Sweet potato planting area in Lixian County, Gansu Province 1600 mu. According to relevant data, in order to improve potato quality and increase people's income, Lixian county has built a 1600 mu first-class seed potato demonstration base for virus-free potatoes in Jiajiagou and Fengdangou of Kuanchuan town. Longshu No.7, Longshu No.6 and Longshu No.3 were used as the main varieties, and the whole film (semi-film) mulching planting mode was adopted.