View source for Hemp

{{About|industrial hemp|its psychoactive variant|Cannabis (drug)|the biology of the plant|Cannabis|other uses|Hemp (disambiguation)}}
[[Image:Cannab2 new.png|thumb|right|The variety of appearances for cannabis. Only ''C. sativa'' (left) is suited for industrial hemp, but it also has medicinal varieties.]]
'''Hemp''' (from [[Old English]] ''[[cannabis (etymology)|hænep]]'') is the name of the soft, durable fibre that is cultivated from plants of the ''[[Cannabis]]'' [[genus]], cultivated for commercial use.

In modern times, hemp has been used for industrial purposes including paper, [[textiles]], [[biodegradable plastic]]s, [[construction]], health food, fuel, and medical purposes<ref>{{cite web|url=http://www.ecofibre.com.au/facts.html|title=Ecofibre Industries Limited - Facts About Hemp}}</ref> with modest commercial success.<ref name="Gertjan"/><ref name="Alberta">{{cite web |
title=Industrial Hemp Production in Alberta |
year=2008 |
url=http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/econ9631 |
author=Atkinson, Gail |
publisher=Government of Alberta, Agriculture and Rural Development}}</ref> In the past three years, commercial success of hemp food products has grown considerably.<ref name="CNBC Special Report">{{cite web|url=http://www.cnbc.com/id/30685661/|title=CNBC Special Report}}</ref><ref>{{cite web|url=http://online.wsj.com/article/SB123069062782044697.html|title=Wall Street Journal: Edible, Affordable Indulgences for 2009}}</ref>

Hemp is one of the faster growing [[biomass]]es known,<ref>"The yield of hemp fibre varies from 400 to 2,500 pounds per acre, averaging 1,000 pounds under favorable conditions." Dewey & Merrrill, Hemp Hurds As Papermaking Material, U.S.D.A. Bulletin No.404, 1916, page 3.</ref> producing up to 25 tonnes of dry matter per [[hectare]] per year,<ref>[http://dx.doi.org/10.1016/S0926-6690(99)00048-5 Agronomy of fibre hemp (Cannabis sativa L.) in Europe]</ref> and one of the earliest domesticated plants known.<ref name="aust">
{{cite web
|url=http://www2.dpi.qld.gov.au/hemp/16241.html
|title=Information paper on industrial hemp (industrial cannabis)
|publisher=www2.dpi.qld.gov.au
|accessdate=2008-07-05
|last=
|first=
}}
</ref> For a crop, hemp is very environmentally friendly, as it requires few [[pesticide]]s<ref name="thehia">
{{cite web
|url=http://www.thehia.org/facts.html
|title=HIA: Resources: Education: FAQs & Facts: Facts
|publisher=www.thehia.org
|accessdate=2008-07-05
|last=
|first=
}}
</ref> and no herbicides.<ref name="thehia2">
{{cite web
|url=http://www.thehia.org/faq7.html
|title=HIA: Resources: Education: FAQs & Facts: FAQs: Answers
|publisher=www.thehia.org
|accessdate=2008-07-05
|last=
|first=
}}
</ref> 
Modern research data on soil fertility is limited. Currently, results indicate that high yield of hemp may require total nutrient levels (field plus fertilizer nutrients) similar to a high yielding wheat crop<ref>[http://www.agriculture.gov.sk.ca/Default.aspx?DN=e60e706d-c852-4206-9959-e4b134782175 D. Risula, and others,  Saskatchewan Ministry of Agriculture, October 2009</ref> 


''Cannabis sativa'' L. subsp. ''sativa'' var. ''sativa'' is the variety grown for industrial use, while ''C. sativa'' subsp. ''indica'' generally has poor fibre quality and is primarily used for production of recreational and medicinal drugs. The major difference between the two types of plants is the appearance and the amount of Δ<sup>9</sup>-[[tetrahydrocannabinol]] (THC) secreted in a resinous mixture by [[Epidermis (botany)|epidermal]] hairs called glandular [[trichomes]], although they can also be distinguished genetically.<ref>Datwyler SL, Weiblen GD. Genetic Variation in Hemp and marijuana (''Cannabis sativa L.'') ''sativa'' plants are taller and less dense. ''Indica'' plants are shorter but a lot more dense than ''sativas''. According to Amplified Fragment Length Polymorphisms. ''Journal of Forensic Sciences''. 2006; 51(2):371-375. {{doi|10.1111/j.1556-4029.2006.00061.x}}</ref> Oilseed and fibre varieties of ''Cannabis'' approved for industrial hemp production produce only minute amounts of this psychoactive drug, not enough for any physical or psychological effects. Typically, hemp contains below 0.3% THC, while cultivars of ''Cannabis'' grown for marijuana can contain anywhere from 6 to over 20%.<ref name=myths>[http://www.naihc.org/hemp_information/content/hemp.mj.html Hemp and Marijuana: Myths & Realities] written by David P. West, Ph.D. for the North American Industrial Hemp Council</ref>

Industrial hemp is produced in many countries around the world.<ref>[[National Non-Food Crops Centre]]. [http://www.nnfcc.co.uk/metadot/index.pl?id=2662;isa=DBRow;op=show;dbview_id=2329 "Hemp"], Retrieved on 2009-03-26.</ref> Major producers include [[Canada]], [[France]], and [[China]]. While more hemp is exported to the United States than to any other country, the [[United States Government]] does not consistently distinguish between [[marijuana]] and the non-psychoactive ''Cannabis'' used for industrial and commercial purposes.<ref name=myths/>

== Uses ==
Hemp is used for a wide variety of purposes, including the manufacture of [[cordage]] of varying [[Tension (mechanics)|tensile strength]], clothing, and nutritional products. The ''[[bast fibre]]s'' can be used in 100% hemp products, but are commonly blended with other organic fibres such as flax, cotton or silk, for apparel and furnishings, most commonly at a 55%/45% hemp/cotton blend. The inner two fibres of hemp are more woody, and are more often used in non-woven items and other industrial applications, such as [[mulch]], animal bedding and litter. The [[Hemp oil|oil from the fruits]] ("seeds") oxidizes (commonly, though inaccurately, called "drying") to become solid on exposure to air, similar to [[linseed]] oil, and is sometimes used in the manufacture of oil-based paints, in creams as a moisturizing agent, for cooking, and in plastics. Hemp seeds have been used in bird seed mix as well.<ref>{{cite web | url=http://www.erowid.org/plants/cannabis/cannabis_culture2.shtml | title=Erowid Cannabis Vault : Culture #2|publisher=www.erowid.org | accessdate=2008-06-20 | last= |first=}}</ref> Hempseed is also widely used as a [[fishing bait]].

