Agriculture: Difference between revisions

'''Agriculture''' is the practice of cultivating plants and livestock.<ref name="Office1999">{{cite book |title=Safety and health in agriculture |url={{google books|plainurl=y|id=GtBa6XIW_aQC|page=77}} |year=1999 |publisher=International Labour Organization |isbn=978-92-2-111517-5 |page=77 |access-date=13 September 2010 |url-status=live |archive-url=https://web.archive.org/web/20110722061757/http://books.google.com/books?id=GtBa6XIW_aQC |archive-date=22 July 2011|quote=defined agriculture as 'all forms of activities connected with growing, harvesting and primary processing of all types of crops, with the breeding, raising and caring for animals, and with tending gardens and nurseries'.}}</ref> Agriculture was the key development in the rise of [[sedentism|sedentary]] [[human civilization]], whereby farming of [[domestication|domesticated]] species created food [[economic surplus|surpluses]] that enabled people to live in cities. The [[history of agriculture]] began thousands of years ago. After gathering wild grains beginning at least 105,000 years ago, nascent farmers began to plant them around 11,500 years ago. Pigs, sheep, and cattle were domesticated over 10,000 years ago. Plants were independently cultivated in at least 11 regions of the world. [[Industrial agriculture]] based on large-scale [[monoculture]] in the twentieth century came to dominate agricultural output, though about 2&nbsp;billion people still depended on [[subsistence agriculture]].

Modern [[agronomy]], [[plant breeding]], [[agrochemical]]s such as [[pesticide]]s and [[fertilizer]]s, and technological developments have sharply increased [[crop]] yields, while causing [[Environmental impact of agriculture|widespread ecological and environmental damage]]. [[Selective breeding]] and modern practices in [[animal husbandry]] have similarly increased the output of meat, but have raised concerns about [[animal welfare]] and environmental damage. Environmental issues include contributions to [[global warming]], depletion of [[aquifer]]s, [[deforestation]], [[antibiotic resistance]], and [[growth hormone]]s in [[industrial meat production]]. Agriculture is both a cause of and sensitive to [[environmental degradation]], such as [[biodiversity loss]], [[desertification]], [[soil degradation]] and [[Climate change and agriculture|global warming]], all of which can cause decreases in crop yield. [[Genetically modified organism]]s are widely used, although some are banned in certain countries.

The major agricultural products can be broadly grouped into foods, fibers, [[fuel]]s and [[raw material]]s (such as [[natural rubber|rubber]]). Food classes include cereals ([[grains]]), [[vegetable]]s, fruits, [[cooking oil|oils]], meat, milk, [[edible mushroom|fungi]] and [[eggs as food|eggs]]. Over one-third of the world's workers are employed in agriculture, second only to the [[service sector]], although in recent decades, the global trend of a decreasing number of agricultural workers continues, especially in developing countries where [[smallholding]] is being overtaken by industrial agriculture and mechanization.

The word ''agriculture'' is a late [[Middle English]] adaptation of Latin {{lang|la|agricultūra}}, from {{lang|la|ager}} 'field' and {{lang|la|cultūra}} '[[Tillage|cultivation]]' or 'growing'.<ref>{{cite book |page=[https://archive.org/details/oxforddictionary0000unse_x2z7/page/14 14] |title=The Oxford Dictionary of Word Histories |editor=Chantrell, Glynnis |publisher=Oxford University Press |year=2002 |isbn=978-0-19-863121-7 |url=https://archive.org/details/oxforddictionary0000unse_x2z7/page/14 }}</ref> While agriculture usually refers to human activities, certain species of [[Attine ants|ant]],<ref>{{cite news |last1=St. Fleur |first1=Nicholas |title=An Ancient Ant-Bacteria Partnership to Protect Fungus |newspaper=The New York Times |date=6 October 2018 |url=https://www.nytimes.com/2018/10/06/science/ants-fungus-amber.html |access-date=14 July 2020}}</ref><ref>{{cite journal |last1=Li |first1=Hongjie |last2=Sosa Calvo |first2=Jeffrey |last3=Horn |first3=Heidi A. |last4=Pupo |first4=Mônica T. |last5=Clardy |first5=Jon |last6=Rabeling |first6=Cristian |last7=Schultz |first7=Ted R. |last8=Currie |first8=Cameron R. |title=Convergent evolution of complex structures for ant–bacterial defensive symbiosis in fungus-farming ants |journal=Proceedings of the National Academy of Sciences of the United States of America |date=2018 |volume=115 |issue=42 |pages=10725 |doi=10.1073/pnas.1809332115 |pmid=30282739 |pmc=6196509 }}</ref> [[termite]] and [[ambrosia beetle|beetle]] have been cultivating crops for up to 60 million years.<ref>{{cite journal |title=The Evolution of Agriculture in Insects |journal=Annual Review of Ecology, Evolution, and Systematics |volume=36 |pages=563–595 |date=December 2005 |doi=10.1146/annurev.ecolsys.36.102003.152626 |author1=Mueller, Ulrich G. |author2=Gerardo, Nicole M. |author3=Aanen, Duur K. |author4=Six, Diana L. |author-link4=Diana Six |author5=Schultz, Ted R.}}</ref> Agriculture is defined with varying scopes, in its broadest sense using natural resources to "produce commodities which maintain life, including food, fiber, forest products, horticultural crops, and their related services".<ref name=Maine /> Thus defined, it includes [[arable farming]], [[horticulture]], [[animal husbandry]] and [[forestry]], but horticulture and forestry are in practice often excluded.<ref name=Maine>{{cite web |url=http://www.maine.gov/education/aged/definition.html |title=Definition of Agriculture |publisher=State of Maine |access-date=6 May 2013 |url-status=live |archive-url=https://web.archive.org/web/20120323075557/http://www.maine.gov/education/aged/definition.html |archive-date=23 March 2012 }}</ref>

[[File:Vavilov-centers updated.jpg|thumb |upright=1.35 |[[Center of origin|Centres of origin]], as numbered by [[Nikolai Vavilov]] in the 1930s. Area 3 (gray) is no longer recognised as a centre of origin, and [[Papua New Guinea]] (area P, orange) was identified more recently.<ref name=Larson2014 /><ref>{{cite journal |last1=Denham |first1=T. P. |title=Origins of Agriculture at Kuk Swamp in the Highlands of New Guinea |journal=Science |volume=301 |issue=5630 |year=2003 |pages=189–193 |doi=10.1126/science.1085255 |pmid=12817084 |s2cid=10644185 }}</ref>]]

