Alfalfa

{{Short description|Plant species in pea family}} {{Other uses}} {{primary sources|date=October 2025}} {{Use dmy dates|date=November 2020}}

{{Speciesbox |image = 75_Medicago_sativa_L.jpg |image_caption = ''Medicago sativa''<ref>This illustration is from Amédée Masclef, Atlas des plantes de France, 1891.{{clarify|date=October 2025}}{{full citation needed|date=October 2025}}</ref> |genus = Medicago |parent = Medicago sect. Medicago |species = sativa |authority = L.<ref> {{cite web |url=http://www.ildis.org/LegumeWeb?sciname=Medicago+sativa |title=Medicago sativa – ILDIS LegumeWeb |publisher=ildis.org |access-date=7 March 2008 }} </ref> |subdivision_ranks = Subspecies |subdivision = * ''M. sativa'' subsp. ''ambigua'' (Trautv.) Tutin * ''M. sativa'' subsp. ''microcarpa'' Urban * ''M. sativa'' subsp. ''sativa'' * ''M. sativa'' subsp. ''varia'' (T. Martyn) Arcang. |synonyms = {{Collapsible list | {{Plainlist | style = margin-left: 1em; text-indent: -1em; | *''Medica sativa'' Lam. *''Medicago afganica'' (Bordere) Vassilcz. *''Medicago beipinensis'' Vassilcz. *''Medicago coerulea'' Ledeb. [Spelling variant] *''Medicago grandiflora'' (Grossh.) Vassilcz. *''Medicago hemicycla'' Grossh. *''Medicago ladak'' Vassilcz. *''Medicago lavrenkoi'' Vassilcz. *''Medicago media'' Pers. *''Medicago mesopotamica'' Vassilcz. *''Medicago ochroleuca'' Kult. *''Medicago orientalis'' Vassilcz. *''Medicago polia'' (Brand) Vassilcz. *''Medicago praesativa'' Sinskaya *''Medicago rivularis'' Vassilcz. *''Medicago sogdiana'' (Brand) Vassilcz. *''Medicago subdicycla'' (Trautv.) Vassilcz. *''Medicago sylvestris'' Fr. *''Medicago tianschanica'' Vassilcz. *''Medicago tibetana'' (Alef.) Vassilcz. *''Medicago trautvetteri'' Sumnev. *''Medicago varia'' Martyn *''Trigonella upendrae'' H.J.Chowdhery & R.R.Rao }} }} |synonyms_ref = <ref>{{cite web |url=http://www.theplantlist.org/tpl1.1/search?q=medicago+sativa |title=The Plant List: A Working List of All Plant Species |access-date=3 October 2014 |archive-date=20 April 2019 |archive-url=https://web.archive.org/web/20190420222420/http://www.theplantlist.org/tpl1.1/search?q=Medicago+sativa |url-status=dead }}</ref> }}

'''''Medicago sativa''''', commonly known as '''alfalfa''' ({{IPAc-en|æ|l|ˈ|f|æ|l|f|ə}}) in North America<ref name="OED lucerne" /> and '''lucerne''' ({{IPAc-en|l|uː|ˈ|s|ɜːr|n}}) in the United Kingdom, South Africa, Australia, and New Zealand,<ref name="M-W lucerne" /><ref>{{cite web |last1=ALA Staff |title=Species: ''Medicago sativa'' (Lucerne) |url=https://bie.ala.org.au/species/https://id.biodiversity.org.au/node/apni/2896123#names |access-date=1 December 2025 |website=Atlas of Living Australia |language=en-AU}}</ref> is a perennial flowering plant in the legume family, Fabaceae.

Native to warmer temperate climates, alfalfa has long been cultivated as livestock fodder, perhaps since antiquity. It is an important forage crop in many countries around the world and is used for grazing, hay, and silage.

==Description==

Alfalfa is a perennial forage legume which normally lives four to eight years but can live more than 20 years, depending on variety and climate.<ref name="eb">{{cite encyclopedia |title=alfalfa (plant) – Britannica Online Encyclopedia |encyclopedia=Britannica.com |url=https://www.britannica.com/EBchecked/topic/14595/alfalfa |access-date=29 June 2011 |archive-url=https://web.archive.org/web/20110607052509/https://www.britannica.com/EBchecked/topic/14595/alfalfa |archive-date=7 June 2011 |url-status=live}}</ref> The plant grows to a height of up to {{convert|1|m|ft|abbr=off|frac=2}}. Its root system typically grows to a depth of {{convert|2-3|m|ft|0|abbr=on}} depending on subsoil constraints<ref name="eb" /> but sometimes grows to a depth of more than {{convert|15|m|ft|abbr=on}} to reach groundwater.

The leaves are typically trifoliolate.<ref name=":0">{{Cite web |title=Alfalfa |url=https://ag.purdue.edu/department/agry/agry-extension/forages/forage-id/legumes/alfalfa.html |access-date=2026-04-06 |website=Purdue University - College of Agriculture |language=en}}</ref> The plant has clusters of 5–20 florets, which are usually purple but can be blue, yellow, or cream. The small seeds are yellowish.<ref name=":0" />

The species has an autotetraploid genome with tetrasomic inheritance.<ref>{{Cite journal |last1=Chen |first1=Haitao |last2=Zeng |first2=Yan |last3=Yang |first3=Yongzhi |last4=Huang |first4=Lingli |last5=Tang |first5=Bolin |last6=Zhang |first6=He |last7=Hao |first7=Fei |last8=Liu |first8=Wei |last9=Li |first9=Youhan |last10=Liu |first10=Yanbin |last11=Zhang |first11=Xiaoshuang |last12=Zhang |first12=Ru |last13=Zhang |first13=Yesheng |last14=Li |first14=Yongxin |last15=Wang |first15=Kun |date=2020-05-19 |title=Allele-aware chromosome-level genome assembly and efficient transgene-free genome editing for the autotetraploid cultivated alfalfa |journal=Nature Communications |language=en |volume=11 |issue=1 |pages=2494 |doi=10.1038/s41467-020-16338-x |pmid=32427850 |pmc=7237683 |bibcode=2020NatCo..11.2494C |issn=2041-1723}}</ref>

{{gallery|mode=packed |Lucerne flowers.jpg|Foliage and flowers |Medicago sativa Alfals006.jpg|Flowers |YellowPrairieFlower.jpg|Yellow flowers |Alfalfa frutos-1.JPG|Mature fruits of ''M. sativa'' var. ''sativa'' |Mesa 002 lhp.jpg|Seeds (actual size ≈ 2mm) |Scythe_in_lucern_field.jpg|Lucerne field }}

==Etymology== According to Merriam-Webster, English use of ''alfalfa'' dates to 1791 and derives from the identical cognate in Spanish, whose origin is {{Transliteration|ar|al-faṣfaṣa}}, of an Arabic dialect.<ref name=Merriam-Webster>{{cite web |url=https://www.merriam-webster.com/dictionary/alfalfa |title=alfalfa noun—Word History |date=19 October 2025 |publisher=Merriam-Webster |access-date=2025-10-24}}</ref> ''Etymology Online'' suggests that ''alfalfa'' derives from the same Spanish cognate ({{Circa|1845}}), from the Spanish predecessor ''alfalfez''; according to "Iberian sources" the word's root was {{Transliteration|ar|al-fisfisa}}, claimed to mean "fresh fodder". Linguist Calvert Watkins suggested that the Arabic word might derive from an Old Iranian compound meaning "horse food".<ref>{{Cite web| author = Harper, Douglas | url=https://www.etymonline.com/word/alfalfa|title=Origin and History of ''Alfalfa''|work=Online Etymology Dictionary|date=2025|access-date=2026-04-03}}</ref>

''Lucerne'', or ''lucern'', as a synonym for alfalfa was borrowed from French, first appearing in written English in 1652.<ref name="OED lucerne">{{Cite OED|Lucerne {{pipe}} Lucern, N. (2). |9562576186}}</ref> The French word was itself a borrowing from the Occitan {{lang|oc|luzerno}}, meaning "glowworm", likely a reference to the bright yellow seeds of some strains of alfalfa.<ref name="M-W lucerne">{{Cite Merriam-Webster|lucerne|access-date=1 December 2025}}</ref>

== Ecology == [[Image:Apis mellifera - Medicago sativa - Valingu.jpg|thumb|Honey bee (''Apis mellifera''), a pollinator on alfalfa flower]]

Alfalfa is considered an insectary plant and may help other crops such as cotton because it harbours predatory and parasitic insects that would protect the other crop if the two were interplanted.<ref name=Leigh>{{cite web | title = Alfalfa as an insectary for beneficial insects | author = Thomas F. Leigh | url = http://alfalfa.ucdavis.edu/+symposium/proceedings/1991/91-49.pdf | date = n.d. | access-date = 26 April 2013 | archive-date = 11 June 2010 | archive-url = https://web.archive.org/web/20100611171811/http://alfalfa.ucdavis.edu/%20symposium/proceedings/1991/91-49.Pdf | url-status = dead }}</ref> Harvesting the alfalfa by mowing the entire crop area destroys the insect population; this can be avoided by mowing in strips so that part of the growth remains.<ref name=Leigh/>

Alfalfa develops extensive taproots that can extend around 6 feet per year in loose soil. This allows the plant to access soil moisture that is not accessible to plants with shallow root systems, making it more resistant to droughts and soil erosion.<ref>{{Cite journal |last1=Samac |first1=Deborah |last2=Malvick |last3=Hollingsworth |last4=Hudelson |last5=Gibbs |date=March 2007 |title=Alfalfa Root Health and Disease Management: A Founfation for Maximizing Production Potential and Stand Life |url=https://www.midwestforage.org/pdf/178.pdf.pdf |journal=Forage Focus}}</ref> This depth of root system, and perenniality of crowns that store carbohydrates as an energy reserve, makes it very resilient.<ref name="ReferenceA">{{Cite journal |last1=Qi |first1=Jiangjiao |last2=Fu |first2=Dongqing |last3=Wang |first3=Xuzhe |last4=Zhang |first4=Fanfan |last5=Ma |first5=Chunhui |date=2023-08-23 |title=The effect of alfalfa cultivation on improving physicochemical properties soil microorganisms community structure of grey desert soil |journal=Scientific Reports |language=en |volume=13 |issue=1 |pages=13747 |doi=10.1038/s41598-023-41005-8 |pmid=37612457 |pmc=10447519 |bibcode=2023NatSR..1313747Q |issn=2045-2322}}</ref>

