Look here for crop freeze prevention in the cold winter

1. Comprehensive prevention of rape frost damage

In rapeseed production, comprehensive anti-freezing measures should be taken for different causes of freezing damage. The first is to pay attention to the selection of varieties with strong cold resistance; secondly, the sowing date should be arranged according to the characteristics of the variety. Early sowing and early planting of varieties with strong winter properties can increase the accumulation of dry matter, realize the early emergence of strong seedlings, and improve the freezing resistance. At the same time, the following management measures are taken:

1. Topdressing seedling fertilizer to prevent freezing of strong seedlings: In order to obtain stable and high yield, it is necessary to achieve "autumn growth" and "winter growth" in the seedling stage to lay the foundation for yield. Should seize the opportunity to topdress the seedling fertilizer. In the seedling stage, top dressing should increase the application of phosphorus and potassium fertilizers to enhance the resistance of rapeseed; appropriately control or reduce the application of nitrogen fertilizer to prevent the plants from being tender and juicy, and the cold resistance will become poor.

2. Cultivating soil and rooting: The height of soil cultivation is generally to cultivate the first leaf at the base, which can loosen the soil and increase the soil temperature, but also can directly protect the roots, which is conducive to root growth and prevent lodging.

3. Irrigate overwintering water: Overwintering water can reduce the temperature difference between day and night, improve the field microclimate, alleviate low temperature attacks, and prevent dead seedlings. Overwintering water must be filled enough and thoroughly.

4. Removal of early stalks and early flowers: Winter Brassica napus should be removed for bolting and flowering before the beginning of spring to reduce freezing damage. After harvesting, a quick-acting nitrogen fertilizer must be applied to compensate for the nutrients in the plant and promote its recovery.

5. Reapplying wax fertilizer: It can increase soil miscellaneous manure, manure, human feces, plant ash and other fertilizers between rows, which can increase the ground temperature by 2 ℃-3 ℃, which has the effect of preventing cold and warming, and can also serve as winter fertilizer Spring effect.

6. Ground cover: straw, thatch and other crops can be covered between rows, which can not only increase soil temperature, but also keep water and moisturizing, but also inhibit the growth of weeds. Straw rot is a good organic fertilizer.

7. Once frost occurs, artificial fumigation shall be adopted at the right time to increase the local environmental temperature and reduce the hazard of frost.

2. Antifreeze measures for fruit trees

1. Irrigate before freezing. Watering or irrigating before freezing, irrigation must be done before cooling down, and watering combined with decomposed human waste or organic fertilizer, the effect is better. After freezing, it is not advisable to re-irrigate to avoid aggravating freezing damage.

2. The trunk is painted white. Before the frost comes, use 10kg quicklime, 1kg sulfur powder, 0.2kg salt, add 30-40kg water and stir evenly, make a paste, and paint the main stem.

3. Cover the tree tray. In winter, cover 10-20 cm thick with straw, thatch, etc. around the tree tray, or cover with mulching film to increase the soil temperature.

Emergency measures after freezing

1. Shake away the snow. The snow on the tree canopy should be shaken off in time or with a long stick to prevent the snow from breaking the branches.

2. Timely irrigation. The tree body loses more water after freezing, and the root system and the tree body are in need of water, so they should be irrigated in time after thawing.

3. Prune in time. After thawing, the injured tree branches should be pruned in time, and the branches and leaves damaged by frostbite and snow should be cut off.

4. Prevent diseases and spray foliar fertilizer. After freezing damage, the resistance of fruit trees decreases, and pesticides should be sprayed to prevent the occurrence of diseases. At the same time, foliar fertilizers should be sprayed in combination with disease prevention to supplement crop nutrition, enhance plant resistance, freeze resistance, and promote growth and development.

3. Heat preservation measures for shed vegetables

For the cultivation of vegetables in cold ceiling rooms, comprehensive measures such as biology, physics, chemistry, and agriculture should be used to keep warm and prevent freezing. This is extremely important for promoting the normal growth of vegetable plants and improving the yield and quality of vegetables. Reasonable cropping arrangements, consider not planting fruits and vegetables and other vegetables that require higher temperatures in winter, and plant leafy vegetables with lower temperature requirements, and plant fruits and vegetables when the temperature picks up in spring. The following insulation measures can be taken in the shed:

1. Prepare hot soil layer. Both decomposed chicken manure and cow manure are thermal organic fertilizers with good air permeability. Before transplanting vegetable seedlings in the shed, fertilize the soil at the ratio of chicken manure: cow manure: soil = 2:2:6 and prepare the ground. Because this mixed growth soil layer has better heat absorption and heat generation performance, it is very beneficial to the root development and growth of vegetable seedlings.

