Why did Tomb-Sweeping Day plant melon beans before and after?

Tomb-Sweeping Day is closely related to agricultural production. As soon as Qingming arrives, the temperature rises and the rainfall increases, which is a good time for spring ploughing and sowing.

In the twenty-four solar terms, Tomb-Sweeping Day and Tomb-Sweeping Day started together, when the sun moved to 15 degrees of the yellow meridian. At this time, the temperature is getting warmer, plants are sprouting, the weather is sunny and clear, everything is thriving, and Qingming is clean. With the arrival of Tomb-Sweeping Day gas, the atmospheric circulation in East Asia turns from winter to spring. The ridge of westerly belt moves frequently, and the low-level high and low pressure appear alternately. The temperature in the Jianghuai area changes greatly, and unstable precipitation such as thunderstorms gradually increases.

"Before and after the Qingming Festival, plant melons and beans". During the Qingming period, the average daily temperature in most parts of China has risen to above 12℃ except the northeast and northwest regions. From north to south to the inside and outside of the Great Wall, there is a busy scene of spring ploughing everywhere. "In the Qingming period, the wheat grows in the third section." Wheat in the southern part of Huanghuai is about to start heading, rape has blossomed, and wheat in the northeast and northwest regions has also entered the jointing stage. In the later stage, we should pay close attention to fertilizer and water management and pest control. Dry farming in the north, early and middle rice in the south of the Yangtze River is in a suitable season for mass sowing, so we should seize the opportunity, seize the sunny day and sow early. Pear blossoms are getting clearer and clearer. At this time, when many kinds of fruit trees enter the flowering stage, attention should be paid to artificial pollination to improve the fruit setting rate. Early rice planting in South China should be cleaned up and fertilized in time. Corn, sorghum and cotton will also be planted everywhere. "Before tomorrow's tea, there will be two buds", and the new buds of tea trees will grow vigorously, so attention should be paid to pest control; Famous tea producing areas are mined one after another, and strict scientific mining is needed to ensure the yield and quality. At this time, the cold air in the north still has a certain influence and the weather is changeable. Attention should be paid to prevent the harm of low temperature and late frost weather to spring sowing crops such as wheat, rice seedlings and flowering fruit trees.