=== Food ===
[[Image:Shelled hemp seeds.jpg|thumb|left|Shelled hemp seeds]]
Hemp seeds contain all the [[essential amino acid]]s and essential fatty acids necessary to maintain healthy human life.<ref>http://www.ratical.org/renewables/hempseed1.html</ref> The seeds can be eaten raw, ground into a meal, sprouted, made into [[hemp milk]] (akin to [[soy milk]]), prepared as tea, and used in baking. The fresh leaves can also be eaten in salads.  Products range from cereals to frozen [[waffle]]s, hemp tofu to nut butters. A few companies produce value added hemp seed items that include the seed oils, whole hemp grain (which is sterilized by law), dehulled hemp seed (the whole seed without the mineral rich outer shell), hemp flour, hemp cake (a by-product of pressing the seed for oil) and hemp protein powder. Hemp is also used in some organic cereals, for non-dairy milk<ref>
{{cite web
|url=http://www.worldpantry.com/cgi-bin/ncommerce/ExecMacro/livingharvest/home.d2w/report
|title=Living Harvest - The Official Website & Online Store - Hemp Seed Nutrition - Unearthing the Benefits of Hemp Seed
|publisher=www.worldpantry.com
|accessdate=2008-07-27
|last=
|first=
}}
</ref> somewhat similar to soy and nut milks, and for non-dairy hemp "ice cream."

Within the UK, the [[Department for Environment, Food and Rural Affairs]] (Defra) has treated hemp as purely a non-food crop. Seed appears on the UK market as a legal food product, and cultivation licences are available for this purpose. In North America, hemp seed food products are sold, typically in health food stores or through mail order.
The [[United States Department of Agriculture]] estimates that "the market potential for hemp seed as a food ingredient is unknown. However, it probably will remain a small market, like those for sesame and poppy seeds."<ref name="ages">http://www.ers.usda.gov/publications/ages001E/ages001Eh.pdf</ref>
{{-}}

==== Nutrition ====
{{Contradict-other|Essential amino acid|here|Contradiction with Essential amino acid|date=August 2010}}

<div align="left">
{| class="wikitable collapsible collapsed" style="width:400px; text-align:center; font-size: 90%;"
! colspan="2" | Typical nutritional analysis of hemp nut (hulled hemp seeds)<ref>http://www.wcranchohemp.com/info.php</ref>
|-
! [[Calorie]]s/100 [[gram|g]]
| 567
|-
! [[Protein]]
| 30.6
|-
! [[Carbohydrate]]
| 10.9
|-
! [[Dietary fiber]]
| 6
|-
! [[Fat]]
| 47.2
|-
! [[Saturated fat]]
| 5.2
|-
! [[Palmitic acid|Palmitic 16:0]]
| 3.4
|-
! [[Stearic acid|Stearic 18:0]]
| 1.5
|-
! [[Monounsaturated fat]]
| 5.8
|-
! [[Oleic acid|Oleic 18:1]] ([[Omega-9]])
| 5.8
|-
! [[Polyunsaturated fat]]
| 36.2
|-
! [[Linoleic acid|Linoleic 18:2]] ([[Omega-6]])
| 27.6
|-
! [[Alpha-linolenic acid|Linolenic 18:3]] ([[Omega-3]])
| 8.7
|-
! [[Gamma-linolenic acid|Linolenic 18:3]] ([[Omega-6]])
| 0.8
|-
! [[Cholesterol]]
| 0&nbsp;mg
|-
! [[Moisture]]
| 5
|-
! [[Ash (analytical chemistry)|Ash]]
|6.6
|-
! [[Vitamin A]] (B-Carotene)
| 4 [[International unit|IU]]
|-
! [[Thiamine]] (Vit B<sub>1</sub>)
| 1 [[milligramme|mg]]
|-
! [[Riboflavin]] (Vit B<sub>2</sub>)
| 1&nbsp;mg
|-
! [[Vitamin B6|Vitamin B<sub>6</sub>]]
| 0&nbsp;mg
|-
! [[Niacin]] (Vit B<sub>3</sub>)
| 0&nbsp;mg
|-
! [[Vitamin C]]
 | 1.0&nbsp;mg
|-
! [[Vitamin D]]
 | 0 IU
|-
! [[Vitamin E]]
| 9 IU
|-
! [[Sodium]]
 | 9&nbsp;mg
|-
! [[Calcium]]
| 74&nbsp;mg
|-
! [[Iron]]
| 4.7&nbsp;mg
|-
|}
</div>
About 30–35% of the weight of hempseed is hempseed oil or [[hemp oil]], an edible oil that contains about 80% [[essential fatty acid]]s (EFAs); i.e., [[linoleic acid]], [[omega-6]] ([[LA]], 55%), [[alpha-linolenic acid]], [[omega-3]] ([[ALA]], 22%), in addition to [[gamma-linolenic acid]], [[omega-6]] ([[GLA]], 1–4%) and [[stearidonic acid]], [[omega-3]] ([[SDA]], 0–2%). Whole hempseed also contains about 25% of a highly-digestible [[protein]], where 1/3 is [[edestin]] and 2/3 are [[albumins]]. Its [[amino acid]]  profile is close to "complete" when compared to more common sources of proteins such as meat, milk, eggs and [[soy]].<ref>Callaway JC (2004). Hempseed as a nutritional resource: an overview. Euphytica 140:65-72.</ref>  The proportions of linoleic acid and alpha-linolenic acid in one tablespoon (15 ml) per day of [[hemp oil]] easily provides human daily requirements for EFAs. Unlike [[flax]]seed oil, hemp oil can be used continuously without developing a deficiency or other imbalance of EFAs.<ref name="Schwab U 2006">Schwab U, Callaway J, Erkkilä A, Gynther J, Uusitupa M, Järvinen T (2006). Effects of hempseed and flaxseed oils on the profile of serum lipids, serum total and lipoprotein lipid concentrations and haemostatic. European Journal of Nutrition 45(8):470-7.</ref>  This has been demonstrated in a clinical study, where the daily ingestion of flaxseed oil decreased the endogenous production of GLA.<ref name="Schwab U 2006"/>

