Geological Origin and 4-in-1 Nutrient Matrix
Polysulphate is manufactured by ICL from polyhalite, an evaporite mineral mined from geological strata deep beneath the North Sea. It is a natural hydrated sulphate salt containing potassium, calcium, and magnesium.
The chemical formula K2Ca2Mg(SO4)4·2H2O yields a balanced multi-nutrient composition: 48% SO3 (19.2% elemental Sulphur), 14% K2O (Potassium), 6% MgO (Magnesium), and 17% CaO (Calcium), completely free of synthetic chemical processing.
- Nutrient composition: 48% SO3 (Sulphur), 14% K2O (Potash), 6% MgO (Magnesium), and 17% CaO (Calcium)
- Mineral form: 100 percent natural polyhalite crystal
- Regulatory status: Fully recognized and registered under the Fertilizer (Control) Order in India
- Organic approval: Certified for organic agriculture with an exceptionally low carbon footprint
Prolonged Slow-Release Dynamics and Soil Health Benefits
Unlike conventional sulfate fertilizers that dissolve immediately and leach rapidly through porous soils, Polysulphate crystals dissolve gradually over an extended period (typically 50-60 days).
This steady release matches crop nutrient uptake dynamics, minimizing sulfur and potassium leaching in high-rainfall sandy soils while providing continuous calcium and magnesium for cell wall strength and chlorophyll synthesis.
- Slow-release curve: Prolonged nutrient availability matching peak crop uptake windows
- Low salt index: Very low salinity index, safe for chloride-sensitive crops and seed furrow placement
- Calcium benefit: 17 percent CaO strengthens cell walls, reduces fruit cracking, and boosts storage life
- Magnesium benefit: 6 percent MgO drives continuous chlorophyll biosynthesis and photosynthetic assimilation
Application Practices and Crop Recommendations
Polysulphate can be applied as a basal broadcast fertilizer, incorporated into soil beds during land preparation, or blended with urea, DAP, and MOP in customized bulk blends.
It is suited for sulfur-demanding oilseeds (mustard, groundnut, soybean), cash crops (sugarcane, potato, onion), pulses, and high-value horticultural plantations.
- Basal application: Broadcast during field preparation or banded along planting rows
- Crop suitability: Oilseeds, pulses, potato, onion, tea, coffee, banana, and vegetables
- Blend compatibility: Fully compatible with urea, DAP, and standard NPK fertilizers without hygroscopic cake formation
- Soil health: Safe for soil microbiome with zero acidification risk
Official source
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Department of Fertilizers, Ministry of Chemicals and Fertilizers ↗Related on KisanPe
Common questions
What four nutrients are contained in ICL Polysulphate?
Polysulphate provides Sulphur (48% SO3 / 19.2% S), Potassium (14% K2O), Magnesium (6% MgO), and Calcium (17% CaO) in a single natural mineral crystal.
Why is Polysulphate less prone to leaching than conventional sulfate fertilizers?
Its natural polyhalite crystalline structure dissolves gradually over 50 to 60 days, providing steady nutrient release aligned with plant uptake rather than rapid leaching.
Is Polysulphate approved for organic farming?
Yes, because Polysulphate is a naturally occurring unrefined mineral with zero synthetic processing, it is certified for use in organic farming systems globally and in India.
General guidance, not personal advice. For your farm, ask your local Krishi Vigyan Kendra or agriculture officer.
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