2. Cover with grass thatch (straw curtain) protective film. According to the local temperature and the temperature of the day, the cover should be uncovered at the right time (it is advisable that the temperature of the shed should be around 18℃ one hour after cover, the cover should be late if it is higher than 18℃, and cover should be early if it is lower than 18℃). At night in a cloudy and snowy weather, cover a layer of cold-proof plastic film outside the grass thatch (straw curtain), which can increase the temperature of the shed by 2℃-3℃. If the seedlings are grown in the shed, a small arch shed should be built on the seedling border, and the effect of heat preservation and moisture preservation will be better with multi-layer covering. Before the arrival of low temperature and freezing damage, spreading plant ash between rows, spreading rice husks, straw, glutinous rice, etc. can improve ground temperature and protect seedlings.

3. Artificial warming and supplement of light. The vegetable production in the shed is not afraid of freezing in the cold, even the lack of sunlight even on cloudy and snowy days. Therefore, enhancing and supplementing the sunlight in the shed is very important to ensure the normal growth of vegetable plants. The method is to hang a reflective film on the back wall of the shed to increase the light intensity of the cultivation bed. You can also install electric lights in the shed. In the case of cloudy and snowy days with low light, turn on the light for about 3 hours each morning and evening. . In this way, the temperature in the shed can be increased, and the photosynthesis of vegetable plants can be promoted. When the temperature in the shed drops to the minimum temperature required by the vegetables, the fire should be increased, but care should be taken not to raise the shed temperature too fast or too high. Also need to pay attention to the flue must be airtight. For the nursery greenhouse, a hotbed, such as an electric hotbed, can be used to cultivate the original seedlings. Frame beds are used for seedling division.

4. Adjust the air in the shed. In the cold winter season, due to low temperature and low ventilation in the shed, it is easy to cause excess oxygen and insufficient carbon dioxide in the air, which has a great impact on the respiration of plants. In this regard, carbon dioxide fertilization techniques, such as smoking, sulfuric acid and ammonium bicarbonate reaction, can be used to adjust the air composition in the shed, supplement the carbon dioxide content, and also enhance the cold resistance of plants.

5. Spray fertilizer solution on foliage. In the case of low temperature and weak sunlight, the ability of the roots of the greenhouse vegetables to absorb nutrients is greatly weakened, especially after freezing damage, the leaves show alkaline atrophy, and the ability of photosynthesis to produce nutrients is even worse. At this time, growth hormones should be used as little as possible or not, and foliar spraying of fertilizer solution should be used to solve the problem, which can supplement the nutrient deficiency of vegetable plants, improve the cold resistance of vegetables and alleviate the harm of freezing damage.

6. Irrigation to protect the roots. Under normal circumstances, the freezing damage of vegetables in greenhouses is mostly caused by lack of water. During the critical period of vegetable plant growth, choose sunny and good weather (temperature above 20℃), and use under-mulch dark irrigation or drip irrigation to irrigate enough soil moisture to maintain moisture, which can effectively prevent freezing damage. This is because water has higher specific heat and slower heat dissipation than air. The soil in the shed has moderate water content and good heat preservation performance. The root system of vegetable plants can be protected from freezing damage.

7. Strengthen management after snow. In snowy weather, when the outdoor temperature is around -10℃, the temperature inside the shed is generally around 16℃, and the temperature difference between inside and outside is relatively small. However, once the weather clears, the temperature in the shed can rise above 30°C at noon. At this time, the air should be repeatedly released to make the temperature difference between the inside and outside of the shed close to the previous few days, and then slowly increase the temperature so that the vegetable plants can adapt to the environment before they can resume normal growth. Otherwise, it will cause "ten days to be depressed, one day to grow rapidly" and flashing, so that when the temperature drops again, freezing damage will occur more easily.

8. Prevent diseases. Freezing damage will reduce the resistance of vegetables and induce the infection of germs. After cooling down, dust or fumigation with aerosol should be used to prevent the occurrence of diseases.

Disclaimer: Some articles on this website are transferred from the Internet. If the legal rights of third parties are involved, please inform this website for handling. phone