The development of agriculture enabled the human population to grow many times larger than could be sustained by [[hunter-gatherer|hunting and gathering]].<ref name=Bocquet-Appel>{{cite journal |author=Bocquet-Appel, Jean-Pierre |title=When the World's Population Took Off: The Springboard of the Neolithic Demographic Transition |journal=Science |date=29 July 2011 |volume=333 |issue=6042 |pages=560–561 |doi=10.1126/science.1208880 |pmid=21798934 |bibcode=2011Sci...333..560B |s2cid=29655920 }}</ref> Agriculture began independently in different parts of the globe,<ref name="Stephens 897–902">{{Cite journal |last1=Stephens |first1=Lucas |last2=Fuller |first2=Dorian |last3=Boivin |first3=Nicole |last4=Rick |first4=Torben |last5=Gauthier |first5=Nicolas |last6=Kay |first6=Andrea |last7=Marwick |first7=Ben |last8=Armstrong |first8=Chelsey Geralda |last9=Barton |first9=C. Michael|date=30 August 2019|title=Archaeological assessment reveals Earth's early transformation through land use |journal=Science |volume=365|issue=6456 |pages=897–902 |doi=10.1126/science.aax1192 |issn=0036-8075 |pmid=31467217 |hdl=10150/634688 |hdl-access=free |bibcode=2019Sci...365..897S |s2cid=201674203}}</ref> and included a diverse range of [[taxa]], in at least 11 separate [[centers of origin<!--this is a term of art in the history of agriculture-->|centres of origin]].<ref name="Larson2014">{{cite journal |doi=10.1073/pnas.1323964111 |title=Current perspectives and the future of domestication studies |journal=PNAS |volume=111 |issue=17 |pages=6139–6146 |year=2014 |last1=Larson |first1=G. |last2=Piperno |first2=D. R. |last3=Allaby |first3=R. G. |last4=Purugganan |first4=M. D. |last5=Andersson |first5=L. |last6=Arroyo-Kalin |first6=M. |last7=Barton |first7=L. |last8=Climer Vigueira |first8=C. |last9=Denham |first9=T. |last10=Dobney |first10=K. |last11=Doust |first11=A. N. |last12=Gepts |first12=P. |last13=Gilbert |first13=M. T. P. |last14=Gremillion |first14=K. J. |last15=Lucas |first15=L. |last16=Lukens |first16=L. |last17=Marshall |first17=F. B. |last18=Olsen |first18=K. M. |last19=Pires |first19=J.C. |last20=Richerson |first20=P. J. |last21=Rubio De Casas |first21=R. |last22=Sanjur |first22=O.I. |last23=Thomas |first23=M. G. |last24=Fuller |first24=D.Q. |doi-access=free |pmid=24757054 |pmc=4035915 |bibcode=2014PNAS..111.6139L}}</ref> Wild grains were collected and eaten from at least 105,000 years ago.<ref>{{cite magazine |last1=Harmon |first1=Katherine |title=Humans feasting on grains for at least 100,000 years |url=http://blogs.scientificamerican.com/observations/humans-feasting-on-grains-for-at-least-100000-years/ |magazine=[[Scientific American]] |access-date=28 August 2016 |date=17 December 2009 |url-status=live |archive-url=https://web.archive.org/web/20160917013143/http://blogs.scientificamerican.com/observations/humans-feasting-on-grains-for-at-least-100000-years/ |archive-date=17 September 2016 }}</ref> From around 11,500 years ago, the eight [[Neolithic founder crops]], [[emmer wheat|emmer]] and [[einkorn wheat]], hulled [[barley]], [[pea]]s, [[lentil]]s, [[Vicia ervilia|bitter vetch]], [[chick pea]]s and [[flax]] were cultivated in the [[Levant]]. Rice was [[Agriculture in China|domesticated in China]] between 11,500 and 6,200 BC with the earliest known cultivation from 5,700 BC,<ref>{{cite journal |pmid=17898767 |year=2007 |last1=Zong |first1=Y. |last2=When |first2=Z. |last3=Innes |first3=J. B. |last4=Chen |first4=C. |last5=Wang |first5=Z. |last6=Wang |first6=H. |title=Fire and flood management of coastal swamp enabled first rice paddy cultivation in east China |volume=449 |issue=7161 |pages=459–462 |doi=10.1038/nature06135 |journal=Nature |bibcode=2007Natur.449..459Z |s2cid=4426729 }}</ref> followed by [[mung bean|mung]], [[soy]] and [[Azuki bean|azuki]] beans. Sheep were domesticated in [[Mesopotamia]] between 13,000 and 11,000 years ago.<ref>{{cite book |title=Sheep and Goat Science |edition=Fifth |last=Ensminger |first=M. E. |author2=Parker, R. O. |year=1986 |publisher=Interstate Printers and Publishers |isbn=978-0-8134-2464-4}}</ref> Cattle were domesticated from the wild [[aurochs]] in the areas of modern Turkey and Pakistan some 10,500 years ago.<ref name="McTavish">{{cite journal |author=McTavish, E. J. |author2=Decker, J. E. |author3=Schnabel, R.D. |author4=Taylor, J. F. |author5=Hillis, D. M. |year=2013 |title=New World cattle show ancestry from multiple independent domestication events |journal=PNAS |volume=110 |issue=15 |pages=E1398–1406 |doi=10.1073/pnas.1303367110 |pmid=23530234 |pmc=3625352 |bibcode=2013PNAS..110E1398M }}</ref> [[Domestic pig|Pig production]] emerged in Eurasia, including Europe, East Asia and Southwest Asia,<ref>{{Cite journal |last1=Larson |first1=Greger |last2=Dobney |first2=Keith |author-link2= Keith Dobney |last3=Albarella |first3=Umberto |last4=Fang |first4=Meiying |last5=Matisoo-Smith |first5=Elizabeth |last6=Robins |first6=Judith |last7=Lowden |first7=Stewart |last8=Finlayson |first8=Heather |last9=Brand |first9=Tina |date=11 March 2005 |title=Worldwide Phylogeography of Wild Boar Reveals Multiple Centers of Pig Domestication |journal=Science |volume=307 |issue=5715 |pages=1618–1621 |doi=10.1126/science.1106927 |pmid=15761152|bibcode=2005Sci...307.1618L |s2cid=39923483 }}</ref> where [[wild boar]] were first domesticated about 10,500 years ago.<ref>{{Cite journal |last1=Larson |first1=Greger |last2=Albarella |first2=Umberto |last3=Dobney |first3=Keith |last4=Rowley-Conwy |first4=Peter |last5=Schibler |first5=Jörg |last6=Tresset |first6=Anne |last7=Vigne |first7=Jean-Denis |last8=Edwards |first8=Ceiridwen J. |last9=Schlumbaum |first9=Angela |date=25 September 2007 |title=Ancient DNA, pig domestication, and the spread of the Neolithic into Europe |journal=PNAS |volume=104 |issue=39 |pages=15276–15281 |doi=10.1073/pnas.0703411104 |pmid=17855556 |pmc=1976408 |bibcode=2007PNAS..10415276L }}</ref> In the [[Andes]] of South America, the potato was domesticated between 10,000 and 7,000 years ago, along with beans, [[coca]], [[llama]]s, [[alpaca]]s, and [[guinea pig]]s. [[Sugarcane]] and some [[List of root vegetables|root vegetables]] were domesticated in [[New Guinea]] around 9,000 years ago. [[Sorghum]] was domesticated in the [[Sahel]] region of Africa by 7,000 years ago. Cotton was domesticated in [[Peru]] by 5,600 years ago,<ref name="Broudy1979">{{cite book |last=Broudy |first=Eric |title=The Book of Looms: A History of the Handloom from Ancient Times to the Present |url={{google books|plainurl=y|id=shN5_-W1RzcC|page=81}} |year=1979 |publisher=UPNE |isbn=978-0-87451-649-4 |page=81 |url-status=live |archive-url=https://web.archive.org/web/20180210232500/{{google books|plainurl=y|id=shN5_-W1RzcC|page=81}} |archive-date=10 February 2018}}</ref> and was independently domesticated in Eurasia. [[Agriculture in Mesoamerica|In Mesoamerica]], wild [[teosinte]] was bred into maize by 6,000 years ago.<ref>Johannessen, S.; Hastorf, C. A. (eds.) ''Corn and Culture in the Prehistoric New World'', Westview Press, Boulder, Colorado.</ref>

[[File:Tomb of Nakht (2).jpg|thumb|left|upright|Agricultural scenes of [[threshing]], a grain store, harvesting with [[sickle]]s, digging, tree-cutting and ploughing from [[Ancient Egyptian agriculture|ancient Egypt]]. Tomb of [[Nakht]], 15th century BC]]

In Eurasia, the [[Sumer]]ians started to live in villages from about 8,000 BC, relying on the [[Tigris]] and [[Euphrates]] rivers and a canal system for irrigation. Ploughs appear in [[pictograph]]s around 3,000 BC; seed-ploughs around 2,300 BC. Farmers grew wheat, barley, vegetables such as lentils and onions, and fruits including dates, grapes, and figs.<ref name=BritMus>{{cite web |title=Farming |url=http://www.mesopotamia.co.uk/staff/resources/background/bg08/home.html |publisher=[[British Museum]] |access-date=15 June 2016 |url-status=dead |archive-url=https://web.archive.org/web/20160616222522/http://www.mesopotamia.co.uk/staff/resources/background/bg08/home.html |archive-date=16 June 2016 }}</ref> [[Ancient Egyptian agriculture]] relied on the [[Nile River]] and its seasonal flooding. Farming started in the predynastic period at the end of the [[Paleolithic]], after 10,000 BC. Staple food crops were grains such as wheat and barley, alongside industrial crops such as [[flax]] and [[papyrus]].<ref name=Janick>{{cite journal |author=Janick, Jules |title=Ancient Egyptian Agriculture and the Origins of Horticulture |journal=Acta Hort. |volume=583 |pages=23–39 |url=https://www.hort.purdue.edu/newcrop/Hort_306/text/lec06.pdf}}</ref><ref>{{cite book |author=Kees, Herman |title=Ancient Egypt: A Cultural Topography |url=https://archive.org/details/ancientegyptcult0000kees |url-access=registration |publisher=University of Chicago Press |date=1961 |isbn=9780226429144 }}</ref> In [[Agriculture in India|India]], wheat, barley and [[jujube]] were domesticated by 9,000 BC, soon followed by sheep and goats.<ref name=gupta>{{cite journal |author=Gupta, Anil K. |title=Origin of agriculture and domestication of plants and animals linked to early Holocene climate amelioration |url=http://repository.ias.ac.in/21961/1/333.pdf |journal=Current Science |volume=87 |issue=1 |year=2004 |page=59 |jstor=24107979}}</ref> Cattle, sheep and goats were domesticated in [[Mehrgarh]] culture by 8,000–6,000 BC.<ref name=Baber>Baber, Zaheer (1996). ''The Science of Empire: Scientific Knowledge, Civilization, and Colonial Rule in India''. State University of New York Press. 19. {{ISBN|0-7914-2919-9}}.</ref><ref name=harrisandgosden385>Harris, David R. and Gosden, C. (1996). ''The Origins and Spread of Agriculture and Pastoralism in Eurasia: Crops, Fields, Flocks And Herds''. Routledge. p. 385. {{ISBN|1-85728-538-7}}.</ref><ref name=Possehl>Possehl, Gregory L. (1996). ''Mehrgarh'' in ''Oxford Companion to Archaeology'', Ed. Brian Fagan. Oxford University Press.</ref> Cotton was cultivated by the 5th–4th millennium BC.<ref>Stein, Burton (1998). ''A History of India''. Blackwell Publishing. p. 47. {{ISBN|0-631-20546-2}}.</ref> Archeological evidence indicates an animal-drawn [[plough]] from 2,500 BC in the [[Indus Valley Civilisation]].<ref name=lal>{{Cite journal |title=Thematic evolution of ISTRO: transition in scientific issues and research focus from 1955 to 2000 |first=R. |last=Lal |journal=Soil and Tillage Research |volume=61 |issue=1–2 |date=2001 |pages=3–12 |doi=10.1016/S0167-1987(01)00184-2}}</ref>

