single superphosphate A product made by reaction of phosphate rock with sulfuric acid, usually containing 7 to 10% P (16 to 22% P2O5), composed of monocalcium phosphate, Ca(H2PO4)2, and gypsum, CaSO4. SSP A fertilizer that is obtained by acid chemical attack of a phosphate rock with sulfuric acid. It contains 16 to 20% P2O5. It comes in the form of grey granules. normal superphosphate ordinary superphoshate phosphorus fertilizer