Usually 64% of traditional high-quality diammonium phosphate contains 18% nitrogen and 46% effective phosphorus pentoxide. The proportion of water-soluble phosphorus pentoxide to available phosphorus is required to be above 87%. Explain what is effective phosphorus pentoxide? What is water-soluble phosphorus pentoxide? Usually the content of phosphate fertilizers is labeled with phosphorus pentoxide. The phosphorus marked on the general fertilizer packaging bag is generally available phosphorus pentoxide, but the high-quality heavy superphosphate has a total phosphorus greater than 46%, available phosphorus greater than 44%, and water-soluble phosphorus greater than 38%. What is total phosphorus? In addition, what is the slurry method? What is traditional law? Let’s briefly talk about these issues today.
1. In the production process of monoammonium phosphate and diammonium phosphate, there are two processes, called the anti-aging agent slurry method and the traditional method. I will not go into details. From the perspective of the user, Just remember that the traditional method is better than the slurry method.
2. The relationship between total phosphorus, available phosphorus and water-soluble phosphorus
Total phosphorus = available phosphorus + ineffective phosphorus
Available phosphorus = water-soluble phosphorus + citron-soluble phosphorus
Available phosphorus is phosphorus that can be absorbed by plants; ineffective phosphorus is temporarily unable to be absorbed. Water-soluble phosphorus refers to the part of phosphorus that can be dissolved in water, called water-soluble phosphorus pentoxide. Usually phosphate fertilizers can only be dissolved in water to form hydrogen phosphate, dihydrogen phosphate and other ion states, which are absorbed by plants. Therefore, the higher the proportion of water-soluble phosphorus, the stronger the quick-acting effect of phosphate fertilizer. Citron-soluble phosphorus, although insoluble in water, can also be absorbed by plants. Definitely not as efficient as water-soluble phosphorus. Why are both diammonium phosphate and double superphosphate granulated? The general purpose of fertilizer granulation is to release nutrients slowly, prevent clumping, and facilitate application. This is the main reason why base fertilizers are usually granular.
Traditional-method premium product Diammonium Phosphate has a nitrogen content of 18%, effective phosphorus pentoxide greater than 46%, and water-soluble phosphorus pentoxide greater than 40%.
High-quality heavy superphosphate, the effective phosphorus pentoxide is greater than 44%, and the water-soluble phosphorus pentoxide is greater than 38%. Compared with 64% diammonium phosphate, heavy superphosphate has 2% less available phosphorus and 8% less ammonia nitrogen than 1 methoxybutanol.
3. Different chemical compositions
The main component of double superphosphate is calcium dihydrogen phosphate monohydrate, which contains part of free acid, has good water solubility and is acidic. The main chemical component of diammonium phosphate is diammonium hydrogen phosphate, which has good water solubility and is alkaline. In order to prevent factors such as agglomeration, packaging is usually performed during production.
For example, most of the soil in Xinjiang is calcareous (alkaline). Heavy superphosphate is an acidic phosphate fertilizer, which can improve the immediate utilization rate of phosphorus. Although diammonium phosphate contains 18% ammonia nitrogen, due to its alkaline nature and the alkaline environment of the soil, ammonia nitrogen can easily volatilize and escape, causing waste. In terms of utilization efficiency, heavy superphosphate is superior to diammonium phosphate. In addition, for saline-alkali soils, especially alkaline soils (high alkalinity), the presence of calcium will reduce the alkalinity of the soil and the dispersion of soil colloids. Reduce soil alkalinity and increase water and air permeability.
4. Application test of diammonium phosphate and double superphosphate on cotton
Experiments have shown that the contribution of heavy superphosphate to the available phosphorus content and phosphorus activation coefficient of cotton field soil is higher than that of diammonium phosphate. The available phosphorus content and phosphorus activation coefficient of cotton fields treated with heavy superphosphate are on average higher than those of diammonium phosphate. Ammonium is 244% and 325% higher.
For soils with higher saline-alkali (especially alkali), it is recommended to apply ordinary calcium phosphate. Ordinary calcium phosphate contains gypsum, which has a better effect on improving saline-alkali soil.
