Mixed or Compound Nitrogen Fertilizers are multi-nutrient fertilizers containing nitrogen along with one or more primary plant nutrients such as phosphorus (P) and potassium (K). They are engineered to deliver balanced nutrition in a single application, improve nutrient-use efficiency, and reduce application frequency, making them ideal for modern, mechanized, and precision agriculture.
These fertilizers are designed to:
✔ Provide balanced nutrition
✔ Offer staged nitrogen release
✔ Improve nutrient-use efficiency
✔ Reduce application frequency
Major Types of Mixed / Compound Nitrogen Fertilizers
| Fertilizer Type | Typical Nutrients | Nitrogen Forms | Notes |
|---|---|---|---|
| Calcium Ammonium Nitrate (CAN) | 26–28% N + Ca/Mg | NH₄⁺ + NO₃⁻ | Safer AN alternative |
| Urea Ammonium Nitrate (UAN) | 28–32% N | NH₂ + NH₄⁺ + NO₃⁻ | Liquid fertilizer |
| Ammonium Phosphate (MAP / DAP) | N + P | NH₄⁺ + PO₄³⁻ | Starter fertilizers |
| NPK Compound Fertilizers | 15-15-15, 20-10-10, 12-32-16 | Mixed | Uniform granules |
| Nitrophosphate Fertilizers | N + P | NH₄⁺ + NO₃⁻ | Nitric-acid route |
Key Characteristics
✔ Multiple nitrogen forms for staged release
✔ Balanced supply of N, P, and K
✔ Uniform nutrient content in each granule
✔ Reduced nutrient losses
✔ Improved fertilizer efficiency
✔ Suitable for precision farming
Strengthening & Metallurgical Behavior
Mixed and compound fertilizers have no structural strengthening role. Their behavior is chemical rather than mechanical:
✔ Controlled nutrient dissolution
✔ Buffering of soil pH effects
✔ Calcium and magnesium act as soil conditioners
📌 Metallurgical relevance is minimal and indirect
Refining & Processing
Compound nitrogen fertilizers are produced through controlled neutralization reactions involving ammonia and mineral acids, followed by granulation or prilling.
✔ Chemical or physical blending
✔ Granulation for uniform nutrient distribution
✔ Coating with anti-caking agents
✔ Tight control of nutrient ratios
📌 Compound fertilizers offer better uniformity than blends
📌 Higher manufacturing complexity than single-nutrient fertilizers
Available Forms
Granular compound fertilizers
Liquid compound fertilizers
Water-soluble NPK formulations
Controlled-release fertilizers
Bulk blended fertilizers
Customized crop-specific grades
Applications
Agriculture: Rice, wheat, maize, oilseeds, pulses, sugarcane, cotton, plantation crops
Horticulture: Fruits, vegetables, turf, lawns, greenhouse production, drip irrigation
Specialty Uses: Micronutrient-enriched grades, soil-conditioning fertilizers, precision agriculture systems
Advantages
✔ Balanced nutrient delivery
✔ Reduced application frequency
✔ Improved nitrogen-use efficiency
✔ Lower labor and logistics costs
✔ Uniform crop growth
✔ Reduced risk of nutrient imbalance
Comparison: Mixed vs Single Nitrogen Fertilizers
| Feature | Mixed / Compound | Single Nitrogen Fertilizers |
|---|---|---|
| Nutrient Balance | High | Low |
| Application Efficiency | High | Medium |
| Management Complexity | Low | High |
| Cost per Bag | Higher | Lower |
| Cost per Nutrient | Optimized | Variable |
Limitations
Higher upfront cost
Less flexible nutrient ratios
Requires soil testing for best results
Improper selection may lead to excess nutrients
Limited suitability for emergency nitrogen correction