Weather harmful to crops in autumn and winter

Frost is a meteorological disaster that harms crops in autumn and winter.

Frost is a common agricultural meteorological disaster, which occurs in winter and spring, and is mostly caused by the cold wave heading south and the temperature dropping sharply below zero degrees Celsius in a short time. Still affected by the cold wave, the weather changed from cloudy to sunny that night, which was caused by strong radiation cooling on the ground. This is what people often say "adding insult to injury".

When the temperature is lower than the ground, the water vapor condenses into white crystals on the surface of the object. The water vapor content is less, and it is called black frost without frost; Frost damage to crops is called frost. First frost, first frost and the first frost solar terms are not the same thing, but three different concepts.

"Frost" refers to white ice crystals 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.

Anti-freezing method recommendation

1, spray antifreeze

Before frost comes, spraying water on crops with a sprayer can make crop leaves condense into water droplets, release latent heat, raise temperature and avoid freezing injury.

Step 2 cover with antifreeze

Generally used to cover vegetables. Straw curtains, mats, plant ash, plastic film and other materials can be used to cover the crop surface about 4 hours before frost, and then removed after sunrise to keep geothermal energy from losing and prevent freezing injury and frost.

3. Self-made anti-frost smoke bomb

It can be made of 30% ammonium nitrate, 30% asphalt and 40% sawdust. Firstly, sawdust and ammonium nitrate are dried, crushed and sieved, then the three materials are mixed and stirred evenly, wrapped into a cylindrical medicinal color, and a medicinal twist or fuse is inserted in the middle. Before the arrival of first frost, it was placed in the ground, and the location can be determined according to the size of the plot. When ignited about 1 hour before the arrival of first frost, a large amount of smoke can be released.