In China, from the 5th century BC there was a nationwide [[granary]] system and widespread [[sericulture|silk farming]].<ref>[[#Needham|Needham]], Vol. 6, Part 2, pp. 55–57.</ref> Water-powered grain mills were in use by the 1st century BC,<ref>[[#Needham|Needham]], Vol. 4, Part 2, pp. 89, 110, 184.</ref> followed by irrigation.<ref>[[#Needham|Needham]], Vol. 4, Part 2, p. 110.</ref> By the late 2nd century, [[heavy plough]]s had been developed with iron ploughshares and [[mouldboard]]s.<ref name="greenberger 2006 11-12">Greenberger, Robert (2006) ''The Technology of Ancient China'', Rosen Publishing Group. pp. 11–12. {{ISBN|1404205586}}</ref><ref>[[Wang Zhongshu]], trans. by K. C. Chang and Collaborators, ''Han Civilization'' (New Haven and London: Yale University Press, 1982).</ref> These spread westwards across Eurasia.<ref>{{cite book |url={{google books|plainurl=y|id=SaJlbWK_-FcC|page=270}} |author=Glick, Thomas F. |page=270 |title=Medieval Science, Technology And Medicine: An Encyclopedia |publisher=Psychology Press |year=2005 |isbn=978-0-415-96930-7 |series=Volume 11 of The Routledge Encyclopedias of the Middle Ages Series}}</ref> Asian rice was domesticated 8,200–13,500 years ago – depending on the [[molecular clock]] estimate that is used<ref name="pnas1">{{Cite journal |last1=Molina |first1=J. |last2=Sikora |first2=M. |last3=Garud |first3=N. |last4=Flowers |first4=J. M. |last5=Rubinstein |first5=S. |last6=Reynolds |first6=A. |last7=Huang |first7=P. |last8=Jackson |first8=S. |last9=Schaal |first9=B. A. |last10=Bustamante |doi=10.1073/pnas.1104686108 |first10=C. D. |last11=Boyko |first11=A. R. |last12=Purugganan |first12=M. D. |title=Molecular evidence for a single evolutionary origin of domesticated rice |journal=Proceedings of the National Academy of Sciences |volume=108 |issue=20 |pages=8351–8356 |year=2011 |pmid=21536870|pmc=3101000|bibcode=2011PNAS..108.8351M }}</ref> – on the Pearl River in southern China with a single genetic origin from the wild rice ''[[Oryza rufipogon]]''.<ref name="nature1">{{cite journal |title=A map of rice genome variation reveals the origin of cultivated rice |journal=Nature |doi=10.1038/nature11532 |year=2012 |last1=Huang |first1=Xuehui |last2=Kurata |first2=Nori |last3=Wei |first3=Xinghua |last4=Wang |first4=Zi-Xuan |last5=Wang |first5=Ahong |last6=Zhao |first6=Qiang |last7=Zhao |first7=Yan|last8=Liu |first8=Kunyan |last9=Lu |first9=Hengyun |last10=Li |first10=Wenjun |last11=Gu |first11=Yunli |last12=Lu |first12=Yiqi |last13=Zhou |first13=Congcong|last14=Fan|first14=Danlin |last15=Weng |first15=Qijun |last16=Zhu |first16=Chuanrang |last17=Huang |first17=Tao |last18=Zhang |first18=Lei|last19=Wang |first19=Yongchun |last20=Feng |first20=Lei |last21=Furuumi |first21=Hiroyasu |last22=Kubo |first22=Takahiko |last23=Miyabayashi|first23=Toshie |last24=Yuan |first24=Xiaoping |last25=Xu |first25=Qun |last26=Dong |first26=Guojun |last27=Zhan |first27=Qilin |last28=Li |first28=Canyang |last29=Fujiyama |first29=Asao|last30=Toyoda |first30=Atsushi |volume=490 |issue=7421 |pages=497–501 |pmid=23034647 |pmc=7518720 |display-authors=8 |bibcode=2012Natur.490..497H |doi-access=free }}</ref> In [[Agriculture in ancient Greece|Greece<!--this is the only link to Agr of ancient Greece-->]] and [[Agriculture in ancient Rome|Rome<!--this is the only link to Agr of ancient Rome-->]], the major cereals were wheat, emmer, and barley, alongside vegetables including peas, beans, and olives. Sheep and goats were kept mainly for dairy products.<ref name="koester 1995 p76-77">Koester, Helmut (1995), ''History, Culture, and Religion of the Hellenistic Age'', 2nd edition, Walter de Gruyter, pp. 76–77. {{ISBN|3-11-014693-2}}</ref><ref name="White">White, K. D. (1970), ''Roman Farming''. Cornell University Press.</ref>

In the Americas, crops domesticated in Mesoamerica (apart from [[teosinte]]) include squash, beans, and [[Theobroma cacao|cacao]].<ref name=Murphy2011>{{cite book |author=Murphy, Denis |title=Plants, Biotechnology and Agriculture |url={{google books|plainurl=y|id=etQsieKuRH8C|page=153}} |year=2011 |publisher=CABI |isbn=978-1-84593-913-7 |page=153}}</ref> Cocoa was being domesticated by the Mayo Chinchipe of the upper Amazon around 3,000 BC.<ref>{{cite news |last1=Davis |first1=Nicola |title=Origin of chocolate shifts 1,400 miles and 1,500 years |url=https://www.theguardian.com/science/2018/oct/29/origin-of-chocolate-shifts-1400-miles-and-1500-years-cacao-ecuador |access-date=31 October 2018 |work=[[The Guardian]] |date=29 October 2018}}</ref>

The [[domestic turkey|turkey]] was probably domesticated in Mexico or the American Southwest.<ref name=Speller>{{cite journal |last1=Speller |first1=Camilla F. |author-link1=Camilla Speller |display-authors=etal |title=Ancient mitochondrial DNA analysis reveals complexity of indigenous North American turkey domestication|journal=PNAS |date=2010 |volume=107 |issue=7 |pages=2807–2812 |doi=10.1073/pnas.0909724107 |pmid=20133614 |pmc=2840336|bibcode=2010PNAS..107.2807S }}</ref> The [[Aztec]]s developed irrigation systems, formed [[Terrace (agriculture)|terraced]] hillsides, fertilized their soil, and developed [[chinampa]]s or artificial islands. The [[Maya civilization|Mayas]] used extensive canal and raised field systems to farm swampland from 400 BC.<ref>{{cite journal |url=http://www.nature.com/news/2010/101105/full/news.2010.587.html|title=Mayans converted wetlands to farmland |author=Mascarelli, Amanda |journal=Nature |date=5 November 2010 |doi=10.1038/news.2010.587}}</ref><ref>{{cite journal |title=Invisible Artifacts: Uncovering Secrets of Ancient Maya Agriculture with Modern Soil Science |journal=Soil Horizons |author=Morgan, John |date=6 November 2013 |doi=10.2136/sh2012-53-6-lf |volume=53 |issue=6 |page=3 |doi-access=free }}</ref><ref name="Spooner 2005 14694–99">{{cite journal |title=A single domestication for potato based on multilocus amplified fragment length polymorphism genotyping |last1=Spooner |first1=David M. |first2=Karen |last2=McLean |first3=Gavin |last3=Ramsay |first4=Robbie |last4=Waugh |first5=Glenn J. |last5=Bryan |journal=[[Proceedings of the National Academy of Sciences|PNAS]] |volume=102 |issue=41 |doi=10.1073/pnas.0507400102 |pmc=1253605 |pages=14694–14699 |pmid=16203994 |year=2005 |bibcode=2005PNAS..10214694S }}</ref><ref name="online">{{cite book |author=Office of International Affairs |title=Lost Crops of the Incas: Little-Known Plants of the Andes with Promise for Worldwide Cultivation |date=1989 |url=http://www.nap.edu/openbook.php?isbn=030904264X&page=92 |work=nap.edu |isbn=978-0-309-04264-2 |page=92|doi=10.17226/1398 }}</ref><ref name="John Michael Francis 2005">{{cite book |author=Francis, John Michael |title=Iberia and the Americas |publisher=[[ABC-CLIO]] |year=2005 |url={{google books|plainurl=y|id=OMNoS-g1h8cC|page=867}} |isbn=978-1-85109-426-4 }}</ref> [[Coca]] was domesticated in the Andes, as were the peanut, tomato, tobacco, and [[pineapple]].<ref name=Murphy2011 /> Cotton was domesticated in [[Peru]] by 3,600 BC.<ref name="Broudy1979 p81">{{cite book |last=Broudy |first=Eric |title=The Book of Looms: A History of the Handloom from Ancient Times to the Present|url={{google books|plainurl=y|id=shN5_-W1RzcC|page=81}} |year=1979 |publisher=UPNE |isbn=978-0-87451-649-4 |page=81}}</ref> Animals including [[llama]]s, [[alpaca]]s, and [[guinea pig]]s were domesticated there.<ref name="RischkowskyPilling2007">{{cite book |last1=Rischkowsky |first1=Barbara |last2=Pilling |first2=Dafydd |title=The State of the World's Animal Genetic Resources for Food and Agriculture |url={{google books|plainurl=y|id=Skpj197tU0oC|page=10 }}|year=2007 |publisher=Food & Agriculture Organization |isbn=978-92-5-105762-9 |page=10}}</ref> In [[History of agriculture in the United States|North America]], the indigenous people of the [[Eastern Agricultural Complex|East domesticated crops]] such as [[sunflower]], tobacco,<ref>{{cite journal |last1=Heiser Jr |first1=Carl B. |year=1992 |title=On possible sources of the tobacco of prehistoric Eastern North America |journal=Current Anthropology |volume=33 |pages=54–56 |doi=10.1086/204032|s2cid=144433864 }}</ref> squash and ''[[Chenopodium]]''.<ref>{{cite book|author=Ford, Richard I. |page=75|title=Prehistoric Food Production in North América|url=https://books.google.com/books?id=eeuzAAAAIAAJ|year=1985|publisher=University of Michigan, Museum of Anthropology, Publications Department|isbn=978-0-915703-01-2}}</ref><ref>Adair, Mary J. (1988) ''Prehistoric Agriculture in the Central Plains.'' Publications in Anthropology 16. University of Kansas, Lawrence.</ref> Wild foods including [[wild rice]] and [[maple sugar]] were harvested.<ref name="Smith2013">{{cite book |last=Smith |first=Andrew |title=The Oxford Encyclopedia of Food and Drink in America |url={{google books|plainurl=y|id=DOJMAgAAQBAJ|page=1}} |year=2013 |publisher=OUP USA |isbn=978-0-19-973496-2 |page=1}}</ref> The domesticated [[strawberry]] is a hybrid of a Chilean and a North American species, developed by breeding in Europe and North America.<ref>{{cite document |last1=Hardigan |first1=Michael A. |title=P0653: Domestication History of Strawberry: Population Bottlenecks and Restructuring of Genetic Diversity through Time |url=https://pag.confex.com/pag/xxvi/meetingapp.cgi/Paper/28409 |publisher=Pland & Animal Genome Conference XXVI 13–17 January 2018 San Diego, California |access-date=28 February 2018}}</ref> The [[Agriculture in the prehistoric Southwest|indigenous people of the Southwest]] and the [[Pacific Northwest]] practiced [[forest gardening]] and [[fire-stick farming]]. The [[Native American use of fire|natives controlled fire]] on a regional scale to create a low-intensity [[fire ecology]] that [[Sustainable agriculture|sustained a low-density agriculture]] in loose rotation; a sort of "wild" [[permaculture]].<ref>{{cite book |title=Fire in California's Ecosystems |url=https://archive.org/details/firecaliforniase00sugi |url-access=limited |editor1=Sugihara, Neil G. |editor2=Van Wagtendonk, Jan W. |editor3=Shaffer, Kevin E. |editor4=Fites-Kaufman, Joann |editor5=Thode, Andrea E. |publisher=University of California Press |year=2006 |page=[https://archive.org/details/firecaliforniase00sugi/page/n433 417] |chapter=17 |isbn=978-0-520-24605-8}}</ref><ref>{{cite book |editor=Blackburn, Thomas C. |editor2=Anderson, Kat |year=1993 |title=Before the Wilderness: Environmental Management by Native Californians |publisher=Ballena Press |isbn=978-0-87919-126-9}}</ref><ref name=Cunningham2010>{{cite book |url={{google books|plainurl=y|id=nuYuYGHwCygC|page=135 }}|pages=135, 173–202 |last=Cunningham |first=Laura |title=State of Change: Forgotten Landscapes of California |publisher=Heyday |year=2010 |isbn=978-1-59714-136-9}}</ref><ref>{{cite book |last=Anderson |first=M. Kat |title=Tending the Wild: Native American Knowledge And the Management of California's Natural Resources |url=https://archive.org/details/tendingwildnativ0000ande |url-access=registration |publisher=University of California Press |year=2006 |isbn=978-0-520-24851-9}}</ref> A system of [[companion planting]] called [[Three Sisters (agriculture)|the Three Sisters]] was developed in North America. The three crops were [[winter squash]], maize, and climbing beans.<ref name="wilson">{{cite book |title=Agriculture of the Hidatsa Indians: An Indian Interpretation |last=Wilson |first=Gilbert |year=1917 |publisher=Dodo Press |isbn=978-1-4099-4233-7 |pages=25 and passim |url=http://www.bookdepository.com/publishers/Dodo-Press |ref=wilson1917 |url-status=dead |archive-url=https://web.archive.org/web/20160314055513/http://www.bookdepository.com/publishers/Dodo-Press |archive-date=14 March 2016 }}</ref><ref name="landon">{{cite journal |last=Landon |first=Amanda J. |title=The "How" of the Three Sisters: The Origins of Agriculture in Mesoamerica and the Human Niche |journal=Nebraska Anthropologist |year=2008 |url=http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1039&context=nebanthro |pages=110–124}}</ref>

