Since the 1990s, the application effect of DAP in agricultural planting in the Three North Region of China has been recognized. With the rapid growth of domestic ammonium phosphate production, the application of large amounts of P fertilizers, from 1981 to 2000, China Grain Fields Soil phosphorus increased at a rate of 11%, and soil total phosphorus and available phosphorus increased by an average of 0.21 g/kg and 5.7 mg/kg. The area of ​​phosphorus-deficient soil has been reduced from 67% in the 1980s to less than 50%, and the area of ​​phosphorus-rich soil has increased from 7% to 15%. Through the use of phosphate fertilizers for many years, available phosphorus levels in soils in northern China's agricultural areas have generally increased, especially for high-yield farmland and vegetable and other economic crops, and the surface available 20-cm soils have high levels of available phosphorus. This shows that under the condition of maintaining crop output in the Three North Region, the available phosphorus retained in the soil has been accumulated, resulting in the phenomenon that the effect of applying ammonium phosphate successively is not as good as the initial effect. This phenomenon is misdirected and the amount of fertilizer is constantly increasing. To increase, the method of application is unreasonably enlarged. For example, some use amounts to 50 kilograms, and some use diammonium phosphate as topdressing and flushing. The requirement of reasonable application of diammonium phosphate today depends on the characteristics of diammonium phosphate, and the amount of fertilizing and the method of application should be adjusted in time according to the changes of available phosphorus content in the soil. In accordance with the principle of balanced fertilization, give full play to the role of ammonium phosphate production. The technology for applying phosphate fertilizers should be adjusted accordingly. Diammonium phosphate is a binary high-concentration compound fertilizer with low nitrogen and high phosphorus content. Diammonium phosphate containing N18%, P2O546% total nutrients up to 64% of the high concentration. The nutrient supply has the characteristics of low nitrogen and high phosphorus without potassium. It is particularly effective on phosphorus-deficient soils. In the early 1980s, the soil in the vast agricultural areas in northern China was generally deficient in phosphorus, which was reflected in the lighter 1000-grain weight of grain crops. At that time, farmers applied diammonium phosphate to various crops, and the effect of increasing production was obvious. So farmers in North China, Northeast China, and Northwest China like to use this fertilizer. By the early 1990s, farmers in the northern region began to reflect that after many years of application of DAP, the effect of fertilizer was not prominent. At the same time, soil fertility surveys and testing data also show that the available phosphorus levels in surface soils in high-yielding agricultural areas are increasing year by year, phosphorus is accumulated in soils, and phosphate fertilizers have a post-effect. This shows that the characteristics of phosphate fertilizers and nitrogen fertilizers are different. Nitrogen fertilizers are lively, and they lose their volatilization, leaching, and denitrification and denitrification after they are applied to farmland. Phosphate fertilizers, however, are not very active, and they not only migrate very slowly in farmland soils, but also have low conversion product activity. Seasonal utilization rate is very low, but the cumulative utilization rate after application is very high. The principle of rational application of diammonium phosphate Ammonium phosphate fertilizer can play an important role. The use of an accurate amount of ammonium phosphate as a seed fertilizer can embody a "smart." The low temperature of spring farmland, the phosphorus activation in soil nutrients pool is slow, and the seedling period of crops is the critical period of phosphorus nutrition. It is sensitive to phosphorus and easy to lack of phosphorus. At this time, phosphorus deficiency, crop seedlings are not strong, and the resistance is poor. . The farmer said: "There is money to buy seeds and no money to buy seedlings." It is difficult to obtain high yield in the later period. There are two key technologies for the use of ammonium phosphate as a seed fertilizer. One is to control the amount of ammonium phosphate to 5 kg/mu. Second, the application site should be applied to the seeds 2 to 3 cm below the slope. No fertilizer contact. For many years farmers in the Sanbei area are accustomed to applying diammonium phosphate seed fertilizers to crops such as spring corn, soybeans and cotton, which has become a fixed measure for high-yield projects. Ammonium phosphate is suitable for basal fertilizers. The large amount of phosphorus in the base fertilizer can guarantee the development of the seeds and fruits at the later stage of the crop growth, and also ensure the yield. Because the phosphorus in diammonium phosphate is three times that of nitrogen, it can be used alone for the base fertilizer of phosphorus-enriched legumes with strong nitrogen-fixing ability, and the application amount is preferably 8-10 kg. When diammonium phosphate is used as the base fertilizer on other crops, appropriate amounts of elemental nitrogen and potassium fertilizers need to be formulated in order to increase the proportion of nitrogen and potassium. The role of crop basal fertilizers is mainly to supplement the nutrients in the middle and later stages. Therefore, ammonium phosphate must be applied deeply. Phosphorus in ammonium phosphate is poorly mobile in soil and can only be increased if it is applied to the distribution area of ​​the main root system of the crop. The depth of different base crops should be different. In particular, fruit trees require 40-60 cm, vegetables 15-20 cm, and food crops 20-30 cm. The amount of basal fertilizer varies depending on the type of crop and the fertilization status of the previous crop. For example, farmland that has been applied with organic fertilizer can use less fertilizer; annual application of ammonium phosphate can reduce or reduce the application of ternary compound fertilizer. The general recommended amount of ammonium phosphate for general food crops is about 10 to 12 kilograms, and cotton acres are 12 to 16 kilograms. About the adjustment of nitrogen and potassium fertilizers and the increase of nitrogen fertilizer ratio, not all of them are added in the base fertilizer, and nitrogen can also be added when topdressing, and the effect will be better. Although DAP is fast-acting, it is not suitable for top-dressing and red-fertilizing. Because when the top dressing is used, the particles of diammonium phosphate are spread on the surface, the dissolution is slow and less, and the dissolved phosphoric acid migrates to the lower layer of the soil with poor performance. At the same time, the mobile side is fixed and the fixed product is insoluble in water. Not absorbed and utilized by roots, loses its effectiveness. If diammonium phosphate is used as water fertilization, phosphorus, which is more expensive, will be carried away from surface runoff, or enriched on the surface and the roots of crops will be mainly released underground. The root system will not be able to fertilize the soil, resulting in poor fertilizer efficiency and causing loss of phosphate fertilizer. , pollute the water environment. This two-way problem should not happen. In short, DAP is a good fertilizer and is used effectively in phosphorus-deficient soils, but its nutrients are not comprehensive, and it is necessary to supplement nitrogen and potassium nutrients and implement balanced fertilization. Also, do not use diammonium phosphate for topdressing and flushing. Digital Safe,Digital Safe Box,Small Digital Safe,Electronic Digital Safe Ningbo Reliance Security Technology CO.,Ltd , https://www.reliancesafes.com