Single Super Phosphate (SSP) is a widely used phosphatic fertilizer produced by treating finely ground rock phosphate with sulphuric acid. It supplies plant-available phosphorus along with sulfur and calcium, making it a balanced and cost-effective fertilizer for root development, crop establishment, and long-term soil fertility improvement.
Product Identification
| Parameter | Specification |
|---|---|
| Active Chemical Components | Ca(H₂PO₄)₂·H₂O + CaSO₄·2H₂O |
| Fertilizer Grade | 0-16-0-11S |
| Category | Partially water-soluble phosphatic fertilizer |
| Phosphorus (P₂O₅) | ~16% |
| Sulfur (S) | ~11% |
| Calcium (Ca) | High |
Chemical Nature
SSP is a chemically acidulated phosphate fertilizer containing monocalcium phosphate dispersed in a gypsum matrix. The gypsum improves sulfur nutrition and soil physical properties while moderating phosphorus release.
Strengthening & Granulation Behavior
Granule integrity and strength arise from:
✔ Crystallization of monocalcium phosphate
✔ Gypsum binding action
✔ Controlled curing time (2–4 weeks)
✔ Optional anti-caking surface coatings
📌 No metallurgical behavior applies (non-metallic compound)
Thermal & Soil Chemical Behavior
Thermal Behavior:
Loses crystal water around ~100 °C
Converts to less soluble phosphates at elevated temperatures
Soil Chemical Behavior:
Gradual phosphorus release
Gypsum improves soil structure
Enhances calcium and sulfur availability
Key Agronomic Characteristics
✔ Supplies three nutrients: phosphorus, sulfur, calcium
✔ Moderate P availability reduces fixation losses
✔ Improves root growth and nodulation
✔ Enhances oil content in oilseed crops
Manufacturing & Processing
SSP is produced through sulphuric acid acidulation:
✔ Phosphate rock grinding
✔ Sulfuric acid reaction
✔ Curing (2–4 weeks)
✔ Granulation (optional)
✔ Drying and screening
Critical Controls:
Acid concentration
Rock reactivity
Curing time
Moisture content
Available Forms
Powder SSP (traditional)
Granular SSP (GSSP) – improved handling
Fortified SSP (Zn-SSP, Boron-SSP)
Applications
Agriculture:
Oilseeds (groundnut, mustard, sunflower)
Pulses, cotton, sugarcane
Rice (basal dose)
📌 Highly suitable for sulfur-deficient soils (common in India)
Industrial:
Soil conditioner
Intermediate for phosphate blends
Limited gypsum applications
Advantages of SSP
Agronomic:
✔ Supplies sulfur and calcium
✔ Improves oilseed yield and quality
✔ Enhances soil microbial activity
✔ Reduces phosphorus fixation
Commercial:
✔ Low cost per hectare
✔ Indigenous production (India)
✔ Simple manufacturing technology
✔ Environmentally safer than high-analysis fertilizers
Limitations & Considerations
Low phosphorus concentration (higher application volume)
Bulk handling challenges
Not suitable for fertigation
Higher transport cost per unit P₂O₅
SSP vs Other Phosphatic Fertilizers
| Parameter | SSP | TSP | DAP | MAP |
|---|---|---|---|---|
| P₂O₅ (%) | 16 | 46 | 46 | 52 |
| Nitrogen | No | No | Yes | Yes |
| Sulfur | Yes | No | No | No |
| Calcium | High | Moderate | Trace | Trace |
| Solubility | Partial | Full | Full | Full |
| Cost / hectare | Low | Medium | High | High |
Why Choose SSP?
✔ Best fertilizer for sulfur-deficient soils
✔ Ideal for oilseed and pulse crops
✔ Improves long-term soil health
✔ Cost-effective for small & marginal farmers
✔ Supports balanced fertilization
Storage & Handling
Store under covered, dry conditions
Avoid stacking too high
Use moisture-resistant bags
Follow FIFO practices to prevent caking
Soil Suitability Summary
| Soil Type | Suitability |
|---|---|
| Neutral soils | Excellent |
| Slightly acidic soils | Good |
| Sulfur-deficient soils | Excellent |
| Highly alkaline soils | Moderate |