What fertilizer is good for onions

What fertilizer to use for onions

Apply 4,000 kg of decomposed organic manure per mu of onion, and add 20 kg of compound fertilizer and 15 kg of urea to the organic manure. Finally, deep plow and harrow the land, and dig trenches to make ridges.

When applying top dressing to onions, mix 1 kg of boron fertilizer with compound fertilizer, potassium chloride, urea, etc. per mu and apply them together in the furrows. You can also combine fertilization with watering to keep the soil moist and promote nutrient absorption.

How to fertilize onions

Onion fertilizer is divided into base fertilizer and topdressing. The best base fertilizer is 4000-5000 kg of decomposed high-quality organic fertilizer per 667 square meters. It should be spread during land preparation and plowed into the soil.

When applying top dressing to onions, apply the remaining 60% nitrogen fertilizer and 40% potassium fertilizer as base fertilizer. You can apply it 2-3 times as top dressing during the peak leaf stage and the early and middle stages of onion bulb formation.

Spring fertilization

The spring fertilization time is March. The amount of nitrogen fertilizer and potassium fertilizer required during onion cultivation is basically equal. Therefore, on the basis of increasing the application of organic fertilizer, the application of potassium fertilizer should be increased, and trace element foliar fertilizer should be sprayed on the leaves to meet the needs of onions for medium and trace element fertilizers for growth and development.

Summer fertilization

The recommended time for fertilizing in summer is June to July. If a large amount of organic fertilizer is applied, less potassium fertilizer can be applied, especially the balanced application of nitrogen fertilizer and potassium fertilizer, to achieve a good yield-increasing effect.

Fall Fertilization

The recommended time for autumn fertilization is October. Applying too much nitrogen fertilizer and watering too much will not only waste nitrogen fertilizer, but the green onions produced will also be unsustainable in storage and their quality will decline.

Winter fertilization

Onions can be covered with ground film in winter. They require a balanced supply of nitrogen, phosphorus, potassium and trace elements. Nitrogen fertilizer alone cannot be applied. After the onion plants are alive, biogas slurry should be applied in time. Generally, it should be applied once every 12-15 days. Each time, 5-8 kg of urea, 4-5 kg ​​of potassium chloride or 15 kg of 16-16-16 three-element compound fertilizer should be applied.

Key points for fertilizing onions

1. When fertilizing onions, it is best not to use large amounts of water, otherwise it will result in low fertilizer utilization rate. In addition, when urea is spread on the surface in summer, the nitrogen element will evaporate and cause leaf fumigation and seedling burning.

2. When fertilizing onions, it is recommended to use compound fertilizer together with organic fertilizer. Compound fertilizer supplements the nitrogen, phosphorus and potassium elements needed for plant growth, while organic fertilizer improves soil quality and supplements a variety of trace elements needed by plants.

3. Onions do not like strong light. They require moderate light intensity. After fertilizing, appropriate light can promote the growth of onion whites and increase the yield of the plants.