The key difference between single double and triple superphosphate is their method of production and composition. Single superphosphate is produced from phosphate rock and sulfuric acid while double superphosphate is produced via the reaction between phosphate rock and low concentration phosphoric acid. Triple superphosphate, on the other hand, is produced from phosphate rock and phosphoric acid.
Superphosphate is a group of fertilizers which provides crops with the phosphate mineral element. Single superphosphate, double superphosphate and triple superphosphate are the three major types of superphosphate.
CONTENTS
1. Overview and Key Difference
2. What is Single Superphosphate
3. What is Double Superphosphate
4. What is Triple Superphosphate
5. Side by Side Comparison – Single vs Double vs Triple Superphosphate in Tabular Form
6. Summary
What is Single Superphosphate?
Single superphosphate or SSP is a mineral fertilizer containing a relatively low percentage of phosphorous. It is the first commercial-grade fertilizer. This fertilizer used to be the most used phosphorous source, but nowadays, triple phosphate has replaced single phosphate since triple superphosphate has a comparatively higher percentage of phosphorous.
We can produce single superphosphate fertilizer via the addition of sulfuric acid to naturally phosphate rock. Earlier, people used ground animal bones for the production of this fertilizer. But later, natural deposits of rock phosphate (apetite) replaced the use of animal bones. In this production process, the addition of sulfuric acid to rock phosphate first forms a semi-solid that requires cooling for several hours in a den. After cooling, it becomes a plastic-like material and we have to keep it for an additional curing step. Then, the semi-solid material gets hardened and we can granulate it according to the desired particle size.
Figure 01: Single Superphosphate is Important for Plant Growth
Single superphosphate can be made on a small scale and on a large scale. This fertilizer usually contains calcium monophosphate and gypsum. The phosphate content in SSP is about 7-9%. Its calcium content is about 18-21%. The pH is normally below 2. This fertilizer also contains a small amount of sulfur.
What is Double Superphosphate?
Double superphosphate is a phosphorus-containing fertilizer which has a moderate phosphorus content. Double superphosphate generally contains about 36% of phosphorus. We denote this fertilizer as DSP. It contains about twice the phosphorous content as single superphosphate. However, the characteristics, appearance and mode of action of DSP are mostly similar to those of SSP. The production process for DSP is similar to that of TSP production but the difference is in the concentration of the phosphoric acid that is used to treat the phosphate rock.
What is Triple Superphosphate?
Triple phosphate (TSP) is a mineral fertilizer containing a high amount of phosphorous. This fertilizer is produced from phosphate rock via the addition of phosphoric acid. It contains more than thrice the phosphorous content of single superphosphate. TSP is highly used due to its high phosphorus content and it is suitable for soils lacking phosphorous.
Figure 02: Appearance of Triple Superphosphate
Phosphorous is important for root development. Most importantly, triple superphosphate only contains phosphorous as a plant nutrient, unlike single superphosphate, which contains sulfur as well.
What is the Difference Between Single Double and Triple Superphosphate?
Single superphosphate is produced from phosphate rock and sulfuric acid, but double superphosphate is produced via the reaction between phosphate rock and low concentration phosphoric acid. Triple superphosphate is also produced from phosphate rock and phosphoric acid. So, this is the key difference between single double and triple superphosphate. We can denote single superphosphate as SSP, double superphosphate as DSP, and triple superphosphate as TSP.
Moreover, another significant difference between single double and triple superphosphate is that single superphosphate has a low phosphorous content and double superphosphate contains a moderate amount of phosphorous, whereas triple superphosphate has a high percentage of phosphorous (about thrice the phosphorous content in SSP). Besides these, single phosphate also contains small amounts of sulfur as a micronutrient, but there are no other important plant nutrients in double and triple superphosphate.
Below infographic summarizes the differences between single double and triple superphosphate.
Summary – Single Double vs Triple Superphosphate
Superphosphates are fertilizers that can provide the phosphate mineral to crops, and there are three types of it; single, double, and triple superphosphates. The single superphosphate is produced from phosphate rock and sulfuric acid, double superphosphate is produced via the reaction between phosphate rock and low concentration phosphoric acid, and triple superphosphate is produced from phosphate rock and phosphoric acid. So, this is the key difference between single double and triple superphosphate.
Reference:
1. “Superphosphates.” Superphosphate – Chemical Economics Handbook (CEH) | IHS Markit, Available here.
2. “Single Superphosphate.” Mosaic Crop Nutrition, Mosaic Crop Nutrition, Available here.
Image Courtesy:
1. “709332” (CC0) via Pxhere
2. “Tripelsuperfosfaat (triple phosphate)” By Rasbak – Own work (CC BY-SA 3.0) via Commons Wikimedia