Selecting appropriate fertilizers is critical for ensuring healthy growth and high yields in soybean cultivation. Soybeans (Glycine max) are nutrient-demanding leguminous crops, making rational fertilization essential for improving productivity and quality. Below are recommended fertilizer types and application methods:

1. Organic Fertilizers

Organic fertilizers, derived from natural sources like animal manure, compost, and green manure, enrich the soil with diverse nutrients while improving structure, water retention, and aeration. Follow these steps for application:

• Choose high-quality, fermented organic fertilizers to ensure microbial activity.
• Apply before planting or during the growth period, with a recommended dose of 2,000–3,000 kg per mu (approx. 0.15 hectares).
• Spread evenly on soil and incorporate into the ground to avoid direct seed contact.
• Avoid mixing with nitrogen fertilizers, as this may hinder soybean growth and fruiting.

2. Chemical Fertilizers

Chemical fertilizers provide targeted nutrients (nitrogen, phosphorus, potassium, microelements) but require careful use:

• Nitrogen fertilizers (e.g., urea, ammonium nitrate): Promote vegetative growth and photosynthesis. Apply 15–20 kg per mu during early and mid-growth stages. Excessive use causes excessive stalk growth, reducing seed formation.
• Phosphate fertilizers (e.g., superphosphate, triple superphosphate): Enhance root development and disease resistance. Apply 10–15 kg per mu in early and mid-stages.
• Potassium fertilizers (e.g., potassium sulfate, potassium chloride): Improve stress resistance and seed quality. Apply 10–15 kg per mu in late growth stages.
• Microelement fertilizers (e.g., borax, ammonium molybdate): Stimulate flower bud differentiation and fruiting. Apply 5–10 kg per mu in late stages.

3. Balanced Compound Fertilizers

Balanced compound fertilizers (NPK) provide comprehensive nutrition for soybeans throughout their lifecycle. Application rates depend on soil tests and plant conditions, typically 20–30 kg per mu.

4. Microfertilizers and Foliar Spraying

• Microfertilizers: Address specific deficiencies (e.g., iron supplements for iron-deficient soils).
• Foliar spraying: Delivers nutrients directly via leaves for quick absorption. For example, boron sprays enhance flower bud differentiation.

5. Key Considerations

• Apply in small doses, multiple times to prevent waste and soil salinization.
• Irrigate after fertilization to aid nutrient absorption.
• Loosen soil before application to improve fertilizer efficiency.
• Monitor plant responses and adjust rates/frequency based on growth and soil moisture.

rational fertilization tailored to soybean growth stages and soil conditions is key to maximizing yields. Observe plant health closely and refine strategies as needed.