A few agricultural proverbs, urgent ~ ~!

1 Spring rain is as expensive as oil, and farmers are more worry-free.

If there is too much rain in spring, a film will form on the surface, and the groundwater will not be distributed, which will make plants rot.

Money can't buy drought in May and fullness in June.

This is the lunar calendar. Wheat is harvested in May, so it will be troublesome if it rains.

Corn is ordered in June, and rain is more conducive to seed germination.

It rains at night, sunny during the day, and food is not plentiful.

Sunny days are good for photosynthesis.

If it is not hot in dog days, the grain will not bear fruit. ...

Winter snow is wheat quilt, and Chun Xue is rotten wheat root.

I can't explain this well. Let me quote.

What are the benefits of snow in winter for crops?

First of all, the newly fallen snowflake is very soft; Snowflakes are porous and there is a lot of air in the pores. Thick snow covers the earth, which can not only reduce the loss of heat in the soil, but also prevent the invasion of cold air on the snow surface. Snow plays the role of "isolation" in the convection and conduction of air heat between the upper and lower snow surfaces. In this way, it is like covering a person with a thick "duck down quilt"-no matter how cold the atmosphere outside is, the temperature on the snow-covered table will not drop very low.

Experiments show that the thermal conductivity of newly fallen snow is only 1% of that of iron. In the coldest day of bullets, the temperature of ten kinds of soil without snow cover can be reduced to -20℃, while the soil with snow cover can maintain a suitable temperature. The following set of figures can illustrate this point.

When the fresh snow depth reaches 6.6 cm, the ground temperature at 5cm is 3.3C higher than that without snow. When the snow depth reaches 10.5cm, the ground temperature at 5 cm is 6.6℃ higher than that without snow. When the snow depth reaches 12.9 cm, the ground temperature at 5 cm is 7. 1C higher than that without snow.

In addition to maintaining the temperature of shallow soil, new snow is also beneficial to prevent winter wheat from freezing injury. When the snow melts in Foshan in spring, a large amount of snow water can not only provide necessary water for crops, but also promote the root system of winter wheat to extend deep into the soil after the snow water penetrates into the soil, which is beneficial to the later growth of wheat.

In addition, snow can also absorb ammonia, hydrogen sulfide, carbon dioxide, sulfur dioxide and other gases in the air. According to the test, the highest nitrogen content in 1 kg snow water can reach 7.5 mg, which is equivalent to five times the nitrogen content in the same weight of rain water. When the snow melts, these nitrides are brought into the soil by the melted snow water, and can be acidified with some in the soil to synthesize various salts, such as ammonia and sulfate to synthesize ammonium salt (namely "ammonium sulfate"), which becomes a good natural fertilizer.

Snow in winter has another advantage. Because of the snow, the circulation of surface air is blocked, so some pests can be suffocated. At the same time, a lot of heat is consumed during snow melting, which reduces the soil temperature. This can freeze the eggs of some overwintering pests and the roots of surface crops (because crops and pests have different cold resistance, Tianjin weather, such low temperature does not harm crops). Adequate snow and water in winter can not only alleviate the drought in that year, but also provide favorable conditions for timely sowing and full seedling growth of spring-sown crops in the coming year.