Hempseed is an adequate source of [[calcium]] and [[iron]]. Whole hempseeds are also a good source of [[phosphorus]], [[magnesium]], [[zinc]], [[copper]] and [[manganese]].

Hempseed contains no [[gluten]] and therefore would not trigger symptoms of [[celiac disease]].

====Storage====
[[Hemp oil]] is a highly unsaturated oil. As such, it has a relatively low smoke point and is not suitable for frying. It is primarily used as a food oil and dietary supplement, and has been shown to relieve the symptoms of eczema (atopic dermatitis){{Citation needed|date=August 2010}}. Hemp oil can spontaneously oxidize and turn rancid within a short period of time if not stored properly; it is best stored in a dark glass bottle, in a refrigerator or freezer (its freezing point is -20°C). [[Preservatives]] ([[antioxidants]]) are not necessary for high quality oils that are stored properly.

===Dietary supplement===
Hemp oil has been shown to relieve the symptoms of [[eczema]] ([[atopic dermatitis]]).<ref>Callaway, JC, Schwab U, Harvimaa I, Halonen P, Mykkänen O, Hyvönen P & Järvinen T (2005). Efficacy of dietary hempseed oil in patients with atopic dermatitis. Journal of Dermatological Treatment 16: 87-94.</ref>

Hemp Seed contains a large dietary supplement of [[omega-3]], higher even than walnuts which contain 6.3% of n-3.

=== Medicine ===
{{Main|Medicinal cannabis}}

Hemp oil has anti-inflammatory properties.<ref name=ani-inflamatory>[http://www.schmoo.co.uk/thclub/hemp.htm Hemp seed oil as an anti-inflammatory]</ref>

=== Fibre ===
[[Image:Hanfstengel.jpg|thumb|right|Hemp stem showing fibres.]]

The fibre is one of the most valuable parts of the hemp plant. It is commonly called [[Bast (biology)|bast]], which refers to the fibres that grow on the outside of the woody interior of the plant's stalk, and under the outer most part (the bark). Bast fibres give the plants strength. Hemp fibres can be between approximately 0.91&nbsp;m (3&nbsp;ft) and 4.6&nbsp;m (15&nbsp;ft) long, running the length of the plant. Depending on the processing used to remove the fibre from the stem, the hemp may naturally be creamy white, brown, gray, black or green.{{Citation needed|date=October 2008}}

The use of hemp for fibre production has declined sharply over the last two centuries, but before the [[industrial revolution]], hemp was a popular fibre because it is strong and grows quickly; it produces 10% more fibre than [[cotton]] and 10% more fibre than [[flax]] when grown on the same land.{{Citation needed|date=September 2007}} Hemp has been used to make paper.  It was often used to make sail [[canvas]], and the word ''canvas'' derives from ''cannabis''.<ref>[http://www.crrh.org/cannabis CRRH, Archaeologists agree that cannabis was among the first crops cultivated by human beings at least over 6,000 years ago, and perhaps more than 12,000 years ago<!-- Bot generated title -->]</ref><ref>[http://www.etymonline.com/index.php?term=canvas Online Etymology Dictionary<!-- Bot generated title -->]</ref>  [[Abaca]], or "[[Manila hemp]]", a relative of the banana plant, replaced its use for rope.  [[Burlap]], made from [[jute]], took over the sacking market.  The paper industry began using [[wood pulp]].  The carpet industry switched over to [[wool]], [[sisal]], and [[jute]], then [[nylon]].  Netting and webbing applications were taken over by [[cotton]] and synthetics.

====Building material====
[[Image:Bloc de chanvre ep 15cm.gif|thumb|right|[[Concrete block]] made with hemp in France]]
In Europe and China, hemp fibres have been used in prototype quantities to strengthen [[concrete]], and in other composite materials for many construction and manufacturing applications.<ref>NNFCC. [http://www.nnfcc.co.uk/metadot/index.pl?id=5973;isa=DBRow;op=show;dbview_id=2539 "Hemp Lime Construction Factsheet"], "[[National Non-Food Crops Centre]]", Retrieved on 17 March 2009</ref> See [[Hempcrete]].

====Composite materials====
A mixture of [[fibreglass]], hemp fibre, [[kenaf]], and [[flax]] has been used since 2002 to make composite panels for automobiles.<ref name="CNBC Special Report"/><ref>{{cite paper |
url=http://www.flexformtech.com/pdf/2006/Composites%20World%20%20%27%20Thermoformable%20Composite%20Panels%27.pdf |
publisher=Composites World |
title=Thermoformable Composite Panels |
year=2006}}</ref> The choice of which [[bast fibre]] to use is primarily based on cost and availability.

