Editing Fertilizer (section)

==Environmental effects==
[[File:Runoff of soil & fertilizer.jpg|thumb|[[Surface runoff|Runoff]] of [[soil]] and fertilizer during a rain storm]]{{See also|Environmental impact of agriculture|Human impact on the nitrogen cycle|Nitrogen fertilizer#Problems with inorganic fertilizer|Nitrogen Cycle}}Synthetic fertilizer used in agriculture has [[Environmental impact of agriculture|wide-reaching environmental consequences]].

According to the [[Intergovernmental Panel on Climate Change|Intergovernmental Panel on Climate Change (IPCC)]] [[Special Report on Climate Change and Land]], production of these fertilizers and associated [[land use]] practices are drivers of [[global warming]].{{sfn|Mbow|Rosenzweig|Barioni|Benton|2019}} The use of fertilizer has also led to a number of direct environmental consequences: [[agricultural runoff]] which leads to downstream effects like [[Dead zone (ecology)|ocean dead zones]] and waterway contamination, [[soil microbiome]] degradation,<ref>{{Cite journal |last1=Chen |first1=Huaihai |last2=Yang |first2=Zamin K. |last3=Yip |first3=Dan |last4=Morris |first4=Reese H. |last5=Lebreux |first5=Steven J. |last6=Cregger |first6=Melissa A. |last7=Klingeman |first7=Dawn M. |last8=Hui |first8=Dafeng |last9=Hettich |first9=Robert L. |last10=Wilhelm |first10=Steven W. |last11=Wang |first11=Gangsheng |date=2019-06-18 |title=One-time nitrogen fertilization shifts switchgrass soil microbiomes within a context of larger spatial and temporal variation |journal=PLOS ONE |language=en |volume=14 |issue=6 |pages=e0211310 |bibcode=2019PLoSO..1411310C |doi=10.1371/journal.pone.0211310 |issn=1932-6203 |pmc=6581249 |pmid=31211785 |doi-access=free}}</ref> and accumulation of toxins in ecosystems. Indirect environmental impacts include: the [[Hydraulic fracturing|environmental impacts of fracking]] for [[natural gas]] used in the [[Haber process]], the agricultural boom is partially responsible for the rapid [[Human population growth|growth in human population]] and large-scale industrial agricultural practices are associated with [[habitat destruction]], [[Biodiversity loss|pressure on biodiversity]] and agricultural [[soil loss]].

In order to mitigate environmental and [[food security]] concerns, the international community has included food systems in [[Sustainable Development Goal 2]] which focuses on creating a [[Effects of climate change on agriculture|climate-friendly]] and [[sustainable food system|sustainable food production system]].<ref name=":17">United Nations (2017) Resolution adopted by the General Assembly on 6 July 2017, [[:File:A RES 71 313 E.pdf|Work of the Statistical Commission pertaining to the 2030 Agenda for Sustainable Development]] ([https://undocs.org/A/RES/71/313 A/RES/71/313])</ref> Most policy and regulatory approaches to address these issues focus on pivoting agricultural practices towards [[Sustainable agriculture|sustainable]] or [[Regenerative agriculture|regenerative agricultural]] practices: these use less synthetic fertilizers, better [[soil management]] (for example [[No-till farming|no-till agriculture]]) and more organic fertilizers.

[[File:GypStack.JPG|thumb|Large pile of [[phosphogypsum]] waste near [[Fort Meade, Florida]].]]
For each ton of phosphoric acid produced by the processing of phosphate rock, five tons of waste are generated. This waste takes the form of impure, useless, radioactive solid called [[phosphogypsum]]. Estimates range from 100,000,000 and 280,000,000 tons of phosphogypsum waste produced annually worldwide.<ref name=Taylor>{{cite journal|doi=10.1016/j.jenvman.2009.03.007|pmid=19406560|title=Environmental Impact and Management of Phosphogypsum|journal=Journal of Environmental Management|volume=90|issue=8|pages=2377–2386|year=2009|last1=Tayibi|first1= Hanan|last2=Choura|first2=Mohamed|last3=López|first3=Félix A.|last4=Alguacil|first4=Francisco J.|last5=López-Delgado|first5=Aurora|bibcode=2009JEnvM..90.2377T |hdl=10261/45241|s2cid=24111765 |hdl-access=free}}</ref>

