New Techniques Based on Existing Knowledge: Production and Dissemination of the Methods of Sweet Potato Cultivation and Roots/Slips Storage in the Ming and Qing Dynasties

Native to the tropical regions of the Americas, sweet potatoes were introduced into China via Southeast Asia in the mid- and late-Ming dynasty. Since sweet potatoes are a tuberous root crop featuring asexual reproduction, their cultivation techniques were different from traditional Chinese cultivation methods for cereals, represented by the five grains. When sweet potatoes first arrived in China, agronomists made a variety of attempts to develop “cultivation methods” for sweet potatoes, eventually achieving localized planting techniques. Later, when sweet potatoes were introduced northwards, the overwinter roots/slips storage method used in Fujian and Zhejiang provinces was no longer applicable in the colder northern provinces, where local farmers gradually began to store sweet potato roots/slips in cellars. These cultivation and roots/slips storage techniques that came into being in the Ming and Qing dynasties were, in fact, not brand-new. Rather, some existing knowledge, including China's traditional methods of planting yams, cereal storage methods, the method of keeping vegetables in cellars in winter, and root storage methods for crops with tuberous roots all served as helpful references for the formation of sweet potato-related new knowledge. As such, this article suggests that a dynamic viewpoint be adopted when studying the development of the cultivation methods of any new crops, and hence offers a new perspective for investigating the cultivation technology history of foreign crops.