Chemical Composition and Soil Dispersion Mechanism
Elemental sulfur is insoluble in water and cannot be absorbed directly by plant roots, which require soluble sulfate (SO4²⁻).
Sulphur bentonite solves this biological challenge by formulating 90% elemental sulfur with 10% swelling sodium bentonite clay pastilles.
- Elemental Sulfur (90% S): Highly concentrated sulfur source providing sustained root nutrition over multiple cropping seasons
- Swelling Bentonite (10% Clay): Absorbs soil moisture and expands, fracturing the pastilles into microscopic elemental sulfur particles
- Biological Oxidation: Soil bacteria (Thiobacillus) oxidize fractured sulfur particles into plant-available sulfate (SO4²⁻)
- Leaching Resistance: Unlike water-soluble sulfate fertilizers that leach away during heavy monsoon rains, sulphur bentonite provides sustained release
Agronomic Impact on Oilseeds, Pulses, and Cereals
Sulfur is an essential component of amino acids (methionine, cysteine) and the synthesis of chlorophyll, vitamins, and plant oils.
Applying sulphur bentonite increases seed oil content in oilseeds and enhances protein content and nodulation in leguminous pulses.
- Mustard & Groundnut: Increases seed weight, pod formation, and oil recovery percentages by 2% to 4%
- Pulses (Chickpea, Pigeon Pea): Stimulates biological nitrogen fixation by enhancing Rhizobium root nodule activity
- Sugarcane & Cereals: Improves nitrogen use efficiency (N:S ratio) and enhances sugar recovery and tiller culm strength
- Soil Conditioning: Mild soil acidifying effect during oxidation, helping unlock bound phosphorus and micronutrients in alkaline soils
Application Rates and Placement Protocols
Sulphur bentonite is applied as a basal broadcast dressing before planting or during primary seedbed preparation.
Because biological oxidation requires time and active soil moisture, apply at sowing rather than as a late top-dressing.
- Basal Soil Dosage: Apply 10 to 15 kg per acre for oilseeds and pulses; 15 to 20 kg per acre for sugarcane and heavy feeding crops
- Soil Moisture Requirement: Adequate soil moisture and warm temperatures (above 15°C) are essential for rapid Thiobacillus bacterial oxidation
- Fertilizer Blending: Compatible with standard basal fertilizers; can be blended with DAP, MOP, or single superphosphate
Official source
Check the latest rules, benefits and forms here. KisanPe is an independent platform and is not a government website.
Ministry of Agriculture - Fertilizer Control Order ↗Related on KisanPe
Common questions
How does sulphur bentonite work in agricultural soil?
Bentonite clay absorbs soil water and swells, breaking the sulfur pastilles into microscopic particles that soil bacteria oxidize into plant-available sulfate.
Why is sulphur bentonite preferred over soluble sulfur in heavy rainfall areas?
Because elemental sulfur does not dissolve immediately, it resists leaching wash-out during heavy monsoon rains, providing continuous season-long nutrition.
What is the typical composition of sulphur bentonite?
It typically contains 90% elemental sulfur and 10% swelling bentonite clay formulated as uniform pastilles.
General guidance, not personal advice. For your farm, ask your local Krishi Vigyan Kendra or agriculture officer.
More Fertilizers & Crop Nutrition guides
Ask Sakhi AI in your language, check live mandi prices or plan a loan with KisanPe tools.