Open-field onion cultivation

Onions have high requirements for soil preparation quality, as their root system is located in the topsoil (5–30 cm) and is characterized by poor branching. For successful crop development, the soil must be well-aerated, loose, and free from predecessors for 4–5 years. Optimal predecessors are winter cereals, legumes, or early tomatoes.

During the growing season, it is important to maintain soil moisture at no less than 70% during the bulb formation stages; however, in the second half of the season, moisture must be reduced to ensure proper maturation and storability of the harvest. The crop is relatively cold-hardy: seedlings can withstand frosts down to -6°C, while full development requires open areas with good lighting.

The production cycle of open-field onions varies depending on the climatic conditions of the region. The crop is grown in a one-year cycle via direct seeding or transplants, or in a two-year cycle using sets. The choice of method depends on the duration of the warm period, with the transplant method being preferable for zones with short summers.