1、Nitrogen nutrition and fertilization of onions (Allium cepa L.)–A

The overview of onion N use and N fertilizer management practices presented in this article can help choose optimal N fertilization practices based on site-specific conditions.

2、Optimizing Fertilization Rate to Achieve High Onion Bulb Yield and High

The objective of this research is to determine the appropriate amount of fertilizer by investigating the effects of different fertilization rates on the growth characteristics and bulb yield of onion.

3、Onion Growth Fertilizer Plan: Fertilization Schedule

Onions require three main macronutrients for optimal growth: nitrogen (N), phosphorus (P), and potassium (K). N promotes vegetative growth and green leaf production, while P enhances root growth, bulb size, and quality.

4、Onion Nutrient Needs and Fertilization Requirements

Learn essential fertilization techniques for onions, including nutrient needs, fertilization stages, and methods to boost yield and quality.

5、(PDF) Estimating Fertilizer Nitrogen

Abstract and Figures Efficient nitrogen (N) fertilizer applications in onion (Allium cepa L.) can reduce input costs and improve fertilizer-use efficiency, while maintaining high yields and...

Fertilizer Management for Onion: NPK Ratio, and Micronutrients

Onions benefit from proper fertilization (ideally based on soil test results), although high nitrogen fertilizers should be used with caution. Excessive nitrogen can delay bulb formation, maturation, and Onion storage.

Onion Irrigation & Fertilization

Excessive nitrogen fertilizer has historically led to nitrate leaching in onions, posing a significant problem. Therefore, applying the proper amount of nitrogen at the right time is crucial to maximize onion production and increase nitrogen use efficiency.

Fertilizing Onions: A Comprehensive Guide

For onions, three macro nutrients stand out: nitrogen, phosphorus, and potassium. Each of these has a distinct role in enhancing growth, supporting optimal yields, and improving overall plant health. Nitrogen is essential for the growth of onions.

Effects of Different Nitrogen and Sulfur Fertilizer Rates on Growth

Hence, the objectives of this study were to evaluate the effect of different levels of sulfur and nitrogen fertilizer on the growth, yield, and quality of onion and evaluate the economic feasibility of the fertilizer application.

How to Fertilize Onion Plants: A Step

Proper fertilization is crucial to ensure healthy growth, robust yields, and high-quality bulbs. This comprehensive guide will walk you through the process of fertilizing onion plants at each growth stage, from planting to harvesting.

Onion is a common vegetable whose growth requires sufficient nutrients. Nitrogen fertilizer plays a critical role in its development, making rational application essential for improving yield and quality. Below are detailed guidelines for nitrogen fertilization in onion cultivation:

1. Understanding Onion’s Nitrogen Needs

• Early Growth Stage: Nitrogen is vital for leafy growth, promoting lush and healthy foliage.
• Mid to Late Growth: Nitrogen demand decreases. Shift focus to phosphorus and potassium fertilizers to support bulb development.
• Maturation Stage: Minimal nitrogen is required. Excessive nitrogen at this stage may compromise quality.

2. Selecting Appropriate Nitrogen Fertilizers

• Choose fertilizers like urea or ammonium nitrate based on soil type and onion variety.
• Opt for environmentally friendly, low-toxicity, and residue-free products to minimize ecological impact.

3. Timing and Application Methods

• Early Stage: Apply urea or ammonium nitrate by mixing with water, spreading evenly, and incorporating into soil.
• Mid Stage: Increase nitrogen slightly. Use foliar spraying (direct application to leaves) to enhance absorption efficiency.
• Late Stage: Reduce nitrogen dosage. Apply via soil or foliar spraying to avoid over-fertilization and root damage.

4. Controlling Dosage and Concentration

• Typical rates: 5–10 kg/mu of urea or 10–15 kg/mu of ammonium nitrate. Adjust based on soil conditions and onion variety.
• Avoid overapplication, which can disrupt soil ecology and lead to excessive vegetative growth.

5. Preventing Nitrogen Leaching

• Mix nitrogen fertilizers with organic matter before application to reduce rainwater runoff.
• For enhanced retention, use ditch fertilization (burying fertilizer in deep soil trenches).

6. Balancing Other Nutrients

• Complement nitrogen with phosphorus and potassium fertilizers to ensure comprehensive nutrition.
• Include micronutrient supplements (e.g., calcium, magnesium) to optimize yield and quality.

Rational nitrogen management—tailored to onion’s growth stages, paired with balanced nutrients—maximizes productivity while safeguarding soil health. Proper timing, dosage, and application techniques are key to successful cultivation.