Overwintering technique of false planting of Onion

Shovel the seedlings out of the field (try not to hurt the roots as far as possible), gently shake off the floating soil, remove rootless, non-growing points, too short, slender seedlings and seedlings with overlong leaves, tillering seedlings and diseases and pests as harmful seedlings, and onion seedlings (the leaf sheath of onion seedlings grows upright; the leaf base cross section is round: the leaf sheath of onion seedlings is upright and slightly curved, and the leaf base is concave). In order to facilitate management, onion seedlings should be graded pseudo-planting, grading standards are: first-class seedlings, bulblets 0.6-0.7 cm, leaves 3-4; secondary seedlings, bulbs 0.4-0.6 cm, leaves 3. While grading, it is tied into small bundles of 80 to 100 trees, which are graded and planted.

The first-class seedlings are pseudo-planted in the sunny border. The sunny border should choose to be behind the wind barrier or other leeward overcast places, first spread a layer of dry sand about 5 cm thick in the border, then pile small ridges 5 to 7 cm high on the dry sand on one side of the border, and then put the first-class seedlings in a row side by bundle behind the ridge. after a row is placed, the soil at the root of the seedlings is 5 to 7 cm in diameter, and then a straw with a diameter of 2 to 3 cm is placed on the soil at intervals between the front and back rows of seedlings. After all the false planting, the soil is used to block the surrounding areas of the bed, so as to prevent ventilation and water penetration.

The second-class seedlings were planted in the cold-proof ditch. In order to prevent the retting of the root, the cold-proof ditch should be chosen in the higher terrain. The specific method is as follows: several ditches are opened in the east-west direction at an interval of 5 to 10 centimeters, with a length of 3 to 5 meters, a width of 25 to 30 centimeters and a depth of 15 to 20 centimeters. The bundled seedlings are tilted 45 degrees to the south and placed in the ditch, obstructing the soil to the top of the leaf sheath. After all pseudo-planting, wind barriers are set around to make the seedlings leeward and overcast, and the outside of the wind barrier is blocked strictly with soil to prevent wind and rain. The heart leaves of seedlings planted by this method will grow slowly, and when the external temperature continues to drop in Northeast China, we should cover the soil or cover crop straw in batches again according to the weather conditions.

Usually pay attention to the weather forecast. Cover the seedlings with plastic film before the overcast snow, remove the film and clean the surrounding snow in time after the snow to prevent snow water from entering the border: ditches, causing rotten seedlings.

By using the above methods, onion seedlings can survive the winter safely until they are planted in the field at the beginning of March of the following year.