Video pictures of scientific planting technology of sweet potato

First, select improved varieties of sweet potato: high-yield varieties are selected according to the characteristics and cultivation uses of sweet potato varieties. The mid-ripe varieties with fertilizer tolerance, slow seedling, early tuber setting, many and neat tuber lumps and long duration of tuber expansion should be selected in spring potato area. For example, Sushu 8, Anping 1, Xushu 34, Xushu 23 can be selected in the areas that are mainly edible; Meiying 1, SL-19, Yushu 12, Yushu 13, etc. are selected in the areas where starch is processed; Yushu 9 and Jishu 10 are selected for dual use; Yushu 10 with high carotene content, high moisture content and high yield can be selected for special purposes, such as fruit and feed. Second, carry out deep ploughing and soil improvement or ridging planting: cover the soil to preserve soil moisture after applying organic fertilizer in the open ditch in early spring, and then turn the center of the ditch into the center of the ridge during soil preparation in spring. When making a ridge, nitrogen, phosphorus and potash fertilizer are first applied to the center of the ridge, and then a fat ridge with a height of 35 cm, a width of 90 cm at the bottom and a width of 20 cm is made. For clay potato fields, cinder, coal ash and fine sand can be added to soil preparation to improve the soil. Third, timely early planting and reasonable planting density: in order to obtain a yield of more than 5000 kg per mu, it generally takes about 180 days to grow sweet potatoes. For this reason, we must do a good job of early planting, and harvest late appropriately, so as to maximize the use of natural growth conditions and prolong the growth period. The suitable planting time in our province is about April 15, and the planting will be finished by April 25 at the latest. In order to plant as early as possible, we can also use plastic film mulching cultivation techniques, so that the planting time can be more than 10 days in advance. In terms of planting density, there are two ways to obtain high yield of sweet potato: one is to rely on close planting to give full play to the role of population production to obtain high yield, and the other is to rely on large piles of sparse planting to fully tap the potential of individual yield increase to obtain high yield. sparse planting field only planted about 5000 plants per mu. The planting density is closely related to the varieties, the short vine varieties such as Yushu 6 and Yushu 10 should plant 4000m 4500 plants per mu, and the medium and long vine varieties such as Xushu 22, Yushu 13 and SL-19 should plant 3000m 3500 plants per mu. Single-row planting is beneficial to the expansion of potato cubes. In the planting method, we can use the method of horizontal shallow planting or boat planting, the soil is about 3 cm deep, so that the temperature difference between day and night is large, which is conducive to the formation of potato lumps, more and neat tubers. Fourth, carry out reasonable fertilization to control the excessive growth and premature senescence of stems and leaves in time: the growth of sweet potato needs the most potassium, followed by nitrogen and less phosphorus. According to the experience of fertilization for high yield of sweet potato in various places, the temperature in spring is low and the continuous time of high temperature in summer is short in northern potato area. The principles of higher soil nutrients in the early growing period, no excess in the middle stage and no de-fertilization in the later stage should be grasped. At the same time, it also depends on the soil fertility, the poor fertility foundation should apply more fertilizer; look at the weather, the amount of nitrogen fertilizer should be properly controlled in the waterlogging year; look at the appearance, those lower than the appearance index of each stage should be properly increased fertilizer to promote growth, otherwise, fertilizer should be controlled; look at the variety, short vine fertilizer tolerant varieties should apply more fertilizer, long vine varieties should control fertilizer. The types of fertilization are mainly soil and miscellaneous fertilizer, supplemented by chemical fertilizer, and combined application of nitrogen, phosphorus and potassium fertilizer. The amount of fertilizer applied to sweet potato: 4500 kg of soil miscellaneous fertilizer, 40 kg of calcium superphosphate, 150 kg of plant ash or 30 kg of potassium sulfate per mu in medium fertility land, and 7500-10 000 kg of soil miscellaneous fertilizer, 40 kg of phosphate fertilizer, 250 kg of plant ash or 40 kg of potassium sulfate and 10 kg of ammonium carbonate per mu in high fertility land. Fertilization method of sweet potato: give priority to base fertilizer, combined with deep fertilization, layered fertilization, the amount of base fertilizer accounts for 75%-80% of the total. Topdressing should be skillful. When planting, use 3 kg urea and 2 kg potassium dihydrogen phosphate per mu to dissolve in 1000-1500 kg water and then irrigate the nest. Using nest fertilizer instead of seedling fertilizer can promote the early development of strong seedlings. When the stem and leaf growth is less than 300 kg per mu in the first ten days of June, nitrogen fertilizer or sweet potato special fertilizer should be applied as tuber fertilizer. From late August to early September, when the dry weight of stems and leaves decreased too fast, when the daily weight loss per mu was more than 20 kg, it could be sprayed with urea 1 kg and potassium dihydrogen phosphate 1 kg plus 100 kg water per mu. Chemical control should be carried out in high-yield fields at the right time, from round plant stage to ridge closure period, and 15% paclobutrazol should be sprayed on the leaves. How to fertilize Sweet Potato and the method of topdressing in the expansion period of Sweet Potato with High yield