Is the meteorological disaster that harms crops in autumn and winter frost or frost?

The meteorological disaster that harms crops in autumn and winter is frost, not frost.

Frost refers to an agricultural meteorological disaster in which the temperature drops to 0℃ or below in the growing season of plants, which mostly occurs 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℃. Although there may not be frost in first frost, there may not be frost in first frost.

Advection frost is caused by the sudden drop of plant temperature due to the invasion of cold air or cold wave, which has a wide range of influence and serious harm. Radiation frost is a clear and windless night, which is caused by the radiation cooling of the surface and the rapid drop of plant body temperature. The influence scope is small and has certain locality. Advection radiation frost occurs frequently, with a wide range of influence and more serious harm.

Prevention methods of frost

1, water spraying method

Before frost occurs, spraying water on the surface of plants with a sprayer can slow down their body temperature and increase the content of water vapor in the atmosphere, and the water vapor condenses and releases heat, thus reducing the frost hazard. On days when frost is obvious, you can spray water many times. Spraying water can increase air humidity, enhance atmospheric inverse radiation, keep the ground warm and reduce temperature difference.

2, before frost irrigation method

Irrigation 3 ~ 5 days before the start of low temperature has the best control effect. Irrigation before frost, the water temperature is higher than the soil temperature at night, water can increase a lot of heat in the soil. The function of irrigation is to increase the heat capacity of soil and make the soil temperature drop slowly, and the other is to increase the air humidity near the ground. Increase the atmospheric inverse radiation, play a role in heat preservation on the ground and protect the ground heat.

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