Overview
Heavy superphosphate is also called double or triple superphosphate (it is customary in the north to call it three-material phosphate fertilizer), referred to as heavy calcium (TSP in English abbreviation). Potassium dihydrogen phosphate is gray-white granular and is one of the existing phosphate fertilizers. One of the chemical phosphate fertilizers with the highest active ingredients. The available phosphorus content of heavy calcium phosphate is equivalent to three times the available phosphorus content of ordinary superphosphate. The main component is water-soluble monocalcium phosphate. Heavy calcium is easily soluble in water and is slightly acidic. It is used in saline-alkaline soils. , which is conducive to achieving acid-base neutralization, improving the soil environment, and promoting crop growth.
Recommended dosage
Heavy calcium is suitable for a variety of soils and crops. It is mainly used as base fertilizer and seed fertilizer and can also be used as top dressing. The content of heavy superphosphate is high, and the dosage is less than that of superphosphate. The dosage is determined according to soil conditions and crop types. Generally, 18-30 kilograms per mu of crops are applied, and nitrogen fertilizer is applied in a timely manner. The amount of fertilizer applied to cotton can be increased appropriately. Fruit trees should be fertilized in circular ditches or holes. For saplings, 1-2 kilograms of fertilizer should be used for each plant, and for mature trees, approximately 2-4 kilograms of fertilizer should be used. Heavy superphosphate has less mobility in the soil and has a better seed fertilizer effect. When used as seed fertilizer, strip application and hole application are used, and antioxidants are used to ensure the good development of crop seedlings and lay the foundation for early maturity and high yield.
The difference between diammonium phosphate and heavy superphosphate
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%. Heavy superphosphate has 2% less available phosphorus and 18% less ammonia nitrogen than 64% diammonium phosphate.
1. 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.
Since most of our Xinjiang soil is calcareous (alkaline), heavy superphosphate is an acidic phosphate fertilizer that can improve the immediate utilization 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.
2. Application test of diammonium phosphate and double superphosphate on cotton
Professor Sheng Jiandong’s team from Xinjiang Agricultural University has conducted cotton field experiments specifically on diammonium phosphate and heavy superphosphate, and concluded that “heavy superphosphate contributes equally to the available phosphorus content and phosphorus activation coefficient of cotton field soil. Higher than diammonium phosphate, the available phosphorus content and phosphorus activation coefficient of cotton fields treated with heavy superphosphate are on average 244% and 325% higher than diammonium phosphate respectively.” For soils with higher saline-alkali (especially alkali), it is recommended to apply Common calcium phosphate contains gypsum, which is more effective in improving saline-alkali land.