Alfalfa exhibits autotoxicity, which means it is difficult for alfalfa seed to grow in existing stands of alfalfa.<ref>{{cite web |last1= Jennings|first1=John |url=https://fyi.extension.wisc.edu/forage/understanding-autotoxicity-in-alfalfa/ |title=Understanding Autotoxicity in Alfalfa |publisher=University of Wisconsin Extension Service (Madison) |access-date=29 June 2011 |archive-url=https://web.archive.org/web/20110614112705/http://www.uwex.edu/ces/forage/wfc/proceedings2001/understanding_autotoxicity_in_alfalfa.htm |archive-date=14 June 2011 |url-status=live}}</ref> Therefore, alfalfa fields are recommended to be rotated with other species (for example, corn or wheat) before reseeding.<ref name="krc">{{cite web |url=http://www.kansasruralcenter.org/publications/alfalfa.pdf |title=Sustainble Agriculture Management Guides |publisher=Kansas Rural Center |access-date=19 April 2013 |url-status=dead |archive-url=https://web.archive.org/web/20120907083135/http://www.kansasruralcenter.org/publications/alfalfa.pdf |archive-date=7 September 2012}}</ref> The exact mechanism of autotoxicity is unclear, with medicarpins and phenols both seeming to play a role.<ref>{{cite web |last1=Volenec |first1=Jeff |last2=Johnson |first2=Keith |title=Managing Alfalfa Autotoxicity |url=https://www.extension.purdue.edu/extmedia/AY/AY-324-W.pdf |website=Purdue University Extension Service}}</ref> The level of autotoxicity in soil depends on soil type (clay soils maintain autotoxicity for longer), cultivar and age of the previous crop. A soil assay can be used to measure autotoxicity.<ref>{{cite web |last=Rankin |first=Mike |date=2021-03-09 |title=Alfalfa autotoxicity remains a mystery |url=https://hayandforage.com/article-3422-alfalfa-autotoxicity-remains-a-mystery.html |url-status=live |archive-url=https://web.archive.org/web/20250818033532/https://hayandforage.com/article-3422-alfalfa-autotoxicity-remains-a-mystery.html |archive-date=2025-08-18 |website=hayandforage.com |language=en}}</ref> Resistance to autotoxicity also varies by cultivar, a tolerant one being 'WL 656HQ'.<ref>{{cite journal |last1=Zhang |first1=Xiao-Yan |last2=Shi |first2=Shang-Li |last3=Li |first3=Xiao-Long |last4=Li |first4=Chang-Ning |last5=Zhang |first5=Cui-Mei |last6=A |first6=Yun |last7=Kang |first7=Wen-Juan |last8=Yin |first8=Guo-Li |title=Effects of Autotoxicity on Alfalfa (Medicago sativa): Seed Germination, Oxidative Damage and Lipid Peroxidation of Seedlings |journal=Agronomy |date=21 May 2021 |volume=11 |issue=6 |pages=1027 |doi=10.3390/agronomy11061027 |doi-access=free|bibcode=2021Agron..11.1027Z }}</ref>

=== Pests and diseases === {{Main|Alfalfa pests|List of alfalfa diseases}}

Like most plants, alfalfa can be attacked by various pests and pathogens. Diseases often have subtle symptoms which are easily misdiagnosed and can affect the leaves, roots, stems, and blossoms.<ref name="Gq2005">{{cite journal |last1=GQ |first1=L. |last2=Huang |first2=H.C. |last3=Acharya |first3=S.N. |last4=Erickson |first4=R.S. |title=Effectiveness of ''Coniothyrium minitans'' and ''Trichoderma atroviride'' in suppression of sclerotinia blossom blight of alfalfa. |journal=Plant Pathol. |date=2005 |volume=54 |issue=2 |pages=204–211|doi=10.1111/j.1365-3059.2005.01119.x |doi-access=free |bibcode=2005PPath..54..204L }}</ref>

Some pests, such as the alfalfa weevil, aphids, and potato leafhopper,<ref>{{Cite web |title=Potato Leafhopper on Alfalfa (Department of Entomology) |url=https://ento.psu.edu/extension/factsheets/potato-leafhopper-alfalfa |url-status=live |archive-url=https://web.archive.org/web/20200724141556/https://ento.psu.edu/extension/factsheets/potato-leafhopper-alfalfa |archive-date=2020-07-24 |website=Department of Entomology (Penn State University)}}</ref> can reduce alfalfa yields dramatically, particularly with the second cutting when weather is warmest.<ref name="osu">{{cite web |last1=Willson |first1=H.R. |last2=Eisley |first2=J.B. |title=Insect Pest Management on Alfalfa, FC-ENT-0031-00 |url=http://ohioline.osu.edu/ent-fact/0031.html |url-status=dead |archive-url=https://web.archive.org/web/20110918121359/http://ohioline.osu.edu/ent-fact/0031.html |archive-date=2011-09-18 |access-date=17 October 2011 |website=Ohio State University Extension}}</ref> Spotted alfalfa aphid, broadly spread in Australia, sucks sap and injects salivary toxins into the leaves.<ref>{{Cite web|url=https://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex728|title=Spotted Alfalfa Aphid|last=Harper|first=A.M.|others=Agriculture Canada Research Station, Lethbridge|date=Jan 2017|website=www1.agric.gov.ab.ca|language=en|access-date=2018-07-26 |url-status=deviated |archive-url=https://web.archive.org/web/20180726201800/https://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex728 |archive-date=26 July 2018}}</ref> Registered insecticides or chemical controls are sometimes used to prevent this, and labels will specify the withholding period before the forage crop can be grazed or cut for hay or silage.<ref name = "osu"/> Alfalfa is susceptible to root rots, including ''Phytophthora'', ''Rhizoctonia'', and Texas root rot.<ref>{{Cite web |last=Partridge |first=J.E. |title=Phytophthora Root Rot of Alfalfa |url=http://nu-distance.unl.edu/homer/disease/agron/alfalfa/AlfPhyt.html |url-status=dead |archive-url=https://web.archive.org/web/20100723141519/http://nu-distance.unl.edu/homer/disease/agron/alfalfa/AlfPhyt.html |archive-date=2010-07-23 |website=University of Nebraska Lincoln Department of Plant Pathology}}</ref><ref>{{cite web|url=http://ohioline.osu.edu/ac-fact/0042.html|archive-url=https://web.archive.org/web/20120718010101/http://ohioline.osu.edu/ac%2Dfact/0042.html|title=Rhizoctonia Root, Stem, and Crown Rot of Alfalfa AC-42-96|access-date=17 October 2011|url-status=dead|archive-date=18 July 2012}}</ref><ref>{{cite web |url=http://pods.dasnr.okstate.edu/docushare/dsweb/Get/Document-2321/EPP-7621web.pdf |title=Phymatotrichum Root Rot |publisher=Pods.dasnr.okstate.edu |access-date=19 April 2013 |archive-date=17 July 2011 |archive-url=https://web.archive.org/web/20110717011018/http://pods.dasnr.okstate.edu/docushare/dsweb/Get/Document-2321/EPP-7621web.pdf |url-status=dead }}</ref> Alfalfa is also susceptible to downy mildew caused by the oomycete species ''Peronospora aestivalis''.<ref name=Constantinescu>{{cite journal |last1= Constantinescu |first1= O. |title= An annotated list of ''Peronospora'' names |date= 1991 |journal= Thunbergia |volume= 15}}</ref>

== Cultivation ==

=== History === Alfalfa is believed to have originated in south-central Asia and was first cultivated in Central Asia.<ref name="Westgate">{{cite book |last=Westgate |first=J. M. |url=http://www.naaic.org/Resources/Alfalfa1908.pdf |title=Alfalfa |publisher=U. S. Department of Agriculture |year=1908 |location=Washington |page=5 |access-date=28 July 2013}}</ref><ref name="Oakley">{{Cite book |last1=Oakley |first1=Russell Arthur |url=https://digital.library.unt.edu/ark:/67531/metadc6202/m1/5/ |title=How to Grow Alfalfa |last2=Westover |first2=Harvey Leroy |date=December 1922 |publisher=United States Department of Agriculture |location=Washington, D.C. |language=en-US |oclc=15432716 |archive-url=https://web.archive.org/web/20240709041556/https://digital.library.unt.edu/ark:/67531/metadc6202/m1/5/ |archive-date=2024-07-09 |url-status=live |via=University of North Texas Libraries}}</ref> According to Pliny (died 79 AD), it was introduced to Greece in about 490 BC when the Persians invaded Greek territory. Alfalfa cultivation is discussed in the fourth-century AD book ''Opus Agriculturae'' by Palladius, stating:<blockquote>One sow-down lasts ten years. The crop may be cut four or six times a year ... A jugerum of it is abundantly sufficient for three horses all the year ... It may be given to cattle, but new provender is at first to be administered very sparingly, because it bloats up the cattle.<ref>{{cite book |last=Palladius |title=Opus Agriculturae |year=1898 |chapter=Book V, § I |chapter-url=https://archive.org/details/opusagriculturae00pall}} Links to online copies are listed at the foot of the Wikipedia article Rutilius Taurus Aemilianus Palladius.</ref></blockquote>

The medieval Arabic agricultural writer Ibn al-'Awwam, who lived in Spain in the later 12th century, discussed how to cultivate alfalfa, which he called {{lang|ar|الفصفصة}} (''{{transliteration|ar|al-fiṣfiṣa}}'').<ref>{{cite book |last=Ibn al-'Awwam |title=Kitāb al-filāḥa |trans-title=Book of Agriculture |chapter=Chapter XXII, § VIII}} Links to online copies in French, Spanish, and Arabic are listed at the foot of the Wikipedia article Ibn al-'Awwam.</ref> A 13th-century general-purpose Arabic dictionary, ''Lisān al-'Arab'', says that alfalfa is cultivated as an animal feed and consumed in both fresh and dried forms.<ref>''Lisān al-'Arab'' is online at [http://www.baheth.info/ Baheth.info] {{Webarchive|url=https://web.archive.org/web/20131029192325/http://www.baheth.info/|date=29 October 2013}}. Search for فصفصة in the dictionary. (The dictionary is also downloadable at Archive.org but that version doesn't have searchable text).</ref>

In the 16th century, Spanish colonists introduced alfalfa to the Americas as fodder for their horses.<ref>{{Cite book |last=Bilello |first=Stanley |url=https://books.google.com/books?id=yZc_DQAAQBAJ&dq=Spanish+colonizers+introduced+alfalfa+to+the+Americas+as+fodder+for+their+horses&pg=PA1 |title=21st Century Homestead: Nitrogen-Fixing Crops |date=2016-10-10 |publisher=Lulu.com |isbn=978-1-365-45290-1 |language=en}}</ref>

In the North American colonies of the eastern US in the 18th century, it was called "alfalfa", and many trials at growing it were made, but generally without sufficiently successful results.<ref name="Oakley" /> Relatively little is grown in the southeastern US today.<ref name="Crop Production 2012" /> Alfalfa seeds were imported to California from Chile in the 1850s. That was the beginning of a rapid and extensive introduction of the crop over the western US<ref name="Westgate" /> and introduced the word "alfalfa" to the English language. Since North and South America now produce a large part of the world's output, the word "alfalfa" has been slowly entering other languages.