===Water===
{{Main|Eutrophication}}
[[File:Aquatic Dead Zones.jpg|thumb|Red circles show the location and size of many [[Dead zone (ecology)|dead zones]].]]
Phosphorus and nitrogen fertilizers can affect soil, surface water, and groundwater due to the dispersion of minerals<ref name=":03" /> into waterways due to high rainfall,<ref name=":0">{{Cite journal |last1=McKay Fletcher |first1=D. M. |last2=Ruiz |first2=S. A. |last3=Dias |first3=T. |last4=Chadwick |first4=D. R. |last5=Jones |first5=D. L. |last6=Roose |first6=T. |date=2021-02-20 |title=Precipitation-optimised targeting of nitrogen fertilisers in a model maize cropping system |url=https://www.sciencedirect.com/science/article/pii/S0048969720375823 |journal=Science of the Total Environment |language=en |volume=756 |pages=144051 |doi=10.1016/j.scitotenv.2020.144051 |pmid=33280884 |bibcode=2021ScTEn.75644051M |s2cid=227522409 |issn=0048-9697}}</ref><ref>{{Cite web|url=https://www.agric.wa.gov.au/high-rainfall-pastures/environmental-impact-nitrogen-and-phosphorus-fertilisers-high-rainfall-areas|title=Environmental impact of nitrogen and phosphorus fertilisers in high rainfall areas|website=Agriculture and Food {{!}} Department of Primary Industries and Regional Development |language=en|access-date=2018-04-09}}</ref> snowmelt and can leaching into groundwater over time.<ref>{{Cite web |title=The Sources and Solutions: Agriculture |url=https://www.epa.gov/nutrientpollution/sources-and-solutions-agriculture |archive-url=https://web.archive.org/web/20230405023648/https://www.epa.gov/nutrientpollution/sources-and-solutions-agriculture |archive-date=5 April 2023 |access-date=2023-05-04 |website=US Environmental Protection Agency |date=12 March 2013 |language=en}}</ref> Agricultural run-off is a major contributor to the eutrophication of freshwater bodies. For example, in the US, about half of all the lakes are [[eutrophic]]. The main contributor to eutrophication is phosphate, which is normally a limiting nutrient; high concentrations promote the growth of cyanobacteria and algae, the demise of which consumes oxygen.<ref name=UllmannEnv/> Cyanobacteria blooms ('[[algal blooms]]') can also produce harmful [[Eutrophication#Toxicity|toxins]] that can accumulate in the food chain, and can be harmful to humans.<ref name="toledo">{{Cite web |url=http://www.toledofreepress.com/2014/08/02/do-not-drink-water-advisory-issued-for-city-of-toledo/ |title=UPDATE (9:30 a.m.): Do-not-drink water advisory lifted for City of Toledo &#124; Toledo Free Press |access-date=5 August 2014 |archive-url=https://web.archive.org/web/20140805005647/http://www.toledofreepress.com/2014/08/02/do-not-drink-water-advisory-issued-for-city-of-toledo/ |archive-date=5 August 2014 |url-status=dead }}</ref><ref>{{cite journal |pmc=3709275|doi=10.3390/toxins5050992 | pmid=23676698 | volume=5 |issue=5 |title=Variations in the microcystin content of different fish species collected from a eutrophic lake |year=2013 |journal=Toxins |pages=992–1009 | last1 = Schmidt | first1 = JR | last2 = Shaskus | first2 = M | last3 = Estenik | first3 = JF | last4 = Oesch | first4 = C | last5 = Khidekel | first5 = R | last6 = Boyer | first6 = GL|doi-access=free }}</ref> Fertilizer run-off can be reduced by using weather-optimized fertilization strategies.<ref name=":0" />

The nitrogen-rich compounds found in fertilizer runoff are the primary cause of serious oxygen depletion in many parts of [[ocean]]s, especially in coastal zones, [[lake]]s and [[river]]s. The resulting lack of dissolved oxygen greatly reduces the ability of these areas to sustain oceanic [[fauna]].<ref>[https://www.nytimes.com/2008/08/15/us/15oceans.html "Rapid Growth Found in Oxygen-Starved Ocean 'Dead Zones'"], NY Times, 14 August 2008</ref> The number of oceanic [[Dead zone (ecology)|dead zones]] near inhabited coastlines is increasing.<ref>{{cite web |author=John Heilprin, Associated Press |url=http://dsc.discovery.com/news/2006/10/20/deadzone_pla.html |title=Discovery Channel :: News&nbsp;– Animals :: U.N.: Ocean 'Dead Zones' Growing |publisher=Dsc.discovery.com |access-date=25 August 2010 |url-status=dead |archive-url=https://web.archive.org/web/20100618192917/http://dsc.discovery.com/news/2006/10/20/deadzone_pla.html |archive-date=18 June 2010 }}</ref>

As of 2006, the application of nitrogen fertilizer is being increasingly controlled in northwestern Europe<ref name=VanGrinsven2012>{{cite journal|last1=Van Grinsven|first1=H. J. M.|last2=Ten Berge|first2=H. F. M.|last3=Dalgaard|first3=T.|last4=Fraters|first4=B.|last5=Durand|first5=P.|last6=Hart|first6=A.|last7=Willems|first7=W. J.|title=Management, regulation and environmental impacts of nitrogen fertilization in northwestern Europe under the Nitrates Directive; a benchmark study |journal=Biogeosciences |date=2012 |volume=9 |issue=12 |pages=5143–5160 |doi=10.5194/bg-9-5143-2012 |bibcode = 2012BGeo....9.5143V |doi-access=free|hdl=1854/LU-3072131 |hdl-access=free }}</ref> and the United States.<ref>{{cite web|title=A Farmer's Guide To Agriculture and Water Quality Issues: 3. Environmental Requirements & Incentive Programs For Nutrient Management|url=http://www.cals.ncsu.edu/wq/wqp/wqpollutants/nutrients/incentives.html|website=cals.ncsu.edu|access-date=3 July 2014|url-status=dead|archive-url=https://web.archive.org/web/20150923200107/http://www.cals.ncsu.edu/wq/wqp/wqpollutants/nutrients/incentives.html|archive-date=23 September 2015}}</ref><ref>{{cite web|last1=State-EPA Nutrient Innovations Task Group|title=An Urgent Call to Action – Report of the State-EPA Nutrient Innovations Task Group|url=https://www.epa.gov/sites/production/files/documents/nitgreport.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://www.epa.gov/sites/production/files/documents/nitgreport.pdf |archive-date=2022-10-09 |url-status=live|website=epa.gov|access-date=3 July 2014|date=2009}}</ref> In cases where eutrophication can be reversed, it may nevertheless take decades<ref>{{Cite web |title=Study shows eutrophic lakes may not recover for a millennium |url=https://news.wisc.edu/study-shows-eutrophic-lakes-may-not-recover-for-a-millennium/ |access-date=2022-11-03 |website=news.wisc.edu|date=13 June 2005 }}</ref> and significant soil management<ref>{{Citation |last=Wilkinson |first=Grace M. |title=Eutrophication of Freshwater and Coastal Ecosystems |date=2017-01-01 |url=https://www.sciencedirect.com/science/article/pii/B9780124095489101605 |encyclopedia=Encyclopedia of Sustainable Technologies |pages=145–152 |editor-last=Abraham |editor-first=Martin A. |place=Oxford |publisher=Elsevier |language=en |doi=10.1016/b978-0-12-409548-9.10160-5 |isbn=978-0-12-804792-7 |access-date=2022-11-03}}</ref> before the accumulated nitrates in [[groundwater]] can be broken down by natural processes.

