What are the causes of frosting and what are the prevention methods?

Causes of Frost Frost is a common agrometeorological disaster, which occurs in winter and spring, and is mostly caused by the

What are the causes of frosting and what are the prevention methods?

Causes of Frost Frost is a common agrometeorological disaster, which occurs in winter and spring, and is mostly caused by the cold wave going south and the temperature dropping sharply below zero degrees Celsius in a short time. After the cold wave, the weather turned from cloudy to sunny that night, which was caused by strong radiation cooling on the ground. Is this what people often say? Worse? . The harm of frost to garden plants is mainly to freeze the water in plant tissues and cells, which leads to physiological drought, injury or death, and causes great losses to garden production.

Frost is generally divided into three types. Frost caused by the invasion of strong cold air in the north is common in early spring and late autumn in the north of the Yangtze River, as well as in winter in South China and Southwest China. Northerners call it? Wind and frost? Weather call? Advection cream? . On a clear and windless night, due to strong radiation and heat dissipation, the ground appears low temperature, which the masses call it? Sunny frost? Or? Static frost? Meteorology is called radiation frost. First, affected by the invasion of strong cold air in the north, the temperature dropped sharply. After the wind stopped, the night was fine, the radiation was strong, and the temperature dropped again, causing frost. This kind of cream is called mixed cream or advection radiation cream, and it is also the most common cream. Once this kind of frost happens, the temperature often drops sharply, and the air is dry and cold, which is easy to wither and die crops and garden plants. Therefore, special attention should be paid to this frost to avoid serious economic losses.

Frost means that during the warm period of a year, the temperature of soil surface and plant surface drops enough to cause crop injury or death. Therefore, when frost occurs, the temperature of the near-surface layer can generally be below 0 degrees; It can also be in the range of more than 0 degrees and less than 5 degrees. When there is frost, white ice crystals may not appear. This situation is called dark frost in some places.

When a cold current passes by and meets the subtropical monsoon there, frost will appear when the cold current is strong.

The way to prevent frost is irrigation.

Irrigation can increase the humidity of air near the ground, protect geothermal energy and raise the temperature (which can be increased by about 2℃). Because of the large heat capacity of water and slow cooling, the site temperature will not drop rapidly. For small area garden plants, water spraying can also be used. The method is to spray water on plants continuously with sprinkler irrigation equipment 1 hour before frost comes. Because the water temperature is higher than the air temperature, when the plants are cold, the water will release heat, and the water temperature is higher than the freezing point to prevent frost, and the effect is better.

covering method

Cover plants with straw, wheat straw, plant ash, weeds, nylon, etc. It can not only prevent the attack of cold air from the outside, but also reduce the loss of geothermal energy, and generally increase the temperature 1-2℃. Some dwarf plants can also be buried in the soil to prevent freezing injury. This method can only prevent a small area of frost, and its advantage is that it takes a long time to prevent freezing.

Smoking method

Half an hour before the frost comes or 1 hour, light it with firewood, cow dung, sawn wood, waste engine oil, red phosphorus or other dust and smoke substances that can produce a lot of smoke. These smog can block the loss of heat on the ground, and the smog itself will also generate some heat, which can generally raise the air temperature near the ground by 1-2℃. However, this method has certain weather conditions, high cost and air pollution, and is not suitable for universal promotion. It is only suitable for preventing short-term frost and the use of rare trees and their nurseries.

Fertilization method

Applying organic fertilizer early before cold wave, especially using semi-decomposed organic fertilizer as base fertilizer, can improve soil structure and enhance its heat absorption and insulation performance. You can also use the semi-decomposed organic fertilizer to emit heat in the process of continuing to decompose, thus increasing the soil temperature. After winter, warm fertilizer can be used to cultivate forest plants, and the antifreeze effect is obvious. Warm fertilizers are commonly used, such as manure, compost and plant ash. This method is simple and feasible, but it should be applied 3-4 days before the frost comes to master the local climate law. After winter, lime water can be used to whitewash the trunks of trees and fruit trees to reduce heat dissipation.

