雅思阅读第081套P3-The hemp revival

The hemp revival

The hemp plant, one of the world’s oldest industrial resources, is back. The rediscovery of this renewable resource is making it the fibre of choice for future textiles, personal care products, building materials, paper and fuel.

Hemp has been grown for paper, textiles, food and medicine throughout human history. The earliest known woven fabric, made of hemp, dates back to the eighth millennium (8000-7000 BC). The majority of all sails, clothes, tents, rugs, towels, paper, rope, twine, art canvas, paints, varnishes and lighting oil were made from hemp. Hemp seeds were regularly used as a source of food and protein for centuries.

Hemp’s drastic decline in use and importance within a matter of fifty years is widely considered to have been brought about by the timber and petrochemical industries in America. By the mid- 1930s, changes in technology were beginning to impact on the hemp industry. Mechanical stripping equipment and machines to conserve hemp’s high-cellulose pulp became available and affordable. Timber and paper holding companies stood to lose billions of dollars if hemp were to be grown on a large scale. A resurgence of the hemp industry also threatened the emerging petro-chemical companies which had patented the chemicals for pulp processing. Newspaper articles began to appear, linking hemp with violent crime. The term used, however, was ‘marijuana’ to distance it from hemp used for industrial purposes. Because few people realised that marijuana and hemp came from the same plant species, virtually nobody suspected that the Marijuana Prohibition of 1938 would destroy the hemp industry.

Supporting the theory that marijuana was banned to destroy the hemp industry, were two articles written just before the Marijuana Prohibition, claiming that hemp was on the verge of becoming a super crop. These articles, which appeared in well-respected magazines, praised the usefulness and potential of hemp. ‘Hemp can be used to produce more than 25,000 products’, and ‘hemp will prove, for both farmer and public, the most profitable and desirable crop that can be grown.’ This was the first time that ‘billion dollar’ was used to describe the value of a crop. Less than one year after these articles were written, the Marijuana Prohibition took effect. To what extent a conspiracy was involved is still being debated, but the important thing is that for thousands of years, hemp was used extensively. Then over a short period, it became illegal in many parts of the world.

Now, however, the focus is on the development of hemp as an industrial resource. Initially, a distinction needs to be made between the two types of hemp. ‘Cannabis has evolved into two basic species. Plants grown for fibre and seed are universally called hemp. Cannabis grown for its drug content is commonly called marijuana or drug cannabis. Drug-type cannabis varies widely in THC content from approximately 1-2% in unselected strains to 10% in the best modern varieties.’ (as cited from Watson 1994). Hemp contains virtually none of the active ingredients of drug-type cannabis (THC). It is not feasible to ‘get high’ on hemp, and most marijuana produces very low-quality fibre. Hemp should never be confused with marijuana, as their roles cannot be reversed.

It is evident that hemp is an extraordinary fibre. Both stems and seeds can be utilised. Most significantly, hemp can be grown without pesticides and herbicides. The plant also has the ability to suppress weeds and soil-borne diseases. Based on the hemp industries which have been established overseas, there is a large demand for hemp products and hemp is proving to be a highly profitable industry. On an annual basis, one acre of hemp will produce as much libre as 2 to 3 acres of cotton. The fibre is stronger and softer than cotton, lasts twice as long and will not mildew. Cotton grows only in warm climates and requires more water and more fertiliser than hemp as well as large quantities of pesticide and herbicide.

Hemp can also be used to produce fibreboard that is stronger and lighter than wood, and is fire retardant. Unlike paper from wood pulp, hemp paper contains no dioxin, or other toxic residue, and a single acre of hemp can produce the same amount of paper as four acres of trees. The trees take 20 years to harvest and hemp takes a single season. In warm climates hemp can be harvested two or even three times a year. On an annual basis, one acre of hemp will produce as much paper as 2 to 4 acres of trees. From tissue paper to cardboard, all types of paper products can be produced from hemp. The quality of hemp paper is superior to tree-based paper. Hemp paper will last hundreds of years without degrading and it can be recycled many more times than tree-based paper.

Today, industrialised nations around the world are waking up to the enormous potential of hemp. While some countries, like China and India, have never had laws against hemp cultivation, others are legalising industrial hemp after many years of lumping it together with marijuana. The products and fabrics that are emerging from the international hemp industry are finding strong demand in an eco-aware global community. Hemp is indeed an agricultural crop for the twenty-first century

SECTION 3: QUESTIONS 27-40

Questions 27-31

Re-order the following letters (A-F) to show the sequence of events according to the passage.

A	Timber and petro-chemical industries threatened
B	Articles praise hemp as a potential billion dollar crop
C	Widespread cultivation of hemp (Example)
D	Prohibition of marijuana
E	Newspaper articles link hemp to violent crime
F	Development of stripping machines