====Paper====
The first identified coarse [[paper]], made from hemp, dates to the early [[Western Han Dynasty]], two hundred years before the nominal invention of [[papermaking]] by [[Cai Lun]], who improved and standardized paper production using a range of inexpensive materials, including hemp ends, approximately 2000 years ago.<ref>{{cite web|url=http://www.chinaculture.org/gb/en_madeinchina/2005-06/28/content_70172.htm|title=Cai Lun Improved the Papermaking Technology|publisher=chinaculture.org}}</ref>

From 1880 to 1933 the hemp grown in the United States had declined from 15,000 to {{convert|1200|acre|km2}}, and that the price of line hemp had dropped from $12.50 per pound in 1914 to $9.00 per pound in 1933.<ref>[http://www.druglibrary.org/schaffer/hemp/taxact/nugent1.htm  H.T. NUGENT:COMMERCIALIZED HEMP (1934-35 CROP) in the STATE OF MINNESOTA]</ref><ref name="News">{{cite web|url=http://www.druglibrary.org/SCHAFFER/hemp/taxact/t10a.htm|title=Additional Statement of H.J. Anslinger, Commissioner of Narcotics|accessdate=2006-03-25}}</ref> 

In 1916, U.S. Department of Agriculture chief scientists Lyster H. Dewe and Jason L. Merrill created paper made from hemp pulp, which they concluded was "favorable in comparison with those used with pulp wood."<ref>Dewey and Merrill, U.S.D.A. Bulletin No. 404, Washington, D.C., October 14, 1916. Page 25</ref><ref>[http://www.gutenberg.org/files/17855/17855-h/17855-h.htm]</ref>

In 1935 hemp started to make a significant rebound from a very low level.<ref name="News" /> In the 1930's Hearst began a campaign against hemp, and published stories in his newspapers associating hemp with marijuana<ref>[http://search.huffingtonpost.com/search/?sp_a=sp100395aa&sp_k=&sp_p=all&sp_f=ISO-8859-1&sp_q=William%20Randolph%20Hearst Search Results - The Huffington Post<!-- Bot generated title -->]</ref> and attacking marijuana usage.<ref>[http://www.a1b2c3.com/drugs/mj004.htm Marijuana Timeline<!-- Bot generated title -->]</ref>

Currently there is a small niche market for hemp pulp. Hemp fiber is mixed with fiber from other sources than hemp. In 1994 was there no significant production of 100 % true hemp paper.<ref name="hempline"/>  World hemp pulp production was believed to be around 120,000 tons per year in 1991 which was about 0.05% of the world's annual pulp production volume.<ref name="Gertjan">{{cite journal |
title=Hemp Pulp and Paper Production |
author=Van Roekel, Gerjan J. |
journal=Journal of the International Hemp Association |
year=1994 |
location=Wageningen, The Netherlands |
url=http://www.druglibrary.org/olsen/hemp/IHA/iha01105.html}}</ref>. This can be compared to a typical pulp mill for wood fibre, which is never smaller than 250,000 tons per annum.<ref name="hempline">[http://www.hempline.com/hemp/hemp_articles/4/ Steam energy:Hemp Pulp & Paper Production, January 1st 1994]</ref> The cost of hemp pulp is approximately six times that of wood pulp,<ref name="Gertjan"/> mostly because of the small size and outdated equipment of the few hemp processing plants in the Western world and hemp is harvested once a year (during August) and needs to be stored to feed the mill the whole year through.  This storage requires a lot of (mostly manual) handling of the bulky stalk bundles, which accounts for a high raw material cost.  Hemp pulp is bleached with [[hydrogen peroxide]], the hydrogen peroxide process is today also commonly used for wood pulp.

====Fabric====
[[Image:Hemp-sack,asabukuro,japan.JPG|thumb|right|A sack made from hemp fibre]]
A modest hemp fabric industry exists. Recent developments in processing have made it possible to soften coarse fibers to a wearable level.

====Cordage====
[[Image:Hemp-rope.jpg|thumb|left|Hemp rope]]
Hemp rope was used in the [[Age of Sail|age of sailing ships]], though the rope had to be protected by [[Tarring (rope)|tarring]], since hemp rope has a propensity for breaking from [[rot]], as the capillary effect of the rope-woven fibres tended to hold liquid at the interior, while seeming dry from the outside.<ref>{{cite web |
url=http://www.uiaa.ch/article.aspx?c=231&a=147 |
archiveurl=http://web.archive.org/web/20070927193022/http://www.uiaa.ch/article.aspx?c=231&a=147 |
archivedate=September 27, 2009 |
title=Our ropes are much stronger than we believe |
author=Schubert, Pit |
publisher=Union Internationale Des Associations D'Alpinisme }}</ref> Tarring was a labor-intensive process, and earned sailors the nickname "[[Jack Tar]]". Hemp rope was phased out when [[Manila hemp|Manila]], which does not require tarring, became widely available. Manila is sometimes referred to as [[Manila hemp]], but is not related to hemp; it is [[Abacá]], a species of [[banana]].

====Animal bedding====
Hemp shives are the core of the stem. In the EU, they are used for animal bedding (horses, for instance), or for horticultural mulch.<ref>NNFCC. [http://www.nnfcc.co.uk/metadot/index.pl?id=7199;isa=DBRow;op=show;dbview_id=2457 "Crop Factsheet: Hemp"], ''[[National Non-Food Crops Centre]]'', 2008-06-09. Retrieved on 2009-05-06</ref> Industrial hemp is much more profitable if both fibres and shives (or even seeds) can be used.