=== Modern cultivation === [[File:Luzerne Kalahari.jpg|thumb|Alfalfa fields in the Kalahari Desert (2017) {{Coord|24|20|21.5|S|018|35|36.4|E|display=inline}}]]

Alfalfa is widely grown throughout the world as forage for cattle. It is most often harvested as hay but can also be made into silage, grazed, or fed as greenchop.<ref>{{cite web |url=http://www.caf.wvu.edu/~forage/library/forglvst/bulletins/salfalfa.pdf |title=Alfalfa in the South |publisher=Caf.wvu.edu |access-date=19 April 2013 |url-status=dead |archive-url=https://web.archive.org/web/20120717124316/http://www.caf.wvu.edu/~forage/library/forglvst/bulletins/salfalfa.pdf |archive-date=17 July 2012}}</ref> Alfalfa usually has the highest feeding value of all common hay crops. It is used less frequently as pasture.<ref name = "krc"/> When grown on soils where it is well-adapted, alfalfa is often the highest-yielding forage plant, but its primary benefit is the combination of high yield per hectare and high nutritional quality.<ref>{{cite web |last1=Lacefield |first1=Garry |last2=Henning |first2=Jimmy |last3=Burris |first3=Roy |last4=Dougherty |first4=Charles |last5=Absher |first5=Curtis |date= |title=Grazing Alfalfa |url=http://www.uky.edu/Ag/AnimalSciences/pubs/id97.pdf |url-status=dead |archive-url=https://web.archive.org/web/20121013124734/http://www.uky.edu/Ag/AnimalSciences/pubs/id97.pdf |archive-date=13 October 2012 |access-date=19 April 2013 |website=University of Kentucky College of Agriculture |publisher=UKY}}</ref>

Its primary use is as feed for high-producing dairy cows because of its high protein content and highly digestible fiber, and secondarily for beef cattle, horses, sheep, and goats.<ref name="uaex.edu">{{cite web |url=http://www.uaex.edu/Other_Areas/publications/PDF/FSA-4000.pdf |title=Alfalfa for Dairy Cattle |publisher=Uaex.edu |access-date=19 April 2013 |archive-date=27 May 2010 |archive-url=https://web.archive.org/web/20100527214258/http://www.uaex.edu/Other_Areas/publications/PDF/FSA-4000.pdf |url-status=dead }}</ref><ref>{{cite web|url=http://www.hayusa.net/alfalfa.html |title=HayUSA, INC. Premium Quality – Alfalfa |publisher=Hayusa.net |access-date=29 June 2011| archive-url= https://web.archive.org/web/20110723142707/http://www.hayusa.net/alfalfa.html| archive-date= 23 July 2011 | url-status= live}}</ref> Alfalfa hay is a widely used protein and fiber source for meat rabbits. In poultry diets, dehydrated alfalfa and alfalfa leaf concentrates are used for pigmenting eggs and meat because of their high content in carotenoids, which are efficient for colouring egg yolk and body lipids.<ref name='feedipedia'>{{cite web| last1=Heuzé | first1=V. | last2=Tran | first2=G. | last3=Boval | first3=M. | last4=Lebas | first4=F. | last5=Lessire | first5=M. | last6=Noblet | first6=J. | last7=Renaudeau | first7=D.| title=Alfalfa (''Medicago sativa'')| url=https://www.feedipedia.org/node/275 | publisher = Feedipedia.org. A programme by INRA, CIRAD, AFZ and FAO| date = 6 October 2013 | access-date = 6 October 2013 }}</ref> Humans also eat alfalfa sprouts in salads and sandwiches.<ref>{{cite web|last=Spottiswood |first=John |url=http://cookeatshare.com/ingredients/alfalfa-sprouts |title=Alfalfa sprouts |publisher=CookEatShare |access-date=29 June 2011| archive-url= https://web.archive.org/web/20110708191500/http://cookeatshare.com/ingredients/alfalfa-sprouts| archive-date= 8 July 2011 | url-status= live}}</ref><ref>{{cite web |url=http://alfalfa.ucdavis.edu/IrrigatedAlfalfa/pdfs/UCAlfalfa8305Industrial_free.pdf |title=Alfalfa for Industrial and Other Uses |publisher=Alfalfa.ucdavis.edu |access-date=19 April 2013 |archive-date=7 October 2011 |archive-url=https://web.archive.org/web/20111007033037/http://alfalfa.ucdavis.edu/IrrigatedAlfalfa/pdfs/UCAlfalfa8305Industrial_free.pdf |url-status=dead }}</ref> Dehydrated alfalfa leaf is commercially available as a dietary supplement in several forms, such as tablets, powders and tea.<ref>{{cite web|url=https://www.nlm.nih.gov/medlineplus/druginfo/natural/patient-alfalfa.html |archive-url=https://web.archive.org/web/20060427232051/http://www.nlm.nih.gov/medlineplus/druginfo/natural/patient-alfalfa.html |url-status=dead |archive-date=27 April 2006 |title=Alfalfa: MedlinePlus Supplements |publisher=Nlm.nih.gov |access-date=29 June 2011}}</ref> Fresh alfalfa can cause bloating in livestock, so care must be taken with livestock grazing on alfalfa.<ref>[http://www.plantdex.com/index.php/species-growing-guides/grasses/240-alfalfa-medicago-sativa Medicago Sativa (Alfalfa)] {{webarchive|url=https://web.archive.org/web/20110816071347/http://www.plantdex.com/index.php/species-growing-guides/grasses/240-alfalfa-medicago-sativa |date=16 August 2011 }}. Plantdex.com. Retrieved on 17 October 2011.</ref>

Alfalfa engages in symbiotic nitrogen fixation with nitrogen-fixing bacteria called rhizobia, including ''Sinorhizobium meliloti.''<ref name="Nodule branching, size, and symbios">{{cite bioRxiv |last1=Paillan |first1=Elizabeth L. |title=Nodule branching, size, and symbiosis outcomes are shaped by natural genetic variation in rhizobial bacteria and alfalfa hosts |date=2025-10-27 |language=en |biorxiv=10.1101/2025.10.27.684485 |last2=Gil-Polo |first2=Alejandra |last3=Guha |first3=Sohini |last4=Swartley |first4=Andy |last5=Burghardt |first5=Liana T.}}</ref> This symbiosis results in the formation of indeterminate nodules (continuously growing) which grow on the root on the root hairs.<ref>{{Cite journal |last1=Capela |first1=Delphine |last2=Filipe |first2=Cédric |last3=Bobik |first3=Christine |last4=Batut |first4=Jacques |last5=Bruand |first5=Claude |date=April 2006 |title=Sinorhizobium meliloti differentiation during symbiosis with alfalfa: a transcriptomic dissection |journal=Molecular Plant-Microbe Interactions |volume=19 |issue=4 |pages=363–372 |doi=10.1094/MPMI-19-0363 |issn=0894-0282 |pmid=16610739 |bibcode=2006MPMI...19..363C }}</ref> S. meliloti, once inside the nodule, will terminally differentiate into bacteroids in which they lose the ability to return to free-living growth in soil. The bacteroids fix atmospheric nitrogen into bioavailable forms such as ammonia. Bacteroids are provided with carbohydrates for growth and return usable nitrogen to the plant.<ref name="Nodule branching, size, and symbios"/> This mutualistic interaction improves soil nitrogen fertility as plant matter is accumulated in the surrounding soil.<ref name="ReferenceA"/>

Symbiosis allows Alfalfa to produce a nutritious feed regardless of available nitrogen in the soil.<ref>{{cite web |url=http://cmgm.stanford.edu/~mbarnett/genome.htm |title=Sinorhizobium meliloti genome home |publisher=Cmgm.stanford.edu |access-date=29 June 2011 |archive-url=https://web.archive.org/web/20110519030012/http://cmgm.stanford.edu/~mbarnett/genome.htm |archive-date=19 May 2011 |url-status=dead }}</ref> Its nitrogen-fixing ability (which increases soil nitrogen) and its use as an animal feed greatly improve agricultural efficiency.<ref>{{cite web |url=https://portal.sciencesocieties.org/Downloads/pdf/B40724.pdf |title=Nitrogen Fixation in Crop Production |publisher=portal.sciencesocities.org |access-date=19 April 2013 |url-status=dead |archive-url=https://web.archive.org/web/20120324033638/https://portal.sciencesocieties.org/Downloads/pdf/B40724.pdf |archive-date=24 March 2012}}</ref><ref>{{cite web |url=http://alfalfa.ucdavis.edu/-files/pdf/alfalfaFactSheet.pdf |title=Commodity Fact Sheet Alfalfa Information compiled by the California Alfalfa and Forage Association |publisher=Alfalfa.ucdavis.edu |access-date=19 April 2013 |archive-date=7 October 2011 |archive-url=https://web.archive.org/web/20111007033047/http://alfalfa.ucdavis.edu/-files/pdf/alfalfaFactSheet.pdf |url-status=dead }}</ref>

Alfalfa can be sown in spring or fall and does best on well-drained soils with a neutral pH of 6.8–7.5.<ref>{{cite web |url=http://cestanislaus.ucdavis.edu/files/299.htm |title=UCANR Web Sites |publisher=Cestanislaus.ucdavis.edu |access-date=29 June 2011 |archive-url=https://web.archive.org/web/20110131223040/http://cestanislaus.ucdavis.edu/files/299.htm |archive-date=31 January 2011 |url-status=dead}}</ref><ref>{{cite web|url=http://forageresearch.tamu.edu/1985/CloverEstablishmentGrowth.pdf |title=Clover Establishment and Growth at Different pH Levels |access-date=2010-05-08 |url-status=dead |archive-url=https://web.archive.org/web/20100626144328/http://forageresearch.tamu.edu/1985/CloverEstablishmentGrowth.pdf |archive-date=26 June 2010 }}</ref> Alfalfa requires sustained levels of potassium and phosphorus to grow well.<ref>{{cite web |url=http://www.ces.purdue.edu/extmedia/AY/AY-331-W.pdf |title=Phosphorus and Potassium Fertilization of Alfalfa |publisher=Ces.purdue.edu |access-date=19 April 2013 |url-status=dead |archive-url=https://web.archive.org/web/20120226233221/http://www.ces.purdue.edu/extmedia/AY/AY-331-W.pdf |archive-date=26 February 2012}}</ref> It is moderately sensitive to salt levels in both the soil and irrigation water, although it continues to be grown in the arid southwestern United States, where salinity is an emerging issue.<ref>[http://extension.missouri.edu/publications/DisplayPub.aspx?P=G4555 G4555 Managing Manure on Alfalfa Hay | University of Missouri Extension] {{Webarchive|url=https://web.archive.org/web/20110727035847/http://extension.missouri.edu/publications/DisplayPub.aspx?P=G4555 |date=27 July 2011 }}. Extension.missouri.edu. Retrieved on 17 October 2011.</ref><ref>{{cite web|url=https://water.usgs.gov/nawqa/studies/mrb/salinity_briefing_sheet.pdf |title=New Findings on Salinity in Streams and Ground Water in the Southwestern United States |publisher=Water.usgs.gov |access-date=19 April 2013}}</ref><ref>{{cite web |url=http://ag.arizona.edu/pubs/crops/az1129.pdf |title=Growing Alfalfa for Seed in Arizona |publisher=Ag.arizona.edu |access-date=19 April 2013 |archive-date=6 June 2011 |archive-url=https://web.archive.org/web/20110606044057/http://ag.arizona.edu/pubs/crops/az1129.pdf |url-status=dead }}</ref> Soils low in fertility should be fertilized with manure or a chemical fertilizer, but correction of pH is particularly important.<ref>[http://www.extension.umn.edu/distribution/cropsystems/DC3814.html Fertilizing Alfalfa in Minnesota] {{webarchive|url=https://web.archive.org/web/20100617020013/http://www.extension.umn.edu/distribution/cropsystems/DC3814.html |date=17 June 2010 }}. Extension.umn.edu. Retrieved on 17 October 2011.</ref> Usually a seeding rate of {{convert|13-20|kg/ha|lb/acre|abbr=on}} is recommended, with differences based upon region, soil type, and seeding method.<ref>[http://www.uwex.edu/CES/crops/AlfSeedingRate.htm Alfalfa seeding rates: how much is too much?] {{Webarchive|url=https://web.archive.org/web/20090706072650/http://www.uwex.edu/CES/crops/AlfSeedingRate.htm |date=6 July 2009 }}. Uwex.edu. Retrieved on 17 October 2011.</ref> A nurse crop is sometimes used, particularly for spring plantings, to reduce weed problems and soil erosion, but can lead to competition for light, water, and nutrients.<ref>[http://msuextension.org/publications/AgandNaturalResources/MT200504AG.pdf MT200504.indd] {{Webarchive|url=https://web.archive.org/web/20110727100857/http://msuextension.org/publications/AgandNaturalResources/MT200504AG.pdf |date=27 July 2011 }}. (PDF) . Retrieved on 17 October 2011.</ref>

