Adding Management of Onion harvesting in Spring by ploughing and cultivating soil in fertilization and watering

onion

First, scientific fertilization: after turning green in spring, the first fertilization was carried out to improve the nutrition for the root growth of onion and lay the foundation for the luxuriant growth of aboveground after onion. Fertilization is mainly fully mature organic fertilizer, 1000 kg per mu, plus 20 kg of superphosphate and 10 kg of potassium sulfate.

When the onion grows to 8 Mel 10 true leaves and the bulb begins to expand, the head-promoting fertilizer is applied 3 times in a row, and the amount of sulfuric acid can be applied 10 Mel 20 kg per square meter, focusing on the middle stage of bulb expansion. At the beginning of bulb expansion, do not apply too much nitrogen fertilizer to avoid onion greed. In the bulb expansion period, potassium sulfate should be added when applying fertilizer, and the amount of potassium sulfate per mu is 5ml / 10kg, because the lack of potassium in onion will lead to its poor storability.

Second, timely watering: onions planted before winter should be watered back to green water in spring, and the return of green water should be timely. Early watering will lower the soil temperature and is not conducive to the growth of onions; too late, it will inhibit the growth of onions and lead to dry tips of leaves.

When the onion bulb begins to expand, the water should be controlled to squat seedlings, and the squatting time should be flexibly controlled according to the soil, climate and onion growth. When the sandy soil or climate is dry, the squatting seedling period should be shortened properly; when the clayey soil, low-lying terrain and rainy soil is rainy, the squatting seedling period should be properly prolonged. The goal is to promote the transformation from onion growth to bulb expansion, which usually takes about 10 days. It is generally believed that the mature tubular leaves of onions turn dark green, the mesophyll is thick, the leaves are waxy, and the color of heart leaves is deepened, which is a sign of stagnation in this period. After squatting seedlings, usually water every 5 days to promote the rapid expansion of the bulb, when there is a part of the onion lodging, stagnant watering to avoid bulb storage after harvest.

Third, ploughing the soil: when the onion is not covered with plastic film, it must be ploughed before squatting seedlings. The intertillage times of clayey soil is more than that of sandy soil, and the intertillage depth should be controlled in 3cm, shallower near the plant and deeper away from the plant. After the onion is ridged, it is ploughed at a standstill. At the same time of ploughing, the soil can be cultivated properly.

Fourth, harvest and storage: generally harvested around the middle of June. Onion bulb maturity sign: in the later stage of bulb expansion, there are no new leaves to enrich the leaf sheath, the pseudostem is hollow, and the onion is dumped from the base of the pseudostem. The maturity of bulbs is related to the characteristics of onion varieties, planting time, climatic conditions and so on. The varieties with short dormancy period and poor storability should be harvested early and begin to harvest when half of the onions are lodging, while the mid-late-maturing varieties should be harvested at 70% lodging.

Harvest should be carried out on sunny days, and it is best to have several sunny days in a row. When harvesting, pull out the whole plant and spread it for 2 murals for 3 days. When drying, only bask the leaves, not the head, and the bulbs are covered with leaves, which can improve the maturity of the bulbs and make the skin monotonous. After that, remove the soil, cut off the whisker roots and withered leaves, and then store them. Some onions are directly braided or bundled for storage without removing leaves after harvest.