====Nitrate pollution====
Only a fraction of the nitrogen-based fertilizers is converted to plant matter. The remainder accumulates in the soil or is lost as run-off.<ref name=Nasir>{{cite book|doi=10.1007/978-94-007-7814-6_5 | pages=55–71| year=2014 | last1=Callisto | first1=Marcos | last2=Molozzi | first2=Joseline | last3=Barbosa | first3=José Lucena Etham | title=Eutrophication: Causes, Consequences and Control | chapter=Eutrophication of Lakes | isbn=978-94-007-7813-9 }}</ref> High application rates of nitrogen-containing fertilizers combined with the high [[water solubility]] of nitrate leads to increased [[Surface runoff#Agricultural issues|runoff]] into [[surface water]] as well as [[Leaching (agriculture)|leaching]] into groundwater, thereby causing [[groundwater pollution]].<ref>{{cite web |author1=C. J. Rosen |author2=B. P. Horgan |url=https://www.extension.umn.edu/garden/yard-garden/lawns/preventing-pollution-problems/ |title=Preventing Pollution Problems from Lawn and Garden Fertilizers |publisher=Extension.umn.edu |date=9 January 2009 |access-date=25 August 2010 |archive-url=https://web.archive.org/web/20140310024038/http://www.extension.umn.edu/garden/yard-garden/lawns/preventing-pollution-problems/ |archive-date=10 March 2014 |url-status=dead }}</ref><ref>{{cite journal |title=Fertilizer-N use efficiency and nitrate pollution of groundwater in developing countries |journal=Journal of Contaminant Hydrology |doi=10.1016/0169-7722(95)00067-4 |volume=20 |issue=3–4 |pages=167–184|bibcode=1995JCHyd..20..167S|year=1995 |last1=Bijay-Singh |last2=Yadvinder-Singh |last3=Sekhon |first3=G.S. }}</ref><ref>{{cite web |url=http://www.nofa.org/tnf/nitrogen.php |title=NOFA Interstate Council: The Natural Farmer. Ecologically Sound Nitrogen Management. Mark Schonbeck |publisher=Nofa.org |date=25 February 2004 |access-date=25 August 2010 |url-status=dead |archive-url=https://web.archive.org/web/20040324090920/http://www.nofa.org/tnf/nitrogen.php |archive-date=24 March 2004 }}</ref> The excessive use of nitrogen-containing fertilizers (be they synthetic or natural) is particularly damaging, as much of the nitrogen that is not taken up by plants is transformed into nitrate which is easily leached.<ref>{{cite journal | year = 2008| title = Roots, Nitrogen Transformations, and Ecosystem Services | journal = Annual Review of Plant Biology | volume = 59 | pages = 341–363 | doi=10.1146/annurev.arplant.59.032607.092932| pmid = 18444903 | last1 = Jackson | first1 = Louise E. | last2 = Burger | first2 = Martin | last3 = Cavagnaro | first3 = Timothy R. | issue = 1 | bibcode = 2008AnRPB..59..341J }}</ref>

Nitrate levels above 10&nbsp;mg/L (10 ppm) in groundwater can cause '[[blue baby syndrome]]' (acquired [[methemoglobinemia]]).<ref>{{cite journal |pmc=1638204 |title = Blue Babies and Nitrate-Contaminated Well Water | pmid=10903623 | volume=108 |issue = 7 |year=2000 |journal=Environ. Health Perspect. |pages=675–8 | last1 = Knobeloch | first1 = L | last2 = Salna | first2 = B | last3 = Hogan | first3 = A | last4 = Postle | first4 = J | last5 = Anderson | first5 = H | doi=10.1289/ehp.00108675|bibcode = 2000EnvHP.108..675K }}</ref> The nutrients, especially nitrates, in fertilizers can cause problems for natural habitats and for human health if they are washed off soil into watercourses or leached through soil into groundwater.<ref>[https://www.usgs.gov/special-topics/water-science-school/science/nitrogen-and-water Nitrogen and Water]</ref> Run-off can lead to fertilizing blooms of algae that use up all the oxygen and leave huge "dead zones" behind where other fish and aquatic life can not live.<ref>{{Cite web |last=Biello |first=David |language= en |date = March 14, 2008|title= Fertilizer Runoff Overwhelms Streams and Rivers--Creating Vast "Dead Zones" |url=https://www.scientificamerican.com/article/fertilizer-runoff-overwhelms-streams/ |access-date= |website= Scientific American}}</ref>

===Soil===

==== Acidification ====
Soil acidification refers to the process by which the pH level of soil becomes more acidic over time. Soil pH is a measure of the soil's acidity or alkalinity and is determined on a scale from 0 to 14, with [[Seven (1995 film)|7]] being neutral. A pH value below 7 indicates acidic soil, while a pH value above 7 indicates alkaline or basic soil.

Soil acidification is a significant concern in agriculture and horticulture. It refers to the process of the soil becoming more acidic over time. {{See also|Soil pH|Soil acidification}}
Nitrogen-containing fertilizers can cause [[soil acidification]] when added.<ref>{{cite journal|doi= 10.1126/science.324_721b |pmid = 19423798 |bibcode = 2009Sci...324..721S | volume=324 |issue = 5928 | title=Eutrophication: More Nitrogen Data Needed |journal=Science |pages=721–722|year = 2009 |last1 = Schindler |first1 = D. W. |last2 = Hecky |first2 = R. E. }}</ref><ref>{{cite journal|doi=10.2136/sssaj2007.0071N | volume=72 | issue=1 | title=Phosphorus Solubility in Response to Acidification of Dairy Manure Amended Soils | journal=Soil Science Society of America Journal | pages=238| bibcode=2008SSASJ..72..238P | year=2008 | last1=Penn | first1=C. J. | last2=Bryant | first2=R. B. }}</ref> This may lead to decrease in nutrient availability which may be offset by [[liming (soil)|liming]]. These fertilizers release ammonium or nitrate ions, which can acidify the soil as they undergo chemical reactions.

When these nitrogen-containing fertilizers are added to the soil, they increase the concentration of hydrogen ions (H+) in the soil solution, which lowers the pH of the soil.

