Hemp

Industrial Production and Uses

Pierre Bouloc, Serge Allegret, Laurent Arnaud, Pierre Bouloc, Serge Allegret, Laurent Arnaud

• Publisher: CAB International
• Year: 2013
• ISBN:
  9781789244076
• Topic: Tecnologia e ingegneria
• Subtopic: Agronomia

Hemp production for industrial purposes continues to grow worldwide, and is currently being used for many applications including house insulation, paper making, animal bedding, fabric, rope making and also as a biofuel. This book brings together international experts to examine all aspects of industrial hemp production, including the origins of hemp production, as well as the botany and anatomy, genetics and breeding, quality assessment, regulations, and the agricultural and industrial economics of hemp production. A translation of Le Chanvre Industriel, this book has been revised and updated for an international audience and is essential reading for Producers of industrial hemp, industry personnel and agriculture researchers and students.

1 Hemp: A Plant with a Worldwide Distribution

Pierre Bouloc
La Chanvriere de L’ Aube (LCDA), France

1.1 Where is Industrial Hemp Grown?

Hemp is thought to have originated in the Yunnan Province of China and its utilitarian form, Cannabis sativa, has spread progressively across the globe. In general, it demonstrates a preference for the temperate zones situated between the 25th and 55th parallels on either side of the equator.

This great versatility is not unusual, for there are many plants, including wheat, that flourish in both the northern and southern hemisphere. Historical records showed that hemp was widely cultivated across most of the planet by people who recognized its great utility.

1.2 Modern-day Industrial Hemp Production

Table 1.1 provides a comprehensive list of all those countries producing industrial hemp, even if their output is small. It bears testimony to the ongoing importance of this crop.

The information provided for the 25 European countries is particularly reliable, as the figures are derived from an industry that is strictly controlled and closely monitored. The subsidies available to support hemp production further ensure the accuracy of these reported figures.

The production of certain other countries, such as the Baltic states and the ten countries who began production in 2003, remains small. We know, however (Chapter 2), that these Baltic states and northern Russia were largely responsible, during the 17th and 18th centuries, for the supply of hemp to the navies of France, Britain and Holland, to name the largest three.

All the new members of the European Union, historically having produced significant hemp crops, have requested authorization to continue production.

Among the countries of Eastern Europe are Russia, Serbia and Romania. Historically, they have devoted significant areas to the production of hemp. Today, their production is modest, although sooner or later financial backing will be found to fund the cultivation of this crop. It should not be forgotten that, despite various financial problems, countries such as Hungary, Poland, Serbia and Ukraine maintain hemp research centres that rival France’s Fédération Nationale des Producteurs de Chanvre (FNPC) in Le Mans.

In Asia, modest production is reported from countries like Korea and Japan. This reflects the political alignment of these two countries with the repressive restrictions of the USA. However, the price of oil, together with current environmental concerns, may well see production increase in these countries, particularly following recent moves in favour of the use of natural fibres.

Table 1.1.

The figures for China have been estimated, as it has been impossible to obtain a reliable estimate. Chinese production is undeniable, however, for:

1. Every year the Chinese export to Europe 5000–6000 t of hemp seed for use as animal (bird) feed. The Chinese also supply neighbouring markets with organic hemp seed, Japan in particular. This allows us to estimate, taking into account yields, a surface area of some 10,000 ha under cultivation.

2. China exports a wide range of clothing, textile and decorative items made from hemp to various countries in the developed world. The existence of dioecious hemp, from which the best fibres for weaving are obtained, can therefore be assumed. The large quantities of exported hemp textiles point to an extensive programme of cultivation.

3. We now know that five large companies cultivate, for their own use, some 50,000 ha. Their crops are produced using modern technologies and are destined for the textile industry.

4. If we add the surface area under cultivation for internal demands, a total area of 65,000 ha under cultivation can be proposed as the absolute minimum.

In Australia, the pioneers of Ecofibre have come a long way in 15 years to re-establish hemp as a legitimate crop. They have lobbied successfully for changes in the law, undertaken seed trials, developed appropriate local farming and harvesting techniques, as well as developing markets, farming agreements and financing plans.

In the USA, the industrial production of hemp is still not permitted by law. That said, the country of prohibition, in which hemp production has been outlawed since 1950, is slowly opening itself to the potential uses of hemp seed. This seed comes from neighbouring Canada. Here, production has been legal since 1998 and is growing rapidly, judging by the production figures for Ontario, Manitoba and Saskatchewan. If we take into account the experiments being undertaken in Quebec, New Brunswick and the Prairies, approximately 12,000 ha were under production in 2009. All these areas were for seed production destined for human consumption. Chapter 16 of this book provides a scientific description of the properties of this seed. The benefits associated with hemp seed are currently being investigated under the aegis of the Canadian Hemp Trade Alliance (CHTA). Further growth in North American hemp production is to be anticipated.

In Africa, there are few figures to report, as production is negligible. The development of hemp production in South Africa remains a possibility, as various pioneers have initiated projects.

1.3 Future Perspectives

Interest is growing across the world, and especially in Europe, in industrial hemp and in natural hemp fibre(s) in particular. The preceding account bears testimony to this.

A growing demand for natural products, our increasing interest in and concern for the environment, together with rising fuel and raw material costs provide, among other factors, a unique opportunity for hemp production.

At the same time, selection techniques, cultivation practices and industrial equipment have all advanced. The most important development, however, concerns our improved ability to use and work with natural fibres. Over the next 10 years, we can expect to see a significant growth in raw production and in the uses found for this remarkable plant and its various constituents.

This book will help all those who seek to develop and diversify their production.

