving a soft plow layer and a level surface.

2. Seed selection. Varieties suitable for planting in Tiandong include: Beijing bean, Yishan Liula, Guidou No. 1, Aijiao bean, Binyang Xiaoqing bean, local yellow bean, etc. Each area can select according to local conditions. Before sowing, select seeds of uniform size and full, plump grains, and sun-dry the seeds.

3. Sowing. Early yellow soybean is sown from late February to mid-March, and late yellow soybean is sown between “Start of Autumn” and “End of Heat”.

4. Reasonable close planting. In principle, early-maturing varieties, lean land, and later sowing all require denser planting; the opposite requires sparser planting. Dense planting should be 30,000-35,000 plants per mu, and sparse planting 20,000-30,000 plants per mu. Drilling or dibbling may be adopted. For dibbling, 3-5 seeds per hole.

5. Base fertilizer. Generally, 500 kg of farmyard manure mixed with 30 kg of calcium-magnesium phosphate fertilizer that has been composted is used per mu.

6. Sowing rate. Generally 4-6 kg per mu.

2. How to do a good job in field management of soybean?

1. Check seedlings, fill gaps, and thin to a stand. After soybean seedlings emerge, check and fill gaps promptly, and thin to a stand when the first compound leaf appears. For dibbling, keep 2 plants per hole; for drilling with a row spacing of 40 cm, for a planned density of 25,000 plants, keep 15 seedlings per meter; for 15,000 plants, keep 9 per meter; for 35,000 plants, keep 24 per meter.

2. Scientific topdressing. Improper topdressing of soybean can cause excessive vegetative growth, lodging, and yield reduction. The principle of topdressing is to apply phosphorus and potassium fertilizer early and appropriate nitrogen fertilizer later. Generally, after thinning to a stand, apply 10 kg per mu of compound fertilizer with 45% content. At the late flowering stage (pod-setting stage), apply 5 kg of urea per mu. For seedlings growing vigorously, the first topdressing may be reduced or omitted.

3. Pest and disease control. The pod-setting stage of spring soybean occurs in hot and rainy weather, making it prone to soybean purple seed stain and downy mildew. The main insect pest of spring soybean is the soybean pod borer, so inspection should be strengthened and control carried out promptly. Trichlorfon 90% crystals, or 50% fenitrothion combined with antidote, chlorothalonil, or ridomil and other pesticides may be used (use according to instructions).