====Accumulation of toxic elements====

=====Cadmium=====
The concentration of [[cadmium]] in phosphorus-containing fertilizers varies considerably and can be problematic.<ref>{{cite journal|last1=McLaughlin|first1=M. J.|last2=Tiller|first2=K. G. |last3= Naidu |first3= R.|last4=Stevens|first4=D. P.|title=Review: the behaviour and environmental impact of contaminants in fertilizers|journal=Soil Research|date=1996|volume=34|issue=1 |pages=1–54 |doi= 10.1071/sr9960001|bibcode=1996SoilR..34....1M }}</ref> For example, mono-ammonium phosphate fertilizer may have a cadmium content of as low as 0.14&nbsp;mg/kg or as high as 50.9&nbsp;mg/kg.<ref name=Lugon2014>{{cite journal |last1= Lugon-Moulin |first1= N. |last2= Ryan|first2=L.|last3=Donini|first3=P.|last4=Rossi|first4=L.|title=Cadmium content of phosphate fertilizers used for tobacco production|journal=Agron. Sustain. Dev. |date= 2006 |volume= 26 |issue= 3 |pages= 151–155|url=http://hal.archives-ouvertes.fr/docs/00/88/63/51/PDF/hal-00886351.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://hal.archives-ouvertes.fr/docs/00/88/63/51/PDF/hal-00886351.pdf |archive-date=2022-10-09 |url-status=live|access-date=27 June 2014|doi=10.1051/agro:2006010|s2cid=13996565 }}</ref> The phosphate rock used in their manufacture can contain as much as 188&nbsp;mg/kg cadmium<ref name=Zapata2004>{{cite web|last1=Zapata|first1=F.|last2=Roy|first2=R.N.|title=Use of Phosphate Rocks for Sustainable Agriculture: Secondary nutrients, micronutrients, liming effect and hazardous elements associated with phosphate rock use|url=http://www.fao.org/docrep/007/y5053e/y5053e0d.htm|website=fao.org|publisher=FAO|access-date=27 June 2014 |date=2004}}</ref> (examples are deposits on [[Nauru]]<ref>{{cite journal |vauthors=Syers JK, Mackay AD, Brown MW, Currie CD |title=Chemical and physical characteristics of phosphate rock materials of varying reactivity |journal= J Sci Food Agric |year=1986 |volume=37 |pages=1057–1064 | doi = 10.1002/jsfa.2740371102 |issue=11|bibcode=1986JSFA...37.1057S }}</ref> and the [[Christmas Island]]s<ref>{{cite journal |author= Trueman NA |title= The phosphate, volcanic and carbonate rocks of Christmas Island (Indian Ocean) |journal=J Geol Soc Aust |year=1965 |volume=12 |issue=2 |pages=261–286 |doi= 10.1080/00167616508728596 |bibcode = 1965AuJES..12..261T }}</ref>). Continuous use of high-cadmium fertilizer can contaminate soil (as shown in New Zealand)<ref name=taylor>{{cite journal | author=Taylor MD | title=Accumulation of Cadmium derived from fertilizers in New Zealand soils |journal=Science of the Total Environment |year=1997 |volume=208 | issue=1–2 |pages=123–126 | doi= 10.1016/S0048-9697(97)00273-8 |bibcode= 1997ScTEn.208..123T | pmid=9496656 }}</ref> and [[Phytotoxicity|plants]].<ref name=Chaney2012>{{cite book|last1=Chaney|first1=R.L.|chapter=Food safety issues for mineral and organic fertilizers |title=Advances in Agronomy|date=2012|volume=117|pages=51–99|publisher=Elsevier |doi=10.1016/b978-0-12-394278-4.00002-7|isbn=9780123942784}}</ref> Limits to the cadmium content of phosphate fertilizers has been considered by the [[European Commission]].<ref name=Oosterhuis2000>{{cite web|last1=Oosterhuis|first1=F.H.|last2=Brouwer|first2=F.M.|last3=Wijnants|first3=H.J.|title=A possible EU wide charge on cadmium in phosphate fertilisers: Economic and environmental implications.|url=http://ec.europa.eu/environment/enveco/taxation/pdf/cadium.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://ec.europa.eu/environment/enveco/taxation/pdf/cadium.pdf |archive-date=2022-10-09 |url-status=live|website=dare.ubvu.vu.nl|access-date=27 June 2014|date=2000}}</ref><ref name=FertilizersEurope2014>{{cite web |last1=|title=Putting all the cards on the table|url=http://www.fertilizerseurope.com/fileadmin/user_upload/news_assets/FI-458-decadmiation__3_.pdf|publisher=fertilizerseurope.com|access-date=|date=2014|work = Fertilizers International |archive-url=https://web.archive.org/web/20140808082824/http://www.fertilizerseurope.com/fileadmin/user_upload/news_assets/FI-458-decadmiation__3_.pdf|archive-date=8 August 2014|url-status=dead}}</ref><ref name=Wates2014>{{cite web|last1=Wates|first1=J.|title=Revision of the EU fertilizer regulation and cadmium content of fertilisers|url=http://www.iatp.org/documents/revision-of-the-eu-fertilizer-regulation-and-cadmium-content-of-fertilisers |website=iatp.org|access-date=27 June 2014|date=2014}}</ref> Producers of phosphorus-containing fertilizers now select phosphate rock based on the cadmium content.<ref name=UllmannEnv>Wilfried Werner "Fertilizers, 6. Environmental Aspects" ''Ullmann's Encyclopedia of Industrial Chemistry'', 2002, Wiley-VCH, Weinheim.{{doi |10.1002/14356007.n10_n05}}</ref>