=== Water and soil purification ===
Hemp can be used as a "mop crop" to clear impurities out of wastewater, such as sewage effluent, excessive phosphorus from chicken litter, or other unwanted substances or chemicals. Eco-technologist Dr. Keith Bolton from Southern Cross University in Lismore, New South Wales, Australia, is a leading researcher in this area. Hemp is being used to clean contaminants at [[Chernobyl disaster|Chernobyl nuclear disaster]] site.<ref>[http://www.mhhe.com/biosci/pae/botany/botany_map/articles/article_10.html Phytoremediation: Using Plants to Clean Soil]</ref>

=== Weed control ===
{{Main|Weed_control#Organic_methods}}
[[Image:Biodiesel.JPG|thumb|100px|Biodiesel sample]]

Hemp, because of its height, dense foliage and its high planting density as a crop, is a very effective and long used method of killing tough weeds in farming by minimizing the pool of weed seeds of the soil.<ref>{{cite web
|url=http://www.gametec.com/hemp/WEED.CTRL.htm
|title=Hemp As Weed Control
|publisher=www.gametec.com
|accessdate=2008-07-09
|last=
|first=
}}
</ref>  Using hemp this way can help farmers avoid the use of herbicides, to help gain [[organic certification]] and to gain the benefits of [[crop rotation]] ''[[wikt:per se|per se]]''.  Due to its rapid, dense growth characteristics, in some jurisdictions hemp is considered a prohibited noxious weed, much like [[Cytisus scoparius|Scotch Broom]].

=== Fuel ===
[[Biofuel]]s, such as [[biodiesel]] and [[alcohol fuel]], can be made from the oils in hemp seeds and stalks, and the fermentation of the plant as a whole, respectively.  Biodiesel produced from hemp is sometimes known as [[hempoline]].<ref>{{cite web | url=http://planetgreen.discovery.com/tv/cool-fuel/episode-sugarcane-hempoline.html | title=COOLFUEL Episode: Sugarcane and Hempoline | accessdate=2009-10-16}}</ref> Hemp biodiesel is clean burning and non-toxic.

[[Henry Ford]] grew industrial hemp on his estate after 1937,<ref name="seeker">
{{cite web
|url=http://www.thetruthseeker.co.uk/print.asp?ID=3774
|title=The Truth Seeker - The Marijuana Trick
|publisher=www.thetruthseeker.co.uk
|accessdate=2008-07-06
|last=
|first=
}}
</ref> possibly to prove the cheapness of methanol production at Iron Mountain. He made plastic cars (the so-called [[Hemp Car]]) with wheat straw, hemp and sisal. (Popular Mechanics, Dec. 1941, "Pinch Hitters for Defense.") Filtered hemp oil can be used directly to power [[diesel engine]]s. In 1892, [[Rudolf Diesel]] invented the diesel engine, which he intended to fuel "by a variety of fuels, especially vegetable and seed oils, which earlier were used for [[oil lamp]]s, i.e. The [[Argand lamp]]."<ref>[http://www.hemp4fuel.com/ Hemp 4 Fuel - Clean Energy Solutions<!-- Bot generated title -->]</ref><ref>[http://www.hempcar.org/petvshemp.shtml Hempcar.org-Pollution: Petrol vs. Hemp<!-- Bot generated title -->]</ref><ref>[http://www.hempcar.org/biofacts.shtml Hempcar.org-Biofuels Facts<!-- Bot generated title -->]</ref>

== Cultivation ==
[[Image:Hempharvesting2.jpg|right|thumb|Hemp being harvested]]
[[Image:CarteChanvreVert.svg|thumb|left|Climate zones well suited for the cultivation of hemp]]

Millennia of [[selective breeding]] have resulted in [[cultivar|varieties]] that look quite different. Also, breeding since circa 1930 has focused quite specifically on producing strains which would perform very poorly as sources of drug material. Hemp grown for fibre is planted closely, resulting in tall, slender plants with long fibres.  Ideally, according to Britain's [[Department for Environment, Food and Rural Affairs]], the herb should be harvested before it flowers. This early cropping is done because fibre quality declines if flowering is allowed and, incidentally, this cropping also pre-empts the herb's maturity as a potential source of drug material. However, in these strains of industrial hemp the [[tetrahydrocannabinol]] (THC) content would have been very low, regardless.

The name ''Cannabis'' is the [[genus]] and was the name favored by the 19th century medical practitioners who helped to introduce the herb's drug potential to modern [[english language|English]]-speaking consciousness. ''Cannabis'' for non-drug purposes (especially ropes and [[textiles]]) was then already well known as hemp.

The name "[[:wiktionary:Marijuana|marijuana]]" is [[Spanish language|Spanish]] in origin and associated almost exclusively with the herb's drug potential.

=== Historical cultivation ===
Hemp has been grown for millennia in Asia and the Middle East for its fibre. Commercial production of hemp in the West took off in the eighteenth century, but was grown in the sixteenth century in eastern England.<ref>[http://www.jstor.org/stable/2434380 New Fossil Evidence for the Past Cultivation and Processing of Hemp (Cannabis sativa L.) in Eastern England Author(s): R. H. W. Bradshaw, P. Coxon, J. R. A. Greig, A. R. Hall Source: New Phytologist, Vol. 89, No. 3 (Nov., 1981), pp. 503-510] Published by: Blackwell Publishing on behalf of the New Phytologist Trust Accessed: 06/07/2009</ref> Because of colonial and naval expansion of the era, economies needed large quantities of hemp for rope and [[oakum]].

==== Harvesting ====
[[Image:Recoltechv.jpg|thumb|right|Industrial hempseed harvesting machine in France.]]
[[Image:Hemp farm.jpg|thumb|right|Thick stands of fibre hemp compete well with weeds.]]

Smallholder plots are usually harvested by hand. The plants are cut at 2 to 3&nbsp;cm above the soil and left on the ground to dry. Mechanical harvesting is now common, using specially adapted cutter-binders or simpler cutters.

The cut hemp is laid in swathes to dry for up to four days. This was traditionally followed by ''[[retting]]'', either water retting (the bundled hemp floats in water) or dew retting (the hemp remains on the ground and is affected by the moisture in dew, and by molds and [[bacterial]] action). Modern processes use steam and machinery to separate the fibre, a process known as [[thermo-mechanical pulping]].

