Editing Fertilizer (section)

===Single nutrient ("straight") fertilizers===
The main nitrogen-based straight fertilizer is [[ammonia]] (NH<sub>3</sub>) [[ammonium]] (NH<sub>4</sub><sup>+</sup>) or its solutions, including:
* [[Ammonium nitrate]] (NH<sub>4</sub>NO<sub>3</sub>) with 34-35% nitrogen is also widely used.
* [[Urea]] (CO(NH<sub>2</sub>)<sub>2</sub>), with 45-46% nitrogen, another popular source of nitrogen, having the advantage that it is solid and non-explosive, unlike ammonia and ammonium nitrate.
* [[Calcium ammonium nitrate]] Is a blend of 20-30% [[limestone]] CaCO<sub>3</sub> or [[Dolomite (mineral)|dolomite]] (Ca,Mg)CO<sub>3</sub> and 70-80% [[ammonium nitrate]] with 24-28  % nitrogen.
*[[Calcium nitrate]] with 15,5% nitrogen and 19% calcium, reportedly holding a small share of the nitrogen fertilizer market (4% in 2007).<ref name="ETE">{{cite book |last=Smil |first=Vaclav |title= Enriching the Earth |publisher= [[Massachusetts Institute of Technology]] |page=135 |url= https://books.google.com/books?id=G9FljcEASycC&pg=PA135 |isbn=978-0-262-69313-4 |year=2004 }}</ref>

The main straight phosphate fertilizers are the [[superphosphate]]s:
* "Single superphosphate" (SSP) consisting of 14–18% P<sub>2</sub>O<sub>5</sub>, again in the form of Ca(H<sub>2</sub>PO<sub>4</sub>)<sub>2</sub>, but also [[phosphogypsum]] ({{chem2|Ca[[SO4]] * 2 H2O}}).
* [[Triple superphosphate]] (TSP) typically consists of 44–48% of P<sub>2</sub>O<sub>5</sub> and no gypsum.

A mixture of single superphosphate and triple superphosphate is called double superphosphate. More than 90% of a typical superphosphate fertilizer is water-soluble.

The main potassium-based straight fertilizer is [[muriate of potash]] (MOP, 95–99% KCl). It is typically available as 0-0-60 or 0-0-62 fertilizer.