Editing Fertilizer (section)

===Micronutrients===
[[Micronutrients]] are consumed in smaller quantities and are present in plant tissue on the order of [[Parts-per notation|parts-per-million]] (ppm), ranging from 0.15 to 400 ppm or less than 0.04% dry matter.<ref>{{cite web|url = http://aesl.ces.uga.edu/publications/plant/Nutrient.asp|title = AESL Plant Analysis Handbook&nbsp;– Nutrient Content of Plant|publisher = Aesl.ces.uga.edu|access-date = 11 September 2015}}</ref><ref name="Mills and Jones, 1996">{{cite book|author1=H.A. Mills |author2=J.B. Jones Jr. |year=1996|title=Plant Analysis Handbook II: A Practical Sampling, Preparation, Analysis, and Interpretation Guide|publisher=Micro-Macro Pub. |isbn=978-1-878148-05-6}}</ref> These elements are often required for enzymes essential to the plant's metabolism. Because these elements enable catalysts (enzymes), their impact far exceeds their weight%age. Typical micronutrients are [[boron]], [[zinc]], [[molybdenum]], [[iron]], and [[manganese]].<ref name=Ull/> These elements are provided as water-soluble salts. Iron presents special problems because it converts to insoluble (bio-unavailable) compounds at moderate soil pH and phosphate concentrations. For this reason, iron is often administered as a [[Chelation|chelate complex]], e.g., the [[Ethylenediaminetetraacetic acid|EDTA]] or [[EDDHA]] derivatives. The micronutrient needs depend on the plant and the environment. For example, [[sugar beet]]s appear to require [[boron]], and [[legume]]s require [[cobalt]],<ref name=Ullmann1>{{Ullmann|doi=10.1002/14356007.a10_323.pub3|title=Fertilizers, 1. General|year=2009|last1=Scherer|first1=Heinrich W.|last2=Mengel|first2=Konrad|last3=Kluge|first3=Günter|last4=Severin|first4=Karl}}</ref> while environmental conditions such as heat or drought make boron less available for plants.<ref>{{Cite web|url=https://www.aspireboron.com/formula|title=Boron Deficiency|access-date=4 March 2019|archive-date=6 March 2019|archive-url=https://web.archive.org/web/20190306044328/https://www.aspireboron.com/formula|url-status=dead}}</ref>