Potential of Industrial Hemp to Displace Fiber from Forests
By Andy Kerr
Industrial hemp fiber has the significant potential to displace fiber currently coming from forests. It won't happen overnight, as first the growing industrial hemp (cannabis sativa) in the United States must again be allowed. After re-legalization, many concurrent and consecutive steps must occur to properly develop the industry. It will take at least a decade or more to gear up.
A coalition of environmental groups has called for a 75% reduction in wood use. This dramatic reduction is both ecologically necessary and feasible using existing technologies. It provides for the continued use of wood for those products for which it cannot be substituted: solid wood furniture, musical instruments and other certain decorative uses of wood. 1
This analysis assumes no increases in recycling of wood products, no improvements in the utilization of wood, and no reduction in demand. As the price of wood fiber increases, these necessary actions will accelerate. Changes in government policy regarding forests and pollution from both logging and processing, overcutting, global competition, and other factors will contribute to drive wood fiber prices higher.
2.6% of US farmland would have to be dedicated to the cultivation of industrial hemp to displace 75% of the US annual wood consumption:
72,000,000 US tons of annual US wood consumption (domestic & imported) 2
x .75 Percentage reasonably converted to tree-free fibers 1
54,000,000 US tons of annual wood consumption reasonably displaced by annual fibers.
÷ 4.5 US tons/acre of usable hemp fiber (both short and long) 3
12,000,000 Acres of farmland necessary to displace 75% of wood consumption (domestic & imported)
÷ 464,053,800 Acres total US cropland 4
2.6 Percent of US cropland to displace 75% wood consumption.
While this is unlikely to happen anytime soon, it does show the potential of farmlands to replace forestlands as our primary fiber sources.
These figures are conservative in that about one-half of the weight of logs going into a pulp mill is water. Hemp figures are dry-weight. Hemp also appears to have a somewhat higher pulping retention factor (the amount of dry weight retained in the pulp) than wood. About 29% of wood consumed is pulped.
Hemp will likely be grown in rotation with major crops like soybeans, corn and wheat. Farmers of these mainstays are looking for a beneficial and profitable rotation crop. Hemp improves the tilth of the soil, doesn't require insecticides or herbicides and leaves the field weed-free for the next crop. In England, hemp grown in rotation with wheat has increased the yields of the latter by 10%. 5 In Ontario, hemp grown in rotation with soybeans has reduced the nematode problem in the latter by 50-80% in the first year. 6
Hemp can make a stronger composite construction product than wood, allowing the use of less material for a given application. Hemp "chips" can be directly substituted for wood chips in oriented strand board, particle board and other panel products. 7 A lumber substitute is also technically feasible. Paper made from hemp can be of better quality and can be recycled more times than paper made from wood pulp.
On price, hemp can be competitive today against wood for paper, at least in the Upper Mid-West. A recent Forest Service study concludes that Wisconsin farmers could very profitably produce hemp to displace the consumption of wood for fine papers made in Wisconsin mills. 8 85% of wood used in Wisconsin paper mills is presently imported from Canada. 9
The same may be true in the American South. According to an executive in a very large transnational paper company with significant holdings in the region, company economists have determined that on feedstock price alone, hemp would cheaper than southern pine chips. Of course, transaction costs such as retooling machinery, management and workers has prevented the switch at this point. This source and company, which both have insisted it remain nameless, are experimenting with kenaf. They view hemp as superior for making paper, but they can learn from kenaf until hemp is again legal to grow in the United States.
The first commercial crop in Canada since 1938 is fostering interest among several Canadian "forest" products companies. 10
Competing on price against wood for construction composites, hemp is not presently competitive in the Pacific Northwest. If chip markets again reach the late-1994 highs (brought on by panic about the new federal forest plan for northern spotted owl forests), then hemp can compete. Chip prices have, within wide fluctuations, been increasing for the past decade. Mill efficiency improvements, coupled with additional factors noted below, will continue to drive up chip prices.
More than consumer demand for tree-free paper, the critical factor that will favor annual fibers such as industrial hemp (and kenaf, bamboo, agricultural field waste, etc.) over wood fiber is the time value of money. In this increasingly competitive economy, an investment that requires several decades for a return cannot compete against shorter-term investments. Industrial rotations of trees are around 30 years in the South and 60 years in the Pacific Northwest, both of which are unacceptable time horizons to a rational economic manager. (There may be valid social and environmental reasons for advocating longer rotation sustainable forestry on private lands, but not economic reasons.)
Fiber companies recognize this and are investing large sums of money in poplar-cottonwood hybrids. Three factors drive these 7-10 year rotations. First, technology exists to make valuable products from such fast-growing, but still relatively small, trees. Second, this is about as long as the financiers will tolerate capital being tied up. Third, in most states, such is considered an agricultural—not a forest—crop. State agricultural practices act, if they exist as all, are more lax than state forest practices laws, if they exist at all. Such crops tend to require large amounts of pesticides and herbicides.
Because hemp is an annual fiber (and the best technically as a wood replacement) and also has a longer and stronger fiber, is naturally brighter (less, if any bleaching) and is much faster growing than wood, it will increasingly out-compete wood fiber in the future.
A major commercial carpet manufacture will soon make a hemp carpet because present synthetics cannot be recycled and cause off-gassing problems when in use. 11
It also has potential to displace cotton by providing a superior product, at a lower cost, and without pesticides. Applications in energy are also possible. 12
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Footnotes
1 A Call to Action: Reducing U.S. Demand for Wood, by Atossa Soltani in Cut Waste, Not Trees: How to Save Forests, Cut Pollution and Create Jobs, Rainforest Action Network, San Francisco, 1995 (Soltani projects reductions in demand, increased recycling, better utilization and other factors not considered here.)
2 US Statistical Abstract, 1993, Table No. 1153, cited in A Call to Action: Reducing U.S. Demand for Wood, by Atossa Soltani in Cut Waste, Not Trees: How to Save Forests, Cut Pollution and Create Jobs, Rainforest Action Network, San Francisco, 1995
3 John Roulac, HEMPTECH, personal communication, 7/1/97
4 ABC News World Reference 3D Atlas, 1995 (187,800,000 hectares * 2.471 hectares/acre)
5 page 11, Hemp Horizons, .John W. Roulac, Chelsea Green Publishing, 1997
6 Industrial Hemp Research Report, Kenex and Ridgetown University of Guelph, Ontario, 1997
7 Hemp in biocomposites, Erwin Lloyd, Journal of the International Hemp Association, Vol. 4, No. 1, 1997.
8 Market Analysis for Hemp Fiber as a Feed Stock for Papermaking, Carl Houtman, USDA Forest Service, Forest Products Laboratory, Madison, WI, 1997.
9 Dr. Neil Jorgeson, Acting Dean College of Agriculture and Life Sciences, University of Wisconsin, personal communication 3/17/97
10 Geof Kime, Hempline, Inc., personal communication, 7/11/97
11 Ray Berard, INTERFACE Research Corp., personal communication, 7/11/97
12 Sustainability of energy crops in Europe: A methodology developed and applied. E. E. Biewinga and G. van der Bijl, Center for Agriculture and Environment, Utrecht, The Netherlands, 1996
October 21, 1998