In most climates, alfalfa is cut three to four times a year, but it can be harvested up to 12 times per year in Arizona and southern California.<ref>[http://www.uwex.edu/ces/crops/uwforage/AlfalfaCutHeight.htm Alfalfa Cutting Height] {{Webarchive|url=https://web.archive.org/web/20100528094802/http://www.uwex.edu/ces/crops/uwforage/AlfalfaCutHeight.htm |date=28 May 2010 }}. Uwex.edu (9 April 1999). Retrieved on 17 October 2011.</ref><ref name="cfaitc">{{Cite web|url=https://learnaboutag.org/|archive-url=https://web.archive.org/web/20081006121003/http://www.cfaitc.org/Commodity/pdf/Alfalfa.pdf|url-status=dead|title=California Agriculture in the Classroom|archive-date=6 October 2008|website=learnaboutag.org}}</ref> Total yields are typically around {{convert|8|t/ha|ST/acre|frac=2|abbr=off}} in temperate environments, but yields have been recorded up to {{convert|20|t/ha|ST/acre|abbr=off|0}}.<ref name = "cfaitc"/> Yields vary with region, weather, and the crop's stage of maturity when cut. Later cuttings improve yield, but with reduced nutritional content.<ref>[http://www.alfalfa.org/pdf/Alfalfa%20for%20Horses%20(low%20res).pdf Alfalfa: The High-Quality Hay for Horses]. (PDF) . Retrieved on 17 October 2011.</ref>

=== Harvesting === [[File:Alfalfa hay, 1915.jpg|thumb|Alfalfa hay on the way to Clayton, New Mexico, circa 1915.]] thumbnail|right|Cylindrical bales of alfalfa

When alfalfa is to be used as hay, it is usually cut and baled.<ref name="uaex">{{Cite web |title=Harvesting Alfalfa Hay |url=http://www.uaex.edu/Other_Areas/publications/PDF/FSA-2005.pdf |url-status=dead |archive-url=https://web.archive.org/web/20100528080559/http://www.uaex.edu/Other_Areas/publications/PDF/FSA-2005.pdf |archive-date=28 May 2010 |access-date=19 April 2013 |website=University of Arkansas Cooperative Extension Service}}</ref> Loose haystacks are still used in some areas, but bales are easier for use in transportation, storage, and feed.<ref>{{Cite web |title=G4570 Reducing Losses when Feeding Hay to Beef Cattle |url=http://extension.missouri.edu/publications/DisplayPub.aspx?P=G4570 |archive-url=https://web.archive.org/web/20110111000456/http://extension.missouri.edu/publications/DisplayPub.aspx?P=G4570 |archive-date=11 January 2011 |access-date=17 October 2011 |website=University of Missouri Extension}}</ref> Ideally, the first cutting should be taken at the bud stage, and the subsequent cuttings just as the field is beginning to flower, or one-tenth bloom because carbohydrates are at their highest.<ref>{{Cite FTP |title=Alfalfa Management Guide—Harvest (3 of 3) |url=ftp://ftp-fc.sc.egov.usda.gov/ID/programs/technotes/tn8_alfalfaguide3.pdf |server=FTP server |url-status=dead |access-date=2011-10-17}}</ref> When using farm equipment rather than hand-harvesting, a swather cuts the alfalfa and arranges it in windrows.<ref>{{Cite web |title=Hay harvesting by Self-Propelled Swather compared with mowing and raking |url=http://ucce.ucdavis.edu/files/repositoryfiles/ca1505p2-64859.pdf |archive-url=https://web.archive.org/web/20110722193626/http://ucce.ucdavis.edu/files/repositoryfiles/ca1505p2-64859.pdf |archive-date=22 July 2011 |access-date=17 October 2011}}</ref> In areas where the alfalfa does not immediately dry out on its own, a machine known as a mower-conditioner is used to cut the hay.<ref name="uaex" /> The mower-conditioner has a set of rollers or flails that crimp and break the stems as they pass through the mower, making the alfalfa dry faster.<ref>{{Cite encyclopedia |title=hay mower-conditioner (agriculture) |encyclopedia=Britannica Online Encyclopedia |url=https://www.britannica.com/EBchecked/topic/257652/hay-mower-conditioner |access-date=17 October 2011}}</ref> After the alfalfa has dried, a tractor pulling a baler collects the hay into bales.

Several types of bales are commonly used for alfalfa. For small animals and individual horses, the alfalfa is baled into small, two-string bales, commonly named by the strands of string used to wrap it. Other bale sizes are three-string, and so on up to half-ton (six-string) "square" bales – actually rectangular, and typically about {{convert|40|x|45|x|100|cm|in|abbr=on}}.<ref name="usda">{{Cite journal |last1=Bauchan |first1=Gary R. |last2=Hossain |first2=M. Azhar |date=2001 |title=Distribution and Characterization of Heterochromatic DNA in the Tetraploid African Population Alfalfa Genome |url=http://ddr.nal.usda.gov/bitstream/10113/22014/1/IND23276500.pdf |url-status=dead |journal=Crop Science |volume=41 |issue=Nov.–Dec |pages=1921–1926 |doi=10.2135/cropsci2001.1921 |issn= |archive-url=https://web.archive.org/web/20120328041828/http://ddr.nal.usda.gov/bitstream/10113/22014/1/IND23276500.pdf |archive-date=28 March 2012 |access-date=19 April 2013 |via=USDA.gov |doi-access=}}</ref> Small square bales weigh from {{convert|25|to|30|kg|lb|abbr=on}} depending on moisture, and can be easily hand separated into "flakes". Cattle ranches use large round bales, typically {{convert|1.4|to|1.8|m|ft|abbr=on|frac=2}} in diameter and weighing from {{convert|500|to|1,000|kg|lb|abbr=on}}. These bales can be placed in stable stacks or in large feeders for herds of horses or unrolled on the ground for large herds of cattle.<ref name = "usda"/> The bales can be loaded and stacked with a tractor using a spike, known as a ''bale spear'' that pierces the center of the bale,<ref>{{Cite web |title=Washburn Company |url=http://www.washburncompany.com/ |url-status=dead |archive-url=https://web.archive.org/web/20100617065325/http://www.washburncompany.com/ |archive-date=17 June 2010 |access-date=8 May 2010}}{{better source needed|date=June 2024}}</ref> or they can be handled with a grapple (claw) on the tractor's front-end loader.

When used as feed for dairy cattle, alfalfa is often made into haylage by a process known as ensiling.<ref name="uaex.edu"/> Rather than being dried to make dry hay, the alfalfa is chopped finely and fermented in silos, trenches, or bags, where the oxygen supply can be limited to promote fermentation.<ref>{{Cite web |last=Harrison |first=Joseph H. |title=The Art and Science of Ensiling Alfalfa |url=http://ucanr.org/alf_symp/1995/95-55.pdf |archive-url=https://web.archive.org/web/20110718045312/http://ucanr.org/alf_symp/1995/95-55.pdf |archive-date=2011-07-18 |website=ucanr.org}}</ref> The anaerobic fermentation of alfalfa allows it to retain high nutrient levels similar to those of fresh forage and is more palatable to dairy cattle than dry hay.<ref>{{Cite journal |last1=Hartnell |first1=G.F. |last2=Hatfield |first2=R.D. |last3=Mertens |first3=D.R. |last4=Martin |first4=N.P. |year=2005 |title=Potential Benefits of Plant Modification of Alfalfa and Corn Silage to Dairy Diets |url=http://cals-cf.calsnet.arizona.edu/animsci/ansci/swnmc/papers/2005/Hartnell_SWNMC%20Proceedings%202005.pdf |journal=Proc. Southwest Nutr. Conf. |pages=156–172 |archive-url=https://web.archive.org/web/20120320151026/http://cals-cf.calsnet.arizona.edu/animsci/ansci/swnmc/papers/2005/Hartnell_SWNMC%20Proceedings%202005.pdf |archive-date=20 March 2012}}</ref> In many cases, alfalfa silage is inoculated with different strains of microorganisms to improve the fermentation quality and aerobic stability of the silage.<ref>{{Cite web |title=The Ensiling Process and Additives |url=http://www.extension.iastate.edu/Publications/PM417H.pdf |access-date=19 April 2013 |publisher=Extension.iastate.edu}}</ref><ref>{{Cite web |title=Alfalfa control test with polymicrobial biofertilizer |url=http://explogrow.com/case-studies/growing-lucerne-with-organic-bio-fertilizer |access-date=17 September 2016}}</ref>

