Editing Nutrition (section)

=== Plant ===
{{Main|Plant nutrition}}
[[File:Photosynthesis en.svg|thumb|Schematic of photosynthesis in plants. The carbohydrates produced are stored in or used by the plant.]]
Most plants obtain nutrients through inorganic substances [[Plant nutrients in soil|absorbed from the soil]] or the atmosphere. Carbon, hydrogen, oxygen, nitrogen, and sulfur are essential nutrients that make up organic material in a plant and allow enzymic processes. These are absorbed ions in the soil, such as [[bicarbonate]], [[nitrate]], [[ammonium]], and [[sulfate]], or they are absorbed as gases, such as carbon dioxide, water, oxygen gas, and [[sulfur dioxide]]. Phosphorus, boron, and silicon are used for [[esterification]]. They are obtained through the soil as [[phosphate]]s, [[boric acid]], and [[silicic acid]], respectively. Other nutrients used by plants are potassium, sodium, calcium, magnesium, manganese, chlorine, iron, copper, zinc, and molybdenum.{{Sfn|Mengel|Kirkby|Kosegarten|Appel|2001|pp=1–3}}

Plants uptake essential elements from the soil through their [[root]]s and from the air (consisting of mainly nitrogen and oxygen) through their [[Leaf|leaves]]. Nutrient uptake in the soil is achieved by [[cation exchange]], wherein [[root hair]]s pump [[hydrogen ion]]s (H<sup>+</sup>) into the soil through [[proton pump]]s. These hydrogen ions displace [[cation]]s attached to negatively charged soil particles so that the cations are available for uptake by the root. In the leaves, [[stomata]] open to take in carbon dioxide and expel [[oxygen]].{{Sfn|Mengel|Kirkby|Kosegarten|Appel|2001|pp=111–135}} Although [[nitrogen]] is plentiful in the Earth's atmosphere, very few plants can use this directly. Most plants, therefore, require nitrogen compounds to be present in the soil in which they grow. This is made possible by the fact that largely inert atmospheric nitrogen is changed in a [[nitrogen fixation]] process to biologically usable forms in the soil by bacteria.<ref>{{cite web |last1=Lindemann |first1=W.C. |last2=Glover |first2=C.R. |date=2003 |url=http://aces.nmsu.edu/pubs/_a/A129/welcome.html |title=Nitrogen Fixation by Legumes |archive-url=https://web.archive.org/web/20130517232720/http://aces.nmsu.edu/pubs/_a/A129/welcome.html |archive-date=17 May 2013 |website=[[New Mexico State University]]}}</ref>

As these nutrients do not provide the plant with energy, they must obtain energy by other means. [[Green plant]]s absorb energy from [[sunlight]] with [[chloroplasts]] and convert it to usable energy through [[photosynthesis]].{{Sfn|Mengel|Kirkby|Kosegarten|Appel|2001|pp=136–137}}