Fertilization Guidelines for Green Onions

Proper fertilization is crucial for ensuring optimal yield and quality in green onion cultivation. The fertilization strategy can be divided into three key stages:

1. Base Fertilizer Application
A substantial application of base fertilizer before planting is fundamental. This provides sustained nutrition throughout the growth cycle. The recommended application rate is approximately 250 kg of compound fertilizer and 20 tons of well-decomposed organic manure per hectare (equivalent to 15 mu). These fertilizers should be evenly incorporated into the soil during deep plowing or bed preparation.

2. Top Dressing (Foliar Application)
Top dressing for green onions is primarily achieved through foliar sprays. Applying a balanced foliar fertilizer rich in secondary and micronutrients effectively promotes vigorous growth and stem thickening. Given the relatively short residual effect of foliar fertilizers, applications are typically repeated at 15-day intervals. Significant improvement is usually visible after 2 to 3 consecutive applications.

3. Micronutrient Management
Beyond the primary macronutrients (Nitrogen, Phosphorus, Potassium), green onions require adequate levels of micronutrients such as Calcium, Manganese, Magnesium, and Boron. Deficiencies in these elements can directly impact plant health and marketable quality. For instance, Calcium deficiency often manifests as irregular white necrotic spots on new leaves and, in severe cases, may lead to root and stem rot. Therefore, supplementation based on soil tests or visual symptom diagnosis is recommended.

Conclusion
In summary, a successful fertilization program for green onions integrates a strong base, timely foliar nutrition, and attention to micronutrient balance. The principle of "little and often" should be followed, with all practices tailored to specific local soil conditions and climatic patterns.