What is the origin of the great summer heat? Ask god for help

Great Summer-[Great Summer] is one of the twenty-four solar terms of the lunar calendar. On July 23rd or 24th every year, the sun reaches longitude 120. Twenty-four solar terms: "in mid-June, ... it was hot, small and small, small at the beginning of the month, and big in the month, and it is still hot now." At this time, it is the hottest period of the year, with the highest temperature and the fastest growth of crops, and droughts, floods and windstorms are the most frequent in most areas. It is very important to grab crops and seeds, prevent drought and drainage, and manage fields. The ancient summer heat in China is divided into three periods: "Rotten grass is firefly; Second, wait for the soil to moisten and cool off the heat; It will be fine when it rains. " There are more than 2000 species of fireflies in the world, which are divided into aquatic and terrestrial species. Terrestrial fireflies lay eggs on hay, and when it is hot, fireflies ovulate, so the ancients thought fireflies were made of rotten grass. The second weather is that the weather becomes sultry and the land is wet. The third kind of weather is frequent thunderstorm, which weakens the heat and humidity, and the weather begins to transition to beginning of autumn. It's yellow day and night in hot summer. For the areas where double-cropping rice is planted in China, the most intense and arduous "double grab" war in a year has begun. As the saying goes: "Early rice grabs the sun, late rice grabs the time", "If you don't mow the grass in summer, you will lack a reed a day". Timely harvesting of early rice can not only reduce the harm caused by wind and rain in the later period, but also ensure a high yield and harvest, making it possible to transplant rice seedlings in time for two nights to strive for sufficient growth period. According to the change of weather, arrange flexibly, cut more on sunny days and variety on cloudy days. We should finish planting for two nights before the end of July, and start in autumn at the latest. In hot summer, you can't get a brick in three days. In hot summer, water evaporates very quickly, especially in the middle and lower reaches of the Yangtze River during the summer drought, and the demand for water for crops planted vigorously is more urgent. It's really "a little summer rain is like silver, and a big summer rain is like gold." The leaf area of cotton during flowering and bolling reaches the maximum in its life, which is the peak of water demand. It is best to require that the soil moisture in the field accounts for 70% ~ 80% of the field capacity. If it is lower than 60%, it will lead to flowering and bolling, so it must be irrigated immediately. It should be noted that it is not advisable to irrigate when the temperature is high at noon, so as to avoid excessive changes in soil temperature and aggravate the shedding of buds and bolls. Soybean flowering and pod setting is also a critical period of water demand, which is very sensitive to water shortage. An agricultural proverb says, "When soybeans bloom, river shrimps touch the ditch." If there is drought, you should water it in time. Summer maize in Huanghuai Plain has been generally jointing and heading, and heading is about to happen, which is the most critical period for yield formation, so it is necessary to guard against the harm of "neck drought". "Rice is laughing in the field and people are jumping in the house." High temperature in midsummer is very beneficial to crop growth, but it has obvious adverse effects on people's work, production, study and life. Generally speaking, there are obviously more people suffering from heatstroke in hot days when the maximum temperature is higher than 35℃. In hot days with the highest temperature above 37℃, the number of people suffering from heatstroke will increase sharply. Especially in the middle and lower reaches of the Yangtze River under the control of subtropical high, the sun is like fire, the wind is small and the humidity is high, which makes people feel sultry. Nanjing, Wuhan and Chongqing, three famous stove cities along the Yangtze River in China, have an average annual hot day of 17 ~ 34 days and 3 ~ 14 days. In fact, there are many places hotter than the "three stoves", such as Anqing, Jiujiang and Wanxian. Among them, the average high temperature days in Guixi, Jiangxi, Hengyang, Hunan and Kaixian, Sichuan exceeded 40 days. The whole middle and lower reaches of the Yangtze River is a big stove, so it is particularly important to do a good job of heatstroke prevention and cooling. In addition, many kinds of crop pests are active in summer, so special attention should be paid to personal protection when applying pesticides at high temperature to avoid poisoning accidents. Hot in summer means hot. Explanation is the hottest solar term in a year. Generally speaking, the summer solar term is the period with the most sunshine and the highest temperature in South China, the period with the most abundant rainfall, the most common thunderstorm and the most concentrated days of high temperature above 30℃ in western South China, and the period with the most frequent occurrence of high temperature above 35℃ in eastern South China. The high temperature around summer is a sign of normal climate, because in Da Chun, higher temperature is beneficial to the flowering and filling of crops. However, if the temperature is too high, it will inhibit the growth of crops and the seed setting rate of rice will decrease obviously. Light, heat and water are at the peak of a year after rainfall in western South China, which promote each other and form good climatic conditions for crop growth in Da Chun, but attention should be paid to flood control and drainage. In eastern South China, high temperature and long sunshine are often accompanied by little rain, which will not only limit the exertion of light and heat advantages, but also aggravate the adverse effects of drought on crops in spring, summer and summer. In order to resist summer drought, we should not only pay attention to water storage in the early stage, but also improve crop cultivation measures according to the climatic characteristics of eastern South China, so as to achieve advantages and avoid disadvantages. Hot summer is the season when jasmine and lotus are in full bloom. The more fragrant jasmine is, the more fragrant it is, giving people a clean and fragrant enjoyment. Noble lotus flowers, not afraid of the hot sun and showers, gather in the morning and evening. The poet praised it as "reflecting the different colors of lotus flowers in the sun", and the vibrant midsummer is gestating a bumper harvest.