=== Production === thumb|upright=1.6|Worldwide alfalfa production

During the early 2000s, alfalfa was the most cultivated forage legume in the world.<ref name=Reddy>{{cite book|author1=M S Reddy|author2=Rodolfo I. Ilao|author3=Patricio S. Faylon|title=Recent Advances in Biofertilizers and Biofungicides (PGPR) for Sustainable Agriculture|url=https://books.google.com/books?id=BOumBgAAQBAJ&pg=PA381|date=10 November 2014|publisher=Cambridge Scholars Publishing|isbn=978-1-4438-7105-1|page=381}}</ref> Worldwide production was around 436 million tons in 2006.<ref name=Reddy/> In 2009, alfalfa was grown on approximately {{convert|30|e6ha|e6acre|abbr=off}} worldwide; of this North America produced 41% ({{convert|11.9|e6ha|e6acre|disp=semicolon|abbr=off}}), Europe produced 25% ({{convert|7.12|e6ha|e6acre|disp=semicolon|abbr=off}}), South America produced 23% ({{convert|7|e6ha|e6acre|disp=semicolon|abbr=off}}), Asia produced 8% ({{convert|2.23|e6ha|e6acre|disp=semicolon|abbr=off}}), and Africa and Oceania produced the remainder.<ref name=Alfalfa_Ningxia>{{cite book|title=Alfalfa Management Guide for Ningxia|year=2009|publisher=United Nations Food and Agriculture Organization|pages=1–2|url=http://www.fao.org/ag/agp/AGPC/doc/ningxia_guide/alfalfa_guide_ningxia.pdf|editor=Cash, Dennis|access-date=3 August 2013|chapter=Chapter 1. Global Status and Development Trends of Alfalfa|chapter-url=http://www.fao.org/ag/agp/AGPC/doc/ningxia_guide/chapter1.pdf|archive-date=24 September 2015|archive-url=https://web.archive.org/web/20150924050741/http://www.fao.org/ag/agp/AGPC/doc/ningxia_guide/alfalfa_guide_ningxia.pdf|url-status=dead}}</ref> The US was the largest alfalfa producer in the world by area in 2009, with {{convert|9|e6ha|e6acre|abbr=off}}, but considerable production area is found in Argentina ({{convert|6.9|e6ha|e6acre|disp=semicolon|abbr=off}}), Canada ({{convert|2|e6ha|e6acre|disp=semicolon|abbr=off}}), Russia ({{convert|1.8|e6ha|e6acre|disp=semicolon|abbr=off}}), Italy ({{convert|1.3|e6ha|e6acre|disp=semicolon|abbr=off}}), and China ({{convert|1.3|e6ha|e6acre|disp=semicolon|abbr=off}}).<ref name=Alfalfa_Ningxia/>

==== United States ==== thumb|Alfalfa fields in the United States

In the United States in 2012, the leading alfalfa-growing states were California, Idaho, and Montana.<ref name="Crop Production 2012">{{cite web|title=Crop Production: 2012 Summary|url=https://usda01.library.cornell.edu/usda/current/CropProdSu/CropProdSu-01-11-2013.pdf|publisher=United States Department of Agriculture National Agricultural Statistics Service|access-date=3 August 2013|page=33|date=January 2013|url-status=dead|archive-url=https://web.archive.org/web/20130713165017/http://usda01.library.cornell.edu/usda/current/CropProdSu/CropProdSu-01-11-2013.pdf|archive-date=13 July 2013}}</ref> Alfalfa is predominantly grown in the northern and western US;<ref name="Crop Production 2012"/> it can be grown in the southeastern US, but leaf and root diseases, poor soils, and a lack of well-adapted varieties are often limitations.<ref>{{cite web|title=Alfalfa in the South|url=http://www.caf.wvu.edu/~forage/library/forglvst/bulletins/salfalfa.pdf|publisher=Certified Alfalfa Seed Council|access-date=3 August 2013|page=2|url-status=dead|archive-url=https://web.archive.org/web/20120717124316/http://www.caf.wvu.edu/~forage/library/forglvst/bulletins/salfalfa.pdf|archive-date=17 July 2012}}</ref>

In California, varieties resistant to the spotted alfalfa aphid (''Therioaphis maculata'') are necessary, but even that is not always enough due to constant resistance evolution.<ref name="SAA-UC-ANR">{{cite web | access-date=2022-07-27 | date=January 2017 | id=3430 | first1=L. D. | first2=E. T. | first3=P. B. | first4=R. F. | first5=V. M. | last4=Long | website=UC Agriculture (UC ANR), UC Integrated Pest Management (UC IPM) | url=https://www2.ipm.ucanr.edu/agriculture/alfalfa/Spotted-alfalfa-aphid/ | last1=Godfrey | last2=Natwick | last3=Goodell | last5=Barlow | title=Spotted Alfalfa Aphid ''Therioaphis maculata'' Agriculture: Alfalfa Pest Management Guidelines}}</ref>

==== Australia ==== Alfalfa grown in Australia prior to the 1970s was from seed brought from Great Britain in the early years of colonization, with production most successful in the Hunter River and Peel River valleys. Hunter River cv. was the first alfalfa variety developed for the Australian environment and was bred from selections of pre-existing alfalfa stands in the Upper Hunter River region.<ref>{{cite journal | last1 = Cameron | first1 = A.G. | last2 = Campbell | first2 = B.G. | title = Register of Australian Herbage Plant cultivars. B. Legumes. 8. Lucerne (a) Medicago sativa (L.) Benth. (lucerne) cv. Hunter River| journal = Australian Journal of Experimental Agriculture | year = 1972 | edition = 2nd | url=https://research.csiro.au/cultivars/wp-content/uploads/sites/162/2017/03/hunter_river.pdf}}</ref> Pest burdens from the spotted alfalfa aphid in the 1970s caused significant destruction of New South Wales alfalfa paddocks, with surviving populations being used as parents for Hunterfield cv. (released 1983). This variety showed significant improvement of resistance to spotted alfalfa aphid.<ref>{{cite journal | last1 = Barnard | first1 = C. | last2 = Drummond | first2 = G. | date = June 1983 | title = Register of Australian Herbage Plant cultivars. B. Legumes. 8. Lucerne (a) Medicago sativa (L.) Benth. (lucerne) cv. Hunterfield | journal = Australian Journal of Experimental Agriculture | volume = 49 | url=https://research.csiro.au/cultivars/wp-content/uploads/sites/162/2017/03/hunter_river.pdf}}</ref>

New South Wales produces 40% of Australia's alfalfa.<ref name="NSW" /> Due to the introduction of the spotted alfalfa aphid (''Therioaphis maculata'') in 1977,<ref>{{Cite journal |last1=Sunnucks |first1=P. |last2=Driver |first2=F. |last3=Brown |first3=W. V. |last4=Carver |first4=M. |last5=Hales |first5=D. F. |last6=Milne |first6=W. M. |date=August 1997 |title=Biological and genetic characterization of morphologically similar Therioaphis trifolii (Hemiptera: Aphididae) with different host utilization |url=https://www.cambridge.org/core/product/identifier/S0007485300037433/type/journal_article |journal=Bulletin of Entomological Research |language=en |volume=87 |issue=4 |pages=425–436 |doi=10.1017/S0007485300037433 |issn=0007-4853|url-access=subscription }}</ref> all varieties grown there must be resistant to it.<ref name="NSW">{{cite web | access-date=2022-07-27 | date=2022-07-27 | title=Lucerne | url=https://www.dpi.nsw.gov.au/agriculture/pastures-and-rangelands/species-varieties/lucerne | website=NSW Department of Primary Industries}}</ref><ref>{{cite web | access-date=2022-07-27 | date=2022-07-27 | title=Lucerne varieties | url=https://www.dpi.nsw.gov.au/agriculture/pastures-and-rangelands/species-varieties/pf/factsheets/lucerne-varieties | website=NSW Department of Primary Industries}}</ref><ref>{{cite web | access-date=2022-07-27 | date=2019-01-11 | title=Lucerne | url=https://agrifutures.com.au/farm-diversity/lucerne/ | website=AgriFutures Australia}}</ref> South Australia is home to 83% of all alfalfa seed production in Australia.<ref>{{cite web|title=Australian Lucerne Seed Industry Synopsis|url=https://www.lucerneaustralia.org.au/lucerne-info/australia-lucerne-seed-industry-synopsis/ |website=Lucerne Australia}}</ref> Much of this seed industry is centred around the town of Keith, South Australia, also encompassing the neighbouring localities of Tintinara, Bordertown, Willalooka, Padthaway and Naracoorte.

=== Alfalfa and bees === thumb|Alfalfa field

Alfalfa seed production requires the presence of pollinators when the fields of alfalfa are in bloom.<ref name = "usda"/> Alfalfa pollination is somewhat challenging because western honey bees, the most commonly used pollinator, are less than ideal for this purpose. The pollen-carrying keel of the alfalfa flower trips and strikes pollinating bees on the head, which helps transfer the pollen to the foraging bee.<ref name = "usda"/> Western honey bees learn to avoid being struck on the head by drawing nectar from the side of the flower. The bees thus collect the nectar but carry no pollen, so they do not pollinate the next flower they visit.<ref name=scinews>{{cite journal | first = Susan | last = Milius | date = 6 January 2007 | title = Most Bees Live Alone: No hives, no honey, but maybe help for crops | journal=Science News | volume = 171 | issue = 1 | pages = 11–3 |doi = 10.1002/scin.2007.5591710110}}</ref> Because older, experienced bees do not pollinate alfalfa well, most pollination is accomplished by young bees that have not yet learned the trick of robbing the flower without tripping the head-knocking keel.

When western honey bees are used to pollinate alfalfa, the beekeeper stocks the field at a very high rate to maximize the number of young bees.<ref name=scinews/> However, western honey bee colonies may suffer protein stress when working alfalfa only because alfalfa pollen protein is deficient in isoleucine, one of the amino acids essential in the diet of honeybee larvae.

Today, the alfalfa leafcutter bee (''Megachile rotundata'') is increasingly used to circumvent these problems.<ref name="pollination">{{Cite web |title=Alfalfa Leafcutter Bee in California |url=http://www.pollination.com/publications/IPSpub01.cfm |archive-url=https://web.archive.org/web/20040415204346/http://www.pollination.com/publications/IPSpub01.cfm |archive-date=15 April 2004 |access-date=17 October 2011 |website=www.pollination.com}}</ref> As a solitary but gregarious bee species, it does not build colonies or store honey but is a very efficient pollinator of alfalfa flowers.<ref name = "pollination"/> The species nests in individual tunnels in wooden or plastic material, supplied by the alfalfa seed growers.<ref name=scinews/> The leafcutter bees are used in the Pacific Northwest, while western honeybees dominate in California alfalfa seed production.<ref name=scinews/>

''M. rotundata'' was unintentionally introduced into the US during the 1940s, and its management as a pollinator of alfalfa has led to a three-fold increase in seed production in the US. The synchronous emergence of the adult bees of this species during alfalfa blooming period in combination with such behaviors as gregarious nesting, and utilization of leaves and nesting materials that have been mass-produced by humans provide positive benefits for the use of these bees in pollinating alfalfa.<ref>{{Cite journal|title = The alfalfa leafcutting bee, Megachile rotundata: the world's most intensively managed solitary bee|journal = Annual Review of Entomology |date = 2011-01-01 |issn= 1545-4487 |pmid= 20809804 |pages= 221–237 |volume= 56 |doi= 10.1146/annurev-ento-120709-144836|first1 = Theresa L.|last1 = Pitts-Singer|first2 = James H.|last2 = Cane|s2cid = 28686610 }}</ref>{{Clarify|reason=confusing run-on sentence|date=December 2025}}

A smaller amount of alfalfa produced for seed is pollinated by the alkali bee, mostly in the northwestern US. It is cultured in special beds near the fields. These bees also have their own problems. They are not portable like honey bees, and when fields are planted in new areas, the bees take several seasons to build up.<ref name=scinews/> Honey bees are still trucked to many of the fields at bloom time.

