Editing Potassium (section)

===Fertilizer===
[[File:Patentkali (Potassium sulfate with magnesium).jpg|thumb|Potassium sulfate/magnesium sulfate fertilizer]]
Potassium ions are an essential component of [[plant]] nutrition and are found in most [[soil]] types.<ref name="g73" /> They are used as a [[fertilizer]] in [[agriculture]], [[horticulture]], and [[hydroponic]] culture in the form of [[potassium chloride|chloride]] (KCl), [[potassium sulfate|sulfate]] ({{chem2|K2SO4}}), or [[potassium nitrate|nitrate]] ({{chem2|KNO3}}), representing the 'K' [[labeling of fertilizer|in 'NPK']]. Agricultural fertilizers consume 95% of global potassium chemical production, and about 90% of this potassium is supplied as KCl.<ref name="g73" /> The potassium content of most plants ranges from 0.5% to 2% of the harvested weight of crops, conventionally expressed as amount of {{chem2|K2O}}. Modern high-[[Crop yield|yield]] agriculture depends upon fertilizers to replace the potassium lost at harvest. Most agricultural fertilizers contain potassium chloride, while potassium sulfate is used for chloride-sensitive crops or crops needing higher sulfur content. The sulfate is produced mostly by decomposition of the complex minerals [[kainite]] ({{chem2|MgSO4*KCl*3H2O}}) and [[langbeinite]] ({{chem2|MgSO4*K2SO4}}). Only a very few fertilizers contain potassium nitrate.<ref name="Kent">{{cite book|pages = 1135–57|first = Amit H. |last = Roy| url = https://books.google.com/books?id=AYjFoLCNHYUC&pg=PA1135|isbn = 978-0-387-27843-8|publisher=Springer|title = Kent and Riegel's handbook of industrial chemistry and biotechnology|date = 2007|bibcode = 2007karh.book...... }}</ref> In 2005, about 93% of world potassium production was consumed by the fertilizer industry.<ref name="USGSYB2006" /> Furthermore, potassium can play a key role in nutrient cycling by controlling litter composition.<ref>{{cite journal |last1=Ochoa-Hueso |first1=R |last2=Delgado-Baquerizo |first2=M |last3=King |first3=PTA |last4=Benham |first4=M |last5=Arca |first5=V |last6=Power |first6=SA |title=Ecosystem type and resource quality are more important than global change drivers in regulating early stages of litter decomposition |journal=Soil Biology and Biochemistry |date=2019 |volume=129 |pages=144–152 |doi=10.1016/j.soilbio.2018.11.009 |bibcode=2019SBiBi.129..144O |s2cid=92606851 |hdl=10261/336676 |hdl-access=free }}</ref>