Frost prevention is the most urgent task at present.

At present, it is in the final period of the formation of autumn grain output. Frost prevention is the key measure to win a bumper harvest of autumn grain and the last battle to fight autumn grain production. Agricultural departments at all levels should take frost prevention as the most urgent task at present, overcome the paralysis and lax thinking and negative fear of difficulties, act quickly, strengthen organizational leadership and strengthen the implementation of responsibilities. A day without a good harvest, a day without relaxing management? Do everything possible to reduce and avoid freezing damage. Widely mobilize the masses to quickly carry out frost prevention work.

In view of the situation that there will be a large-scale cooling in Northeast China, it is necessary to quickly organize farmers to invest in the action of frost prevention and harvest, and go all out to implement preventive measures. All localities should make full use of radio, television, newspapers and other media to widely publicize the grim situation and significance of frost prevention, educate and guide grassroots cadres and farmers to effectively enhance their awareness of frost prevention, make frost prevention a conscious action of cadres and the masses, and quickly form a working situation in which cadres and the masses at all levels mobilize.

Implement the key measures to prevent frost.

Agricultural departments at all levels should keep close contact with meteorological departments, timely grasp the accurate forecast of frost, timely release early warning information, seize the best opportunity, organize the masses to prevent frost, and effectively improve the prevention effect. In crops, we should highlight crops such as corn and soybeans. In terms of plots, we should take greedy plots and low-lying plots as the focus of prevention. In terms of preventive measures, it is necessary to spray cold-resistant preparations according to local conditions to enhance the stress resistance of crops; Using artificial smoking to improve the local environmental temperature; Take measures such as removing empty stalk plants, stripping stalks and drying in the sun. For crops harmed by light frost, we should guide the masses to harvest late in time, promote after-ripening and improve quality in line with the principle of no frost and no sickle.

Strengthen anti-frost guidance and service.

The main leaders of agricultural departments at all levels should rely on the front command, personally study and deploy, and supervise the implementation. It is necessary to organize cadres and agricultural technicians to go deep into the front line of frost prevention, work in pieces and carry out their responsibilities. It is necessary to grasp the first level and implement it layer by layer, help the grassroots and the masses face to face to solve the practical difficulties encountered in their work, and ensure that the funds, materials and technology for frost prevention are in place. All localities should strengthen the supervision of frost prevention work, form a special working group, carry out key supervision in all localities, and strive to minimize freezing damage and losses.

Food suitable for frosty weather. beef

Many places in Chinese mainland have the custom of eating beef in the first frost. For example, in Yulin, Guangxi, residents here are used to eating fried noodles with beef and rice noodles for breakfast, fried radish with beef for lunch or dinner, or a beef brisket pot to replenish energy and pray for warmth and strength in winter. Besides beef, mutton and rabbit meat, it is also suitable for the first frost.

Beef has high nutritional value, which is ancient? Beef tonifies qi, just like astragalus? Say; Compendium of Materia Medica points out that beef is ok? Anzhong Yiqi, spleen and stomach, deficiency, bones and muscles, edema and moisture? . Chinese medicine believes that beef entering the spleen and stomach meridian is a good product for nourishing the spleen and stomach. Western nutritionists believe that beef is high in protein and low in fat, so it is delicious, loves to eat, and likes to eat? Favorite real person? Good name.

Beef can nourish the spleen and stomach, especially in autumn. Beef also has the function of tonifying kidney, so men can eat more. At the same time, you can also eat fried beef, braised beef brisket and stewed yam with beef bone marrow.

Recommended recipe: stewed beef with pumpkin

Ingredients: 250 grams of beef, 500 grams of pumpkin, ginger slices and a small amount of edible salt.

Exercise:

1. Wash and slice the pumpkin; Wash beef, cut into pieces, blanch in boiling water, remove and drain for later use. Add beef pieces and ginger slices to the soup pot, add water, bring to a boil with high fire, and simmer for 45 minutes.

2. Pour in pumpkin slices, cover with low heat and cook for 20 minutes until the pumpkin and beef are soft and rotten; Add salt and mix well to taste.