The rusty patched bumble bee, ''Bombus affinis'', is important to the agricultural industry as well as for the pollination of alfalfa.<ref name="Evans">{{Cite web |url = http://www.xerces.org/wp-content/uploads/2009/03/xerces_2008_bombus_status_review.pdf |title = Status Review of Three Formerly Common Species of Bumble Bee in the Subgenus Bombus |access-date = 10 October 2015 |website = The Xerces Society for Invertebrate Conservation |last = Evans |first = Elaine |archive-url = https://web.archive.org/web/20160304000902/http://www.xerces.org/wp-content/uploads/2009/03/xerces_2008_bombus_status_review.pdf |archive-date = 4 March 2016 |url-status = dead }}</ref> It is known that members of this species pollinate up to 65 different species of plants, and it is the primary pollinator of key dietary crops, such as cranberries, plums, apples, onions, and alfalfa.<ref name="Canada-2010">{{Cite web |title = COSEWIC Assessment and Status Report on the Rusty–patched Bumble Bee Bombus affinis in Canada – 2010 - Species at Risk Public Registry |url= http://registrelep-sararegistry.gc.ca/default.asp?lang=En&n=0F864E45-1|website = registrelep-sararegistry.gc.ca |access-date= 2015-10-11 |author=Environment Canada|date = 15 December 2010}}</ref>

=== Varieties === thumbnail|Small square bales of alfalfa

Considerable research and development has been done with alfalfa. Older cultivars such as 'Vernal' have been the standard for years, but many public and private varieties better adapted to particular climates are available.<ref>{{cite web|url=http://ohioline.osu.edu/agf-fact/0014.html|title=Alfalfa Variety Characteristics, AGF-014-92|access-date=17 October 2011|archive-url=https://web.archive.org/web/20150215021558/http://ohioline.osu.edu/agf-fact/0014.html |archive-date=15 February 2015|url-status=dead}}</ref> Private companies release many new varieties each year in the US.<ref name = "msu">{{cite web |url=http://msuextension.org/publications/AgandNaturalResources/MT199303AG.pdf |title=Alfalfa Variety Selection |publisher=Msuextension.org |access-date=19 April 2013 |archive-url=https://web.archive.org/web/20130326180653/http://msuextension.org/publications/AgandNaturalResources/MT199303AG.pdf |archive-date=26 March 2013 |url-status=dead }}</ref>

Most varieties go dormant in the fall, with reduced growth in response to low temperatures and shorter days.<ref name = "msu"/> 'Nondormant' varieties that grow through the winter are planted in long-season environments such as Mexico, Arizona, and Southern California, whereas 'dormant' varieties are planted in the Upper Midwest, Canada, and the Northeast.<ref name = "msu"/> 'Nondormant' varieties can be higher-yielding, but they are susceptible to winter-kill in cold climates and have poorer persistence.<ref name = "msu"/>

Most alfalfa cultivars contain genetic material from ''sickle medick'' (''M.'' ''falcata''), a crop wild relative of alfalfa that naturally hybridizes with ''M. sativa'' to produce ''sand lucerne'' (''M. sativa'' ssp. ''varia''). This species may bear either the purple flowers of alfalfa or the yellow of sickle medick, and is so called for its ready growth in sandy soil.<ref>Joseph Elwyn Wing, ''Alfalfa Farming in the U.S.'' 79 (Sanders Publishing Co. 1912)".</ref> Traits for insect resistance have also been introduced from ''M. glomerata'' and ''M. prostrata'', members of alfalfa's secondary gene pool.<ref>Vincent HA, Wiersema J, Dobbie SL, Kell SP, Fielder H, Castañeda Alvarez NP, Guarino L, Eastwood R, Leόn B, Maxted N. 2012. [http://www.cwrdiversity.org/checklist/genepool-details.php?id%5b%5d=29&id%5b%5d=290&id%5b%5d=288& A prioritised crop wild relative inventory to help underpin global food security.]{{dead link|date=January 2018 |bot=InternetArchiveBot |fix-attempted=yes }} (in preparation).</ref>

thumb|Watering an alfalfa field

==== Genetic modification ==== Genetically modified alfalfa includes Roundup Ready Alfalfa (RRA), which tolerates herbicide.<ref>[http://www.isaaa.org/gmapprovaldatabase/event/default.asp?EventID=11&Event=J101 ISSAA GM database approval entry for alfalfa event MON-00101]</ref>

In 2005, after completing a 28-page environmental assessment<ref name=NonregGrant>[https://www.aphis.usda.gov/sites/default/files/04_11001p_pea.pdf USDA/APHIS Environmental Assessment] United States Department of Agriculture, Animal and Plant Health Inspection Service, Biotechnology Regulatory Services, October 2004. Retrieved 13 November 2011</ref> the United States Department of Agriculture (USDA) granted RRA nonregulated status<ref>[http://www.federalregister.gov/articles/2005/06/27/E5-3323/monsanto-co-and-forage-genetics-international-availability-determination-of-nonregulated-status-for Monsanto Co. and Forage Genetics International; Availability Determination of Nonregulated Status for Alfalfa Genetically Engineered for Tolerance to the Herbicide Glyphosate] Federal Register, Animal and Plant Health Inspection Service, 27 June 2005. Retrieved 12 November 2011</ref> under Code of Federal Regulations Title 7 Part 340,<ref>Code of Federal Regulations, Title 7: Agriculture [http://www.ecfr.gov/cgi-bin/retrieveECFR?gp=1&SID=900d0f56a13e2b84951cc23e36b6d10b&h=Lf=t07.sgm&r=PART&n=7y5.1.1.1.10&ty=HTML Part 340—Introduction of Organisms and Products Altered or Produced Through Genetic Engineering Which Are Plant Pests or Which There Is Reason to Believe Are Plant Pests] {{Webarchive|url=https://web.archive.org/web/20151222094846/http://www.ecfr.gov/cgi-bin/retrieveECFR?gp=1&SID=900d0f56a13e2b84951cc23e36b6d10b&h=Lf=t07.sgm&r=PART&n=7y5.1.1.1.10&ty=HTML |date=22 December 2015 }}</ref> which regulates, among other things, the introduction (importation, interstate movement, or release into the environment) of organisms and products altered or produced through genetic engineering that are plant pests or that there is reason to believe are plant pests. Monsanto had to seek deregulation to conduct field trials of RRA, because the RRA contains a promoter sequence derived from the plant pathogen figwort mosaic virus.<ref name=NonregGrant />

The USDA granted the application for deregulation, stating that the RRA with its modifications: "(1) Exhibit no plant pathogenic properties; (2) are no more likely to become weedy than the nontransgenic parental line or other cultivated alfalfa; (3) are unlikely to increase the weediness potential of any other cultivated or wild species with which it can interbreed; (4) will not cause damage to raw or processed agricultural commodities; (5) will not harm threatened or endangered species or organisms that are beneficial to agriculture; and (6) should not reduce the ability to control pests and weeds in alfalfa or other crops."<ref name=NonregGrant /> Monsanto started selling RRA and within two years, more than 300,000 acres were devoted to the plant in the US.<ref name=OrloffPutnam>Steve Orloff and Dan Putnam [http://alfalfa.ucdavis.edu/+symposium/2011/files/talks/11WAS-25_Orloff_RRAlfalfa.pdf Roundup Ready Alfalfa—What Have We Learned to Date?] {{Webarchive|url=https://web.archive.org/web/20130412061504/http://alfalfa.ucdavis.edu/+symposium/2011/files/talks/11WAS-25_Orloff_RRAlfalfa.pdf |date=12 April 2013 }} Proceedings, 2011 Western Alfalfa & Forage Conference, Las Vegas, NV, 11–13 December 2011</ref>

The granting of deregulation was opposed by many groups, including growers of non-GM alfalfa who were concerned about gene flow into their crops.<ref name=NonregGrant /> In 2006, the Center for Food Safety, a US non-governmental organization that is a critic of biotech crops, and others, challenged this deregulation in the United States District Court for the Northern District of California.<ref name = SupremeCourt>[https://www.supremecourt.gov/opinions/09pdf/09-475.pdf Monsanto et al v Geertson Seed Farms et al] {{Webarchive|url=https://web.archive.org/web/20220305201932/https://www.supremecourt.gov/opinions/09pdf/09-475.pdf |date=5 March 2022 }}, Supreme Court of the United States, Decision no 09-475, 21 June 2010. Retrieved 13 November 2011</ref> Organic growers were concerned that the GM alfalfa could cross-pollinate with their organic alfalfa, making their crops unsalable in countries that ban the growing of GM crops.<ref>[https://www.theatlantic.com/food/archive/2010/06/supreme-court-on-modified-foods-who-won/58526/ Supreme Court on Modified Foods: Who Won?], by Barry Estabrook, 'The Atlantic'. 22 June 2010. Retrieved 22 June 2010.</ref> The District Court ruled that the USDA's environmental assessment did not address two issues concerning RRA's effect on the environment,<ref>These two issues were: 1) evaluation of the risk that complete deregulation of RRA would lead to cross-pollination or the transmission of the gene conferring glyphosate tolerance from RRA to conventional alfalfa 2) evaluation of the risk that growing RRA might lead to the development of Roundup-resistant weeds.</ref> and in 2007, required the USDA to complete a much more extensive environmental impact statement (EIS). Until the EIS was completed, they banned further planting of RRA but allowed land already planted to continue.<ref name=OrloffPutnam /><ref>[http://www.aphis.usda.gov/brs/pdf/Alfalfa_Ruling_20070503.pdf Memorandum and Order Re: Permanent Injunction] {{Webarchive|url=https://web.archive.org/web/20120303204524/http://www.aphis.usda.gov/brs/pdf/Alfalfa_Ruling_20070503.pdf |date=3 March 2012 }} United States District Court for Northern California, Case No C 06-01075 CR, 3 May 2007. Retrieved 13 November 2011</ref> The USDA proposed a partial deregulation of RRA but this was also rejected by the District Court.<ref name = SupremeCourt/> Planting of RRA was halted.

