Saving Trees with Marijuana

by Aldis Ozols

Visitors to Toulouse, France, are confronted by the sight of more than 8,000 hectares of lush marijuana plants waving gently in the breeze, while in the central USSR, over 40,000 hectares are under cultivation. These are not the hallucinations of terminal dope-fiends, but government-backed plantations used to supply raw material for paper manufacture. In Australia, the Industries Assistance Commission is considering hemp farming as one of the alternatives to woodchipping old-growth forests.

The exclusive use of trees from virgin forest in paper manufacture is a disease of the latter part of this century. Paper, of course, has been an integral part of human civilization for thousands of years. Common teaching has it that the Egyptians produced the first crude writing material by pounding soaked papyrus reeds on flat rocks to fashion a coarse form of paper. In fact, for thousands of years before this the Chinese had been creating a fine and durable paper with fiber pulp derived from the common hemp plant, of the family Cannabanaceae.

Indeed, until the first third of this century the marijuana plant was the dominant source for paper production. Most surviving texts from last century, including practically all the bibles and encyclopedias, were printed on hemp paper directly, or on so-called "rag paper" from cloth originally derived from hemp fiber.

By far the bulk of hemp fiber was produced to supply the needs of wind-propelled navies. In fact, the word 'canvas' is a Dutch derivative of 'cannabis'. With the replacement of sail by steam power the area under cultivation contracted greatly. The development of synthetic fibers and high speed, large output automated production processes made further inroads into the demand for natural fibers. This was exacerbated by the slow development of machinery capable of processing hemp fiber on a large and economical scale, such as that developed for the cotton industry.

A further factor was the political suppression of the use of marijuana by some disadvantaged minorities in American society. After thousands of years of productive cultivation by many different cultures it was deemed necessary to apply the full force of the police and judiciary to eradicate this "threat" to humanity.

Even so, the extremely favorable weight to strength ratio of hemp fiber retains for it a place in industry. Most readers would be familiar with hemp rope and hemp fiber widely available at hardware stores for plumbing purposes, and some of the finest linens produced in the world are a blend of not flax and cotton but hemp and cotton. An extensive cottage industry in Italy produces clothing from hemp.

This versatile plant also has properties that could save our native forests. Cellulose for paper derived from the cultivation of hemp occurs in two physical forms. The outer bark of the stem yields the long, strong fibers that have been used since time immemorial for rope and cloth. These have to be separated from the pith, or phloem, at the center of the plant by a process known as retting. What results from the separation process is referred to as hemp hurds and would generally be considered a waste product, but for the pioneering work of Lester Dewey of the US Department of Agriculture in 1916.

In an attempt to increase the efficiency of the hemp industry, Mr Dewey conducted experiments with the paper manufacturers of his day to establish the suitability of hurd pulp as a paper substrate. Adapting existing processes, he found that a paper could be produced that satisfied all the requirements of the printing industry and, in fact, exceeded in strength and folding endurance that produced from wood stock. The importance of this work is that the usable yield per hectare is increased from approximately 160kg/hectare of long fiber to 1010kg/hectare of hurds for paper manufacture. Under these circumstances it is possible to produce as much paper from ten hectares of hemp as from forty hectares of trees!

Also significant is the difference in lignin content between wood and hemp pulp. This averages 30-40% in wood but only 3-4% for hurds. It is the removal of lignin that requires much of the harsh chemical treatment that makes the current Kraft process such an environmental disaster.

The large scale cultivation of hemp can be carried out in an environmentally sensitive fashion. The suitability of Australia as a location for hemp cultivation was established as early as 1845, when Dr Francis Campbell conducted small scale experiments. He found that the loamy soils of the river flats from the Hunter region to Grafton provided ideal conditions. This land is presently devoted to cattle grazing, and along with much other Australian agricultural land, suffers from infestation of noxious weeds and gross soil erosion. As reported in Scientific American in 1915, two or three seasons of hemp cultivation will largely clear a field of weeds due to the dense shock of leaves produced, while the deep tap-root system aerates and stabilizes the soil. In fact, early farmers used hemp to prevent soil erosion after forest fires.

Land already devoted to pasture can be readily adapted to hemp cultivation without disrupting dwindling native habitats. The leaf, which has no place in the paper-making process, makes an excellent fodder. Marijuana leaf is used to fatten stock in Borneo and other Asian countries with excellent results, while the seed, due to its high vegetable content, is currently widely used as a bird seed.

It is not my intention in this article to debate the merits or otherwise of marijuana as a social drug. It is, however important to realize that while the plant grown for fiber and that cultivated for smoking are the same species, the conditions under which fiber plants must be grown render them totally unsuitable for drug use, with almost undetectable levels of THC.

The possibility of using hemp fiber cultivation to save native forests in Australia is being researched by Dr Andrew Katelaris, who provided the information in this article. He can be contacted care of P.O.Box 451, Strawberry Hills, 2012, NSW, Australia.

This article was originally published in Simply Living magazine, Volume 4, No 3, June 1990. Please credit if reprinted.