尿素是一种高浓度氮肥，是一种中性速效肥料，也可用于生产各种复合肥。没有任何残留在土壤中有害物质,长期应用无不良影响,畜牧业可以用作反刍动物饲料,尿素后,土壤脲酶、水解碳酸铵与碳酸氢铵后,可以被作物吸收利用,因此,作物的尿素4 ~ 8天前施肥,以下,恒亿化学为大家详细解释如何尿素的应用程序和使用注意事项,让我们看看!
　　Urea is a kind of high concentration nitrogen fertilizer, a kind of neutral and quick acting fertilizer, which can also be used to produce various compound fertilizers. There is no harmful substance left in the soil, and there is no adverse effect after long-term application. Animal husbandry can be used as feed for ruminants. After urea, soil urease, hydrolyzed ammonium carbonate and ammonium bicarbonate can be absorbed and utilized by crops. Therefore, urea of crops can be fertilized 4-8 days ago. Below, Hengyi chemical will explain how to apply urea and precautions for use in detail, let's have a look!
　　1. 平衡施肥
　　1. Balanced fertilization
　　尿素是纯氮肥，不含磷、钾等作物生长所必需的大量元素，因此，在进行追肥时应在土壤试验的基础上，采用配方施肥技术，平衡施入氮、磷、钾。首先，将作物整个生育期所需的全部磷、钾肥和部分(约30%)氮肥进行组合整地。剩余70%左右的氮肥(尿素)作为追肥，其中肥料需求的关键期和作物的最高效率期约为60%，后期约为10%。只有氮、磷、钾三种肥料合理配合，科学施用，才能使追肥尿素的利用率提高。
　　Urea is a pure nitrogen fertilizer, which does not contain a large number of elements necessary for crop growth, such as phosphorus and potassium. Therefore, formula fertilization technology should be used to balance the application of nitrogen, phosphorus and potassium on the basis of soil test. First of all, all P, K and part (about 30%) of nitrogen fertilizer needed for the whole growth period of crops are combined for land preparation. The remaining 70% of nitrogen fertilizer (urea) is used as top dressing, of which the critical period of fertilizer demand and the highest efficiency period of crops are about 60% and the latter period is about 10%. Only when the three fertilizers of nitrogen, phosphorus and potassium are combined reasonably and applied scientifically can the utilization rate of top dressing urea be increased.
　　2. 及时跟进
　　2. Follow up in time
　　在农业生产中，经常会出现一些不合理的施肥现象:每年春小麦青绿期开始后，农民都趁机灌溉绿水尿素或冲进麦田;在玉米的苗期，农民在雨前把尿素撒到地里。尿素灌溉配合大白菜苗期生长;番茄在苗期浇水时，浇尿素等。这样的施肥尿素，虽然使用了化肥，但浪费现象严重(氨气挥发，尿素颗粒流失)，还会导致营养生长过于旺盛，小麦、玉米后期倒伏，番茄“吹花”，卷心菜包心延迟等不良现象发生。
　　In agricultural production, there are often some unreasonable fertilization phenomena: every year after the green period of spring wheat begins, farmers take the opportunity to irrigate the green water urea or rush into the wheat field; in the seedling period of corn, farmers sprinkle the urea into the field before the rain. Urea irrigation is combined with the growth of Chinese cabbage at seedling stage, and urea is applied to tomato at seedling stage. This kind of fertilizer urea, although the use of chemical fertilizer, but serious waste (ammonia volatilization, urea particles loss), will lead to the growth of nutrition is too strong, wheat, corn later lodging, tomato "blow flowers", cabbage Baoxin delay and other adverse phenomena.
　　每一种作物都有一个特定的吸收氮、磷和钾的关键时期。这一时期缺肥(氮、磷、钾)，作物产量下降，品质下降，影响是巨大的，即使下次施肥充足，对作物产量的影响，品质也是不可逆转的。此外，还有一个最大的增效期，即作物的施肥可以获得较高的产量，作物的施肥效率最高。从以上分析可以看出，只有在作物营养和效率最高的关键时期，施肥才能提高肥料的利用率，从而达到高产优质的目的。
　　Each crop has a specific critical period of absorption of nitrogen, phosphorus and potassium. During this period, the yield and quality of crops decreased due to the lack of fertilizer (n, P, K). Even if the next fertilization is sufficient, the quality will be irreversible. In addition, there is also a maximum efficiency period, that is, the fertilization of crops can obtain higher yield, and the fertilization efficiency of crops is the highest. From the above analysis, we can see that only in the critical period of the highest nutrition and efficiency of crops, fertilization can improve the utilization rate of fertilizer, so as to achieve the purpose of high yield and high quality.
　　施用尿素作为追肥时，应在作物临界需氮期和最高效率期的前一周施用。不同作物的需肥关键期和最大肥效是不同的。例如，小麦、玉米等禾本科作物的氮素需求关键期处于分蘖期、穗分化期、棉花处于结铃期。小麦拔节至孕穗期、水稻分蘖期至拔节期、玉米大角口期、番茄果实期、甘蓝莲座期、向日葵花蕾期、大豆早花期等是氮素效率最高的时期。
　　When applying urea as topdressing, it should be applied in the week before the critical nitrogen requirement period and the highest efficiency period. The critical period and the maximum fertilizer efficiency of different crops are different. For example, the key period of nitrogen demand for Gramineae crops such as wheat and maize is in tillering stage, ear differentiation stage, and cotton is in Bolling stage. From jointing to booting stage of wheat, from tillering stage to jointing stage of rice, from bighorn mouth stage of corn, from tomato fruit stage, from lotus seed stage of cabbage, from flower bud stage of sunflower to early flowering stage of soybean, the nitrogen efficiency is the highest.

　　3.及时表面处治
　　3. Timely surface treatment
　　氨基脲作为肥料,需要转化为碳酸铵土壤胶体吸附,反过来,被作物吸收,这个过程需要6 ~ 7天,这里的尿素是第一个土壤水分融化,慢慢转化为碳酸铵后,因此,尿素做肥料的应用,应该是氮的关键时期最大的农作物和肥料效率阶段耕地前1周,不是太早或太迟。
　　As fertilizer, semicarbazide needs to be converted into ammonium carbonate soil colloid for adsorption. In turn, it needs to be absorbed by crops. This process takes 6-7 days. Urea here is the first soil water to melt, after slowly converting into ammonium carbonate. Therefore, the application of urea as fertilizer should be the first week before the most important crop and fertilizer efficiency stage of nitrogen, not too early or too late.
　　4. 应用土壤深度
　　4. Applied soil depth
　　使用方法不当很容易造成尿素失水、氨挥发等氮素流失现象，造成肥料浪费、劳动力成本增加，同时也大大降低了尿素的利用率。
　　Improper use of urea can easily lead to water loss, ammonia volatilization and other nitrogen loss, resulting in fertilizer waste, labor cost increase, and greatly reduce the utilization rate of urea.
　　正确的使用方法是:玉米、小麦、番茄、白菜和其他作物的应用程序,应该在作物20厘米的距离,挖深孔15 ~ 20厘米,土壤中的肥料后土壤覆盖,不是太干后7天浇水。当土壤干旱严重确实需要浇水时，应小浇1次，不要漫灌，以防止尿素随水分流失。
　　The right way to use it is: for the application of corn, wheat, tomato, cabbage and other crops, it is necessary to dig 15-20cm deep holes at a distance of 20cm from the crops, and cover the soil with fertilizer in the soil, not water it for 7 days after it is too dry. When the soil drought is serious and it really needs to be watered, it should be watered once in a small way, and do not be flooded, so as to prevent the loss of urea with water.