[[Indigenous Australians]], long supposed to have been nomadic [[hunter-gatherers]], practised systematic burning, possibly to enhance natural productivity in fire-stick farming.<ref>{{cite journal |last=Jones |first=R. |doi=10.1007/BF03400623 |title=Fire-stick Farming|journal=Fire Ecology |volume=8 |issue=3 |pages=3–8 |year=2012 |doi-access=free }}</ref> The [[Gunditjmara]] and other groups developed eel farming and fish trapping systems from some 5,000 years ago.<ref>{{cite journal |last=Williams |first=Elizabeth |year=1988 |title=Complex Hunter-Gatherers: A Late Holocene Example from Temperate Australia |journal=Archaeopress Archaeology |volume=423}}</ref> There is evidence of 'intensification' across the whole continent over that period.<ref>{{cite book |last=Lourandos |first=Harry |year=1997 |title=Continent of Hunter-Gatherers: New Perspectives in Australian Prehistory |publisher=Cambridge University Press}}</ref> In two regions of Australia, the central west coast and eastern central, early farmers cultivated yams, native millet, and bush onions, possibly in permanent settlements.<ref>{{cite book |last=Gammage |first=Bill |author-link=Bill Gammage |date=October 2011 |title=The Biggest Estate on Earth: How Aborigines made Australia |url={{google books |plainurl=y |id=aUddY9fGkNMC}} |publisher=Allen & Unwin |isbn=978-1-74237-748-3 |pages=281–304}}</ref><ref name=b1 />

[[File:Islamic Spain agricultural scene.jpg|thumb|upright=0.9|The [[Arab Agricultural Revolution]], starting in [[Al-Andalus]] (Islamic Spain), transformed agriculture with improved techniques and the diffusion of crop plants.<ref name=Watson />]]

In the Middle Ages, both [[Arab Agricultural Revolution|in the Islamic world]] and in Europe, agriculture transformed with improved techniques and the diffusion of crop plants, including the introduction of sugar, rice, cotton and fruit trees (such as the orange) to Europe by way of [[Al-Andalus]].<ref name=Watson>{{cite journal |first=Andrew M. |last=Watson |date=1974 |title=The Arab Agricultural Revolution and Its Diffusion, 700–1100 |journal=The Journal of Economic History |volume=34 |issue=1 |pages=8–35 |doi=10.1017/s0022050700079602}}</ref><ref name=NatGeographic2015>{{cite book |author=National Geographic |title=Food Journeys of a Lifetime |url={{google books|plainurl=y|id=h2Q5BgAAQBAJ|page=126}} |year=2015 |publisher=[[National Geographic Society]] |isbn=978-1-4262-1609-1 |page=126}}</ref> After 1492 the [[Columbian exchange]] brought New World crops such as maize, potatoes, tomatoes, [[sweet potato]]es and [[manioc]] to Europe, and Old World crops such as wheat, barley, rice and [[turnip]]s, and livestock (including horses, cattle, sheep and goats) to the Americas.<ref>{{cite web |url=http://www.gilderlehrman.org/history-by-era/american-indians/essays/columbian-exchange |title=The Columbian Exchange |publisher=The Gilder Lehrman Institute of American History |author=Crosby, Alfred |access-date=11 May 2013 |url-status=live |archive-url=https://web.archive.org/web/20130703092537/http://www.gilderlehrman.org/history-by-era/american-indians/essays/columbian-exchange |archive-date=3 July 2013}}</ref>

[[Pastoralism]] involves managing domesticated animals. In [[nomadic pastoralism]], herds of livestock are moved from place to place in search of pasture, fodder, and water. This type of farming is practised in arid and semi-arid regions of [[Sahara]], Central Asia and some parts of India.<ref>{{cite book |last=Blench |first=Roger |title=Pastoralists in the new millennium |publisher=FAO |date=2001 |pages=11–12 |url=http://www.odi.org.uk/work/projects/pdn/eps.pdf |url-status=live |archive-url=https://web.archive.org/web/20120201000745/http://www.odi.org.uk/work/projects/pdn/eps.pdf |archive-date=1 February 2012 |df=dmy-all }}</ref>

