By Jim Bauder and Linzy Carlson
MSU Land Resources and Environmental Sciences
BOZEMAN -- Most people know that industrial hemp has been a source of rope, cloth and paper since ancient times, but few recognize its incredible potential today. It represents an ecologically stable, renewable source of raw materials to make such diverse products as automobile fuel, plastics, building materials and food for animals and people.
The agronomics of hemp are pretty standard. Start with a light textured soil with a pH of 6.0-7.5 worked into a firm, level seedbed at 45 to 50 degrees Fahrenheit. Using a regular grain drill, seed 35-60 pounds per acre (depending on seed weight and germination rate). Because hemp plant density chokes out weeds, it grows well without herbicides. It naturally resists attack from bugs and fungi, reducing the need for pesticides and fungicides. In contrast, almost half of all agricultural chemicals used in the U.S. are applied to cotton. Hemp requires 12-16 inches of water over the course of its 120-150 day growing season. Harvesting hemp involves either swathing and baling it for fiber use or combining it for seed. Hemp can be grown for both fiber and seed, but this often sacrifices the quality of both. Yields range from 3-4 tons/acre for fiber and 300-600 pounds/acre for seed, depending on soil quality.
Once harvested, hemp seed can be processed into oil, which can then be made into oil for human consumption, lotions, soaps, salves and plastics. Hemp seed can also be made into flour, wine, beer and even candy. The seed is highly nutritious, containing more essential fatty acids than any other source. It is high in B-vitamins and contains 35 percent dietary fiber. It is second only to soybeans in complete protein and is actually more digestible by humans.
Hemp can be manufactured into biodegradable plastic products, such as plant-based cellophane and resins, and materials previously made entirely from synthetic fibers. For example, the automobile industry has been using natural fibers, similar to those from hemp, in composite materials used to make door panels and moldings and for insulation, carpets and fabrics. The aviation industry has also been taking a closer look at natural fiber, because in plane crashes people often die not only from the impact but also from inhalation of toxic fumes from burning synthetic materials. Aside from being more ecologically friendly than synthetics, natural fibers lead to stronger, lighter products while causing less wear and tear on manufacturing equipment.
Important early documents, such as the Declaration of Independence, were written on hemp paper, so making paper from hemp and other natural fibers is certainly not new technology. In today's age of recycling, hemp can be added to recycled pulp to add strength, since each time paper is recycled the original wood fibers get short and weaker. Hemp paper can be recycled seven times, while wood paper only lasts three recyclings. Hemp fiber has less lignin than wood pulp, thus reducing the quantity of environmentally hazardous chemicals needed for processing. Plus, the finished hemp paper has no acid, so it does not become brittle and yellow with age.
One of the downsides of hemp is that it is potentially a noxious weed. It has the potential to escape, and it is very competitive and a very efficient in its water use.
Perhaps the most exciting use of hemp is in the production of biofuels, the diesel and gasoline-like fuels made from hemp oil, vegetable oil or animal fats. Once again, this is not new technology. In 1895 Dr. Rudolf Diesel invented the first peanut oil powered diesel engine and Henry Ford strongly supported using ethanol made from American grown oilseed crops, such as hemp. Wood paper and petroleum based fuels and plastics came to dominate the markets, but relatively recent concerns of smog, acid rain, health problems and dependence on foreign oil have revived thoughts of hemp's many benefits. And there are numerous advantages to hemp-derived biofuels for both gasoline and diesel engines. The following list deals with a specific biofuel called biodiesel.
Biodiesel is the only alternative fuel that runs in any conventional, unmodified diesel engine. Its use can extend the life of diesel engines, because it is more lubricating than petroleum diesel fuel. Fuel consumption, auto ignition, power output and engine torque are relatively unaffected by biodiesel and it is a proven fuel with over 30 million successful US road miles and over 20 years of use in Europe.
It can be stored anywhere that petroleum diesel fuel is stored. Biodiesel is as biodegradable as sugar, 10 times less toxic than table salt and has a high flashpoint of about 300 degrees Fahrenheit compared to petroleum diesel fuel, which has a flash point of 125 degrees F.
When burned in a diesel engine, biodiesel replaces the exhaust odor of petroleum diesel with a smell something akin to french fries. Biodiesel is 11 percent oxygen by weight and contains no sulfur, so instead of creating sulfur-based smog and acid rain as by-products, it produces oxygen instead. Biodiesel can be made from domestically produced, renewable oilseed crops such as hemp.
Biodiesel is the only alternative fuel in the US to complete EPA Tier I Health Effects Testing under section 211(b) of the Clean Air Act, which provide the most thorough inventory of environmental and human health effects attributes that current technology will allow. The Congressional Budget Office, Department of Defense, US Department of Agriculture and others have determined that biodiesel is the low cost alternative fuel option for fleets to meet requirements of the Energy Policy Act.
Ask any American what environmental problems they are most concerned with and undoubtedly the response will contain mention of rapidly filling landfills, air and water pollution and the adverse affects of these factors on earth's plant, animal and human population. Ask any American farmer what needs to be done to help the flailing agricultural economy and part of the solution will probably entail integration of alternative crops into conventional farming operations. With this in mind, hemp may help provide both economic and ecological stability.
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For additional information or to receive a regular email distribution of agronomy notes such as the one above, Jim Bauder can be contacted by email at "firstname.lastname@example.org" or by calling 406-994-5685 at Montana State University.
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