Because of its high yield, drought tolerance, waterlogging tolerance and saline-alkali tolerance, sweet potato spread rapidly after it was introduced into China. During the Qing Dynasty, a series of high-yield crops such as sweet potato and corn also contributed to the sharp increase of population at that time, and some even called it "the prosperous time of Kanggan". In addition, sweet potato is also a kind of food with high nutritional content. Besides being edible, it can also be used for sugar making and wine making, and it is a high-quality crop with a wide range of uses.
As for when sweet potatoes were introduced into China, it is currently recognized that it was in the middle and late Ming Dynasty.
During the Wanli period of the Ming Dynasty, Chen Zhenlong, a Fujian native who felt that the future of the imperial examination was hopeless, was influenced by the prevailing business atmosphere in the southeast coast at that time and began to engage in lucrative overseas trade, running between Fujian and Luzon.
At that time, Luzon had become a colony of Spaniards, and the Spaniards on the island often went to the Ming Dynasty to purchase a large number of raw silk, tea and porcelain, and the silver from America poured into the Ming Dynasty. In Fujian, which is located on the southeast coast, many people were engaged in the trade industry between Fujian and Luzon. There were a large number of Chinese on Luzon Island, and Fujian was a "middle-class child, living outside". While making money in Luzon, Chen Zhenlong also tasted sweet potatoes.
The sweet potato that Chen Zhenlong saw in Luzon is not only drought-tolerant and easy to live, but also can be eaten raw and cooked. It tastes delicious and has very high economic value and the role of saving the world. Therefore, the idea of bringing it back to the Central Plains came into being. If successful, it will surely be a beautiful thing that can benefit all people.
However, the Spanish who occupied Luzon Island at that time banned the spread of sweet potatoes. Chen Zhenlong tried twice, but it failed. On the contrary, it attracted the attention of the Spanish. Until the third time, Chen Zhenlong coated the sweet potato vines with mud and wrapped them on a cable. Finally, he successfully brought them back to Fuzhou. However, when he first arrived in Fujian, Chen Zhenlong was afraid that the sweet potatoes were "out of soil", so he only planted them in his own open space and did not promote them immediately.
Compared with rice and wheat, the yield of sweet potato is simply amazing.
According to the historical records, the yield of wheat per mu in ancient north was only 300 Jin, and the yield of rice in south was 577 Jin on average, which was only obtained after a series of water conservancy construction and agricultural technology progress in Ming Dynasty.
Comparatively speaking, the yield of sweet potato is touching. In the late Ming Dynasty, sweet potato has been widely planted, which can be planted twice a year. The yield per mu can reach 2000 kg in spring and 1000 kg in summer, which is 6000 kg.
To put it more bluntly, the output of sweet potato is more than ten times than that of rice and wheat. The field that can only support one person can support ten people if it is replanted with sweet potato, and the adaptability of sweet potato is very strong. Many lands that are not suitable for planting conventional food crops such as rice and wheat can grow sweet potatoes, which makes the cultivated land area expand rapidly.
Sweet potato was first popularized in the southeast, but its promotion in Jiangnan was full of twists and turns.
According to the Records of Zhangzhou Prefecture in the Wanli Period of the Ming Dynasty, shortly after Chen Zhenlong brought sweet potatoes back, Fujian suffered from drought, and the grain output dropped sharply. Chen Jinglun, Chen Zhenlong's son, dedicated sweet potato seedlings to the official government and began to popularize them in various places. Because of their easy living and high yield, sweet potatoes quickly spread and saved a lot of lives, and soon became an important food crop for people in Fujian and southern Zhejiang to survive.
At the same time when Chen Zhenlong brought back sweet potatoes from Luzon, some Zhejiang businessmen brought back sweet potato vines from Japan and planted them in temples in Zhejiang, but only as ornamental plants. Until the early Qing Dynasty, when Chen Jinglun's grandchildren went to Jiangsu and Zhejiang to promote sweet potatoes, they found that the rich people in the south of the Yangtze River were dismissive of sweet potatoes.
With the relocation of the sea and the flow of immigrants, sweet potatoes have been spread throughout the country.
After the establishment of the Qing Dynasty, the "Order to Move to the Sea" was officially issued, and all coastal people were moved to the inland mountainous areas, and all coastal ships, houses and rice fields were destroyed. During the decades-long activities of moving to the sea, a large number of people were forced to go to the mountains, so people who died were everywhere, and those who survived by luck could only survive in barren mountainous areas.
The land in inland mountainous areas is barren, and the cultivated land is scarce, and there are very few crops that can be planted, especially the land that can grow traditional crops such as rice and wheat. In this case, sweet potato has become a life-saving crop and has been popularized.
In addition, in the early Qing Dynasty, in order to fill the population vacancy in Sichuan, a large-scale Huguang movement was carried out again. Among the immigrants, besides a large number of Huguang people, there were also many immigrants from Jiangxi, Guangdong and Guangxi, as well as millions of Hakkas. It was this large-scale migration that brought sweet potatoes to Sichuan, which was deeply inland.
During the Qianlong period, sweet potatoes were basically planted all over the Yangtze River basin and its south, and sweet potatoes spread to the north because of several droughts at that time. With the efforts of Chen Zhenlong's descendants Chen Shiyuan and others, sweet potatoes were first introduced to Shandong and Henan, and then began to spread throughout the north. By the late Qianlong period, sweet potatoes had become an extremely common crop in the north.
Sweet potatoes, that is, sweet potatoes and sweet potatoes, were introduced into China not in one direction, but from different directions. Chen Zhenlong was only one of them, but the time when sweet potatoes were introduced into China was roughly in the Wanli period of the Ming Dynasty.