=== Varieties ===
There are broadly three groups of ''Cannabis'' varieties being cultivated today:

* Varieties primarily cultivated for their fibre, characterized by long [[Plant stem|stems]] and little branching, extreme red, yellow, blue or purple coloration, or thickness of stem and solid core, such as hemp cannabis oglalas, and more generally called industrial hemp.
* Varieties grown for [[seed]] from which [[hemp oil]] is extracted or which can be dehulled.
* Varieties grown for [[medicine|medicinal]], [[spiritual use of cannabis|spiritual development]] or [[cannabis (drug)|recreational]] purposes.

A nominal, if not legal distinction is often made between hemp, with concentrations of the psychoactive chemical THC far too low to be useful as a drug, and ''Cannabis'' used for medical, recreational, or spiritual purposes.

=== Diseases ===
{{Main|List of hemp diseases}}
Hemp plants can be vulnerable to various [[pathogen]]s, including [[bacteria]], [[fungi]], [[nematodes]], [[viruses]] and other miscellaneous pathogens. Such diseases often lead to reduced fibre quality, stunted growth, and death of the plant.  These diseases rarely affect the yield of a hemp field, so hemp production is not traditionally dependent on the use of pesticides.

== History ==
{{multiple image
 | align     = right
 | direction =vertical
 | header    = 
 | header_align = center
 | header_background = 
 | footer    = 
 | footer_align = center
 | footer_background = 
 | width     = 150

 | image1    = YangshaoCordmarkedAmphoraBanpoPhase4800BCEShaanxi.jpg|
 | width1    = 150
 | alt1      = 
 | caption1  = [[Yangshao culture]] (ca. 4800 BCE) [[amphora]] with impressed hemp cord design

 | image2    = Chinese-ma-hemp.png
 | width2    = 150
 | alt2      = 
 | caption2  = ''Má'', the Mandarin word for hemp. In China, the use of hemp has been shown to go back at least 10,000 years.
}}

[[Image:Cannabissativadior.jpg|thumb|left|''[[Cannabis sativa]]'' from ''[[Vienna Dioscurides]]'', 512 A.D.]]

Hemp use dates back to the [[Stone Age]], with hemp fibre imprints found in pottery shards in [[China]] and [[Taiwan]]<ref name=Stafford>Stafford, Peter. 1992. ''Psychedelics Encyclopedia''.  Berkeley, California, Ronin Publishing, Inc. ISBN 0-914171-51-8</ref> over 7,000 years old.  They were also later used to make clothes, shoes, ropes, and an early form of [[paper]].<ref name=Stafford/> Contrary to the traditional view that [[Cai Lun]] invented paper in around 105 AD, specimens of hemp paper were found in the [[Great Wall of China]] dating back 200 years earlier.{{Citation needed|date=March 2009}}

The classical Greek historian [[Herodotus]] (ca. 480 BC) reported that the inhabitants of [[Scythia]] would often inhale the vapours of hemp smoke, both as ritual and for their own pleasurable recreation (''Hist.'' 4:73-75).

In [[Late Middle Ages|late medieval]] [[Holy Roman Empire|Germany]] and [[Italy in the Middle Ages|Italy]], hemp was employed in cooked dishes, as filling in [[pie]]s and [[torte]]s, or boiled in a [[soup]].<ref>''Regional Cuisines of Medieval Europe: A Book of Essays'' (2002), edited by Melitta Weiss Adamson ISBN 0-415-92994-6 pg. 98, 166</ref>

Hemp in later Europe was mainly cultivated for its fibres, and was used for ropes on many ships, including those of [[Christopher Columbus]]. The use of hemp as a cloth was centred largely in the countryside, with higher quality [[textiles]] being available in the towns.

The Spaniards brought hemp to the Western Hemisphere and cultivated it in [[Chile]] starting about 1545.<ref name="osu">
{{cite web
|url=http://extension.oregonstate.edu/catalog/html/sb/sb681/
|title=Feasibility of Industrial Hemp Production in the United States Pacific Northwest, SB681
|publisher=extension.oregonstate.edu
|accessdate=2008-06-18
|last=
|first=
}}
</ref> However, in May 1607, "hempe" was among the crops Gabriel Archer observed being cultivated by the natives at the main [[Powhatan]] village, where [[Richmond, Virginia]] is now situated;<ref>Gabriel Archer, ''A Relatyon of the Discoverie of Our River...'', printed in ''Archaeologia Americana'' 1860, p. 44. [[William Strachey]] (1612) records a native ([[Powhatan]]) name for hemp (''weihkippeis'').</ref> and in 1613, [[Samuell Argall]] reported wild hemp "better than that in England" growing along the shores of the upper Potomac.  As early as 1619, the first Virginia [[House of Burgesses]] passed an Act requiring all planters in Virginia to sow "both English and Indian" hemp on their plantations.<ref>[http://etext.lib.virginia.edu/etcbin/jamestown-browse?id=J1036 Proceedings of the Virginia Assembly, 1619], cf. the 1633 Act: [http://vagenweb.org/hening/vol01-09.htm ''Hening's Statutes at Large'', p. 218]</ref> The [[Puritans]] are first known to have cultivated hemp in [[New England]] in 1645.<ref name="osu"/>
[[Image:Producer of marihuana.jpg|left|thumb| United States "Marihuana" production permit.  In the United States, hemp cultivation is [[Legal issues of cannabis|legally prohibited]], but during [[World War II]] farmers were encouraged to grow hemp for cordage, to replace [[Manila hemp]] previously obtained from [[Japan]]ese-controlled areas. The U.S. government produced a film explaining the uses of hemp, called ''[[Hemp for Victory]]''.]]

In 1937, the [[Marihuana Tax Act of 1937]] was passed in the United States. It levied a tax on anyone who dealt commercially in cannabis, hemp, or marijuana. It was repealed by an overriding law in 1970.

