Editing Physiological plant disorder (section)

==Nutrient deficiencies==
[[File:20120817 9999 103u.JPG|thumbnail|Iron deficiency.]]
Poor growth and a variety of disorders such as leaf discolouration ([[chlorosis]]) can be caused by a shortage of one or more plant nutrients. Poor plant uptake of a nutrient from the soil (or other growing medium) may be due to an absolute shortage of that element in the growing medium, or because that element is present in a form that is not available to the plant.<ref name=Mengel2001>{{cite book|last1=Mengel|first1=K.|last2=Kirkby|first2=E.A.|title=Principles of plant nutrition|date=2001|publisher=Kluwer Academic Publishers|location=Dordrecht|isbn=079237150X|edition=5th}}</ref> The latter can be caused by incorrect [[Soil pH|pH]], shortage of water, poor root growth or an excess of another nutrient.<ref name=Mengel2001 /> Plant nutrient deficiencies can be avoided or corrected using a variety of approaches including the consultation of experts on-site, the use of [[Soil test|soil]] and [[Plant tissue test|plant-tissue]] testing services, the application of prescription-blend [[fertilizer]]s, the application of fresh or well-decomposed [[Organic fertilizer|organic matter]], and the use of biological systems such as [[cover crop]]s, [[intercropping]], [[Crop rotation|improved fallows]],<ref>{{cite web|title=Improved fallows|url=http://teca.fao.org/read/7769|website=teca.fao.org|publisher=FAO|accessdate=10 April 2015|quote=Improved fallow is also land resting from cultivation but the vegetation comprises planted and managed species of leguminous trees, shrubs and herbaceous cover crops. These cover crops rapidly replenish soil fertility in one or at most two growing seasons. They shorten the time required to restore soil fertility; they help to improve farmland productivity because the plant vegetation that follows them is superior in quality; and they increase the range of outputs, because the woody fallow species can also produce fuel wood and stakes.|archive-url=https://web.archive.org/web/20171113160657/http://teca.fao.org/read/7769|archive-date=13 November 2017|url-status=dead}}</ref> [[Ley farming|ley]] cropping, [[permaculture]], or [[crop rotation]].

Nutrient (or mineral) deficiencies include:
*[[Boron deficiency (plant disorder)|Boron deficiency]]
*[[Calcium deficiency (plant disorder)|Calcium deficiency]]
*[[Iron deficiency (plant disorder)|Iron deficiency]]
*[[Magnesium deficiency (plants)|Magnesium deficiency]]
*[[Manganese deficiency (plant)|Manganese deficiency]]
*[[Molybdenum deficiency (plant disorder)|Molybdenum deficiency]]
*[[Nitrogen deficiency]]
*[[Phosphorus deficiency]]
*[[Potassium deficiency (plants)|Potassium deficiency]]
*[[Zinc deficiency (plant disorder)|Zinc deficiency]]