Analysis on the Characteristics of Two Kinds of Fertilization for Chinese Yam

Chinese yam is a potato crop, is a favorite vegetable, it not only has high nutritional value, unique flavor, but also can be used in medicine. Due to the increase in market demand, the planting area of Chinese yam has been expanding in recent years. Farmers often ask about fertilization in the cultivation of iron yam through the hotline. The following lists the characteristics of two different types of fertilization in the current Chinese yam production for reference. First, some farmers in Hebei, Henan and other places have been planting yam for many years and can obtain a yield level of more than 4000 kg per mu, which is characterized by organic fertilizer and supplemented by the application of appropriate amount of chemical fertilizer. First of all, turn the loess soil deeply before planting and apply sufficient basic fertilizer. 5 square of mature organic fertilizer is applied per mu, and 25 kg of common calcium and 10 kg of potassium sulfate are mixed to make the soil layer 30 cm deep soft and fertile. Just more than a month after planting, water control is not topdressing. When the seedling vine grows to 30-40 cm long, a small amount of nitrogen fertilizer and a small amount of water should be applied according to the seedling growth. The first nitrogen fertilizer and water cannot be used openly; if used, it will promote the seedling vine on the ground and slow down the growth of underground roots, resulting in "running seedlings", resulting in difficult management and reduced yield in the later stage. The second topdressing should wait until the vine seedlings are on the shelf and the growth advantage of the vine seedlings is basically formed, and then apply nitrogen fertilizer again, such as urea 15kg / mu or ammonium bicarbonate 30kg / mu. This is to promote the growth of stems, leaves and roots in the turning period of aboveground growth, and the third topdressing is in the middle stage of root expansion, adding urea 10 kg / mu. The last two times of topdressing are in the rainy season, the soil moisture is better, and the fertilizer effect is obvious. Last year, agricultural promoters in Wenxian County, Henan Province suggested that in addition to 15 kg / mu of urea, 10 kg of potash fertilizer was added to the second topdressing, and the effect was good. This set of experience in fertilizing yam has been widely quoted locally. The key to applying a large amount of organic fertilizer and less chemical fertilizer is to grasp the application technology of chemical fertilizer and to obtain high yield of yam safely and safely through 2-3 times topdressing of nitrogen and potash fertilizer in the middle stage of growth. The key technology of topdressing nitrogen fertilizer is to grasp the time of topdressing nitrogen fertilizer, especially the time of topdressing nitrogen for the first time and the amount of nitrogen fertilizer, which should be used properly and should not be used. Otherwise, there will be the problem of "running seedlings". At present, with the expansion of the planting area of iron bar yam, due to the small amount of organic fertilizer in the new producing areas, the problem of balanced fertilization of iron bar yam becomes more prominent in the new producing areas dominated by chemical fertilizer supply. Second, under the condition that there is not enough organic fertilizer, the proportion of chemical fertilizer in the fertilization of Chinese yam is relatively large, and the technical essentials of balanced fertilization should pay attention to the following points: the base fertilizer of Chinese yam should be deeply applied below 25cm and 30cm. The type of base fertilizer should be combined with organic fertilizer and arrange to loosen the soil and dry the soil. The chemical fertilizer in the base fertilizer is mainly phosphorus and potassium, and the nitrogen fertilizer is supplemented by nitrogen fertilizer and the principle of stable application of nitrogen fertilizer. Generally, the nitrogen in the base fertilizer only uses ammonium or amide without nitric acid. The topdressing of Chinese yam is mainly composed of available nitrogen fertilizer and potassium fertilizer. Nitrogen can be partially mixed with nitric acid and ammonium, but it can be solid or liquid. In the topdressing period, Chinese yam mainly grows seedlings in the early growth stage and long roots in the later stage. In the topdressing period, it is necessary to control nitrogen and water in the early stage, timely and appropriate amount of topdressing and irrigation in the middle stage, and the combination of nitrogen and potassium fertilizer in the root expansion period. The times of topdressing was 2-3 times, that is, applying strong seedling fertilizer, suitable nitrogen and potassium fertilizer in transition period and nitrogen fertilizer in root expansion stage.