Onion root system shallow, like moi

Onion root system shallow, like moisture not drought-resistant, water absorption capacity is weak, like high soil moisture. After sowing, before and after cutting seedlings, roots and leaves grow slowly, the soil should be kept moist. Vegetative growth period and bulblet expansion period are the key periods of determining yield, they grow rapidly and meet the requirement of sufficient soil water. The relative humidity of the air is 60-70% , humidity is too large easy to cause disease. Conversely, if the relative humidity is too low, it will seriously affect the expansion of light bulbs, leading to yield reduction and quality degradation . 12 weeks before harvest, water should be controlled to ensure that the rapid ripening of bulbs to prevent cracking . The onion is suitable to be planted in the neutral sandy loam with loose soil, deep soil, sufficient nutrition, good permeability, good water and fertilizer retention, PH6-8, low air humidity and high soil humidity. Onion is a kind of long sunshine crop. The requirement of light condition is higher than that of leaf vegetables and root vegetables. To meet the needs of flower bud differentiation, vegetative growth, and bulb formation,