March 26, 2010 – Once the areas major agricultural product, hemp is making a comeback in the Altiplano area of Granada, Spain. Until the late nineteen sixties industrial hemp growing formed the backbone of this wholly agricultural area of Spain. Towards the end of the Franco era, with the invention of nylon and the mechanization of agriculture most of the population was forced off the land to find work on the coast and major cities.

With the advent of the eco-age the interest in industrial hemp is being revived as it is a major constituent of eco-bricks, a vital component of sustainable housing.

Hemp comes from the Anglo Saxon word ‘haemp’ and is the popular name for plants of the cannabis genus. Hemp usually refers to the strains of the plant cultivated exclusively for industrial use as opposed to cannabis which is associated with pot and similar drugs.

Hemp has a huge variety of uses but continues to be overshadowed by the cannabis connotation of illegal drugs, with which it is often confused. However hemp can legally be grown, under licence, in many countries, including the European Union countries and Canada.

Cannabis sativa L. is the variety primarily grown for industrial purposes, it is a fast growing plant and has been cultivated for many thousand of years being used to make rope, clothing, paper, hemp oil and medicines. Growing hemp improves the condition of the ground and reduces ambient contamination. It is a robust plant that requires neither herbicides nor pesticides during its cultivation.

Hemp as an industrial material has a ten thousand year history. The first recorded use of hemp was as a cloth fabric, found in China as far back as 8000BC.C. Circa 4000B.C. hemp started to be used, again in China, to make ropes and as food. 2000 years later, the Chinese hemp oils and medicine were in use. By 1000B.C. its use had spread to India and Greece where the first instances of hemp paper were found.

By the 6th century hemp was being used in Europe in some amazing ways, in France a hemp reinforced bridge was built and it is still in use today. The hemp fibre also found uses in sailmaking, caulking materials, fishing nets and lines. In later years hemp was used to make a variety of foodstuffs including butter and beer. By the 15th century Renaissance painters were using hemp canvases.

Today industrial hemp is used to make a staggering variety of products ranging from medicines, body care products, building and insulating materials, clothing, textiles, food, fuel, livestock food and bedding, plastics and paper.

In the building industry hemp bricks, because of their sustainability and excellent insulation properties, are being used to construct external and internal walls of ecological homes. In this area of Spain the external walls of an eco house will consist of a eco-bricks, manufactured in Guadix with the proprietary name of Cannabric®.

Cannabric® derives its properties from industrial hemp fibres (cáñamo). The hemp bricks are made up of industrial hemp fibres, slaked lime and a mixture of innert mineral materials. The bricks combine the functions of a load bearing wall that is fire-resistant and does not require the addition of thermal or acoustic insulation.

The most important component of the eco-brick is industrial hemp which has a very low thermal conductivity (0.048W/m²k) producing a brick with vastly superior insulation properties against both cold and heat. The mineral component of the bricks gives them their mechanical strength. Being a solid brick, with a high specific heat, it has the optimal thermal properties to protect against heat.

These characteristics make hemp bricks the ideal choice in areas of southern Europe where there are extremes in temperature through summer and winter.

The mechanical strength of the block starts with formation of insoluble hydrates. The strength increases over time with the carbonation of the free lime, (a constituent of slaked lime) by moisture and carbon dioxide present in the air. Another important factor in the progressive curing of the eco-bricks is the gradual petrifaction of the industrial hemp by the lime and minerals present in the bricks.

Due to its unique composition the hemp bricks allow the transpiration and diffusion of water vapour between the inside and outside of the building equalising humidity within the building thus avoiding humid and cold areas and minimising condensation on the inside wall surfaces.

Slaked lime acts as the binder, basically holding the brick together, but it has other uses. The slaked lime acts as a filler protecting the brick against water entry via the external surfaces exposed to rain and snow. On the other hand it provides a protection for the industrial hemp fibres against fungal and parasite attack.

The hemp bricks when laid endwise are used for the construction of external walls thirty centimeters thick. The internal walls built with hemp bricks are thinner being half the thickness. The delightful, popular cave homes of this area of Andalusia are naturally ecological in that they are re-developed from ancient derelict cave houses. As far as practical re-cycled materials are utilised and, as such, their environmental impact and carbon footprints are minimal.

It is ironic that this area of Spain, the Altiplano, until the late nineteen sixties, was renown as an industrial hemp growing area. The hemp growing era came to an end with the introduction of nylon, farm mechanisation and the growing freedom of movement coinciding with the end of the Franco regime. The combination of these factors threw large numbers of agricultural workers out of work. As a result the village populations sufferred a catastrophic decline with those leaving migrationg to the Costas and principal cities in search of employment.

As a result of these traumatic changes in demographic the remaining population was mainly aged, the villages incomes dropped to near poverty level and many empty houses fell into disrepair.

Most of the land workers who moved away lived in cave houses which are now being revitalised by the growing demand for eco-properties.

1) Hemp is among the oldest industries on the planet, going back more than 10,000 years to the beginnings of pottery. The Columbia History of the World states that the oldest relic of human industry is a bit of hemp fabric dating back to approximately 8,000 BC.

2) Presidents Washington and Jefferson both grew hemp. Americans were legally bound to grow hemp during the Colonial Era and Early Republic. The federal government subsidized hemp during the Second World War and US farmers grew about a million acres of hemp as part of that program.

3) Hemp Seed is far more nutritious than even soybean, contains more essential fatty acids than any other source, is second only to soybeans in complete protein (but is more digestible by humans), is high in B-vitamins, and is 35% dietary fiber. Hemp seed is not psychoactive and cannot be used as a drug. See TestPledge.com

4) The bark of the hemp stalk contains bast fibers which are among the Earth’s longest natural soft fibers and are also rich in cellulose; the cellulose and hemi-cellulose in its inner woody core are called hurds. Hemp stalk is not psychoactive. Hemp fiber is longer, stronger, more absorbent and more insulative than cotton fiber.

