Why cold rice urea slow down?
Case: Meng, manager of agribusiness marketer in Qian’an County, Jilin Province, reported to the agrochemical experts through a hotline that farmers of some rice varieties are unwilling to choose urea when purchasing fertilizer in spring, but they purchase ammonium sulfate, but there is no stock of ammonium sulfate in the warehouse. Manager Meng said farmers did not choose urea, mainly because last year when transplanting rice, all rice fields that used urea as a fertilizer were generally slow, while a few rice fields with ammonium sulfate or ammonium chloride returned faster. Even individual farmers use ammonium bicarbonate to return significantly faster than urea. Manager Meng asked experts to analyze the case and make corresponding suggestions. Analysis: First of all, I would like to talk about the reason why paddy field transplants use urea to slow down and slow down. Because urea is a fertilizer containing high concentrations of molecular organic nitrides. Although it is water-soluble, the application to the paddy field soon dissolves, but the molecular urea that is directly absorbed and utilized by the roots of crops in general is few. After urea is applied to the soil, it can be absorbed by the crop root system only after it is hydrolyzed to ammonium nitrogen under the action of urease. The ammonium nitrogen fertilizer can be directly absorbed by the rice roots without conversion, and it is helpful for the growth of the return period. The rate of conversion of urea to ammonium depends on the amount and activity of urease in the soil. The amount and activity of urease mainly depend on factors such as soil fertility, soil temperature, moisture, and acidity and alkalinity. Under medium fertility conditions, the effect of soil temperature maximum. When the soil temperature is around 10°C, it takes at least 2 to 3 weeks for all the urea to be converted to ammonium. When the soil temperature rises to 10°C to 20°C, it will take 7 to 10 days, and only 20°C or more. The conversion is faster. When transplanting rice in cold regions of Jilin Province, the soil temperature is not high, and if urea is used, the fertilizer effect will be slow, affecting the speed of slowing down. In addition to urea, nitrogen fertilizers often used in paddy fertilization in cold regions can be used for a variety of ammonium nitrogen fertilizers. First, currently ammonium sulfate approved by some farmers is optional, but do not use it annually or in large quantities because paddy fields are flooded. If a large amount of sulfate remains, it will be reduced to sulfur or hydrogen sulfide. At the root level, this is detrimental to rice root growth. Moreover, domestic production of ammonium sulfate is not much. Second, ammonium bicarbonate can be used. The advantage is that the cost is low and the speed is significantly faster. It is only necessary to pay attention to the fertilization site, and it must not be sprinkled on the soil surface of the paddy field. It must be applied 8 to 10 cm below the soil. Third, diammonium phosphate, which is a nitrogen-phosphorus binary compound fertilizer, contains both a large amount of water-soluble phosphorus and a small amount of ammonium nitrogen, and is most suitable for seed and seedling fertilizer applications. Fourth, optional ammonium chloride. The nitrogen fertilizer is suitable in paddy field, but the saline soil soil cannot be used. Although the issue discussed in this case is the issue of nitrogen fertilizers, there is currently a problem of excessive nitrogen fertilizer application in some areas, and everyone should pay full attention. Therefore, the basal fertilizer to be applied before the paddy field is planted is preferably a three-component fertilizer containing nitrogen, phosphorus and potassium. As for compound fertilizer varieties, in addition to the appropriate proportion of N, P and K, it is also necessary to look at the forms of nutrients. The fertilizer efficiency of ammonium-based compound fertilizers is faster than that of urine-based compound fertilizers. In addition, paddy field can not choose nitro-containing compound fertilizer. In order to reduce costs, some farmers choose to use single fertilizers instead of compound fertilizers. In addition to nitrogen fertilizers, phosphorus and potassium fertilizers are also selected. For phosphate fertilizers, calcium can be selected. Not only does it contain multiple nutrients, but its price is relatively low. Second, phosphorus fertilizer can be selected heavy calcium or ammonium phosphate. As for potassium, potassium chloride is generally used Sensitive Adhesive Bandage,Sensitive Breathable Plaster,Non-Stick Absorbent Compress Plaster,Sensitivity Medical Adhesive Plaster RFX+CARE Manufacturing Co.,Ltd. , https://www.rk-rfxcare.com