Diammonium Hydrogen Phosphate丨CAS 7783-28-0

Diammonium hydrogen phosphate丨CAS 7783-28-0, is an inorganic salt composed of ammonia and phosphoric acid, with the chemical formula (NH₄)₂HPO₄. It is a highly soluble, fast-acting source of nitrogen and phosphorus, two essential macronutrients for plant growth. DAP is widely used in agriculture, fire retardants, yeast fermentation, water treatment, and other industrial applications. Due to its balanced nutrient content and relatively low cost, DAP is one of the most commonly used phosphate fertilizers globally.

A. Agriculture and Fertilizer Use
1.Primary Fertilizer
o DAP contains 18% nitrogen (N) and 46% phosphorus pentoxide (P₂O₅), making it a potent starter fertilizer.
o Promotes early root development, especially in crops such as wheat, corn, rice, sugarcane, and vegetables.
2.Seedbed Preparation
o Often applied at planting to ensure young roots have immediate access to phosphorus, which is critical for early growth and root establishment.
3.Foliar and Fertigation Application
o Highly soluble in water, allowing for drip irrigation, fertigation, or foliar feeding in precision agriculture.
4.Nutrient Blends
o Mixed with other fertilizers to create custom formulations suited to crop-specific nutrient demands.
B. Industrial and Technical Applications
1.Fire Retardants
o Used in the production of flame-retardant coatings, especially for wood, fabric, and paper.
o Forms a char layer that slows down combustion and heat transfer.
2.Yeast Nutrient in Fermentation
o Acts as a nutrient supplement in the fermentation industry, supporting yeast growth in the production of wine, beer, and ethanol.
3.Water Treatment
o Occasionally used to inhibit corrosion and scale formation in industrial water systems.
4.Electronics and Ceramics
o Applied in ceramic glazing and metal finishing, and sometimes in crystal growing due to its purity and consistent composition.

A. Balanced Nutrient Supply
● Offers a dual nutrient source:
o Nitrogen for vegetative growth.
o Phosphorus for root development, flower formation, and energy transfer (ATP synthesis).
● Enhances early-season vigor, crop stand, and stress resistance.
B. High Solubility and Rapid Availability
● Dissolves quickly in water, ensuring fast uptake of nutrients.
● Particularly valuable in intensive crop systems and hydroponic applications.
C. Low Salt Index
● Compared to some other fertilizers, DAP has a moderate salt index, reducing the risk of seedling damage when applied close to seeds.
D. Economical and Versatile
● Offers a cost-effective method of delivering essential nutrients.
● Can be applied via broadcasting, banding, foliar spray, or irrigation, depending on the cropping system.
E. Improves Soil Fertility
● Over time, builds soil phosphorus levels, supporting long-term fertility.
● Acts as a temporary pH buffer, helping to raise the pH in slightly acidic soils due to its alkaline nature upon dissolution.

A. Application Timing
● Best applied at planting or pre-plant soil incorporation for crops needing early phosphorus.
● Can also be applied during critical growth stages to enhance flowering and fruit setting.
B. Typical Crops
● Cereals: Wheat, barley, corn.
● Vegetables: Potatoes, tomatoes, leafy greens.
● Fruits: Grapes, apples, citrus.
● Industrial crops: Cotton, sugar beet.
C. Rates and Methods
● Application rates depend on soil test results and crop requirements, often ranging from 50–200 kg/ha.
● Suitable for broadcast, banded, or in-row placement, and also effective in liquid fertilizer mixes.

Diammonium hydrogen phosphate丨CAS 7783-28-0 is a powerful and versatile fertilizer that delivers critical nitrogen and phosphorus to crops, promoting vigorous growth, root establishment, and higher yields. Beyond agriculture, its uses in fermentation, fire retardants, and water treatment reflect its broad utility. With proper management, DAP is a cost-effective and environmentally responsible input that continues to support modern, sustainable agricultural systems.