Why does triple superphosphate reduce the amount of fertilizer that must be transported?

Triple superphosphate reduces the amount of fertilizer that must be transported because it significantly increases the concentration of the useful nutrient content.

In the production of ordinary superphosphate, the process involves adding sulfuric acid to phosphate rock, which creates "dead weight" in the form of calcium sulfate. By replacing sulfuric acid with phosphoric acid during manufacturing, producers create triple superphosphate. This process ensures that all the calcium from the original rock is converted into calcium monophosphate, eliminating the unnecessary weight of the calcium sulfate byproduct.1

As a result, the useful content of the fertilizer—expressed as the percentage of phosphoric oxide—increases from approximately 20 percent in ordinary superphosphate to about 45 percent in the triple variety. This higher concentration provides a better than twofold reduction in the total material that must be distributed to deliver the same amount of essential nutrients to farmlands.1