Second, white pomelo

At the time of the first frost, the second stage of rice harvest in the south of Taiwan Province Province was ripe, which was also the harvest period of white pomelo in Madou Town, Tainan. what's up King of grapefruit? Dabaiyou, as its name implies, has a higher evaluation than Wendan, so there is? Experts eat white pomelo, laymen eat Wendan? Statement. Top grade white pomelo, sweet and sour. If it is stained with plum powder, it tastes better. Because the fruit is sweet and juicy, it can be eaten by patients with heat cough and diabetes, and also has the effects of relieving alcoholism, lowering blood pressure, reducing fever and restoring physical strength.

White pomelo pulp contains pomelo peel sweetness, new orange peel sweetness, orange peel sweetness and sugar, and is rich in vitamin C, mineral potassium and organic acids. Its nature is cold, sweet and sour, and it can strengthen the stomach, promote digestion, quench thirst, relieve fatigue and lower blood sugar. Eating more pulp can not only increase nutrition, but also be beneficial to health.

The quality of white pomelo, orchard soil environment is a congenital condition, so brand certification can not be ignored. The so-called white pomelo with good quality, soft and juicy taste, high sweetness and slight acidity, is the best; From the appearance, the fruit stalk should be as flat as possible, and the peel should be smooth and complete, weighing about 1.5 ~ 2kg. It feels thin and heavy in your hand, and the flesh is light yellow, full and juicy, which is the top grade. When the acidity of white pomelo is high, as long as it is kept in the shade, the acidity will naturally decrease and become sweet with the passage of time; In the whole white pomelo, the pulp near the peel is fuller, sweeter and more stable in quality than the part with seeds near the core.

Third, duck meat.

On the day of the first frost, people in Taiwan Province province in southern Fujian should take supplements, which is what we often say in the north? Stick to autumn? . There is a proverb in southern Fujian called? It's better to make up the first frost in one year. . From this little proverb, we can fully express the people's attention to the first frost solar terms in Fujian and Taiwan. Therefore, every time the first frost comes, the ducks in Fujian and Taiwan will sell very well, and sometimes they will be out of stock, which is in short supply. The bosses who are happy to sell ducks can't control their mouths.

Eating duck can dispel autumn dryness. Ducks and chickens are birds, but their functions are quite different. It is well known that chicken is especially suitable for winter tonic. A chicken in September every year will keep you healthy in the coming year? Statement. Ducks belong to waterfowl. Hu Sihui, an imperial doctor in Yuan Dynasty, said in Drinking Goodness that duck meat is sweet in taste, cold in nature, non-toxic, nourishing internal deficiency, disinfecting and clearing heat, and benefiting waterways. Can be used for treating headache, insomnia due to yin deficiency, cough due to lung heat, nephritis edema, dysuria, low fever, etc. Regular consumption of duck meat is most beneficial to those with physical deficiency and yin deficiency, edema, loss of appetite, dry stool and low fever. Therefore, the hot and dry season in summer and autumn is most suitable for eating ducks. In contrast, other meats such as pigs, cattle and sheep are slightly inferior.

People always have it? Boiled soup is not fresh without chicken, and it is not delicious without duck. Putting some duck meat in the soup on weekdays is also very helpful to absorb nutrition. Duck soup contains a lot of amino acids needed by human body, but now, the older the duck meat, the higher its nutritional value. On weekdays, people drink old duck soup because it needs to add a lot of fresh animal raw materials, so they usually take older birds because it tastes more fragrant than young ones. Therefore, you should choose the old duck soup.

Recommended recipe: tea tree mushroom old duck soup

Ingredients: half a duck, 200g Agrocybe aegerita, onion, ginger, aniseed, salt and cooking wine.

Exercise:

1. Wash Agrocybe aegerita and soak it in cold water for about 2 hours. Wash the ducks and soak them in cold water, mainly blood. Chop the duck into large pieces, put it in cold water until the pot boils, remove the floating foam and remove it for later use.