2 The History of Hemp

Serge Allegret
La Chanvriere de L’ Aube (LCDA), France

2.1 Introduction

Industrial hemp makes for an interesting and intriguing book title, for the uninitiated will be largely ignorant of this plant and its industrial role.

The contemporary significance of this subject may not, at first, be obvious to the reader. Few, other than a small number of professionals and botanists, will have set eyes on this plant of some 3 m in height, growing thickly in fields like millions of tall, green pencils, for that is about how thin they are in optimal culture.

Who is aware that, in 2009, of the 29 million ha (Mha) under cultivation in France, 12,000 ha were devoted to the cultivation of hemp? Only chance will bring people into contact with this plant. Only our grandparents and great grandparents will be able to draw on their memories of the hemp plant and provide explanations to enlighten younger generations.

And yet hemp has accompanied humans from their earliest industrial endeavours. It is now several thousand years since humans transformed hemp into serviceable products, and for a long time, hemp was one of our most important commodities, and was recognized as such. And then, little by little, it fell into disuse, becoming a statistical non-entity and eventually just a word in our dictionaries.

After a period of great utility, bordering on the indispensable, it fell victim to various industrial discoveries. Coal-fired steam engines saw it disappear from the shipbuilding industry, where it had previously supplied both sails and rope, while synthetic fibres replaced it as a material for use in the textiles industry.

Towards the end of the 20th century, humans suddenly became conscious of their insensitive brutality towards the natural world. They could no longer ignore the widespread and overwhelming levels of pollution and the fact that natural resources were not infinite, as previously thought, but were disappearing little by little.

The late but necessary reaction of humans to this situation has been to institute measures designed to save the environment. There has been a growing realization that what has been used up has gone forever.

It is the ambition of the authors of this book to detail all the uses of this ancient plant and to show that, following on from its distinguished history, the hemp plant can expect a great future. In presenting the history of hemp, this book will show its principal uses and demonstrate its historical importance.

Drawing on various sources, the book will explain how hemp has accompanied humans in their day-to-day life and how it has supported them in their battles.

In the past, hemp has known both highs and lows, and it is possible that, like the phoenix from the ashes, it is now making a comeback.

The book will demonstrate and present the history of this plant, while at the same time fully acknowledging that this is not an exhaustive account.

2.2 The Various Forms of Cannabis

‘Hemp? … Hemp did you say? What? As in the stuff rope, string, bags and plumbing oakum (or tow) is sometimes made of?’ These might be the answers volunteered in response to a researcher posing questions about ‘hemp’ to passers-by. If asked about ‘cannabis’, or worse, ‘marijuana’, however, the same people would be much more forthcoming for they would have heard of this ‘drug’ and be able to talk about it in one way or another.

Marijuana is not to be our subject, however, for there is within the genus Cannabis variation so great that botanists cannot stop arguing about whether to make a separate species (Small, 1979). Thus, one often finds sources that allocate the drug types of cannabis to the species Cannabis indica, and the others – including what we are today calling ‘industrial hemp’ (though formerly just ‘hemp’) – to the species C. sativa (‘sativa’ being the specific applied to plants commonly found in agriculture, L., ‘cultivated’). That division has now been rejected.

In 1753, Carl von Linnĕ was the first to classify Cannabis using his new system of binomial nomenclature. Since that time, the genus has been placed in Moraceae (Mulberry), then Urticaceae (nettles), before graduating to its own family, Cannabaceae, which it now shares with Humulus (hops) and, just recently, Celtis (hackberry). Botanists may revisit these associations yet again once modern DNA-based tools are applied, so it may be wise to regard them merely as suggestions.

Clarke (1999) has reviewed the current view of the species-level classification: three different systems each with its adherents. Since all Cannabis is interfertile (i.e. there is no ‘species barrier’ or sexual incompatibility between types), a practical taxonomy is currently in vogue by which varieties are classified by their chemical profile, a so-called ‘chemotaxonomy’ (Hillig, 2004, 2005). The key to this taxonomy is the genetic presence of alleles for the contrasting cannabinoids, tetrahydrocannabinol (THC) and cannabidiol (CBD) (covered later). Drug varieties of Cannabis overproduce THC, whereas ‘industrial’ (meaning fibre and oil) varieties have very little THC, and also much less of the resin that bears it.

Whether high in THC and copious in resin production, or low in THC with stems made to yield a long, strong fibre, the Cannabis that is found across the world bears the mark of the ancient breeder. With the probable exception of the degenerate ‘ruderalis’ type – which may or may not be a vestige of the wild ancestor – Cannabis of every type (no less than all our other domesticated crops) has the traits sought and enhanced by humans.

Out of this vast variation, our focus here is on the ‘sativa’ types bred for something other than their resin. Historically, that has meant the stem (or ‘bast’) fibre. In recent times, increasingly, varieties selected for the seed and its nutritional profile are emerging, though traditionally the seed was a secondary product of fibre production, used only in a few cultures of Eastern Europe and Russia.

The naming conventions of western botanical science aside, the trail of this plant is found in local names, its centrality reflected in the proliferation of appellations.

In France, names for local Cannabis varieties are preserved in regional dialects:

• Aube et Haute Saône: cheneville

• Berry: chaude

• Bresse: chenève

• Forez: chinève

• Franche-Comté: chenove

• Languedoc: carbe, etc.

• Limousin: chanabal

• Mâconnais: chernière

• Meuse: chenevoux

• Normandy: cambre

• Picardy: canve

• Poitou: chenebeau

• Provence: cannabal, cannebière

• Région toulousaine: carbenal

• Rouergue: canabou

• Saintonge: charve or cherve

• Savoie: stenève

• Vivarais: chanalier

• Walloon...