Soil Nutrient Requirements
Onion seeds require fertile, well-draining soil with a pH between 6.0 and 7.5. Nutrient requirements include a basal application of organic matter like farmyard manure, followed by a balanced NPK (nitrogen, phosphorus, potassium) fertilizer. Nitrogen is split into a basal dose and a top-dressing after transplanting, while phosphorus and potassium are typically applied before or at planting. Sulfur, zinc, and other micronutrients are also important for quality and growth.