Seedling protection technology of autumn spinach overwintering

Autumn spinach is an overwintering vegetable sown in autumn and harvested in spring. It overwintered from the end of November to the beginning of March of the following year for more than 100 days, so under the condition of long-term low temperature and dryness, how to ensure safe overwintering is the key to harvest. First, pour frozen water. Pouring frozen water must be "one fixed" and "two suitable". "Yi Ding" means to decide whether or not to pour frozen water according to the water content of the soil. Generally, the absolute water content of sandy loam soil is less than 15%, loam soil is less than 17%, and clay is less than 20%. Frozen water should be poured. "two suitability" means timely watering and proper watering. The appropriate time to pour frozen water is when the plough layer of the soil can defrost during the day and freeze at night. Proper watering means that the amount of frozen water should not be too large or too small. Generally, it is appropriate to connect the soil moisture on the bottom. Second, catch up with the overwintering fertilizer. Topdressing overwintering fertilizer can increase the content of soil nutrients, which can be used in winter and spring, and promote the weak to become strong. It is especially important for vegetable fields with low base fertilizer, poor soil fertility and weak seedling condition. Therefore, it should be combined with frozen water topdressing overwintering fertilizer, generally applying urea 10 kg or ammonium sulfate 20 kg per mu, topdressing with water. Third, mulch to protect against cold. The absolute low temperature in the severe cold period in the northern region is very disadvantageous to the vegetable seedlings to survive the winter safely, so the mulch should be used to prevent the cold to ensure the seedlings to survive the winter safely. Mulching can generally be carried out after all the soil in the plough layer is frozen. The mulch is a farm fertilizer rich in organic matter and crushed and mashed, sprinkling about 1000 kilograms per mu.