The first frost is coming, how to prevent crops from being affected?

When the first frost comes, the most worrying thing is the agricultural workers, who have worked hard for a year, waiting for the harvest to bring hope to their homes. So, what precautions should be taken before the first frost comes, so that crops will not be affected? Let's take a look.

What is frost?

Frost means that during the growing season, the surface temperature of soil or the temperature near plant canopy drops below 0℃ in a short time at night, the surface temperature of plants drops rapidly, the water in plants freezes, the metabolic process is destroyed, and cells are squeezed by ice cubes, causing harm. When frost occurs, plants are harmed by low temperature, not just by frost. If the relative humidity of the air is low, "white frost" may not be seen, and frost may also appear. Usually, people also call the frost without "white frost" as "black frost".

First, how to prevent crops from freezing during the first frost-agricultural anti-freezing methods

To cultivate cold-resistant varieties, it is necessary to arrange crop varieties reasonably according to the local frost occurrence law and the length of frost-free period to prevent greed for green and late maturity. Strengthen on-site management. For example, through pruning and chemical control, cotton can promote growth and development, promote early maturity, and pick more flowers before frost.

Second, how to prevent crops from freezing during the first frost-physical frost prevention method.

1, irrigation method, which is an economical and effective anti-freezing method. Irrigation can increase the heat capacity and thermal conductivity of soil, increase the humidity and temperature of air, and reduce radiation heat dissipation. Practice has proved that the leaf surface temperature of irrigated field crops at night is 65438 0-2 degrees Celsius higher than that of non-irrigated field crops. The frost prevention effect is better on the day of irrigation or the day after irrigation. The best irrigation time is when the cold air has just calmed down and the frost has not yet appeared.

Frost means that the surface temperature of soil or the temperature near plant canopy drops below 0℃ in a short time at night during the growing season.

2. Smoking method: generally, when frost is about to happen, the smoke is ignited, so that the smoke accumulates and heats up to become a curtain, which can reduce thermal radiation, slow down cooling and increase the temperature between plants. You can choose firewood that smokes easily. This method can increase the temperature between plants by 0.5-2 degrees Celsius. Smoking with chemicals to prevent frost is more labor-saving, economical and effective than using firewood, but we should choose medicinal materials that are harmless to people and crops.

3. Covering method is suitable for antifreeze of small-area crops. Straw curtains, mats, clay pots, plastic sheets and plant ash can be used to cover vegetables and other crops, so that the heat in the field is not easily lost and the harvest period is delayed.

The defensive measures against frost are summarized as follows:

1. Taking fundamental measures, such as building water conservancy projects, planting shelterbelts and carrying out farmland capital construction, can improve farmland microclimate and prevent freezing injury.

2. Choose the location and sowing date according to the crop type to avoid frost.

3, flexible application of ripening technology, rational fertilization and irrigation to prevent green, promote early maturity and avoid frost.

4. Before frost comes, measures such as irrigation, spraying, smoking, covering and heating should be taken to prevent frost.