Single Super Phosphate - SSP
SSP is the most popular phosphatic fertilizer after DAP as it contains 3 major plant nutrients namely Phosphorus, Sulphur and Calcium along with traces of many micro-nutrients. SSP is indigenously available and supply can be made at short notice. Oilseed farmers have special preference for SSP.
SSP can be efficiently used if applied in the recommended dose after soil testing. SSP should be placed properly below the seed alongwith combined use of compost and Bio-fertilisers. Soil pH should be brought near neutral with soil amendments in order to improve P use efficiency. All these precautions, if taken timely, may double SSP use efficiency and result in better use of SSP.
SSP is a grey to brownish coloured material containing monocalcium phosphate and calcium sulphate in almost equal proportions. The material is slightly hygroscopic and needs moisture proof packing to avoid lump formation on storage.
SSP is preferred for oilseed crops as sulphur is integral part of many edible oils. Since acidic soil are poor in calcium so SSP is useful in acidic soils as calcium helps increasing yields. Increasing sulphur deficiency almost all over India is making SSP still more popular.
SSP is the only Sulphur providing fertilizer in India which contains water soluble phosphorus easily taken up by plants. However, sulphur and calcium take a little more time for solubilization and plant uptake.
For efficient Use of SSP, the following is recommended:-
- Soil Testing : For efficient use of this fertilizer, soil must be tested for phosphorus contents. It will help in application of only required amount of SSP. This will also help in reducing cost of cultivation.
- Basal Dose : SSP is the best suited fertilizer for basal dose as through this we can apply full dose of phosphorus. So SSP gives the best combination with urea fertilizer. SSP is also the best fertilizer for pulses where higher phosphorus is needed as starter dose.
- Placement of SSP : Since phosphorus is immobile in soil, its source (SSP) should be placed at a distance where plant roots can easily reach. SSP should be placed below seed.
- Soil Amendments : Phosphorus, gives best results in neutral soils. But in case of alkaline, excessive presence of calcium makes complexes with phosphorus and ultimately results in poor phosphorus recovery. So bringing soil reaction to neutral by adding gypsum and leaching can only improve P use efficiency of SSP.
|Parameter(By weight)||Powdered SSP||Granulated SSP|
|Moisture||12.0% (Max.)||5.0% (Max.)|
|Free Phosphoric Acid (P2O5)||4.0% (Max.)||4.0% (Max.)|
|Water soluble phosphate (P2O5)||14% (Min.)||14.5% (Min.)|
|Sulphur (S)||11% (Min.)||11% (Min.)|
|Particle size >1 mm||-||>90%|
|Particle size <1 mm||-||<5%|