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Cannabis plants growing in controlled conditions. Picture: 123RF
Cannabis plants growing in controlled conditions. Picture: 123RF

Hemp isn’t intoxicating. Unlike strains of cannabis such as sativa or indica, it is virtually impossible to get a “high” from consuming it, in whatever form, since it contains only minuscule amounts tetrahydrocannabinol. As such, the plant is cultivated in a number of countries for an array of economic benefits.

In SA, the cultivation  of hemp for research and industrial purposes was legalised in October 2021, making the country one of only 11 African nations to take that stance.

While most countries that farm the crop are in the northern hemisphere, the plant is more suited to the tropical and subtropical climate of Sub-Saharan Africa.

One of the main reasons for the cultivation of hemp around the world is the harvesting of textile-grade fibres. The outer part of hemp’s stems can be used to make textiles. These can be processed further for the manufacture of rope, clothing, shoes and the interior upholstery of vehicles.

The benefits of hemp over cotton show the need for local cotton farmers to evaluate which of the two is more viable in the local setting. As SA is a net cotton importer, the introduction of hemp for textiles could turn the tide and result in net exports of plant textile fibres.

Some of the advantages of hemp over cotton are:

  • It grows faster. Hemp can be harvested in 12 weeks, half the time it takes for cotton to reach maturity.
  • On an equal area of land a farmer will harvest twice as much fibre from hemp as from cotton. It therefore makes more efficient use of land.
  • Hemp needs 2,100l of water for a kilogram of fibre-grade textiles — about about a quarter of cotton’s water requirement.
  • Hemp is a carbon negative plant. A hectare of industrial hemp can absorb as much as 22 tonnes of CO2. It therefore offers one of the fastest methods of converting carbon dioxide into biomass.
  • Unlike cotton, hemp rarely needs pesticides or herbicides. Its dense canopy and bitter nature keep weeds and pests under control.
  • It is possible to replant hemp for several consecutive years, without degrading soil quality or reducing the yield.
  • Textiles made from hemp are more durable than cotton fabric, encourage better aeration and are easier to process (dye).

Competitive edge

Almost all components of the hemp plant can be used or processed for a variety of purposes. That gives it an edge over most key crops. Hemp seeds are highly nutritious, comprising 20%-25% protein, 25%-35% fats and 10%-15% fibre, plus several vitamins and minerals. Hemp seed is in demand in advanced economies, with consumers using them in baked bread, cereal, salads and protein-shakes, so there is a ready export market. 

The whole hemp plant can also be fermented to produce ethanol, which can be used as motor vehicle fuel. Ethanol is also suitable for power stations, which can generate electricity to the national grid. Moreover, hemp can be used to manufacture biodiesel. In this regard, if the government promoted the cultivation of the plant mandatory fuel blending for diesel engines could be introduced, with local hemp serving as the source of biodiesel.

Such policies would have a direct impact on local employment and stimulate economic growth, as they lead to the development of new local industries and supply chains.

Hemp fibres can also be used to produce cheaper and more environmentally friendly vehicle batteries. A  study by David Mitlin of Clarkson University in New York compared hemp batteries to graphene ones, and concluded that the plant is similar to graphene in terms of energy storage and weight.

In addition, the research outlined that hemp batteries would be cheaper to manufacture. Further advances in research into hemp’s energy storage capabilities may lead to breakthroughs such as the replacement of lithium batteries in electric vehicles.

Hemp can be used to make 100% biodegradable plastics, unlike those manufactured from oil, coal and natural gas. Such biodegradable plastics become part of the natural environment after only a few months. Hemp plastics don’t contain toxins that could be harmful if the products are used for serving food, or when they are burnt and the smoke is inhaled.

Plastics made from the plant can also be far stronger than conventional containers. Due to their resilient nature, as far back as 1941 car maker Henry Ford manufactured a vehicle incorporating hemp plastics in an attempt to create a light, fast and fuel-efficient car.

Green plastics

More recently Bruce Dietzien, founder of DrawdownHemp and Renew Sports Cars, made a vehicle using 100% hemp plastics in 2016. The body of the vehicle was reportedly 10 times stronger than steel and dent resistant. Several prominent commercial vehicle manufacturers, including Mercedes-Benz, Audi, Peugeot, BMW, Volvo and Volkswagen, use hemp plastics for a number of components such as dashboards, windscreens and arm rests.

The plant is also used in the manufacture of a number of medicines such as analgesics (painkillers), antidepressants, sleeping medication and anticonvulsion drugs. There are plenty of other applications too, including animal feed, building materials, paints, cosmetics and paper.

The growth of industrial hemp in SA is hamstrung by a few issues, which if resolved could result in significant growth. Rural and township farmers need to be incorporated into the sector by providing them with accessible permits. Hemp should be cultivated outdoors and indoors so that it can truly be a commercial crop.

At present SA’s industrial hemp is strictly cultivated indoors, in greenhouses, which limits the number of entrants into the sector. Supportive government policy such as using hemp products in government building projects and for uniforms used by staff and students in public institutions, could be crucial for growth.

Awareness campaigns, agricultural extension services and quick processing of permit applications would help provide sustainable growth for the sector.  

• Tutani is a political economy analyst.

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