Single super phosphate (SSP) was the first commercial mineral fertilizer and it led to the development of the modern plant nutrient industry. This material was once the most commonly used fertilizer, but other phosphorus (P) fertilizers have largely replaced SSP because of its relatively low P content. SSP can easily be produced on a small scale to meet regional needs. Since SSP contains both monocalcium phosphate (MCP, also called calcium dihydrogen phosphate) and gypsum, no problems arise with phosphogypsum byproduct disposal unlike the manufacture of other common P fertilizers. The general chemical reaction is: Ca3 (PO4)2 [rock phosphate] + 2 H2SO4 [sulfuric acid] → Ca (H2PO4)2 [monocalcium phosphate] + 2 CaSO4 [gypsum] SSP is an excellent source of three plant nutrients. The P component reacts in soil similarly to other soluble fertilizers. The presence of both P and sulfur (S) in SSP can be an agronomic advantage where both of these nutrients are deficient. In agronomic studies where SSP is demonstrated to be superior to other P fertilizers, it is usually due to the S and/or Ca that it contains. When locally available, SSP has found wide-spread use for fertilizing pastures where both P and S are needed. As a source of P alone, SSP often costs more than other more concentrated fertilizers, therefore it has declined in popularity.
The advantage of using Superphosphate as a fertilizer is that the phosphoric acid is fully water soluble, but when Superphosphate is applied to the soil, it is converted into soluble phosphate. This is due to precipitation as calcium, iron or aluminum phosphate, which is dependent on the soil type to which the fertilizer is added, be it alkaline or acidic garden soil. All soil types can benefit from the application of Superphosphate as a fertilizer. It is used in conjunction with an organic fertilizer and should be applied at sowing or transplant time
Specification of Granulated Single Supper Phosphate