From the twentieth century, intensive agriculture increased productivity. It substituted synthetic fertilizers and pesticides for labour, but caused increased water pollution, and often involved farm subsidies. In recent years there has been a backlash against the [[environmental awareness|environmental effects]] of conventional agriculture, resulting in the [[organic farming|organic]], [[Regenerative agriculture|regenerative]], and [[sustainable agriculture]] movements.<ref name="motherjones1" /><ref>{{cite web |publisher=The World Bank |year=1995 |url=http://econ.worldbank.org/external/default/main?pagePK=64165259&theSitePK=469372&piPK=64165421&menuPK=64166093&entityID=000009265_3970311122936 |title=Overcoming agricultural pollution of water: the challenge of integrating agricultural and environmental policies in the European Union, Volume 1 |access-date=15 April 2013 |author=Scheierling, Susanne M. |url-status=dead |archive-url=https://web.archive.org/web/20130605112426/http://econ.worldbank.org/external/default/main?pagePK=64165259&theSitePK=469372&piPK=64165421&menuPK=64166093&entityID=000009265_3970311122936 |archive-date=5 June 2013}}</ref> One of the major forces behind this movement has been the [[European Union]], which first certified [[organic food]] in 1991 and began reform of its [[Common Agricultural Policy]] (CAP) in 2005 to phase out commodity-linked farm subsidies,<ref>{{cite web |publisher=European Commission |year=2003 |url=http://ec.europa.eu/agriculture/capreform/index_en.htm |title=CAP Reform |access-date=15 April 2013 |url-status=live |archive-url=https://web.archive.org/web/20101017124251/http://ec.europa.eu/agriculture/capreform/index_en.htm |archive-date=17 October 2010}}</ref> also known as [[Decoupling and re-coupling|decoupling]]. The growth of organic farming has renewed research in alternative technologies such as [[integrated pest management]], selective breeding,<ref>{{Cite book |last1=Poincelot |first1=Raymond P. |title=Toward a More Sustainable Agriculture |chapter=Organic Farming |journal=Towards a More Sustainable Agriculture |pages=14–32 |doi=10.1007/978-1-4684-1506-3_2 |year=1986 |isbn=978-1-4684-1508-7 }}</ref> and [[controlled-environment agriculture]].<ref name=":1">{{Cite news |url=http://www.agweek.com/business/agriculture/4527042-cutting-edge-technology-will-change-farming |title=The cutting-edge technology that will change farming |work=Agweek |date=9 November 2018 |access-date=23 November 2018 |archive-url=https://web.archive.org/web/20181117020138/http://www.agweek.com/business/agriculture/4527042-cutting-edge-technology-will-change-farming |archive-date=23 November 2018}}</ref><ref>{{Cite news |author=Charles, Dan |url=https://www.npr.org/sections/thesalt/2017/11/02/561462293/hydroponic-veggies-are-taking-over-organic-and-a-move-to-ban-them-fails |title=Hydroponic Veggies Are Taking Over Organic, And A Move To Ban Them Fails |work=[[NPR]] |date=3 November 2017 |access-date=24 November 2018}}</ref> Recent mainstream technological developments include [[genetically modified food]].<ref>[http://www.bis.gov.uk/files/file15655.pdf GM Science Review First Report] {{webarchive |url=https://web.archive.org/web/20131016100707/http://www.bis.gov.uk/files/file15655.pdf |date=16 October 2013 }}, Prepared by the UK GM Science Review panel (July 2003). Chairman David King, p. 9</ref> Demand for non-food biofuel crops,<ref>{{cite journal |author1=Smith, Kate |author2=Edwards, Rob |date=8 March 2008 |url=http://www.heraldscotland.com/2008-the-year-of-global-food-crisis-1.828546 |title=2008: The year of global food crisis |journal=The Herald |url-status=live |archive-url=https://web.archive.org/web/20130411220739/http://www.heraldscotland.com/2008-the-year-of-global-food-crisis-1.828546 |archive-date=11 April 2013}}</ref> development of former farm lands, rising transportation costs, [[Climate change and agriculture|climate change]], growing consumer demand in China and India, and [[population growth]],<ref>{{cite journal |url=http://www.csmonitor.com/2008/0118/p08s01-comv.html |title=The global grain bubble |journal=The Christian Science Monitor |date=18 January 2008 |access-date=26 September 2013 |url-status=live |archive-url=https://web.archive.org/web/20091130063759/http://www.csmonitor.com/2008/0118/p08s01-comv.html |archive-date=30 November 2009}}</ref> are threatening [[food security]] in many parts of the world.<ref>{{cite news |url=http://news.bbc.co.uk/1/hi/world/7284196.stm |title=The cost of food: Facts and figures |publisher=BBC |date=16 October 2008 |access-date=26 September 2013 |url-status=live |archive-url=https://web.archive.org/web/20090120025945/http://news.bbc.co.uk/1/hi/world/7284196.stm |archive-date=20 January 2009}}</ref><ref>{{cite journal |author=Walt, Vivienne |date=27 February 2008 |url=http://www.time.com/time/world/article/0,8599,1717572,00.html |title=The World's Growing Food-Price Crisis |journal=Time |url-status=dead |archive-url=https://web.archive.org/web/20111129211855/http://www.time.com/time/world/article/0,8599,1717572,00.html |archive-date=29 November 2011 }}</ref><ref name="guardian.co.uk">Watts, Jonathan (4 December 2007). [https://www.theguardian.com/world/2007/dec/04/china.business "Riots and hunger feared as demand for grain sends food costs soaring"] {{webarchive|url=https://web.archive.org/web/20130901074034/http://www.theguardian.com/world/2007/dec/04/china.business |date=1 September 2013 }}, ''The Guardian'' (London).</ref><ref name="timesonline.co.uk">Mortished, Carl (7 March 2008).[http://www.timesonline.co.uk/tol/news/environment/article3500975.ece "Already we have riots, hoarding, panic: the sign of things to come?"] {{webarchive|url=https://web.archive.org/web/20110814134028/http://www.timesonline.co.uk/tol/news/environment/article3500975.ece |date=14 August 2011}}, ''The Times'' (London).</ref><ref name="ReferenceA">Borger, Julian (26 February 2008). [https://www.theguardian.com/environment/2008/feb/26/food.unitednations "Feed the world? We are fighting a losing battle, UN admits"] {{webarchive|url=https://web.archive.org/web/20161225150554/https://www.theguardian.com/environment/2008/feb/26/food.unitednations |date=25 December 2016}}, ''The Guardian'' (London).</ref> The [[International Fund for Agricultural Development]] posits that an increase in [[smallholding|smallholder agriculture]] may be part of the solution to concerns about [[food prices]] and overall food security, given the favorable experience of Vietnam.<ref>{{cite web |url=http://www.ifad.org/operations/food/farmer.htm |title=Food prices: smallholder farmers can be part of the solution |publisher=International Fund for Agricultural Development |access-date=24 April 2013 |url-status=dead |archive-url=https://web.archive.org/web/20130505224355/http://www.ifad.org/operations/food/farmer.htm |archive-date=5 May 2013 }}</ref> [[soil retrogression and degradation|Soil degradation]] and diseases such as [[stem rust]] are major concerns globally;<ref>{{cite web |url=http://www.fao.org/agriculture/crops/rust/stem/rust-report/stem-ug99racettksk/en/ |title=Wheat Stem Rust – UG99 (Race TTKSK)|publisher=FAO|access-date=6 January 2014|url-status=live|archive-url=https://web.archive.org/web/20140107064545/http://www.fao.org/agriculture/crops/rust/stem/rust-report/stem-ug99racettksk/en/|archive-date=7 January 2014}}</ref> approximately 40% of the world's agricultural land is seriously degraded.<ref>Sample, Ian (31 August 2007). [https://www.theguardian.com/environment/2007/aug/31/climatechange.food "Global food crisis looms as climate change and population growth strip fertile land"] {{webarchive |url=https://web.archive.org/web/20160429094959/https://www.theguardian.com/environment/2007/aug/31/climatechange.food |date=29 April 2016}}, ''The Guardian'' (London).</ref><ref>{{cite news |url=http://news.mongabay.com/2006/1214-unu.html |title=Africa may be able to feed only 25% of its population by 2025 |archive-url=https://web.archive.org/web/20111127175559/http://news.mongabay.com/2006/1214-unu.html |archive-date=27 November 2011 |work=[[Mongabay]] |date=14 December 2006 |access-date=15 July 2016 |url-status=dead }}</ref> By 2015, the agricultural output of China was the largest in the world, followed by the European Union, India and the United States.<ref name=UNCTAD2017 /> Economists measure the [[total factor productivity]] of agriculture and by this measure agriculture in the United States is roughly 1.7 times more productive than it was in 1948.<ref>{{cite web |publisher=USDA Economic Research Service |url=http://www.ers.usda.gov/data/agproductivity/ |title=Agricultural Productivity in the United States |date=5 July 2012 |access-date=22 April 2013 |url-status=dead |archive-url=https://web.archive.org/web/20130201021133/http://www.ers.usda.gov/Data/AgProductivity/ |archive-date=1 February 2013 }}</ref>

Agriculture, specifically farming, remains a hazardous industry, and farmers worldwide remain at high risk of work-related injuries, lung disease, [[noise-induced hearing loss]], skin diseases, as well as certain cancers related to chemical use and prolonged sun exposure. On [[industrial agriculture|industrialized farms]], injuries frequently involve the use of [[agricultural machinery]], and a common cause of fatal agricultural injuries in developed countries is [[Rollover protection structure|tractor rollovers]].<ref name="aginjury">{{cite web |url=https://wwwa.cdc.gov/niosh/topics/aginjury/ |title=NIOSH Workplace Safety & Health Topic: Agricultural Injuries |publisher=Centers for Disease Control and Prevention |access-date=16 April 2013 |url-status=live |archive-url=https://web.archive.org/web/20071028181205/http://www.cdc.gov/niosh/topics/aginjury/ |archive-date=28 October 2007}}</ref> Pesticides and other chemicals used in farming can be [[Health effects of pesticides|hazardous to worker health]], and workers exposed to pesticides may experience illness or have children with birth defects.<ref name=NIOSH_pest>{{Cite journal |url=https://www.cdc.gov/niosh/docs/2012-108/ |title=NIOSH Pesticide Poisoning Monitoring Program Protects Farmworkers |publisher=Centers for Disease Control and Prevention |access-date=15 April 2013 |url-status=live |archive-url=https://web.archive.org/web/20130402004253/http://www.cdc.gov/niosh/docs/2012%2D108/ |archive-date=2 April 2013|doi=10.26616/NIOSHPUB2012108 |year=2011 |doi-access=free }}</ref> As an industry in which families commonly share in work and live on the farm itself, entire families can be at risk for injuries, illness, and death.<ref name="NIOSH Agri">{{cite web |url=https://www.cdc.gov/niosh/topics/agriculture/ |title=NIOSH Workplace Safety & Health Topic: Agriculture |publisher=Centers for Disease Control and Prevention |access-date=16 April 2013 |url-status=live |archive-url=https://web.archive.org/web/20071009224012/http://www.cdc.gov/niosh/topics/agriculture/ |archive-date=9 October 2007 }}</ref> Ages 0–6 May be an especially vulnerable population in agriculture;<ref name=WeicheltGorucu2018>{{Cite journal |last1=Weichelt |first1=Bryan |last2=Gorucu |first2=Serap |date=17 February 2018 |title=Supplemental surveillance: a review of 2015 and 2016 agricultural injury data from news reports on AgInjuryNews.org |url=http://injuryprevention.bmj.com/content/early/2018/02/16/injuryprev-2017-042671 |journal=Injury Prevention |volume=25 |issue=3 |pages=injuryprev–2017–042671 |doi=10.1136/injuryprev-2017-042671 |pmid=29386372|s2cid=3371442 }}</ref> common causes of fatal injuries among young farm workers include drowning, machinery and motor accidents, including with all-terrain vehicles.<ref name="NIOSH Agri" /><ref name=WeicheltGorucu2018 /><ref>{{Cite journal |author=The PLOS ONE staff |date=6 September 2018 |title=Correction: Towards a deeper understanding of parenting on farms: A qualitative study |journal=PLOS ONE |volume=13 |issue=9 |pages=e0203842 |doi=10.1371/journal.pone.0203842 |issn=1932-6203 |pmc=6126865 |pmid=30188948 |bibcode=2018PLoSO..1303842. }}</ref>

In [[subtropics|subtropical]] and [[arid]] environments, the timing and extent of agriculture may be limited by rainfall, either not allowing multiple annual crops in a year, or requiring irrigation. In all of these environments perennial crops are grown (coffee, chocolate) and systems are practiced such as agroforestry. In [[Temperateness|temperate]] environments, where ecosystems were predominantly [[grassland]] or [[prairie]], highly productive annual farming is the dominant agricultural system.<ref name="CS" />

Livestock production systems can be defined based on feed source, as grassland-based, mixed, and landless.<ref name="FAO lps">{{cite web |author1=Sere, C. |author2=Steinfeld, H. |author3=Groeneweld, J. |year=1995 |url=http://www.fao.org/WAIRDOCS/LEAD/X6101E/x6101e00.htm#Contents|title=Description of Systems in World Livestock Systems – Current status issues and trends |publisher=U.N. Food and Agriculture Organization |access-date=8 September 2013 |url-status=live |archive-url=https://web.archive.org/web/20121026004040/http://www.fao.org/WAIRDOCS/LEAD/X6101E/X6101E00.HTM#Contents |archive-date=26 October 2012 }}</ref> {{as of|2010}}, 30% of Earth's ice- and water-free area was used for producing livestock, with the sector employing approximately 1.3&nbsp;billion people. Between the 1960s and the 2000s, there was a significant increase in livestock production, both by numbers and by carcass weight, especially among beef, pigs and chickens, the latter of which had production increased by almost a factor of 10. Non-meat animals, such as milk cows and egg-producing chickens, also showed significant production increases. Global cattle, sheep and goat populations are expected to continue to increase sharply through 2050.<ref name=LP>{{cite journal |title=Livestock production: recent trends, future prospects |author=Thornton, Philip K. |doi=10.1098/rstb.2010.0134 |pmid=20713389 |journal=Philosophical Transactions of the Royal Society B |date=27 September 2010 |volume=365 |issue=1554 |pages=2853–2867 |doi-access=free |pmc=2935116 }}</ref> [[Aquaculture]] or fish farming, the production of fish for human consumption in confined operations, is one of the fastest growing sectors of food production, growing at an average of 9% a year between 1975 and 2007.<ref>{{cite journal |url=http://content.time.com/time/health/article/0,8599,1663604,00.html |title=Fish Farming's Growing Dangers |journal=Time |author=Stier, Ken |date=19 September 2007|url-status=live |archive-url=https://web.archive.org/web/20130907071708/http://content.time.com/time/health/article/0,8599,1663604,00.html |archive-date=7 September 2013 }}</ref>