=====Fluoride=====
Phosphate rocks contain high levels of fluoride. Consequently, the widespread use of phosphate fertilizers has increased soil fluoride concentrations.<ref name=Chaney2012 /> It has been found that food contamination from fertilizer is of little concern as plants accumulate little fluoride from the soil; of greater concern is the possibility of fluoride toxicity to livestock that ingest contaminated soils.<ref name=Loganathan2008>{{cite book|last1=Loganathan|first1=P.|last2=Hedley|first2=M.J.|last3=Grace|first3=N.D.|title=Reviews of Environmental Contamination and Toxicology |chapter=Pasture Soils Contaminated with Fertilizer-Derived Cadmium and Fluorine: Livestock Effects |date=2008|volume=192|pages=29–66|doi=10.1007/978-0-387-71724-1_2|pmid=18020303|isbn=978-0-387-71723-4}}<!--|access-date=1 July 2014--></ref><ref name=Cronin2000>{{cite journal|last1=Cronin|first1=S. J.|last2=Manoharan|first2=V.|last3=Hedley|first3=M. J.|last4=Loganathan|first4=P.|title=Fluoride: A review of its fate, bioavailability, and risks of fluorosis in grazed-pasture systems in New Zealand|journal=New Zealand Journal of Agricultural Research|date=2000|volume=43|issue=3|pages=295–3214|doi=10.1080/00288233.2000.9513430|doi-access=free|bibcode=2000NZJAR..43..295C }}<!--|access-date=1 July 2014--></ref> Also of possible concern are the effects of fluoride on soil microorganisms.<ref name=Loganathan2008 /><ref name=Cronin2000 /><ref name=Wilke1987>{{cite journal|last1=Wilke|first1=B.M.|title=Fluoride-induced changes in chemical properties and microbial activity of mull, moder and mor soils|journal=Biology and Fertility of Soils|date=1987|volume=5|issue=1 |pages=49–55|doi=10.1007/BF00264346|bibcode=1987BioFS...5...49W |s2cid=1225884}}<!--|access-date=1 July 2014--></ref>

=====Radioactive elements=====
The radioactive content of the fertilizers varies considerably and depends both on their concentrations in the parent mineral and on the fertilizer production process.<ref name=Chaney2012 /><ref name=Mortvedt2014>{{cite web|last1=Mortvedt|first1=JJ|last2=Beaton|first2=JD|title=Heavy Metal and Radionuclide Contaminants in Phosphate Fertilizers|url=http://www.scopenvironment.org/downloadpubs/scope54/6mortvedt.htm|access-date=16 July 2014|url-status=dead|archive-url=https://web.archive.org/web/20140726193234/http://www.scopenvironment.org/downloadpubs/scope54/6mortvedt.htm|archive-date=26 July 2014}}</ref> Uranium-238 concentrations can range from 7 to 100 pCi/g (picocuries per gram) in phosphate rock<ref name=EPA2016>{{cite web|url=https://www.epa.gov/radiation/tenorm-fertilizer-and-fertilizer-production-wastes|title=TENORM: Fertilizer and Fertilizer Production Wastes|date=2016|publisher=US EPA|access-date=30 August 2017}}</ref> and from 1 to 67 pCi/g in phosphate fertilizers.<ref name=Khater2008>{{cite web|last1=Khater|first1=A. E. M.|title=Uranium and heavy metals in phosphate fertilizers|url=http://www.radioecology.info/Bergen2008/proceedings/26.%20Khater%20Uranium%20P.pdf|website=radioecology.info|access-date=17 July 2014|date=2008|archive-url=https://web.archive.org/web/20140724225807/http://www.radioecology.info/Bergen2008/proceedings/26.%20Khater%20Uranium%20P.pdf|archive-date=24 July 2014|url-status=dead}}</ref><ref name=NCRP1987>{{cite book|last1=NCRP|title=Radiation Exposure of the U.S. Population from Consumer Products and Miscellaneous Sources|date=1987|publisher=National Council on Radiation Protection and Measurements|pages=29–32|url=http://f3.tiera.ru/1/genesis/575-579/575000/1160670d5da187ab055c34ebc07487cf|access-date=17 July 2014}}{{dead link|date=January 2018 |bot=InternetArchiveBot |fix-attempted=yes }}</ref><ref>{{cite journal |author=Hussein EM |title=Radioactivity of phosphate ore, superphosphate, and phosphogypsum in Abu-zaabal phosphate |journal=Health Physics |year=1994 |volume=67 |pages=280–282 | doi = 10.1097/00004032-199409000-00010 |pmid=8056596 |issue=3}}</ref> Where high annual rates of phosphorus fertilizer are used, this can result in uranium-238 concentrations in soils and drainage waters that are several times greater than are normally present.<ref name=NCRP1987 /><ref>{{cite journal |vauthors=Barisic D, Lulic S, Miletic P |title=Radium and uranium in phosphate fertilizers and their impact on the radioactivity of waters |journal=Water Research |year=1992 |volume=26 |pages=607–611 | doi = 10.1016/0043-1354(92)90234-U |issue=5|bibcode=1992WatRe..26..607B }}</ref> However, the impact of these increases on the [[Sievert#Dose examples|risk to human health]] from radinuclide contamination of foods is very small (less than 0.05 m[[Sievert|Sv]]/y).<ref name=NCRP1987 /><ref name=Hanlon2012>{{cite web|last1=Hanlon|first1=E. A.|title=Naturally Occurring Radionuclides in Agricultural Products|url=http://edis.ifas.ufl.edu/ss441|website=edis.ifas.ufl.edu|publisher=University of Florida|access-date=17 July 2014|date=2012|archive-date=25 July 2014|archive-url=https://web.archive.org/web/20140725171240/http://edis.ifas.ufl.edu/ss441|url-status=dead}}</ref><ref name=Sharpley1987>{{cite journal|last1=Sharpley|first1=A. N.|last2=Menzel|first2=R. G.|title=The impact of soil and fertilizer phosphorus on the environment|journal=Advances in Agronomy|date=1987|volume=41|pages=297–324|doi=10.1016/s0065-2113(08)60807-x|isbn=9780120007417|s2cid=83005521 }}</ref>

