Abstract:
This nutrient management guide is designed to assist onion growers and crop advisors in producing a high-quality crop while protecting the environment from excess nutrients. Nutrient management strategies recommended here are based on data accumulated over many growing seasons with many different onion varieties in Idaho, Washington, and Oregon. This publication provides current information on:
• How onions grow and how their growth pattern affects nutrient needs
• Timing and amount of crop nutrient uptake
• Keys to managing nitrogen efficiently
• Ways to monitor crop N status during the growing season
• How to assess the need for P, K, S, and micronutrient fertilization
• Fertilizer sources and application methods
• How to assess the need for lime on sandy soils in the Columbia Basin
