Twenty-four solar terms and a little summer heat: Chan Ming Levin wants a little summer heat.

Every year around July 7th, when the sun reaches the longitude 105 degrees, it is the summer solar term. "Twenty-four solar terms" said: "June Festival ... summer, summer also. In terms of heat, it is small at the beginning of the month and big in the month. Today, the heat is still small. " It can be seen that "light summer heat" is a solar term reflecting the hot weather. It is said that "light summer" is a light summer, not very hot. So far, the average daily temperature in most parts of the country is around 25℃, which has entered the "dog days" that people often say. "Fu Tian" is divided into three parts: the first, the middle and the last. It is a miscellaneous solar term besides the twenty-four solar terms, and it is also the division of hot seasons in ancient times, which is convenient for arranging agricultural activities.

Around the "Little Summer", except the winter and spring wheat crops are being harvested in the northeast and northwest regions, the summer and autumn crops in most parts of the country have entered the most prosperous period due to the high temperature, abundant rain and sufficient sunshine, and the farmland management has also entered a relatively busy period at this time. This can be seen from the popular agricultural proverbs everywhere. For example, "radish grows on the head, vegetables grow on the second day, and cabbage grows on the third day", "sweet potatoes are planted in the heat" and "crops grow on mung beans before and after the heat".

In the "Little Summer" season, the early rice is in the late filling stage, and the early-maturing variety "Dashu" should be kept wet and dry in the field before harvesting. Mid-season rice has been jointing, so it should be topdressing panicle fertilizer according to the growth to promote large panicle and more grains. Single-season late rice is diversifying and should be fertilized as soon as possible. In order to control plant diseases and insect pests, double-cropping late rice seedlings should be given enough "marriage fertilizer" 5- 17 days before sowing. "It's hot in summer, and the pruning of cotton never stops." Cotton in most cotton areas begins to blossom and bear bolls, which is the most vigorous growth time. At the same time of heavy application of flower boll fertilizer, it is necessary to trim, thresh and remove old leaves in time to coordinate the distribution of nutrients in plants, enhance ventilation and light transmission, improve the microclimate of the population and reduce the shedding of buds and bolls. The high temperature in midsummer is also the season when aphids, red spiders and other pests flourish. Timely control of pests and diseases is another important link in field management.

Since the beginning of "Little Summer", the plum rains in the Jianghuai Valley have ended one after another, and the vast areas in the east of China, such as the north of Huaihe River and Qinling Mountains, have entered the rainy season due to the influence of the southeast monsoon, and the rainfall has increased significantly and is relatively concentrated. South China, Southwest China and Qinghai-Tibet Plateau are also affected by the southwest monsoon, and the rainfall is also abundant. This is the agricultural proverb "Little summer and big summer will kill a mouse".

But at this time, the middle and lower reaches of the Yangtze River are generally controlled by subtropical high.

In hot and rainy weather, frequent summer droughts have a great impact on agricultural production, so it is very important to store water as soon as possible to prevent drought. The agricultural proverb "It rains on rainy days, and there is rice in the pot" and "It is not drought in summer, so hit a few stones on an acre of land" are all talking about the importance of rain at this time.

Entering the "light summer" solar term will make people degenerate. Although it is rainy season, due to the influence of monsoon climate, it is often dry without rain, and people are looking forward to autumn. People pray for long rain. As the saying goes, "three days without rain is a bit dry, five days without rain is a great drought", which is a reflection of the climate characteristics in North China and Huanghuai areas at this time. Early disasters at this time will cause serious harm to rice, cotton, corn, soybean, sweet potato and even fruit trees, especially in ancient times when farmland water conservancy was relatively backward. The well-known folk song "The sun burns like a fire, and the wild rice in Tian He is burnt by half ..." is the most vivid description of farmland drought. Therefore, "the hardship on the earth is related to agriculture, rural areas and farmers, and we must get enough water to expect a bumper harvest in one year" (here, "agriculture, rural areas and farmers" refers to spring ploughing, summer harvest and autumn harvest), and the rain on this festival is what farmers are most concerned about. After thousands of years' observation and experience, the working people in our country have summed up many meteorological proverbs for forecasting rainfall, such as "It rains for forty-five days in Mao Mao", "It rains in the south wind in Mao Mao", "There are three fogs on the head, and the rain is dew", "It rains in Mao Mao, and it is clear day and night", "It rains and thunders in Mao Mao, and Huangmei returns" and so on. These proverbs can still be used for reference in some underdeveloped rural areas.