In June 2009, a divided three-judge panel on the 9th U.S. Circuit Court of Appeals upheld the District Court's decision.<ref name="nytimes.com"/> Monsanto and others appealed to the US Supreme Court.<ref name="nytimes.com">[https://www.nytimes.com/gwire/2010/06/21/21greenwire-supreme-court-lifts-ban-on-planting-gm-alfalfa-57894.html Supreme Court Lifts Ban on Planting GM Alfalfa] by Jennifer Koons, NYT, 21 June 2010 (Retrieved 21 June 2010)</ref>

On 21 June 2010, in ''Monsanto Co. v. Geertson Seed Farms'', the Supreme Court overturned the District Court decision to ban planting RRA nationwide as there was no evidence of irreparable injury.<ref>[http://www.scotuswiki.com/index.php?title=Monsanto_Company_v._Geertson_Seed_Farms Monsanto Company v. Geertson Seed Farms] at ScotusWiki – Briefs and Documents, etc.</ref> They ruled that the USDA could partially deregulate RRA before an EIS was completed. The Supreme Court did not consider the District Court's ruling disallowing RRA's deregulation and consequently RRA was still a regulated crop waiting for USDA's completion of an EIS.<ref name = SupremeCourt/>

This decision was welcomed by the American Farm Bureau Federation, Biotechnology Industry Organization, American Seed Trade Association, American Soybean Association, National Alfalfa and Forage Alliance, National Association of Wheat Growers, National Cotton Council, and National Potato Council.<ref>{{Cite web |title=Ag Groups Applaud Supreme Court Ruling On Biotech Alfalfa |url=https://www.medicalnewstoday.com/releases/192547 |access-date=2026-01-03 |website=Medical News Today |language=en}}</ref> In July 2010, 75 members of Congress from both political parties sent a letter to Agriculture Secretary Tom Vilsack asking him to immediately allow limited planting of genetically engineered alfalfa.<ref>{{Cite web |title=Seed World |url=https://www.seedworld.com/ |access-date=2026-01-03 |website=Seed World |language=en-US}}</ref><ref>[http://www.landolakesinc.com/stellent/groups/public/@lolinc/documents/web_content/ecmp2-0126480.pdf Letter by 75 Members of Congress to Vilsack] {{webarchive|url=https://web.archive.org/web/20150219160621/http://www.landolakesinc.com/stellent/groups/public/%40lolinc/documents/web_content/ecmp2-0126480.pdf |date=19 February 2015 }} Retrieved 1 November 2012</ref> However the USDA did not issue interim deregulatory measures, instead focusing on completing the EIS. Their 2,300-page EIS, published in December 2010, concluded that RRA would not affect the environment.<ref>[http://www.aphis.usda.gov/biotechnology/downloads/alfalfa/gt_alfalfa%20_feis.pdf Glyphosate-Tolerant Alfalfa Events J101 and J163: Request for Nonregulated Status Final Environmental Impact Statement] {{Webarchive|url=https://web.archive.org/web/20130301100225/http://www.aphis.usda.gov/biotechnology/downloads/alfalfa/gt_alfalfa%20_feis.pdf|date=1 March 2013}}, United States Department of Agriculture, December 2010. Retrieved 13 November 2011</ref>

Three of the biggest natural food brands in the US lobbied for a partial deregulation of RRA,<ref>Staff (24 February 2011) [http://ofbf.org/news-and-events/news/1253/ Deregulation of genetically modified alfalfa stirs debate about 'coexistence'] {{Webarchive|url=https://web.archive.org/web/20150219160701/http://ofbf.org/news-and-events/news/1253/ |date=19 February 2015 }} Ohio Farm Bureau Federation Inc., Retrieved 1 November 2011</ref> but in January 2011, despite protests from organic groups, Secretary Vilsack announced that the USDA had approved the unrestricted planting of genetically modified alfalfa and planting resumed.<ref>[http://www.aphis.usda.gov/biotechnology/alfalfa_eis.shtml USDA - Roundup Ready® Alfalfa Environmental Impact Statement (EIS)] {{webarchive |url=https://web.archive.org/web/20080924100325/http://www.aphis.usda.gov/biotechnology/alfalfa_eis.shtml |date=24 September 2008 }}, United States Department of Agriculture, December 2010. Retrieved 13 November 2011</ref><ref>Gilla, Carey and Doering, Christopher [https://www.reuters.com/article/gmo-alfalfa-usda-idUSN2727513020110127 UPDATE 3-U.S. farmers get approval to plant GMO alfalfa] {{Webarchive|url=https://web.archive.org/web/20150924150815/http://www.reuters.com/article/2011/01/27/gmo-alfalfa-usda-idUSN2727513020110127 |date=24 September 2015 }} Reuters US Edition, 27 January 2011. Retrieved 28 April 2011</ref><ref>{{Cite news |date=2011-01-28 |title=USDA Officially Approves Genetifically Modified Alfalfa |url=https://www.huffingtonpost.com/2011/01/28/vilsack-usda-gmo-alfalfa-monsanto_n_815513.html |archive-url=https://web.archive.org/web/20180914021943/https://www.huffingtonpost.com/2011/01/28/vilsack-usda-gmo-alfalfa-monsanto_n_815513.html |archive-date=14 September 2018 |access-date=2026-01-03 |work=HuffPost |language=en-US |url-status=live }}</ref> Secretary Vilsack commented, "After conducting a thorough and transparent examination of alfalfa ... APHIS [<nowiki/>Animal and Plant Health Inspection Service] has determined that [RRA] is as safe as traditionally bred alfalfa."<ref>USDA News Release No. 0035.11, 27 January 2011. [http://www.usda.gov/wps/portal/usda/usdahome?contentidonly=true&contentid=2011/01/0035.xml USDA Announces Decision to Fully Deregulate Roundup Ready Alfalfa] {{webarchive|url=https://web.archive.org/web/20150910020304/http://www.usda.gov//wps/portal/usda/usdahome?contentidonly=true&contentid=2011%2F01%2F0035.xml |date=10 September 2015 }}</ref> About {{convert|20|e6acre|e6ha|abbr=off}} of alfalfa were grown in the US, the fourth-biggest crop by acreage, of which about 1% were organic. Some biotechnology officials forecast that half of the US alfalfa acreage could eventually be planted with GM alfalfa.<ref name = wsj1/>

The National Corn Growers Association,<ref name=NCGA>Staff (20 January 2011) [https://archive.today/20130129022659/http://www.minnesotafarmguide.com/news/opinion/national-corn-growers-assn-supports-deregulation-of-roundup-ready-alfalfa/article_cff8d344-24c8-11e0-87f8-001cc4c03286.html National Corn Growers Assn. supports deregulation of Roundup Ready alfalfa] The Minnesota Farm Guide, Retrieved 1 November 2012</ref> the American Farm Bureau Federation,<ref>Tannen, Benjamin (14 March 2011) [https://www.law.upenn.edu/blogs/regblog/2011/03/usda-fully-deregulates-genetically-modified-alfalfa.html USDA Fully Deregulates Genetically Modified Alfalfa] {{Webarchive|url=https://web.archive.org/web/20121107005952/https://www.law.upenn.edu/blogs/regblog/2011/03/usda-fully-deregulates-genetically-modified-alfalfa.html |date=7 November 2012 }} University of Pennsylvania Law School, RegBlog News, Retrieved 1 November 2012</ref> and the Council for Biotech Information<ref>Staff (27 January 2011) [http://www.biotech-now.org/food-and-agriculture/farmer-gene/2011/01/bio-applauds-usda-decision-to-deregulate-biotech-alfalfa BIO Applauds USDA Decision to Deregulate Biotech Alfalfa] {{Webarchive|url=https://web.archive.org/web/20130522075734/http://www.biotech-now.org/food-and-agriculture/farmer-gene/2011/01/bio-applauds-usda-decision-to-deregulate-biotech-alfalfa |date=22 May 2013 }} Biotech Now, Retrieved 1 November 2012</ref> warmly applauded this decision. Christine Bushway, CEO of the Organic Trade Association, said, "A lot of people are shell-shocked. While we feel Secretary Vilsack worked on this issue, which is progress, this decision puts our organic farmers at risk."<ref name = wsj1>Tomson, Bill and Kilman, Scott [https://www.wsj.com/articles/SB10001424052748703399204576108601430251740 USDA Won't Impose Restrictions on Biotech Alfalfa Crop] Wall Street Journal, 27 January 2011. Retrieved 27 April 2011</ref> The Organic Trade Association issued a press release in 2011 saying that the USDA recognized the impact that cross-contamination could have on organic alfalfa and urged them to place restrictions to minimize any such contamination.<ref>[http://www.organicnewsroom.com/2011/01/organic_industry_wants_farmers_1.html Organic Trade Association's Organic Newsroom: Organic industry wants farmers protected in the marketplace] {{Webarchive|url=https://web.archive.org/web/20120720220824/http://www.organicnewsroom.com/2011/01/organic_industry_wants_farmers_1.html |date=20 July 2012 }}. Organicnewsroom.com (20 January 2011). Retrieved on 8 February 2011.</ref> However, organic farming groups, organic food outlets, and activists responded by publishing an open letter saying that planting the "alfalfa without any restrictions flies in the face of the interests of conventional and organic farmers, preservation of the environment, and consumer choice".<ref>{{cite web |url=http://www.unfi.com/OpenLetter_GEAlfalfa.aspx |title=We Stand United in Opposition to GE Alfalfa |date=31 January 2011 |access-date=19 March 2011 |url-status=dead |archive-url=https://web.archive.org/web/20110302133913/http://www.unfi.com/OpenLetter_GEAlfalfa.aspx |archive-date=2 March 2011}}</ref> In addition to House Agriculture Committee Chairman Frank Lucas, Senator Debbie Stabenow (Chairwoman of the Senate Agriculture Committee) and Senator Richard Lugar strongly supported the decision, respectively stating that it would give growers "the green light to begin planting an abundant, affordable and safe crop"<ref name="Stabenow">Staff (January 2011) [http://www.agri-pulse.com/Stabenow_Welcomes_USDA_Alfalfa_Decision_20110127H.asp Senate Ag's Stabenow, House Ag's Lucas welcome biotech alfalfa deregulation] Agri-Pulse Communications Inc., Retrieved 1 November 2012</ref> and give farmers and consumers the "choice ... in planting or purchasing food grown with GM technology, conventionally, or organically".<ref>Harsch, John H. (27 January 2011) [http://www.agri-pulse.com/Lugar_Supports_GE_Alfalfa_Decision_20110127H.asp Sen. Lugar strongly supports GE alfalfa deregulation, to avoid 'government control'] Agri-Pulse Communications Inc., Retrieved 1 November 2012</ref> In a joint statement, US Senator Patrick Leahy and Representative Peter DeFazio said the USDA had the "opportunity to address the concerns of all farmers", but instead "surrender[ed] to business as usual for the biotech industry".<ref>{{Cite web |date=January 27, 2011 |title=USDA's Decision Thursday On Genetically Engineered Alfalfa – Leahy And DeFazio Warn About USDA Decision Lifting All Protections For Organic And Conventional Farmers |url=http://www.leahy.senate.gov/press/press_releases/release/?id=61836a8b-018c-43f6-82c1-04b3016e27d6 |archive-url=https://web.archive.org/web/20120503122459/http://www.leahy.senate.gov/press/press_releases/release/?id=61836a8b-018c-43f6-82c1-04b3016e27d6 |archive-date=2012-05-03 |access-date=2024-07-15 |website=Patrick Leahy}}</ref>