5) According to the Department of Energy, hemp as a biomass fuel producer requires the least specialized growing and processing procedures of all hemp products. The hydrocarbons in hemp can be processed into a wide range of biomass energy sources, from fuel pellets to liquid fuels and gas. Development of biofuels could significantly reduce our consumption of fossil fuels and nuclear power.

6) Hemp grows well without herbicides, fungicides, or pesticides. Almost half of the agricultural chemicals used on US crops are applied to cotton.

7) Hemp produces more pulp per acre than timber on a sustainable basis, and can be used for every quality of paper. Hemp paper manufacturing can reduce wastewater contamination. Hemp’s low lignin content reduces the need for acids used in pulping, and it’s creamy color lends itself to environmentally friendly bleaching instead of harsh chlorine compounds. Less bleaching results in less dioxin and fewer chemical byproducts.
Hemp fiber paper resists decomposition, and does not yellow with age when an acid-free process is used. Hemp paper more than 1,500 years old has been found. It can also be recycled more times.

9) Hemp fiberboard produced by Washington State University was found to be twice as strong as wood-based fiberboard.

10) Eco-friendly hemp can replace most toxic petrochemical products. Research is being done to use hemp in manufacturing biodegradable plastic products: plant-based cellophane, recycled plastic mixed with hemp for injection-molded products, and resins made from the oil, to name just a very few examples.

TODAY’S HEMP INDUSTRY

AUSTRALIA – Tasmania research trials began in 1995. Victoria commercial production since1998. New South Wales has research. In 2002 Queensland began production.

AUSTRIA has a hemp industry including production of hempseed oil, medicinals and Hanf magazine.

CANADA started to license research crops in 1994 on an experimental basis. In addition to crops for fibre, one seed crop was experimentally licensed in 1995. Many acres were planted in 1997. Licenses for commercial agriculture saw thousands of acres planted in 1998. 30,000 acres planted in 1999. In 2000, due to speculative investing,12,250 acres were sown. In 2001 ninety-two farmers grew 3,250 acres. A number of Canadian farmers are now growing organically certified hemp crops.

CHILE has grown hemp in the recent past for seed oil production.

CHINA is the largest exporter of hemp paper and textiles. The fabrics are of excellent quality. (ma)

DENMARK planted its first modern hemp trials in 1997. Committed to utilizing organic methods.

FINLAND had a resurgence of hemp in 1995 with several small test plots. A seed variety for northern climates was developed: Finola, previously know by the breeder code ‘FIN-314′. In 2003, Finola was accepted to the EU list of subsidized hemp cultivars. (hamppu)

FRANCE harvested 10,000 tons in 1994. France is the main source of low-thc producing hempseed. (chanvre)

GERMANY only banned hemp in 1982, but research began in 1992 and many technologies and products are being developed. Clothes and paper are being made from imported raw materials. Germany lifted the ban on growing hemp November, 1995. Mercedes and BMW use hemp fiber for composites. (hanf)

GREAT BRITAIN lifted hemp prohibition in 1993. Animal bedding, paper and textiles have been developed. A government grant was given to develop new markets for natural fibers. 4,000 acres were grown in 1994. Subsidies of $230 Eng. pounds per acre are given by the govt. for growing.

HUNGARY is rebuilding their hemp industry, and is one of the biggest exporters of hemp cordage, rugs and hemp fabric to the U.S. They also export hemp seed and hemp paper. Fiberboard is also made. (kender)

INDIA has large stands of naturalized Cannabis and uses it for cordage, textiles, and seed oil.

JAPAN has a religious tradition requiring the Emperor wear hemp garments, so there is a small plot maintained for the imperial family only. They have a thriving retail market selling a variety of hemp products. (asa)

NETHERLANDS is conducting a four year study to evaluate and test hemp for paper, and is developing processing equipment. Seed breeders are developing new strains of low-thc varieties. (hennep)

NEW ZEALAND started hemp trials in 2001. Various cultivars are being planted in the North and South.

POLAND currently grows hemp for fabric and cordage and manufactures hemp particle board. They have demonstrated the benefits of using hemp to cleanse soils contaminated by heavy metals. (konopij)

ROMANIA was the largest commercial producer of hemp in Europe in the late 80’s and early 90’s. Total acreage in 1993 was 40,000 acres. Some of it is exported to Hungary for processing. They also export to Western Europe and the United States. (cinepa)

RUSSIA maintains the largest hemp germ plasm collection in the world at the N.I. Vavilov Scientific Research Institute of Plant Industry (VIR) in Saint Petersburg. They are in need of funds. (konoplya)

SLOVENIA grows hemp and manufactures currency paper.

SPAIN grows and exports hemp pulp for paper and produces rope and textiles. (cañamo)

SWITZERLAND is a producer of hemp and hosts one of the largest hemp events: Cannatrade.

EGYPT, KOREA, PORTUGAL, THAILAND, and the UKRAINE also produce hemp.

USA – The United States granted the first hemp permit in over 40 years to Hawaii for an experimental quarter acre plot in 1999. The license has been renewed since. Importers and manufacturers have thrived using imported raw materials. Twenty-two states in the United States have introduced legislation. VT, HI, ND, MT, MN, IL, VA, NM, CA, AR, KY, MD, WV have passed legislation for support, research, or cultivation. The National Conference of State Legislators has endorsed industrial hemp for years.

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