But what is the truth? If we compare the "prosperous period of Kanggan" with other periods known as the prosperous period of three generations, we will find that both the quality and quantity are far less than those of the previous generation, and there is a rare trend of overall decadence and collapse in history.
The progress of agricultural planting methods has greatly increased the grain output. After harvesting early rice in some areas of Guangdong, insert late rice; After harvesting late rice, plant rape or sweet potato three times a year. Jiangxi's soil is thin, so it is impossible to plant late rice after early rice harvest, so buckwheat is planted and harvested twice a year. Due to the popularization of multiple cropping in South China, the grain output can be increased by more than 6 billion kilograms every year.
During the Qing Dynasty, the number of farmers specializing in vegetable production increased. Vegetable farmers in the suburbs of Beijing use equipment such as "fire room" and "cellar" to cultivate fresh vegetables such as leeks and cucumbers in winter and sell them in the market. During the Qianlong period, cotton was planted in some areas in Hebei Province where cotton was not planted. Before the Qing Dynasty, sugar cane was planted in the southeast coastal provinces. Sugarcane planted in some places in Guangdong is often a row of thousands of hectares, which looks like reeds from a distance.
During the Qing Dynasty, the large increase in population was mainly due to the popularity of American plants such as corn, sweet potatoes and potatoes. Corn, sweet potatoes, potatoes and other crops have been imported from America through Nanyang since the Ming Dynasty. In Ming Dynasty, Xu Guangqi's Agricultural Administration Encyclopedia described in detail the planting, storage and processing methods of sweet potato. Talking about the techniques of sweet potato seedling overwintering, stem cutting and seed classification, cutting, cellar storage and dry storage is the first book to systematically introduce the cultivation methods of sweet potato. Since then, North Korean scholar Chen Shiyuan has written Biography of Golden Potato, which describes cold bed seedling raising, and Bao's Four Techniques describes vine turning technology, and sweet potato planting technology has gradually improved. However, high-yield crops such as sweet potato also have their weaknesses: low and single nutrition, poor taste and low deep processing value. As a temporary emergency, long-term staple food will inevitably lead to malnutrition and a sharp decline in physical fitness, which will inevitably affect people's normal intellectual development. After more than 0/00 years of prosperity from the early Qing Dynasty to the middle Qing Dynasty, the "Sweet Potato Prosperity" finally came to an end.