[[Nutrient management]] includes both the source of nutrient inputs for crop and livestock production, and the method of use of manure produced by livestock. Nutrient inputs can be chemical inorganic fertilizers, manure, [[green manure]], compost and minerals.<ref name="PCP Soil">"Soil and Land", pp. 165–210 in [[#Acquaah|Acquaah]]</ref> Crop nutrient use may also be managed using cultural techniques such as crop rotation or a [[fallow]] period. Manure is used either by holding livestock where the feed crop is growing, such as in managed intensive rotational grazing, or [[Manure spreader|by spreading]] either dry or liquid formulations of manure on cropland or [[pasture]]s.<ref name="CS nutrient">"Nutrition from the Soil", pp. 187–218 in [[#Chrispeels|Chrispeels]]</ref><ref name="Soil nutrient">Brady, N. C.; Weil, R. R. (2002). "Practical Nutrient Management" pp. 472–515 in ''Elements of the Nature and Properties of Soils''. Pearson Prentice Hall, Upper Saddle River, NJ. {{ISBN|978-0135051955}}</ref>

Domestication of plants has, over the centuries increased yield, improved disease resistance and [[drought tolerance]], eased harvest and improved the taste and nutritional value of crop plants. Careful selection and breeding have had enormous effects on the characteristics of crop plants. Plant selection and breeding in the 1920s and 1930s improved pasture (grasses and clover) in New Zealand. Extensive X-ray and ultraviolet induced mutagenesis efforts (i.e. primitive genetic engineering) during the 1950s produced the modern commercial varieties of grains such as wheat, corn (maize) and barley.<ref>{{cite journal|last=Stadler |first=L. J. |author-link=Lewis Stadler |author2=Sprague, G.F. |title=Genetic Effects of Ultra-Violet Radiation in Maize: I. Unfiltered Radiation |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=22 |issue=10 |pages=572–578 |date=15 October 1936 |url=http://www.pnas.org/cgi/reprint/22/10/579.pdf |doi=10.1073/pnas.22.10.572 |access-date=11 October 2007 |pmid=16588111 |pmc=1076819 |archive-url=https://web.archive.org/web/20071024233407/http://www.pnas.org/cgi/reprint/22/10/579.pdf |archive-date=24 October 2007 |url-status=live |bibcode=1936PNAS...22..572S }}</ref><ref>{{cite book |last=Berg |first=Paul |author2=Singer, Maxine |title=George Beadle: An Uncommon Farmer. The Emergence of Genetics in the 20th century |url=https://archive.org/details/georgebeadleunco0000berg |url-access=registration |publisher=Cold Springs Harbor Laboratory Press |date=15 August 2003 |isbn=978-0-87969-688-7 }}</ref>

 

Agriculture is both a cause of and sensitive to [[environmental degradation]], such as [[biodiversity loss]], [[desertification]], [[soil degradation]] and [[Climate change and agriculture|global warming]], which cause decrease in crop yield.<ref>{{cite web |title=Making Peace with Nature: A scientific blueprint to tackle the climate, biodiversity and pollution emergencies |year=2021 |publisher=United Nations Environment Programme |url=https://www.unep.org/resources/making-peace-nature |access-date=9 June 2021}}</ref> Agriculture is one of the most important drivers of environmental pressures, particularly habitat change, climate change, water use and toxic emissions. Agriculture is the main source of toxins released into the environment, including insecticides, especially those used on cotton.<ref>{{cite web |url=http://www.unep.org/resourcepanel/Publications/PriorityProducts/tabid/56053/Default.aspx |title=Priority products and materials: assessing the environmental impacts of consumption and production |author=International Resource Panel |publisher=United Nations Environment Programme |year=2010 |access-date=7 May 2013 |url-status=dead |archive-url=https://web.archive.org/web/20121224061455/http://www.unep.org/resourcepanel/Publications/PriorityProducts/tabid/56053/Default.aspx |archive-date=24 December 2012 }}</ref> The 2011 UNEP Green Economy report stated that agricultural operations produced some 13 per cent of anthropogenic global greenhouse gas emissions. This includes gases from the use of inorganic fertilizers, agro-chemical pesticides, and herbicides, as well as fossil fuel-energy inputs.<ref name="unep.org">{{cite web |title=Towards a Green Economy: Pathways to Sustainable Development and Poverty Eradication |publisher=UNEP |year=2011 |url=https://www.unenvironment.org/search/node?keys=Towards+a+Green+Economy%3A+Pathways+to+Sustainable+Development+and+Poverty+Eradication |access-date=9 June 2021}}</ref>  

A senior UN official, Henning Steinfeld, said that "Livestock are one of the most significant contributors to today's most serious environmental problems".<ref>{{cite web |url=http://www.fao.org/newsroom/en/news/2006/1000448/index.html |title=Livestock a major threat to environment |publisher=UN Food and Agriculture Organization |date=29 November 2006 |access-date=24 April 2013 |archive-url=https://web.archive.org/web/20080328062709/http://www.fao.org/newsroom/en/news/2006/1000448/index.html |archive-date=28 March 2008 |url-status=live}}</ref> Livestock production occupies 70% of all land used for agriculture, or 30% of the land surface of the planet. It is one of the largest sources of [[greenhouse gas]]es, responsible for 18% of the world's [[greenhouse gas emissions]] as measured in CO₂ equivalents. By comparison, all transportation emits 13.5% of the CO₂. It produces 65% of human-related [[nitrous oxide]] (which has 296 times the global warming potential of CO_2,) and 37% of all human-induced [[methane]] (which is 23 times as warming as CO₂.) It also generates 64% of the [[ammonia]] emission. Livestock expansion is cited as a key factor driving [[deforestation]]; in the Amazon basin 70% of [[Deforestation of the Amazon Rainforest|previously forested area]] is now occupied by pastures and the remainder used for feedcrops.<ref name="LEAD">{{cite web |archive-url=https://web.archive.org/web/20080625012113/http://www.virtualcentre.org/en/library/key_pub/longshad/A0701E00.pdf |archive-date=25 June 2008 |last1=Steinfeld |first1=H. |last2=Gerber |first2=P. |last3=Wassenaar |first3=T. |last4=Castel |first4=V. |last5=Rosales |first5=M. |last6=de Haan |first6=C. |year=2006 |publisher=U.N. Food and Agriculture Organization |location=Rome |url=http://www.virtualcentre.org/en/library/key_pub/longshad/A0701E00.pdf |title=Livestock's Long Shadow – Environmental issues and options |access-date=5 December 2008}}</ref> Through deforestation and [[land degradation]], livestock is also driving reductions in biodiversity. Furthermore, the UNEP states that "[[methane emissions]] from global livestock are projected to increase by 60 per cent by 2030 under current practices and consumption patterns."<ref name="unep.org" />

Agriculture accounts for 70 percent of withdrawals of freshwater resources.<ref>{{cite web |editor=Molden, D. |url=http://www.iwmi.cgiar.org/About_IWMI/Strategic_Documents/Annual_Reports/2006_2007/pdf/IWMI%20Annual%20Report%202006-07.pdf |title=Findings of the Comprehensive Assessment of Water Management in Agriculture |website=Annual Report 2006/2007 |publisher=International Water Management Institute |access-date=6 January 2014 |url-status=live |archive-url=https://web.archive.org/web/20140107031305/http://www.iwmi.cgiar.org/About_IWMI/Strategic_Documents/Annual_Reports/2006_2007/pdf/IWMI%20Annual%20Report%202006-07.pdf |archive-date=7 January 2014}}</ref><ref>{{Cite web|title=On Water|url=https://www.eib.org/en/publications/eib-big-ideas-on-water|access-date=7 December 2020|website=European Investment Bank|language=en}}</ref> Agriculture is a major draw on water from [[aquifer]]s, and currently draws from those underground water sources at an unsustainable rate. It is long known that aquifers in areas as diverse as northern China, the [[Ganges|Upper Ganges]] and the western US are being depleted, and new research extends these problems to aquifers in Iran, Mexico and Saudi Arabia.<ref>{{cite web |url=http://green.blogs.nytimes.com/2012/08/13/stressed-aquifers-around-the-globe/|title=Stressed Aquifers Around the Globe |author=Li, Sophia |date=13 August 2012 |access-date=7 May 2013 |website=[[The New York Times]] |url-status=live |archive-url=https://web.archive.org/web/20130402141530/http://green.blogs.nytimes.com/2012/08/13/stressed-aquifers-around-the-globe/ |archive-date=2 April 2013 }}</ref> Increasing pressure is being placed on water resources by industry and urban areas, meaning that [[water scarcity]] is increasing and agriculture is facing the challenge of producing more food for the world's growing population with reduced water resources.<ref>{{cite web |url=http://www.fao.org/ag/magazine/0511sp2.htm |title=Water Use in Agriculture |date=November 2005 |publisher=FAO |access-date=7 May 2013 |url-status=dead |archive-url=https://archive.today/20130615091527/http://www.fao.org/ag/magazine/0511sp2.htm |archive-date=15 June 2013 }}</ref> [[Farm water|Agricultural water]] usage can also cause major environmental problems, including the destruction of natural wetlands, the spread of water-borne diseases, and land degradation through salinization and waterlogging, when irrigation is performed incorrectly.<ref>{{cite web|url=http://www.fao.org/ag/magazine/0303sp1.htm |title=Water Management: Towards 2030 |date=March 2003 |publisher=[[Food and Agriculture Organization]] |access-date=7 May 2013 |url-status=dead |archive-url=https://web.archive.org/web/20130510184315/http://www.fao.org/ag/magazine/0303sp1.htm |archive-date=10 May 2013 }}</ref>

