1. Land selection: select sandy loam or loam fields with high and dry terrain, good drainage and deep and soft soil layer, and the soil quality should be consistent from top to bottom. There is a thin and sticky soil layer on the lower floor, which can be dug or planted when digging ditches. The soil should be slightly acidic to neutral. Chinese yam cannot be continuously cropped, and it is rotated every three years 1 time.
2. Ditching and soil preparation: For long-rooted varieties, dig deep trenches in the north-south direction according to the row spacing of 1m, with a width of 28-30cm and a depth of 140cm. When digging, the upper and lower layers of soil are piled on both sides of the ditch, and 20 cm of sand at the bottom of the ditch is dug out and crushed on the spot. After airing for a few days, the bottom soil shall be leveled and compacted first, and then the bottom soil and the top soil shall be filled separately. Leveling and compacting every 20cm 1 pass, and removing all sundries. In order to facilitate ditching, it is generally to excavate alternately first, and then excavate the remaining half ditch after half ditch is filled.
3. Seed block treatment: 20-25 days before each planting, select the hard root head at the top of the disease-free block that meets the characteristics of the planted varieties as seeds, soak one end in hydrated lime powder, and then put it in the sun for a few days to disinfect and promote germination. Breeding with roots can't expand the planting area. To increase the reproductive coefficient, it is necessary to cut off the roots for reproduction. That is, select a thin root with a length of 1m and a transverse diameter of 2.4-4.5cm, cut it into several small sections with a length of 15-20cm, mark the upper and lower ends with wool, then dip each section in lime and put it horizontally in the sun to dry the seeds until there are fine cracks at the end of the section. When the seeds are dry, handle them carefully to prevent scratches. At the same time, we should do a good job in wind, rain and freezing.
4. Planting: When the local temperature rises above 12℃ and the ground temperature is stable above 10℃, it will be planted in late April in North China, in the middle and early April in the Yangtze River basin and in March-April in South China. Before planting, dig a deep ditch around the field, the depth is about 1m, and the width is 0.6-0.8m, which communicates with the outer ditch. If the site length exceeds 20m, waist ditch should be added to ensure rapid drainage in rainy season. Then pull a rope in the center of the planting row, with the row spacing of 5-6cm, and drill holes in the ditch with the thickness of 10- 12cm at the row spacing of 20cm, and go deep into the bottom of loose soil layer. The upper end of the seed potato is placed horizontally on the hole along the direction of the ditch to guide the new roots to extend vertically and grow evenly, reaching the standards of export and purchase. After a ditch is drained, it is covered with soil and ridged, and the ridge height is 10cm.
5. Apply sufficient base fertilizer: after planting and before emergence, turn the soil between rows on both sides of the planting ditch for 20-30cm, and apply base fertilizer. Organic fertilizer and inorganic fertilizer should be applied together, with decomposed manure or manure of 2000-4000kg/667m2, urea of 20-25kg, calcium superphosphate 15kg and potassium sulfate of 25-35kg, and fully mixed with ploughed soil.
6. Field management: 1, supporting vines. As soon as the yam emerges, it is necessary to set up scaffolding in time to guide the vines to grow upwards. Generally, thin bamboo poles or branches are used to insert the herringbone frame, and the height of the frame is 2-2.5m. If limited by materials, it should be at least as high as1.5m.. Brackets should be firmly inserted to prevent being blown down by typhoon. 2, intertillage filling. In the early growth stage, intertillage weeding in Qin Ying is generally carried out 1 time every half month until the stems and vines grow on the first half frame, and then weeds are pulled out. It is necessary to dig out part of the soil between the rows outside the frame and fill it in the rows inside the frame, so that high ridges are formed inside the frame, and furrows with a depth of 20 cm and a width of 30 cm are formed between the rows outside the frame, which is convenient for drainage in rainy season. 3. Top dressing. When the stems and vines are in the first half of the frame, topdressing for l times, and applying urea 10- 15kg/667m2 according to the plant growth. Only when there are fewer strong seedlings and more weak seedlings can the balanced development of the whole field be realized. In the future, when the stems and vines are full, if there is a phenomenon of yellow thinning, 1 time can be applied again. 4. Irrigation and drainage. Yam is a drought-tolerant crop, but it should be watered properly if it is to produce high yield. Generally, before and after 1 topdressing, if the soil turns white after a long drought, it should be lightly watered 1-2 times until the soil surface is wet. At the turn of summer and autumn, if the dry and hot weather lasts for more than 1 week, cold water should be poured in the morning to fight drought. Yam is more afraid of waterlogging, so it is necessary to clear the ditch and drain in time in rainy season to ensure that there is no water in the field.
Eliminate pests and diseases
1. Pest control
Flammulina velutipes, crickets and grubs have drilled many holes in the underground tuber of yam, and sometimes they sleep in the tuber. Flammulina velutipes itself has a membrane, so it is not easy for drugs to penetrate into its body and kill it. Stomach poison is better. Comprehensive measures should be taken to prevent it, and the methods are as follows:
(1) dig deep into the land. Dig the land 25-30cm deep before winter, and turn the overwintering adults and larvae to the surface, so that they will freeze to death, get sunburned or be preyed by natural enemies.
(2) Applying decomposed organic fertilizer. Fully decomposed organic fertilizer can change the air permeability and water permeability of soil, make crops grow healthily, and enhance the ability of disease resistance and insect resistance. Crop rotation is also a powerful measure to control pests and diseases, and it is generally better to rotate once every 3-4 years.
(3) The poison valley was mixed with 90% trichlorfon 0. 1.5 kg for 30 times, and the pesticide was applied every 667 square meters 1.5-2.5 kg. Sprinkle it on the soil surface, and then loosen the surface soil with a hoe, so that part of the medicine is in the soil and part is on the soil surface.
(4) 0. 1.5 kg of 30-fold solution of 90% trichlorfon, mixed with 5 kg of fried wheat bran or bean cake (or cottonseed cake) to make poisonous erbium, which has a better effect in windless and sultry evening, and water with the weight of 1- 1.5 times should be added when mixing. Or mix 40%-50% dimethoate EC 100g with 5 kg of water and 50 kg of erbium (wheat bran, bean cake, corn chips, etc.). ) For the kind that is fried until fragrant, plant it once every 2 meters, plant a pit with the size of a bowl every 3-4 meters, put a pinch of erbium poison before covering the soil, and use 1.5 erbium poison every 667 square meters. This method is very good for controlling crickets and grubs.
(5) Irrigate the roots with 40% methyl isofenphos EC 1500 times solution, and irrigate each plant with 0. 15-0.2 kg of liquid medicine. Or use 2% methyl isofenphos powder, 3-4 kg per 667 cubic meters, and sprinkle it on the surface soil of nearby plants, and then mix the soil and powder evenly with a hoe. This method has special effects on the control of grubs and needle worms. Or use 800 times of 90% trichlorfon solution to irrigate 0. 15-0.2 kg per plant.