In March 2011, the non-profit Center for Food Safety appealed the deregulation decision,<ref>[http://www.huffingtonpost.com/maria-rodale/we-stand-united-in-opposi_b_816637.html Maria Rodale: We Stand in Opposition to GE Alfalfa]. Huffingtonpost.com. Retrieved on 8 February 2011.</ref> which the District Court for Northern California rejected in 2012.<ref>{{cite journal | url=http://online.liebertpub.com/doi/abs/10.1089/blr.2012.9900 | doi=10.1089/blr.2012.9900 | title=Nigeria Passes Law Allowing Genetically Modified Plants | journal=Biotechnology Law Report | date=2012 | volume=31 | issue=2 | page=153 | url-access=subscription }}</ref>

== Safety concerns == Alfalfa sprouts may contain microbiological pathogens, mainly from ''Salmonella'' or ''E.'' ''coli'', which have caused numerous food product recalls and illness outbreaks, putting sprouts into a "high risk" category for food safety.<ref name="ontario" /><ref name="cdc">{{cite web |date=28 February 2023 |title=''Salmonella'' Outbreak Linked to Alfalfa Sprouts |url=https://www.cdc.gov/salmonella/typhimurium-12-22/index.html |archive-url=https://web.archive.org/web/20221230183437/https://www.cdc.gov/salmonella/typhimurium-12-22/index.html |archive-date=30 December 2022 |access-date=7 October 2023 |publisher=US Centers for Disease Control and Prevention}}</ref><ref name="baker">{{cite web |author1=Kimberly Baker |date=1 December 2016 |title=The Food Safety of Sprouts: Factsheet |url=https://www.clemson.edu/extension/food/food2market/factsheets/7-the-food-safety-of-sprouts-factsheets.html |access-date=7 October 2023 |publisher=Consumer Food Safety Program, Cooperative Extension, Clemson University}}</ref> People with weakened immune systems, such as the elderly, pregnant women, or those taking prescription drugs affecting the immune system, should not eat sprouts.<ref name="baker" />

With long-term human consumption of alfalfa seeds, several safety concerns and medication interactions may result, including possible reactions similar to lupus erythematosus, an autoimmune disease.<ref name="mlp">{{cite web |date=24 September 2021 |title=Alfalfa |url=https://medlineplus.gov/druginfo/natural/19.html |access-date=7 October 2023 |publisher=MedlinePlus, U.S. National Library of Medicine}}</ref>

Other concerns are for women during pregnancy or breast-feeding, hormone-sensitive conditions (such as breast, uterine, and ovarian cancers), and for people with diabetes.<ref name="mlp" /> Alfalfa may interact with warfarin (e.g. Coumadin), birth control pills (contraceptive drugs), and estrogens.<ref name="mlp" />

=== Toxicity of canavanine === Raw alfalfa seeds and sprouts are a source of the amino acid canavanine. Much of the canavanine is converted into other amino acids during germination, so sprouts contain much less canavanine than unsprouted seeds.<ref>{{cite book |author=Jay D. Mann |url=https://books.google.com/books?id=ebW4QzlolAUC&pg=PA45 |title=How to Poison Your Spouse the Natural Way: A Guide to High-Risk Dining |publisher=JDM & Associates |year=2004 |isbn=978-1-877139-73-4 |page=45}}</ref> Canavanine competes with arginine, resulting in the synthesis of dysfunctional proteins. Raw unsprouted alfalfa has toxic effects in primates, including humans, which can result in lupus-like symptoms and other immunological diseases in susceptible individuals.<ref name="pmid6178289">{{Cite journal |last1=Bardana Jr |first1=E. J. |last2=Malinow |first2=M. R. |last3=Houghton |first3=D. C. |last4=McNulty |first4=W. P. |last5=Wuepper |first5=K. D. |last6=Parker |first6=F |last7=Pirofsky |first7=B |year=1982 |title=Diet-induced systemic lupus erythematosus (SLE) in primates |journal=American Journal of Kidney Diseases |volume=1 |issue=6 |pages=345–52 |doi=10.1016/s0272-6386(82)80005-x |pmid=6178289}}</ref><ref name="pmid1862241">{{Cite journal |last1=Montanaro |first1=A |last2=Bardana Jr |first2=E. J. |year=1991 |title=Dietary amino acid-induced systemic lupus erythematosus |journal=Rheumatic Disease Clinics of North America |volume=17 |issue=2 |pages=323–32 |doi=10.1016/S0889-857X(21)00573-1 |pmid=1862241}}</ref> Stopping consumption of alfalfa seeds can reverse the effects.<ref>{{Cite journal |last1=Herbert |first1=V. |last2=Kasdan |first2=T. S. |date=1 October 1994 |title=Alfalfa, vitamin E, and autommune disorders |journal=The American Journal of Clinical Nutrition |volume=60 |issue=4 |pages=639–640 |doi=10.1093/ajcn/60.4.639 |pmid=8092103}}</ref>

=== Phytoestrogens and effect on livestock fertility === Alfalfa, like other leguminous crops, is a source of phytoestrogens,<ref>{{cite journal|last=Saloniemi|first=Hannu|author2=Wähälä, Kristiina|author3=Nykänen-Kurki, Päivi|author4= Kallela, Kaarlo|author5= Saastamoinen, Ilkka|pmid=7892287|doi=10.3181/00379727-208-43825|volume=208|issue=1|title=Phytoestrogen content and estrogenic effect of legume fodder|date=January 1995|journal=Proceedings of the Society for Experimental Biology and Medicine|pages=13–7|bibcode=1995ExpBM.208...13S |s2cid=40324719}}</ref> including spinasterol,<ref>{{cite web|title=Chemical Substance - alpha-Spinasterol|url=http://webprod.hc-sc.gc.ca/nhpid-bdipsn/ingredReq.do?id=3052&lang=eng|publisher=Health Canada|access-date=3 August 2013|date=8 July 2013|archive-date=24 December 2013|archive-url=https://web.archive.org/web/20131224051603/http://webprod.hc-sc.gc.ca/nhpid-bdipsn/ingredReq.do?id=3052&lang=eng|url-status=dead}}</ref> coumestrol, and coumestan.<ref name=CPPIS>{{cite web |title=Notes on poisoning: alfalfa |url=http://www.cbif.gc.ca/eng/species-bank/canadian-poisonous-plants-information-system/all-plants-common-name/canadian-poisonous-plants-information-system-alfalfa-common-name/?id=1370403267050 |work=Canadian Poisonous Plants Information System |publisher=Canadian Biodiversity Information Facility |access-date=30 October 2014 |date=8 July 2014}}</ref> Because of this, grazing on alfalfa during breeding can cause reduced fertility in sheep and dairy cattle if not effectively managed.<ref name=CPPIS/><ref name="Fields-2019">{{Cite journal|last1=Fields|first1=R. L.|last2=Moot|first2=D. J.|last3=Sedcole|first3=J. R.|last4=Barrell|first4=G. K.|s2cid=91082792|date=2019|title=Recovery of ovulation rate in ewes following their removal from an oestrogenic lucerne forage|journal=Animal Production Science|language=en|volume=59|issue=3|pages=493|doi=10.1071/AN17586|issn=1836-0939}}</ref>

Coumestrol levels in alfalfa have been shown to be elevated by fungal infection, but not significantly under drought stress<ref>Fields, R.L., D.J. Moot, and G.K. Barrell. 2017. [http://www.agronomyaustraliaproceedings.org/images/sampledata/2017/24_ASA2017_Fields_Rachel_Final.pdf Coumestrol content of lucerne under drought stress], Proceedings of the 18th Australian Society of Agronomy Conference, Ballarat, Australia.</ref> or aphid infestation.<ref>{{Cite journal|last1=Fields|first1=Rachel L.|last2=Barrell|first2=Graham K.|last3=Gash|first3=Alan|last4=Zhao|first4=Jenny|last5=Moot|first5=Derrick J.|date=2018|title=Alfalfa Coumestrol Content in Response to Development Stage, Fungi, Aphids, and Cultivar|journal=Agronomy Journal|language=en|volume=110|issue=3|pages=910|doi=10.2134/agronj2017.09.0535|issn=0002-1962|doi-access=free|bibcode=2018AgrJ..110..910F |hdl=10182/10252|hdl-access=free}}</ref> Grazing management can be utilised to mitigate the effects of coumestrol on ewe reproductive performance, with full recovery after removal from alfalfa.<ref name="Fields-2019" /> Coumestrol levels in unirrigated crops can be predicted practically using weather variables.<ref>{{Cite journal|last1=Fields|first1=Rachel Lilian|last2=Sedcole|first2=J. Richard|last3=Barrell|first3=Graham Keith|last4=Moot|first4=Derrick Jan|date=2019-10-02|title=Prediction of coumestrol content in unirrigated lucerne crops using weather variables|journal=New Zealand Journal of Agricultural Research|language=en|volume=62|issue=4|pages=528–542|doi=10.1080/00288233.2018.1519512|bibcode=2019NZJAR..62..528F |s2cid=92277149|issn=0028-8233}}</ref>

{{nutritional value | name=Alfalfa seeds, sprouted, raw | kJ=96 | water=93 g | protein=4 g | fat=0.7 g | carbs=2.1 g | fiber=1.9 g | calcium_mg=32 | iron_mg=0.96 | magnesium_mg=27 | phosphorus_mg=70 | potassium_mg=79 | sodium_mg=6 | zinc_mg=0.92 | manganese_mg=0.188 | vitC_mg=8.2 | thiamin_mg=0.076 | riboflavin_mg=0.126 | niacin_mg=0.481 | pantothenic_mg=0.563 | vitB6_mg=0.034 | folate_ug=36 | vitK_ug=30.5 | source_usda = 1 | note=[https://fdc.nal.usda.gov/food-details/168384/nutrients Link to USDA Database entry] }}

== Nutrition == Raw alfalfa seed sprouts are 93% water, 2% carbohydrates, and 4% protein.<ref>[https://fdc.nal.usda.gov/food-details/168384/nutrients USDA Database entry]</ref>

=== Sprouts ===

Sprouting alfalfa seeds is the process of germinating seeds at the immature stage for use as a garnish on various food preparations, such as salads. Although sprouts may be grown in soil, they are more commonly germinated in a soilless medium using drums, trays or racks.<ref name="ontario">{{cite web |title=Overview of food safety for sprouts and microgreens |url=https://www.ontario.ca/page/overview-food-safety-sprouts-and-microgreens |publisher=Ministry of Agriculture, Food and Rural Affairs, Government of Ontario |access-date=7 October 2023 |date=1 March 2022}}</ref>

{{gallery|mode=packed |AlfalfaSprouts1.jpg|Close up of alfalfa sprouts }}

==See also== *Cover crop *Green manure

== References == {{format footnotes|section|date=October 2025}} {{Reflist}}

== External links == {{Wikibooks}} {{Cookbook}}

*{{Commons inline|italic=on}} *{{Wikispecies inline|Medicago sativa|''Medicago sativa''}} *{{Wiktionary inline}} * [https://gutenberg.org/ebooks/67533 The Book of Alfalfa: History, Cultivation and Merits by F. D. Coburn]

Category:Forages Category:Medicago Category:Nitrogen-fixing crops Category:Plants used in traditional Chinese medicine Category:Pollination management Category:Vegetables

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