=====Other metals=====
Steel industry wastes, recycled into fertilizers for their high levels of [[zinc]] (essential to plant growth), wastes can include the following [[Toxic heavy metal|toxic metals]]: [[lead]]<ref name="community.seattletimes.nwsource.com">{{cite web |last=Wilson |first=Duff |url=https://archive.seattletimes.com/archive/19970703/2547772/fear-in-the-fields----how-hazardous-wastes-become-fertilizer----spreading-heavy-metals-on-farmland-is-perfectly-legal-but-little-research-has-been-done-to-find-out-whether-its-safe |title=Business &#124; Fear in the Fields&nbsp;– How Hazardous Wastes Become Fertilizer&nbsp;– Spreading Heavy Metals on Farmland Is Perfectly Legal, But Little Research Has Been Done To Find Out Whether It's Safe |publisher=Community.seattletimes.nwsource.com |date=3 July 1997 |access-date=25 August 2010 |archive-date=18 November 2010 |archive-url=https://web.archive.org/web/20101118013539/http://community.seattletimes.nwsource.com/archive/?date=19970703&slug=2547772 |url-status=live }}</ref> [[arsenic]], [[cadmium]],<ref name="community.seattletimes.nwsource.com"/> chromium, and nickel. The most common toxic elements in this type of fertilizer are [[Mercury (element)|mercury]], lead, and arsenic.<ref name="pirg.org">{{cite web |url=http://www.pirg.org/toxics/reports/wastelands/ |title=Waste Lands: The Threat of Toxic Fertilizer |publisher=Pirg.org |date=3 July 1997 |access-date=25 August 2010 |archive-date=26 November 2010 |archive-url=https://web.archive.org/web/20101126211622/http://www.pirg.org/toxics/reports/wastelands/ |url-status=dead }}</ref><ref>{{cite web |author=mindfully.org |url=http://www.mindfully.org/Farm/Toxic-Waste-Fertilizers.htm |title=Waste Lands: The Threat of Toxic Fertilizer Released by PIRG Toxic Wastes Found in Fertilizers Cat Lazaroff / ENS 7may01 |publisher=Mindfully.org |access-date=25 August 2010 |url-status=dead |archive-url=https://web.archive.org/web/20020111124358/http://www.mindfully.org/Farm/Toxic-Waste-Fertilizers.htm |archive-date=11 January 2002 }}</ref><ref name=FAO2004>{{cite book|last1=Zapata|first1=F|last2=Roy|first2=RN|title=Use of phosphate rocks for sustainable agriculture|date=2004|publisher=FAO|location=Rome|page=82|url=ftp://ftp.fao.org/docrep/fao/007/y5053e/y5053e00.pdf|access-date=16 July 2014}}{{Dead link|date=August 2018 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> These potentially harmful impurities can be removed; however, this significantly increases cost. Highly pure fertilizers are widely available and perhaps best known as the highly water-soluble fertilizers containing blue dyes used around households, such as [[Miracle-Gro]]. These highly water-soluble fertilizers are used in the plant nursery business and are available in larger packages at significantly less cost than retail quantities. Some inexpensive retail granular garden fertilizers are made with high purity ingredients.

====Trace mineral depletion====
Attention has been addressed to the decreasing concentrations of elements such as iron, zinc, copper and magnesium in many foods over the last 50–60 years.<ref name=Davis2004>{{cite journal|last1=Davis|first1=D.R.|last2=Epp|first2=M.D.|last3=Riordan|first3=H.D.|title=Changes in USDA Food Composition Data for 43 Garden Crops, 1950 to 1999|journal=Journal of the American College of Nutrition|date=2004|volume=23|issue=6|pages=669–682|doi=10.1080/07315724.2004.10719409|pmid=15637215|s2cid=13595345}}</ref><ref name=Thomas2007>{{cite journal|last1=Thomas|first1=D.|title=The mineral depletion of foods available to us as a nation (1940–2002) – A Review of the 6th Edition of McCance and Widdowson|journal=Nutrition and Health|date=2007|volume=19|issue=1–2|pages=21–55|doi=10.1177/026010600701900205|pmid=18309763|s2cid=372456}}</ref> [[Intensive farming]] practices, including the use of synthetic fertilizers are frequently suggested as reasons for these declines and organic farming is often suggested as a solution.<ref name=Thomas2007 /> Although improved crop yields resulting from NPK fertilizers are known to dilute the concentrations of other nutrients in plants,<ref name=Davis2004 /><ref name=Jarrell1981>{{cite journal|last1=Jarrell|first1=W.M.|last2=Beverly|first2=R.B.|title=The Dilution Effect in Plant Nutrition Studies|journal=Advances in Agronomy|date=1981|volume=34|pages=197–224|doi=10.1016/s0065-2113(08)60887-1|isbn=9780120007349}}</ref> much of the measured decline can be attributed to the use of progressively higher-yielding crop varieties that produce foods with lower mineral concentrations than their less-productive ancestors.<ref name=Davis2004 /><ref name=Fan2008>{{cite journal|last1=Fan|first1=M. S.|last2=Zhao|first2=F. J.|last3=Fairweather-Tait|first3=S. J.|last4=Poulton|first4=P. R.|last5=Dunham|first5=S. J.|last6=McGrath|first6=S. P.|title=Evidence of decreasing mineral density in wheat grain over the last 160 years.|journal=[[Journal of Trace Elements in Medicine and Biology]]|date=2008|volume=22|issue=4|pages=315–324|doi=10.1016/j.jtemb.2008.07.002|pmid=19013359|bibcode=2008JTEMB..22..315F |url=https://repository.rothamsted.ac.uk/download/763262a2ea615fca85841d665060d217a464dfdf38f0213ae494ada7217517b9/2790912/Fan%20et%20al%20BBK%20wheat%20mineral%20density%20manuscript%20inc%20figures_.doc}}</ref><ref name=Zhao2009>{{cite journal|last1=Zhao|first1=F. J.|last2=Su|first2=Y. H.|last3=Dunham|first3=S. J.|last4=Rakszegi|first4=M.|last5=Bedo|first5=Z.|last6=McGrath|first6=S. P.|last7=Shewry|first7=P. R.|title=Variation in mineral micronutrient concentrations in grain of wheat lines of diverse origin.|journal=Journal of Cereal Science|date=2009|volume=49|issue=2|pages=290–295|doi=10.1016/j.jcs.2008.11.007}}</ref> It is, therefore, unlikely that organic farming or reduced use of fertilizers will solve the problem; foods with high nutrient density are posited to be achieved using older, lower-yielding varieties or the development of new high-yield, nutrient-dense varieties.<ref name=Davis2004 /><ref name=Saltzman2013>{{cite journal|last1=Saltzman|first1=A.|last2=Birol|first2=E.|last3=Bouis|first3=H. E.|last4=Boy|first4=E.|last5=De Moura|first5=F.F.|last6=Islam|first6=Y.|last7=Pfeiffer|first7=W. H.|title=Biofortification: progress toward a more nourishing future|journal=Global Food Security|date=2013|volume=2|issue=1 |pages=9–17|doi=10.1016/j.gfs.2012.12.003|bibcode=2013GlFS....2....9S }}</ref>

