2 land selection. Yam is drought-tolerant, but not waterlogging-tolerant. Therefore, it is suitable for planting in high dry land with good drainage. Yam has strict requirements on soil, and it is suitable to be slightly acidic to neutral. Deep, loose and fertile sandy loam or sandy soil is beneficial to tuber growth, with high yield and good quality. Top-down soil quality is required to be consistent. Yam can't be continuous cropping. Generally, it is rotated once every three years.
3. Soil preparation and fertilization. Yam likes organic fertilizer, but it is necessary to avoid direct contact between tuber and fertilizer, otherwise it will affect the normal growth of tuber. Long-column varieties should dig deep into the land before winter, and dig deep ditches in the north-south direction according to the row spacing of1m. The deep trench of frozen soil is 25-30cm deep and 0.8- 1.2m deep. The soil is dry. When thawing in the following spring, the excavated soil will be mixed with fully decomposed soil and miscellaneous fertilizer, with a dosage of 5000 kg per mu. Then backfill it into the ditch. Every 25 cm.
4 sows. Plant when the local temperature rises above 12℃ and the ground temperature is stable above 9 ~ 10℃. Before planting, a ditch with a depth of about 1m and a width of 60 ~ 80 cm should be dug around the field and connected with the outer ditch. If the length of the site exceeds 20 meters, waist ditch should be added to ensure rapid drainage in rainy season. A ditch with a width of 10 ~ 15 cm and a depth of 30 ~ 40 cm is opened at the boundary, and 5 ~ 2.5~5kg of diammonium hydrogen phosphate, 2.5~5kg of urea and 5kg of calcium superphosphate are applied as seed fertilizer per mu, covering 20 ~? 30cm, put the yam plants into the ditch along the ridge according to the plant spacing 15 ~ 20 cm, and cover the soil with 8 ~ 10 cm.
5 on-site management. (1) Germination stage. The germination period takes about 50 days from germination to emergence. In order to keep the soil moisture, the planting ditch can be covered with soil and ridged, and then leveled after the seedlings are unearthed. When planting, water is poured enough, and basically no water is poured from germination to emergence.
(2) Pruning period. It takes about 60 days from germination to germination. When yam leaves the vine after emergence, it is necessary to support the vine in time. Generally, thin bamboo poles or branches are inserted on the herringbone frame, and the height of the frame should be 2.0 ~ 2.5m The support should be firmly inserted to prevent it from being blown down by the wind. Usually, seedlings are produced from seed stems. If there are several seedlings, when the height of the seedlings reaches 7.0 ~ 8.0 cm, leave thick vines and remove the rest. Generally, pruning is not needed, but 2 ~ 3 lateral branches are removed at the base, which is beneficial to nutrient concentration and increase yield.
6 late fertilizer and water management. Yam is a drought-tolerant crop, but it should be watered properly. In the early stage of vigorous stem and leaf growth, if the soil is dry, water can be poured every 7 ~ 10 days to keep the soil dry and wet. Yam is afraid of waterlogging. Clear the ditch in time in rainy season to ensure that there is no water in the field. Fertilization can be carried out before the scaffold. When the stems and vines are already on the upper part of the frame, the fertilizer can be applied again. In the future, if the stems and vines have yellow leaves when they are full, they can be applied again.