What are the characteristics of rain crops?

Rain-indicates that the precipitation begins and the rainfall gradually increases.

Gregorian calendar every February 18 or so is a rainy solar term. At this time, the sun reaches 330 degrees of the yellow meridian, which is the solar term of "rain". Rain has two meanings, one is that the weather gets warmer and the precipitation increases gradually, and the other is that there is less snow and more rain. "Twenty-four solar terms" said: "In the first month, water is in the sky. Spring belongs to wood, but there must be water for those who grow wood, so there is rain in beginning of spring. If the east wind melts, it will disperse into rain. " After the "rain", the temperature in most parts of China rose to above 0℃, the daily average temperature in Huanghuai Plain reached about 3℃, the average temperature in Jiangnan was about 5℃, the temperature in South China was above 10℃, and the average temperature in North China was still below 0℃. Before and after rainfall, rape and winter wheat generally turn green and grow, which requires high water content. "Spring rain is as expensive as oil", so proper precipitation is particularly important for crop growth. At this time, the precipitation in North China, Northwest China and Huanghuai areas is generally less, which often cannot meet the needs of agricultural production. If there is little rain in early spring, the best economic benefit can be obtained by timely spring irrigation before and after the rain. In the area south of Huaihe River, it is mainly to strengthen intertillage and hoeing, and at the same time, do a good job in clearing ditches and draining water in the field to prevent excessive spring rain from causing wet damage and rotten roots. As the saying goes, "Water the flowers with wheat, water the flowers with vegetables", and the coated rape should be topdressing with moss fertilizer in time to compete for more pods. South China's double-cropping early rice seedling cultivation has begun, so we should pay attention to "cold tail and warm head", and strive to sow all the seedlings at once.