An alternative argument is that the way to "save the environment" and prevent famine is by using pesticides and intensive high yield farming, a view exemplified by a quote heading the Center for Global Food Issues website: 'Growing more per acre leaves more land for nature'.<ref name="DAvery">{{cite book |author=Avery, D.T. |year=2000 |title=Saving the Planet with Pesticides and Plastic: The Environmental Triumph of High-Yield Farming |url=https://archive.org/details/savingplanetwith00aver |url-access=registration |publisher=Hudson Institute |location=Indianapolis}}</ref><ref>{{cite web |publisher=Center for Global Food Issues |url=http://www.cgfi.org |title=Center for Global Food Issues |access-date=14 July 2016 |url-status=dead |archive-url=https://web.archive.org/web/20160221143850/http://www.cgfi.org/ |archive-date=21 February 2016}}</ref> However, critics argue that a trade-off between the environment and a need for food is not inevitable,<ref name="WH">Lappe, F. M.; Collins, J.; Rosset, P. (1998). [http://oregonstate.edu/instruct/bi430-fs430/Documents-2004/10B-DEVEL%20WORLD/World%20Hunger--Twelve%20Myths.pdf "Myth 4: Food vs. Our Environment"], pp. 42–57 in ''World Hunger, Twelve Myths'', Grove Press, New York. {{ISBN|9780802135919}}</ref> and that pesticides simply replace [[good agricultural practices|good agronomic practices]] such as crop rotation.<ref name="CS Pest" /> The [[Push–pull agricultural pest management]] technique involves intercropping, using plant aromas to repel pests from crops (push) and to lure them to a place from which they can then be removed (pull).<ref name=PushPull>{{Cite journal|author1=Cook, Samantha M. |author2=Khan, Zeyaur R. |author3=Pickett, John A. |year=2007 |title=The use of push-pull strategies in integrated pest management |journal=Annual Review of Entomology |volume=52|pages=375–400 |doi=10.1146/annurev.ento.52.110405.091407 |pmid=16968206}}</ref>

 

[[Climate change]] and agriculture are interrelated on a global scale. Global warming affects agriculture through changes in [[instrumental temperature record|average temperatures]], rainfall, and [[extreme weather|weather extremes]] (like storms and heat waves); changes in pests and diseases; changes in atmospheric [[carbon dioxide]] and ground-level [[ozone]] concentrations; changes in the nutritional quality of some foods;<ref name=science-news>{{cite news |first=Susan |last=Milius |url=https://www.sciencenews.org/article/nutrition-climate-change-top-science-stories-2017-yir|title=Worries grow that climate change will quietly steal nutrients from major food crops|date=13 December 2017|work=[[Science News]]|access-date=21 January 2018}}</ref> and changes in [[current sea level rise|sea level]].<ref>Hoffmann, U., Section B: Agriculture – a key driver and a major victim of global warming, in: Lead Article, in: Chapter 1, in {{cite book |editor=Hoffmann, U. |title=Trade and Environment Review 2013: Wake up before it is too late: Make agriculture truly sustainable now for food security in a changing climate |url=http://unctad.org/en/pages/PublicationWebflyer.aspx?publicationid=666 |publisher=United Nations Conference on Trade and Development (UNCTAD) |location=Geneva, Switzerland |year=2013 |archive-url=https://web.archive.org/web/20141128140551/http://unctad.org/en/pages/PublicationWebflyer.aspx?publicationid=666 |archive-date=28 November 2014  |pages=3, 5}}</ref> Global warming is already affecting agriculture, with effects unevenly distributed across the world.<ref name="porter summary">Porter, J. R., ''et al''., Executive summary, in: [http://ipcc-wg2.gov/AR5/images/uploads/WGIIAR5-Chap7_FINAL.pdf Chapter 7: Food security and food production systems] (archived [https://web.archive.org/web/20141105164634/https://ipcc-wg2.gov/AR5/images/uploads/WGIIAR5-Chap7_FINAL.pdf 5 November 2014]), in {{cite book |year=2014 |author=IPCC AR5 WG2 A |editor=Field, C. B. |title=Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part A: Global and Sectoral Aspects. Contribution of Working Group II (WG2) to the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC) |url=http://www.ipcc.ch/report/ar5/wg2/ |publisher=Cambridge University Press |display-editors=etal |pages=488–489}}</ref> Future climate change will probably negatively affect [[crop yield|crop production]] in [[low latitude]] countries, while effects in northern [[latitude]]s may be positive or negative.<ref name="porter summary" /> Global warming will probably increase the risk of [[food insecurity]] for some vulnerable groups, such as the [[poverty|poor]].<ref>Paragraph 4, in: Summary and Recommendations, in: {{cite book |author=HLPE |title=Food security and climate change. A report by the High Level Panel of Experts (HLPE) on Food Security and Nutrition of the Committee on World Food Security |url=http://www.fao.org/cfs/cfs-hlpe/reports/hlpe-food-security-and-climate-change-report-elaboration-process/en/ |publisher=Food and Agriculture Organization of the United Nations |location=Rome, Italy |date=June 2012 |archive-url=https://web.archive.org/web/20141212075812/http://www.fao.org/cfs/cfs-hlpe/reports/hlpe-food-security-and-climate-change-report-elaboration-process/en/ |archive-date=12 December 2014  |page=12}}</ref>

Animal husbandry is also responsible for greenhouse gas production of {{CO2}} and a percentage of the world's methane, and future land infertility, and the displacement of wildlife. Agriculture contributes to climate change by [[Human impact on the environment|anthropogenic]] emissions of greenhouse gases, and by the conversion of non-agricultural land such as forest for agricultural use.<ref>Section 4.2: Agriculture's current contribution to greenhouse gas emissions, in: {{cite book |author=HLPE |title=Food security and climate change. A report by the High Level Panel of Experts (HLPE) on Food Security and Nutrition of the Committee on World Food Security |url=http://www.fao.org/cfs/cfs-hlpe/reports/hlpe-food-security-and-climate-change-report-elaboration-process/en/ |publisher=Food and Agriculture Organization of the United Nations |location=Rome, Italy |date=June 2012 |archive-url=https://web.archive.org/web/20141212075812/http://www.fao.org/cfs/cfs-hlpe/reports/hlpe-food-security-and-climate-change-report-elaboration-process/en/ |archive-date=12 December 2014  |pages=67–69}}</ref> Agriculture, forestry and land-use change contributed around 20 to 25% to global annual emissions in 2010.<ref>Blanco, G., ''et al''., Section 5.3.5.4: Agriculture, Forestry, Other Land Use, in: [http://report.mitigation2014.org/report/ipcc_wg3_ar5_chapter5.pdf Chapter 5: Drivers, Trends and Mitigation] (archived [https://web.archive.org/web/20141230092610/http://report.mitigation2014.org/report/ipcc_wg3_ar5_chapter5.pdf 30 December 2014)], in: {{cite book |year=2014 |author=IPCC AR5 WG3 |editor=Edenhofer, O. |title=Climate Change 2014: Mitigation of Climate Change. Contribution of Working Group III (WG3) to the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC) |url=http://www.ipcc.ch/report/ar5/wg3/ |publisher=Cambridge University Press |display-editors=etal |url-status=dead |archive-url=https://web.archive.org/web/20141127222605/http://www.ipcc.ch/report/ar5/wg3/ |archive-date=27 November 2014  |page=383}}. Emissions aggregated using 100-year [[global warming potential]]s from the [[IPCC Second Assessment Report]].</ref> A range of policies can reduce the risk of negative climate change impacts on agriculture,<ref>Porter, J. R., ''et al''., Section 7.5: Adaptation and Managing Risks in Agriculture and Other Food System Activities, in [http://ipcc-wg2.gov/AR5/images/uploads/WGIIAR5-Chap7_FINAL.pdf Chapter 7: Food security and food production systems] (archived [https://web.archive.org/web/20141105164634/https://ipcc-wg2.gov/AR5/images/uploads/WGIIAR5-Chap7_FINAL.pdf 5 November 2014]), in {{cite book |year=2014 |author=IPCC AR5 WG2 A |editor=Field, C.B. |title=Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part A: Global and Sectoral Aspects. Contribution of Working Group II (WG2) to the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC) |url=http://www.ipcc.ch/report/ar5/wg2/ |publisher=Cambridge University Press |display-editors=etal |pages=513–520}}</ref><ref>Oppenheimer, M., ''et al''., Section 19.7. Assessment of Response Strategies to Manage Risks, in: [http://ipcc-wg2.gov/AR5/images/uploads/WGIIAR5-Chap19_FINAL.pdf Chapter 19: Emergent risks and key vulnerabilities] (archived [https://web.archive.org/web/20141105164634/https://ipcc-wg2.gov/AR5/images/uploads/WGIIAR5-Chap19_FINAL.pdf 5 November 2014]), in {{cite book |year=2014 |author=IPCC AR5WG2 A |editor=Field, C.B. |title=Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part A: Global and Sectoral Aspects. Contribution of Working Group II (WG2) to the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC) |url=http://www.ipcc.ch/report/ar5/wg2/ |publisher=Cambridge University Press |display-editors=etal |page=1080}}</ref> and greenhouse gas emissions from the agriculture sector.<ref>Summary and Recommendations, in: {{cite book |author=HLPE |title=Food security and climate change. A report by the High Level Panel of Experts (HLPE) on Food Security and Nutrition of the Committee on World Food Security |url=http://www.fao.org/cfs/cfs-hlpe/reports/hlpe-food-security-and-climate-change-report-elaboration-process/en/ |publisher=Food and Agriculture Organization of the United Nations |location=Rome, Italy |date=June 2012 |archive-url=https://web.archive.org/web/20141212075812/http://www.fao.org/cfs/cfs-hlpe/reports/hlpe-food-security-and-climate-change-report-elaboration-process/en/ |archive-date=12 December 2014  |pages=12–23}}</ref><ref>Current climate change policies are described in {{cite book |author=Annex I NC |title=6th national communications (NC6) from Parties included in Annex I to the Convention including those that are also Parties to the Kyoto Protocol |url=http://unfccc.int/national_reports/annex_i_natcom/submitted_natcom/items/7742.php |publisher=United Nations Framework Convention on Climate Change |date=24 October 2014 |archive-url=https://web.archive.org/web/20140802030817/http://unfccc.int/national_reports/annex_i_natcom/submitted_natcom/items/7742.php |archive-date=2 August 2014 }} and {{citation |author=Non-Annex I NC |title=Non-Annex I national communications |url=http://unfccc.int/national_reports/non-annex_i_natcom/items/2979.php |publisher=United Nations Framework Convention on Climate Change |date=11 December 2014 |archive-url=https://web.archive.org/web/20140913171139/http://unfccc.int/national_reports/non-annex_i_natcom/items/2979.php |archive-date=13 September 2014 }}</ref><ref>Smith, P., ''et al''., Executive summary, in: [http://report.mitigation2014.org/report/ipcc_wg3_ar5_chapter5.pdf Chapter 5: Drivers, Trends and Mitigation] (archived [https://web.archive.org/web/20141230092610/http://report.mitigation2014.org/report/ipcc_wg3_ar5_chapter5.pdf 30 December 2014)], in: {{cite book |year=2014 |author=IPCC AR5 WG3 |editor=Edenhofer, O. |title=Climate Change 2014: Mitigation of Climate Change. Contribution of Working Group III (WG3) to the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC) |url=http://www.ipcc.ch/report/ar5/wg3/ |publisher=Cambridge University Press |display-editors=etal |url-status=dead |archive-url=https://web.archive.org/web/20141127222605/http://www.ipcc.ch/report/ar5/wg3/ |archive-date=27 November 2014  |pages=816–817}}</ref>