Hemp was used extensively by the United States during World War II. Uniforms, canvas, and rope were among the main textiles created from the hemp plant at this time.<ref>{{cite journal
 | last1=
 | first1    = Alden P
 | last2     = Armagnac
 | first2    =
 | year      = 1943
 | title     = Plant Wizards Fight Wartime Drug Peril
 | journal   = 
 | publisher =
 | volume    =
 | issue     = September
 | pages     = 62–63
 | url=
 | doi=
}}</ref>  Much of the hemp used was cultivated in [[Kentucky]] and the [[Midwest]].

Historically, hemp production had made up a significant portion of [[antebellum]] Kentucky's economy.  Before the [[American Civil War]], many slaves worked on [[plantation economy|plantations]] producing hemp.<ref>[http://www.druglibrary.org/schaffer/hemp/history/slavery.htm James F. Hopkins, "Slavery in the Hemp Industry"], Drug Library</ref>

During World War II, the U.S. produced a short 1942 film, ''[[Hemp for Victory]]'', promoting hemp as a necessary crop to win the war.

By the early twentieth century, the advent of the [[steam engine]] and the [[diesel engine]] ended the reign of the [[sailing ship]].  The production of iron and steel for cable and ships' hulls further eliminated natural fibres in marine use.  Hemp had long since fallen out of favour in the sailing industry in preference to Manila hemp.

== Countries that produce hemp ==
Over 30 countries produce industrial hemp including Australia, Austria, Canada, China, Great Britain, France, Russia and Spain.<ref>
{{cite web|url=http://azhemp.org/Archive/Package/Legal/legal.html|title=Hemp vs. Marijuana|publisher=azhemp.org|accessdate=2008-06-18|last=|first=}}</ref>

From the 1950s to the 1980s the [[Soviet Union]] was the world's largest producer (3,000&nbsp;km² in 1970).  The main production areas were in [[Ukraine]],<ref>[http://www.aginukraine.com/bast/bast01.htm Hemp research and growing in Ukraine]</ref> the [[Kursk]] and [[Oryol|Orel]] regions of [[Russia]], and near the [[Poland|Polish]] border. Since its inception in 1931, the Hemp Breeding Department at the Institute of [[Bast fibre|Bast]] Crops  in [[Hlukhiv]] (Glukhov), Ukraine, has been one of the world's largest centres for developing new hemp varieties, focusing on improving fibre quality, per-hectare yields, and low [[tetrahydrocannabinol|THC]] content.<ref>[http://news2000.org.ua/print?a=%2Fpaper%2F5463 Hemp will help Ukraine to grow wealthy] {{ru icon}}</ref><ref>[http://mojo.calyx.net/~olsen/HEMP/IHA/jiha5111.html Interview with Dr. V. G. Virovets, the head of the Hemp Breeding Department at the Institute of Bast Crops] (1998) {{en icon}}</ref>

Other important producing countries were [[China]], [[North Korea]], [[Hungary]], the former [[Socialist Federal Republic of Yugoslavia|Yugoslavia]], [[Romania]], [[Poland]], [[France]] and [[Italy]].

[[Image:Kamidana.jpg|thumb|Typical Japanese [[Shinto shrine]] with paper streamers & rope made out of unprocessed hemp fibre.]]

In [[Japan]], hemp was historically used as paper and a fibre crop. There is archaeological evidence that cannabis was used for clothing and the seeds were eaten in Japan right back to the [[Jōmon period]] (10,000 to 300 BCE). Many [[Kimono]] designs portray hemp, or  "Asa" ({{lang-ja|麻}}), as a beautiful plant. In 1948 marijuana was restricted as a narcotic drug. The ban on marijuana imposed by the United States authorities was alien to Japanese culture, as the drug had never been widely used in Japan before.  Though these laws against marijuana are some of the world's strictest, allowing five years imprisonment for possession of the drug, they exempt hemp growers, whose crop is used to make robes for Buddhist monks and loincloths for sumo wrestlers.  Because marijuana use in Japan has doubled in the past decade, these "loopholes" have recently been called into question.<ref>{{cite web|url=http://online.wsj.com/article/SB123612257155123461.html|title=In Drug-Leery Japan, Arrests for Marijuana Are on the Rise|author=Yuka Hayashi|publisher=Wall Street Journal|date=2009-03-04}}</ref>

Uruguay has also approved a project of hemp production as of the second half of 2010.

[[France]] is Europe's biggest producer, with 8,000 hectares cultivated. [[Canada]] (9,725 ha in 2004),<ref>[http://www.hc-sc.gc.ca/dhp-mps/substancontrol/hemp-chanvre/about-apropos/stat/05-stat-eng.php]</ref> the [[United Kingdom]], and [[Germany]] all resumed commercial production in the 1990s. British production is mostly used as [[bed (furniture)|bed]]ding for [[horse]]s; other uses are under development.  The largest outlet for German fibre is composite automotive panels. Companies in Canada, UK, United States, and Germany among many others process hemp seed into a growing range of [[food]] products and [[cosmetics]]; many traditional growing countries still continue to produce [[textile]] grade fibre.

