Complete Guide to Crop Overwintering Methods, Latest Freeze-Protection Techniques Summary
Every year, with the arrival of winter, temperatures drop and the weather turns cold. During cultivation, if crops are not carefully managed, freeze damage can occur, affecting yields after the start of spring. To prevent crops from suffering freeze damage during overwintering, the following methods are introduced to prevent freeze damage, and farmers may adopt them as appropriate according to actual conditions.
1. Windbreak method
The method is to make windbreaks 1-1.5 m high from straw alongside the vegetable beds, with 1 windbreak set every 3-4 beds.
2. Mulching method
In the afternoon before frost arrives, cover the vegetable beds and vegetables with straw, rice straw, etc., which can reduce mechanical damage from wind and cold. Use 100 kg of rice straw per mu. It should be spread loosely and sparsely, and the vegetables must not be completely covered, so as to prevent effects on photosynthesis.
3. Winter irrigation method
Irrigating before frost can raise the temperature by 2°C-3°C after the cold wave passes.
4. Soil banking method
Before freezing, in combination with intertillage, bank broken soil around the roots, which can loosen the soil, raise soil temperature, and directly protect the roots. However, intertillage and soil banking must be carried out before the soil freezes, and the depth should preferably be 7-10 cm.
5. Ditching and drainage method
Open the “three ditches” well to ensure that ditches, canals, and fields are unobstructed, so that frozen water can be drained promptly.
6. Ash scattering method
First, before low-temperature freeze damage arrives, scatter a thin layer of plant ash on the vegetables; second, scatter plant ash between the rows.
7. Applying organic fertilizer and spraying nutrient solution
Before frost, use insulating farmyard manure such as pig and cattle manure or soil and miscellaneous fertilizer, and bank it around the stems and roots of the vegetable plants, which can raise soil temperature by 2°C-3°C. Topdressing should preferably be carried out on sunny days, at 1000-1500 kg per mu. At the same time, spray plant nutrient solutions such as “Yunda 120” brassinolide, Lufenwei, and Aiduoshou to improve the cold resistance of the plants.
8. Smoking method
Pile weeds, straw, dead branches, fallen leaves, etc. around the vegetable field, and light smoke at the corners on the windward side before frost arrives, which can disperse the cold wave. However, be sure to prevent burning the vegetables.
9. Nitrogen control method
During the seedling stage, appropriately reduce the amount of nitrogen fertilizer. Do not apply nitrogen fertilizer excessively, so as to avoid poor cold resistance of the plants. Topdressing should be early to promote strong vegetable seedlings. Before low temperatures arrive, do not apply quick-acting nitrogen fertilizer. It is advisable to apply phosphorus and potassium fertilizer once to enhance the cold resistance of the vegetables.
Although there have long been folk proverbs passed down by word of mouth such as “timely snow foretells a bumper harvest” and “cold winter, abundant autumn,” in fact, winter cold-protection work must not be taken lightly. Timely snow and winter cold can freeze overwintering pests to death, but as the saying goes, “things reverse when they reach an extreme.” If no prevention and control are carried out, cold weather can likewise freeze overwintering crops to death, so preventing freeze damage is particularly important.