Technological advancements help provide farmers with tools and resources to make farming more sustainable.<ref>{{cite web |url=http://croplife.intraspin.com/pesticides/paper.asp?id=461 |author=Safefood Consulting, Inc.|title=Benefits of Crop Protection Technologies on Canadian Food Production, Nutrition, Economy and the Environment |year=2005 |publisher=CropLife International |access-date=24 May 2013 |url-status=dead |archive-url=https://archive.today/20130706005846/http://croplife.intraspin.com/pesticides/paper.asp?id=461 |archive-date=6 July 2013}}</ref> Technology permits innovations like [[conservation tillage]], a farming process which helps prevent land loss to erosion, reduces water pollution, and enhances [[carbon sequestration]].<ref>{{cite journal |author=Trewavas, Anthony |title=A critical assessment of organic farming-and-food assertions with particular respect to the UK and the potential environmental benefits of no-till agriculture |journal=Crop Protection |year=2004 |pages=757–781 |doi=10.1016/j.cropro.2004.01.009 |volume=23 |issue=9}}</ref> Other potential practices include [[conservation agriculture]], [[agroforestry]], improved [[Convertible husbandry|grazing]], avoided grassland conversion<!--WHAT?-->, and [[biochar]].<ref>{{Cite journal |last1=Griscom |first1=Bronson W. |last2=Adams |first2=Justin |last3=Ellis |first3=Peter W. |last4=Houghton |first4=Richard A. |last5=Lomax |first5=Guy |last6=Miteva |first6=Daniela A. |last7=Schlesinger |first7=William H. |last8=Shoch |first8=David |last9=Siikamäki|first9=Juha V.|last10=Smith |first10=Pete |last11=Woodbury |first11=Peter |date=2017 |title=Natural climate solutions |journal=Proceedings of the National Academy of Sciences |volume=114 |issue=44 |pages=11645–11650 |doi=10.1073/pnas.1710465114 |pmid=29078344 |pmc=5676916 |bibcode=2017PNAS..11411645G |issn=0027-8424}}</ref><ref>{{Cite book |title=Negative Emissions Technologies and Reliable Sequestration: A Research Agenda |publisher=National Academies of Sciences, Engineering, and Medicine |year=2019 |isbn=978-0-309-48452-7 |pages=117, 125, 135 |doi=10.17226/25259|pmid=31120708 |last1=National Academies Of Sciences |first1=Engineering }}</ref> Current mono-crop farming practices in the United States preclude widespread adoption of sustainable practices, such as 2-3 crop rotations that incorporate grass or hay with annual crops, unless negative emission goals such as soil carbon sequestration become policy.<ref>{{Cite book |url=https://www.nap.edu/catalog/25259/negative-emissions-technologies-and-reliable-sequestration-a-research-agenda |title=Negative Emissions Technologies and Reliable Sequestration: A Research Agenda |publisher=National Academies of Sciences, Engineering, and Medicine |year=2019 |isbn=978-0-309-48452-7 |page=97 |doi=10.17226/25259|pmid=31120708 |last1=National Academies Of Sciences |first1=Engineering }}</ref>

Indirect consumption includes the manufacture of fertilizers, pesticides, and farm machinery.<ref name="ncseonline.org" /> In particular, the production of [[nitrogen fertilizer]] can account for over half of agricultural energy usage.<ref>{{cite journal |title=Energy and the food system |author1=Woods, Jeremy |author2=Williams, Adrian |author3=Hughes, John K. |author4=Black, Mairi |author5=Murphy, Richard |date=August 2010 |doi=10.1098/rstb.2010.0172 |pmid=20713398 |pmc=2935130 |journal=Philosophical Transactions of the Royal Society |volume=365 |pages=2991–3006 |issue=1554 |doi-access=free }}</ref> Together, direct and indirect consumption by US farms accounts for about 2% of the nation's energy use. Direct and indirect energy consumption by U.S. farms peaked in 1979, and has since gradually declined.<ref name="ncseonline.org" /> [[Food systems]] encompass not just agriculture but off-farm processing, packaging, transporting, marketing, consumption, and disposal of food and food-related items. Agriculture accounts for less than one-fifth of food system energy use in the US.<ref name="css.snre.umich.edu">{{cite web |author1=Heller, Martin |author2=Keoleian, Gregory |year=2000 |title=Life Cycle-Based Sustainability Indicators for Assessment of the U.S. Food System |publisher=University of Michigan Center for Sustainable Food Systems |url=http://css.snre.umich.edu/css_doc/CSS00-04.pdf |access-date=17 March 2016 |url-status=dead |archive-url=https://web.archive.org/web/20160314094203/http://css.snre.umich.edu/css_doc/CSS00-04.pdf |archive-date=14 March 2016 }}</ref><ref name="ers.usda.gov" />

However, {{as of|2009|lc=y}}, there was still a significant amount of policy-driven distortion in global agricultural product prices. The three agricultural products with the greatest amount of trade distortion were sugar, milk and rice, mainly due to taxation. Among the [[oilseed]]s, sesame had the greatest amount of taxation, but overall, feed grains and oilseeds had much lower levels of taxation than livestock products. Since the 1980s, policy-driven distortions have seen a greater decrease among livestock products than crops during the worldwide reforms in agricultural policy.<ref name=LloydCroserAnderson2013 /> Despite this progress, certain crops, such as cotton, still see subsidies in developed countries artificially deflating global prices, causing hardship in developing countries with non-subsidized farmers.<ref>{{Cite news |url=https://www.theguardian.com/global-development/poverty-matters/2011/may/24/american-cotton-subsidies-illegal-obama-must-act |title=America's $24bn subsidy damages developing world cotton farmers |author=Kinnock, Glenys |date=24 May 2011 |access-date=16 April 2013 |newspaper=The Guardian |url-status=live |archive-url=https://web.archive.org/web/20130906122834/http://www.theguardian.com/global-development/poverty-matters/2011/may/24/american-cotton-subsidies-illegal-obama-must-act |archive-date=6 September 2013 }}</ref> Unprocessed commodities such as corn, soybeans, and cattle are generally graded to indicate quality, affecting the price the producer receives. Commodities are generally reported by production quantities, such as volume, number or weight.<ref>{{cite web |title=Agriculture's Bounty |url=http://www.ibrc.indiana.edu/studies/AgriculturesBounty.pdf |date=May 2013 |access-date=19 August 2013 |url-status=live |archive-url=https://web.archive.org/web/20130826100413/http://www.ibrc.indiana.edu/studies/AgriculturesBounty.pdf |archive-date=26 August 2013 }}</ref>

There are many influences on the creation of agricultural policy, including consumers, agribusiness, trade lobbies and other groups. [[Agribusiness]] interests hold a large amount of influence over policy making, in the form of [[lobbying]] and [[campaign contribution]]s. Political action groups, including those interested in environmental issues and labor unions, also provide influence, as do lobbying organizations representing individual agricultural commodities.<ref>{{cite journal |url=http://faculty.missouri.edu/ikerdj/papers/SFT-Corporatization%20of%20Fm%20Pol%20(9-10).htm |title=Corporatization of Agricultural Policy |author=Ikerd, John |journal=Small Farm Today Magazine |year=2010 |url-status=live |archive-url=https://web.archive.org/web/20160807024012/http://faculty.missouri.edu/ikerdj/papers/SFT-Corporatization%20of%20Fm%20Pol%20(9-10).htm |archive-date=7 August 2016 }}</ref> The [[Food and Agriculture Organization of the United Nations]] (FAO) leads international efforts to defeat hunger and provides a forum for the negotiation of global agricultural regulations and agreements. Dr. Samuel Jutzi, director of FAO's animal production and health division, states that lobbying by large corporations has stopped reforms that would improve human health and the environment. For example, proposals in 2010 for a voluntary code of conduct for the livestock industry that would have provided incentives for improving standards for health, and environmental regulations, such as the number of animals an area of land can support without long-term damage, were successfully defeated due to large food company pressure.<ref>{{cite news |url=https://www.theguardian.com/environment/2010/sep/22/food-firms-lobbying-samuel-jutzi |title=Corporate Lobbying Is Blocking Food Reforms, Senior UN Official Warns: Farming Summit Told of Delaying Tactics by Large Agribusiness and Food Producers on Decisions that Would Improve Human Health and the Environment |author=Jowit, Juliette |date=22 September 2010 |newspaper=The Guardian |access-date=8 May 2018}}</ref>