Fertilizers are, in fact, more likely to solve trace mineral deficiency problems than cause them: In Western Australia deficiencies of [[zinc]], copper, [[manganese]], iron and [[molybdenum]] were identified as limiting the growth of broad-acre crops and pastures in the 1940s and 1950s.<ref name=Moore>{{cite book|last=Moore|first=Geoff|title=Soilguide – A handbook for understanding and managing agricultural soils|year=2001|publisher=Agriculture Western Australia|location=Perth, Western Australia|isbn=978-0-7307-0057-9|pages=161–207|url=https://researchlibrary.agric.wa.gov.au/bulletins/2/}}</ref> Soils in Western Australia are very old, highly weathered and deficient in many of the major nutrients and trace elements.<ref name="Moore"/> Since this time these trace elements are routinely added to fertilizers used in agriculture in this state.<ref name="Moore"/> Many other soils around the world are deficient in zinc, leading to deficiency in both plants and humans, and zinc fertilizers are widely used to solve this problem.<ref>{{cite web|url=https://www.scribd.com/doc/36383515/Zn-in-Soils-and-Crop-Nutrition-2008 |title=Zinc in Soils and Crop Nutrition |publisher=Scribd.com |date=25 August 2010 |access-date=17 June 2012}}</ref>

====Changes in soil biology====
{{Further|soil biology}}
High levels of fertilizer may cause the breakdown of the [[Symbiosis|symbiotic]] relationships between plant roots and [[mycorrhiza]]l fungi.<ref>{{cite book|last=Carroll and Salt|first=Steven B. and Steven D.|title=Ecology for Gardeners|year=2004|publisher=Timber Press|location=Cambridge|isbn=978-0-88192-611-8}}</ref>

===Organic agriculture===
Two types of agricultural management practices include organic agriculture and conventional agriculture. The former encourages soil fertility using local resources to maximize efficiency. Organic agriculture avoids synthetic agrochemicals. Conventional agriculture uses all the components that organic agriculture does not use.<ref>{{Cite journal|last1=Gomiero|first1=T.|last2=D. Pimental & M.G Paoletti|date=2011|title=Environmental Impact of Different Agricultural Management Practices: Conventional vs. Organic Agriculture.|journal=Critical Reviews in Plant Sciences|volume=30|issue=1–2|pages=95–124|via=Taylor & Francis Online|doi=10.1080/07352689.2011.554355|bibcode=2011CRvPS..30...95G |s2cid=83736589}}</ref>

===Hydrogen consumption and sustainability===
Most fertilizer is made from dirty hydrogen.<ref>{{Cite web |title=Hydrogen and Ammonia fertilizers for Sustainable Agriculture and New Global Framework for Managing Nature programs {{!}} Department of Economic and Social Affairs |url=https://sdgs.un.org/partnerships/hydrogen-and-ammonia-fertilizers-sustainable-agriculture-and-new-global-framework |access-date=2024-06-30 |website=sdgs.un.org}}</ref> Ammonia is produced from [[natural gas]] and air.<ref name="Appl">{{cite encyclopedia|last=Appl|first=Max|chapter=Ammonia, 2. Production Processes|encyclopedia=Ullmann's Encyclopedia of Industrial Chemistry|year=2000|publisher=Wiley-VCH|location=Weinheim, Germany|isbn=978-3-527-30673-2|pages=139–225 |doi=10.1002/14356007.o02_o11}}</ref> The cost of natural gas makes up about 90% of the cost of producing ammonia.<ref name="Sawyer2001">{{cite journal |author=Sawyer JE |title=Natural gas prices affect nitrogen fertilizer costs |journal=IC-486 |volume=1 |page=8 |year=2001 |url=http://www.ipm.iastate.edu/ipm/icm/2001/1-29-2001/natgasfert.html |archive-date=25 July 2017 |access-date=3 April 2007 |archive-url=https://web.archive.org/web/20170725101213/http://www.ipm.iastate.edu/ipm/icm/2001/1-29-2001/natgasfert.html |url-status=dead }}</ref> The increase in price of natural gases over the past decade, along with other factors such as increasing demand, have contributed to an increase in fertilizer price<!-- over which period? -->.<ref>{{cite news|url=http://www.ers.usda.gov/Data/FertilizerUse/|title=Table 8—Fertilizer price indexes, 1960–2007.|url-status=dead|archive-url=https://web.archive.org/web/20100306075446/http://www.ers.usda.gov/Data/FertilizerUse/|archive-date=6 March 2010}}</ref>

