Phosphorus-containing fertilizer

Phosphorus containing fertilizers Phosphates are the basic substances in these fertilizers. Phosphorus is also essential for plants. Phosphorus compounds are produced by powdering rock phosphate and adding sulfuric acid to it. The resulting products - phosphoric acid and calcium salts (from the rock) are directly applied to the soil to increase its phosphorus content. Potassium fertilizers examples Potassium chloride, Potassium nitrate etc. A complete fertilizer contains nitrogen, phosphorus and potassium in a fixed ratio. This is called NPK fertilizer. 

Feeding the world s rapidly increasing population requires that farmers produce ever-larger and healthier crops. Every year they add hundreds of millions of tons of chemical fertilizers to the soil to increase crop quality and yield. In addition to carbon dioxide and water, plants need at least six elements for satisfactory growth. They are N, P, K, Ca, S, and Mg. The preparation and properties of several nitrogen- and phosphorus-containing fertilizers illustrate some of the principles introduced in this chapter. 

Sulfuric acid has many uses but one of the largest uses is for fertilizer manufacture. Primary nutrients for plants are nitrogen, phosphorus and potassium. The major use of sulfuric acid in fertilizer manufacture is in the production of phosphoric acid, which in turn is used to produce phosphorus-containing fertilizers. 

Phosphorus is an essential plant nutrient required for cellular DNA and other biomolecules. It is utilized by plants as H2PO4 and HPO ions. Phosphate minerals that can be used to manufacture phosphorus-containing fertilizers occur in a number of places throughout the world. In the United States, Florida has especially abundant phosphate resources, largely as fluorapatite, Ca5(P04)3F, as well as hydroxyapatite, Ca5(P04)30H. These phosphate minerals are too insoluble to serve directly as fertilizers and are treated with phosphoric acid and sulfuric acid to make superphosphates that are much more soluble and available to plants ... 

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