Hemp is not legal to grow in the U.S. under Federal law because of its relation to marijuana, and any imported hemp products must meet a [[zero tolerance (food policy)|zero tolerance]] level. It is considered a controlled substance under the [[Controlled Substances Act]] (P.L. 91-513; 21 U.S.C. 801 et seq.).  Some states have defied Federal law and made the cultivation of industrial hemp legal. These states&nbsp;— North Dakota, Hawaii, Kentucky, Maine, Maryland, Montana, West Virginia, and Vermont&nbsp;— have not yet begun to grow hemp because of resistance from the federal [[Drug Enforcement Administration]].<ref>[http://minnesotaindependent.com/27887/hemp-hemp-hooray-bill-aims-to-aid-farmers-with-new-but-controversial-crop Hemp, hemp, hooray: Bill aims to aid farmers with new but controversial crop]</ref> 

Commercial production (including cultivation) of industrial hemp has been permitted in Canada since 1998, under licenses and authorization issued by Health Canada. In 2009, hemp was harvested on 5450 [[hectares]] of Canadian land.<ref>[http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/econ9631 Government of Alberta: Industrial Hemp Production in Canada, February 2, 2010]</ref>

== Industrial growth under licence ==
[[File:Industrialhemp.jpg|left|thumb|Industrial hemp production in [[France]]]]
Licences for hemp cultivation are issued in the [[European Union]], [[Canada]], in all states of [[Australia]], and nine states in the [[United States]].<ref>
{{cite web
|url=http://news.findlaw.com/prnewswire/20090629/29jun20091931.html
|title=Oregon Passes Hemp Bill
|accessdate=2009-07-20
}}</ref>

In the [[United Kingdom]], these licences are issued by the [[Home Office]] under the [[Misuse of Drugs Act 1971]].  When grown for non-drug purposes hemp is referred to as '''industrial hemp''', and a common product is [[Fibre crop|fibre]] for use in a wide variety of products, as well as the seed for nutritional aspects as well as for the oil. '''Feral hemp''' or '''ditch weed''' is usually a naturalized fibre or oilseed strain of ''Cannabis'' that has escaped from cultivation and is self-seeding.

[[Victoria (Australia)|Victoria]], [[Queensland]] and most recently [[New South Wales]] issue licences to grow hemp for industrial use. Victoria was an early adopter in 1998, and has reissued the regulation in 2008.<ref>
{{cite web
|url=http://www.dms.dpc.vic.gov.au/Domino/Web_Notes/LDMS/PubLawToday.nsf/b12e276826f7c27fca256de50022686b/69FF479D20FC0F06CA2574EC0012EDDF/$FILE/08-98sr001.pdf
|format=PDF|title=Drugs, Poisons and Controlled Substances (Industrial Hemp) Regulations 2008
|publisher=www.dms.dpc.vic.gov.au
|accessdate=2008-11-24
|last=
|first=
}}
</ref>
Queensland has allowed industrial production under licence since 2002<ref>
{{cite web
|url=http://www2.dpi.qld.gov.au/hemp/16239.html
|title=Guidelines for engaging in the commercial production of industrial hemp in Queensland
|publisher=dpi.qld.gov.au
|accessdate=2008-11-24
|last=
|first=
}}
</ref> where the issuance is controlled under the Drugs Misuse Act 1986.<ref>
{{cite web
|url=http://www.legislation.qld.gov.au/LEGISLTN/CURRENT/D/DrugsMisuseA86.pdf
|format=PDF|title=Drugs Misuse Act 1986
|publisher=www.legislation.qld.gov.au
|accessdate=2008-11-24
|last=
|first=
}}
</ref>
Most recently New South Wales now issues licences<ref>
{{cite web
|url=http://www.dpi.nsw.gov.au/agriculture/field/field-crops/fibres/hemp/commercial-production
|title=Opportunities to engage in commercial low THC hemp fibre and seed production in NSW
|publisher=www.dpi.nsw.gov.au
|accessdate=2008-11-24
|last=
|first=
}}
</ref> under a law that came into effect as at 6 November 2008, the Hemp Industry Regulations Act 2008 (No 58).<ref>
{{cite web
|url=http://www.legislation.nsw.gov.au/viewtop/inforce/subordleg+475+2008+FIRST+0+N/
|title=Hemp Industry Regulation 2008
|publisher=legislation.nsw.gov.a
|accessdate=2008-11-24
|last=
|first=
}}
</ref>

Vermont and North Dakota have passed laws enabling hemp licensure. Both states are waiting for permission to grow hemp from the Drug Enforcement Administration (DEA). Currently, North Dakota representatives are pursuing legal measures to force DEA approval.<ref name="North Dakota DEA">[http://www.votehemp.com/legal_cases_ND.html North Dakota Case]</ref>
Oregon has licensed industrial hemp as of August, 2009.<ref name ="Oregon State Legislature">[http://www.leg.state.or.us/09reg/measures/sb0600.dir/sb0676.b.html 75th Oregon Legislative Assembly&nbsp;&mdash; 2009 Regular Session Senate Bill 676]</ref>

== See also ==
* [[Cannabrick construction]]
* [[Fabric#Plant textiles|Plant textiles]]
* [[Hemp for Victory]]
* [[Hemp Industries Association]]
* [[Hempcrete]]
* [[Natural fibre]]
* [[Vote Hemp]]

== References ==
{{Wiktionary|hemp}}
{{Commons category|Hemp}}
{{Reflist}} <!-- multi-column mode unusable -->

{{fibers}}
{{Bioenergy}}

[[Category:Hemp| ]]
[[Category:Cannabis]]
[[Category:Energy crops]]
[[Category:Fiber plants]]
[[Category:Fodder]]
[[Category:Medicinal plants]]
[[Category:Building materials]]
[[Category:Non-food crops]]

[[ar:قنب]]
[[cs:Konopí seté]]
[[da:Almindelig Hamp]]
[[de:Nutzhanf]]
[[es:Cáñamo]]
[[eo:Kanabo]]
[[fr:Chanvre]]
[[hr:Konoplja]]
[[it:Canapa (tessile)]]
[[he:קנבוס]]
[[hu:Kender]]
[[mk:Коноп]]
[[nl:Hennep]]
[[ja:麻]]
[[no:Hamp]]
[[pl:Konopie]]
[[pt:Cânhamo]]
[[ru:Пенька]]
[[sr:Индустријска конопљa]]
[[fi:Hamppu]]
[[sv:Hampa]]
[[zh:麻]]
[[Category:2Fix]]