What are the advantages of foliar fertilizer?

What are the advantages of foliar fertilizer? Please also understand the netizens to help introduce with the rapid development of agriculture, foliar fertilizer is gradually accepted by farmers, farming network sorted out the advantages of foliar fertilizer, listed below in detail for netizens' reference. The main advantages of foliar fertilizer are as follows: first, the fertilizer efficiency of foliar fertilizer is high in general conditions. after the application of nitrogen, phosphorus and potassium fertilizer, it is often fixed and leached, which reduces the fertilizer efficiency due to the influence of soil acidity, soil water content and soil microorganisms. Foliar fertilization can avoid this phenomenon and improve fertilizer efficiency. Foliar fertilizer is sprayed directly on the leaf surface without picking up the soil, so as to avoid unfavorable factors such as soil adsorption and leaching, so the utilization rate is relatively high, and the total amount of fertilizer can be reduced. And foliar fertilization not only has a high utilization rate, but also can stimulate root absorption. Under the condition of maintaining the same yield, 25% of the nitrogen and phosphorus fertilizer applied to the soil can be saved by multiple foliar spraying. Second, foliar fertilizer saves time and labor, such as spraying foliar fertilizers and pesticides at one time, which can not only save operating costs, but also improve the efficiency of some pesticides. The experimental results show that the inorganic and organic nitrogen compounds in foliar fertilizer can promote the absorption and transfer of pesticides, and the surface activator can improve the diffusivity of fertilizer on the leaf and prolong the absorption time of soluble nutrients. The pH value of foliar fertilizer can produce buffer effect and improve the absorption rate of some pesticides. Third, the effect of foliar fertilizer is faster than that of root fertilizer, and foliar fertilizer can quickly improve plant nutrition. Generally speaking, foliar fertilization is faster than root absorption. For example, foliar spraying 1-2% urea aqueous solution can absorb 1 gamma 3 after 24 hours; spraying 2% concentration of superphosphate extract can be sent to all parts of the plant after 5 minutes. It can be seen that foliar fertilization can supplement the nutrients needed by plants in a short time and ensure the normal growth of plants. Fourth, foliar fertilizer pollution low nitrate is one of the carcinogens. Due to unscientific and excessive application of nitrogen fertilizer, nitrate exists and accumulates in surface water system and vegetable crops, which has attracted more and more attention. 75% of the nitrate inhaled by people comes from vegetable crops, so foliar fertilization on vegetables can not only reduce the application of nitrogen fertilizer in the soil, maintain the established yield, and can not get pollution-free vegetables. Fifth, foliar fertilizer targeted to strengthen what crops lack what to make up for? In the process of plant growth and development, if there is a lack of a certain element, its deficiency will be quickly reflected from the leaf surface. For example, when crops are deficient in nitrogen, they often show yellow seedlings; when they are deficient in phosphorus, the seedlings grow late; when they are deficient in potassium, the plants grow late, the leaves are dark green, and finally there are orange and orange faded spots. The deficiency of crop leaves can be improved by spraying the missing elements at the same time. Excellent point 6, foliar fertilizer can supplement the deficiency of nutrient absorption by roots at seedling stage, the root system is underdeveloped, the absorptive capacity is weak, and it is easy to appear the phenomenon of seedling yellow and seedling weakness. In the later stage of plant growth, due to the decline of root function, the ability of absorbing nutrients is poor. Therefore, foliar fertilization can increase yield. Especially for fruit trees and vegetables, the effect of foliar fertilization is more obvious. However, the concentration and primary dosage of foliar fertilizer are limited and cannot be sprayed in large quantities, especially a large number of nutrient elements and secondary nutrient elements, so they can be used for trace elements with less use. What should be paid attention to in foliar spraying urea? what are the methods of foliar fertilization?