Superphosphate fertilizers have a high content of the nutrient phosphate. One of the three nutrients essential to healthy plant growth, phosphate can be applied in a high concentration with a superphosphate fertilizer to plants ranging from houseplants to agricultural crops. Several different types of this fertilizer have been created for different needs.
The three different types of superphosphate fertilizers are distinguished by the amount of phosphate in them. Single superphosphate is the mildest grade, and contains between 16 and 20 percent phosphate. It is typically available in a liquid or a dry formula, both of which are used with the same efficiency by plants. It is also known as normal superphosphate fertilizer. Dicalcium superphosphate is the next grade, which contains anywhere from 35 to 38 percent phosphate, depending on the mix and brand.
The strongest version of superphosphate fertilizer is triple phosphate. Also known as concentrated superphosphate, it is typically combined with another type of fertilizer to be applied as a compound. Triple superphosphate is more frequently used in an agricultural setting or with commercial crops; there are several processes used to create this type of fertilizer, and in most cases it is available as a granular form. All three types of superphosphate are usually made with a naturally occurring substance called rock phosphate. While this can be applied as a fertilizer in its raw form, putting it through the chemical reactions to create other types of fertilizer has been found to make it more effective.
A superphosphate fertilizer is made with a process that involves creating a reaction between the raw phosphate rock and an appropriate percentage of sulfuric acid and water. The process that creates superphosphate fertilizers releases chemicals into the air, adding to air pollution and water pollution. Controlling these waste products means producing the fertilizer in a complicated process that must be overseen in order to ensure the least amount of waste product is released into the environment.
When applied to the soil, a superphosphate fertilizer raises the amount of phosphorus available to plants. Regardless of type of plant, all require a healthy amount of phosphorus in order to survive. This nutrient is present in every cell of the plant, and is vital in maintaining the strength of the cell structure. A high level of phosphorus also increases the rate of movement of water throughout the plant structure, makes leaves healthier, and helps the plant produce better and more viable seeds.