1. Rattan cutting: after the harvest of sweet potatoes in autumn, select the frost free and disease free robust potato vines, remove the leaves, retain a 1cm petiole, and cut them every two sections.
2. Forced dormancy: put the cut potato vines into 0.5% Ampheteline solution for soaking for two minutes, and take out to dry the surface water.
3. Sand screening: ordinary yellow sand is filtered with a sieve to remove large grains of sand and impurities, and water is sprayed. The humidity is determined by the ability of sand to disperse after being squeezed and loosened.
4. Shazang: first, dig a pit on the ground, which is unlimited in length and width, and is 1.2 meters deep. Then place the potato vines in the pit with a layer of sand and a layer of vines, leaving a gap of 1cm between the vines. The thickness of each layer of sand shall not be less than 3 cm, and the thickness of the top layer of sand shall not be less than 15 cm. The surface of the sand shall be covered with plastic film. In areas with heavy frost, the film shall be covered with straw or straw curtains. In the spring of the next year, when sweet potatoes are planted, they can be cut out.
