Is autumn frost or frost harmful to crops?

The meteorological disaster that harms crops in autumn is frost.

Frost is a common agrometeorological disaster, which means that the temperature drops suddenly and the surface temperature drops below 0℃, causing damage to crops and even death. Frost usually appears in autumn, winter and spring. It is different from frost. "Frost" is a white ice crystal that condenses directly on objects when the water vapor in the air near the ground reaches saturation and the ground temperature is lower than 0℃. When there is frost, it is not necessarily frost. There may not be frost in first frost, and there may not be frost in first frost.

First frost and the first frost solar terms are not the same thing, but three different concepts. "Frost" refers to a white ice crystal formed by condensation of water vapor on the ground in cold weather; "Frost" refers to a common agricultural meteorological disaster phenomenon; The "first frost" solar term refers to the season that reflects the sudden drop of temperature.

Recommended anti-freezing methods:

1, irrigation method

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.

2. 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.

Baidu encyclopedia-frost