====Contribution to climate change====
{{See also|Greenhouse gas emissions from agriculture}}
The amount of [[greenhouse gas]]es [[carbon dioxide]], [[methane]] and [[nitrous oxide]] produced during the [[Haber process|manufacture]] and use of nitrogen fertilizer is estimated as around 5% of [[anthropogenic greenhouse gas emissions]]. One third is produced during the production and two thirds during the use of fertilizers.<ref>{{cite web |title=Carbon emissions from fertilizers could be reduced by as much as 80% by 2050 |url=https://www.sciencedaily.com/releases/2023/02/230209114736.htm |website=Science Daily |publisher=University of Cambridge |access-date=17 February 2023}}</ref> Nitrogen fertilizer can be converted by [[Nitrous oxide#Soil|soil bacteria]] to [[nitrous oxide]], a [[greenhouse gas]].<ref>{{Cite web|title=How Fertilizer Is Making Climate Change Worse|url=https://www.bloombergquint.com/onweb/synthetic-fertilizer-ammonium-nitrate-makes-climate-change-worse|access-date=2021-03-25|website=BloombergQuint|date=10 September 2020 |language=en}}</ref> Nitrous oxide emissions by humans, most of which are from fertilizer, between 2007 and 2016 have been estimated at 7 million tonnes per year,<ref>{{Cite journal|last1=Tian|first1=Hanqin|last2=Xu|first2=Rongting|last3=Canadell|first3=Josep G.|last4=Thompson|first4=Rona L.|last5=Winiwarter|first5=Wilfried|last6=Suntharalingam|first6=Parvadha|last7=Davidson|first7=Eric A.|last8=Ciais|first8=Philippe|last9=Jackson|first9=Robert B.|last10=Janssens-Maenhout|first10=Greet|last11=Prather|first11=Michael J.|date=October 2020|title=A comprehensive quantification of global nitrous oxide sources and sinks|url=https://www.nature.com/articles/s41586-020-2780-0|journal=Nature|language=en|volume=586|issue=7828|pages=248–256|doi=10.1038/s41586-020-2780-0|pmid=33028999|bibcode=2020Natur.586..248T|hdl=1871.1/c74d4b68-ecf4-4c6d-890d-a1d0aaef01c9 |s2cid=222217027|issn=1476-4687|archive-url=https://web.archive.org/web/20201013034950/https://www.nature.com/articles/s41586-020-2780-0|archive-date=13 October 2020|hdl-access=free}} [http://eprints.whiterose.ac.uk/166534/ Alt URL]</ref> which is incompatible with limiting global warming to below 2&nbsp;°C.<ref>{{Cite web|date=2020-10-07|title=Nitrogen fertiliser use could 'threaten global climate goals'|url=https://www.carbonbrief.org/nitrogen-fertiliser-use-could-threaten-global-climate-goals|access-date=2021-03-25|website=Carbon Brief|language=en}}</ref>

===Atmosphere===
[[File:AtmosphericMethane.png|thumb|Global [[methane]] concentrations (surface and atmospheric) for 2005; note distinct plumes]]
Through the increasing use of nitrogen fertilizer, which was used at a rate of about 110 million tons (of N) per year in 2012,<ref name=FAO2012>{{cite book|last1=FAO|title=Current world fertilizer trends and outlook to 2016|date=2012|publisher=Food and Agriculture Organization of the United Nations|location=Rome|page=13|url=ftp://ftp.fao.org/ag/agp/docs/cwfto16.pdf|archive-url=https://web.archive.org/web/20170518105637/ftp://ftp.fao.org/ag/agp/docs/cwfto16.pdf|url-status=dead|archive-date=2017-05-18|access-date=3 July 2014}}</ref><ref>{{cite journal |doi=10.1038/nature06592|bibcode = 2008Natur.451..293G | volume=451 |issue = 7176 | title=An Earth-system perspective of the global nitrogen cycle |journal=Nature |pages=293–296 |pmid=18202647 | last1 = Gruber | first1 = N | last2 = Galloway | first2 = JN|year = 2008 |doi-access = free }}</ref> adding to the already existing amount of reactive nitrogen, [[nitrous oxide]] (N<sub>2</sub>O) has become the third most important [[greenhouse gas]] after carbon dioxide and methane. It has a [[global warming potential]] 296 times larger than an equal mass of carbon dioxide and it also contributes to stratospheric ozone depletion.<ref>[http://www.initrogen.org/fileadmin/user_upload/2007_docs/2007-N-joint-policy-brief.pdf "Human alteration of the nitrogen cycle, threats, benefits and opportunities"] {{webarchive|url=https://web.archive.org/web/20090114121452/http://initrogen.org/fileadmin/user_upload/2007_docs/2007-N-joint-policy-brief.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://initrogen.org/fileadmin/user_upload/2007_docs/2007-N-joint-policy-brief.pdf |archive-date=2022-10-09 |url-status=live |date=14 January 2009 }} [[UNESCO]]&nbsp;– [[Scientific Committee on Problems of the Environment|SCOPE]] Policy briefs, April 2007</ref>
By changing processes and procedures, it is possible to mitigate some, but not all, of these effects on anthropogenic [[climate change]].<ref name=Roy2002>{{cite journal|last1=Roy|first1=R. N.|last2=Misra|first2=R. V.|last3=Montanez|first3=A.|title=Decreasing reliance on mineral nitrogen-yet more food|journal=Ambio: A Journal of the Human Environment|date=2002|volume=31|issue=2|pages=177–183|doi=10.1579/0044-7447-31.2.177|pmid=12078007|bibcode=2002Ambio..31..177R |s2cid=905322|url=http://www.planta.cn/forum/files_planta/decreasing_reliance_on_mineral_nitrogenyet_more_food_364.pdf|access-date=3 July 2014|url-status=dead|archive-url=https://web.archive.org/web/20150924074035/http://www.planta.cn/forum/files_planta/decreasing_reliance_on_mineral_nitrogenyet_more_food_364.pdf|archive-date=24 September 2015}}</ref>

[[Methane emissions]] from crop fields (notably rice [[paddy field]]s) are increased by the application of ammonium-based fertilizers. These emissions contribute to global climate change as methane is a potent greenhouse gas.<ref name="Stimulation by ammonium-based fertilizers of methane oxidation in soil around rice roots">{{cite journal|last1=Bodelier|first1=Paul|author2=Peter Roslev|author3=Thilo Henckel|author4=Peter Frenzel|date=November 1999|title=Stimulation by ammonium-based fertilizers of methane oxidation in soil around rice roots |journal=Nature|volume=403|pages=421–424 |pmid=10667792|issue=6768|doi=10.1038/35000193 |bibcode=2000Natur.403..421B|s2cid=4351801}}</ref><ref name=Banger2012>{{cite journal|last1=Banger|first1=K.|last2=Tian|first2=H.|last3=Lu|first3=C.|title=Do nitrogen fertilizers stimulate or inhibit methane emissions from rice fields?|journal=Global Change Biology|date=2012|volume=18|issue=10|pages=3259–3267|doi=10.1111/j.1365-2486.2012.02762.x|pmid=28741830|bibcode=2012GCBio..18.3259B|s2cid=31666406 }}</ref>