Sweet potato is native to South America and the big and small Antilles, and is widely planted in tropical and subtropical areas all over the world, and also in most parts of China.
Sweet potato is a kind of food crop with high yield and strong adaptability, which is closely related to industrial and agricultural production and people's life. Truffle is not only the main grain, but also an important raw material for food processing, starch and alcohol manufacturing industries. Roots, stems and leaves are excellent feeds.
Sweet potato was first planted in Mexico and Colombia in Central America, and then brought to the Philippines and other countries by the Spanish. Sweet potato was introduced to China for the first time in Wanli period at the end of Ming Dynasty, and entered China in three ways-Yunnan, Guangdong and Fujian.
It is generally believed that sweet potato was introduced into China in the 21st year of Wanli (1593). In the Ming Dynasty, Chen Zhenlong, a native of Changle, Fujian, who had been doing business in Luzon (the Philippines) for many years, and his son Chen Jinglun saw a local root crop called "sweet potato", which was "as big as a fist, with scarlet skin, crisp and juicy heart, edible both raw and cooked, high yield and barren tolerance". Chen Zhenlong decided to introduce sweet potatoes to China when he thought of his hometown of Fujian, where there are many mountains and few fields, poor land and insufficient food. During the period of 1593, the Philippines was colonized by Spain, and it was forbidden to leave the country because sweet potatoes were imported. After careful planning, Chen Zhenlong "screwed potato vines into the water rope" and smeared sludge on the rope surface. 1593 In the early summer, he cleverly escaped the inspection of colonial checkpoints and "crossed the sea alone". Sail for seven days and return to Xiamen, Fujian in late May of the lunar calendar. Sweet potato is called "sweet potato" because it comes from outside Fujian. Chen's introduction of sweet potato is discussed in Xu Guangqi's Agricultural Records and Tan Qian's Miscellaneous Jujube.
After sweet potato was introduced into China, it showed the excellent characteristics of strong adaptability and no occupation of land, and its yield was high. "The yield per mu is dozens of stones, which is 20 times better than that of seed grain". Coupled with "moist and edible, or boiled or ground into powder, raw food such as kudzu, cooked food such as honey, and food such as water chestnut", it can quickly spread to the mainland. At the beginning of the 17th century, serious floods occurred in the south of the Yangtze River, resulting in crop failure and displacement of hungry people. At that time, scientist Xu Guangqi was living in his home in Shanghai because of his father's death. He learned that the sweet potato planted in Fujian and other places is a good crop to save the famine, so he introduced it from Fujian to Shanghai and then to Jiangsu, and the harvest was good.
Chen Chuangui, the fifth grandson of Chen Zhenlong, introduced sweet potatoes to Zhejiang in the early years of Kangxi, and his son Chen Shiyuan took several younger generations to Henan, Hebei, Shandong and other places for extensive publicity to persuade them to plant sweet potatoes. According to the account, when Chen Shiyuan taught to grow sweet potatoes in the ancient town of Jiaozhou, Shandong Province, he personally cultivated seedlings, cut vines and branches, and harvested them in autumn, so he got a lot of potatoes, which were widely circulated and planted in competition. Sweet potato soon spread in North China.
During the Qianlong period, many places were planted by the government. In Zhili, the emperor even "encouraged planting in Zhili". Thanks to the active promotion of the government and the public, sweet potato soon spread widely throughout the country, becoming the fourth largest food crop in China after rice, wheat and corn. Sweet potato 1733 spread to Sichuan, 1735 spread to Yunnan and 1752 spread to Guizhou. Since then, traces of sweet potatoes have spread all over the southwest.