INDUSTRIAL HEMP
UNDERSTANDING THE OPPORTUNITY FOR UK FARMERS
This article was “Written by Camilla Hayselden-Ashby, Nuffield Scholar 2021 Hemp, Cannabis with a low level of the psychoactive compound THC (tetrahydrocannabinol), has seen a global upsurge in interest in the last decade. This has been driven by the growing popularity of CBD as a food supplement, demand for environmentally sustainable products and changes in legislation around cannabis growing. The global hemp market is projected to reach $15.26 billion by 2027. There are three key parts of the hemp plant which can be harvested; seed, stem material and flower.
Flower CBD, extracted from hemp flowers, has seen a boom in popularity in recent years and is taken for anxiety, inflammation and pain relief. This is a high-value output, but UK farmers will have to wait to take advantage as current industrial hemp licensing prohibits processing of flower and leaf material. As a result, the CBD oil sold in the UK is all imported. In the Channel Isles this restriction has been lifted, allowing farmers such as Jersey Hemp to tap into this growth market.
Seed
This growth in the demand for the crop is generating interest among UK farmers. Although the area cultivated in the UK is small (820ha in 2020 according to the BHA), hemp has huge potential as a financially and environmentally sustainable break crop. This could not come at a better time as farmers look to diversify in the transition from BPS, and reduce their carbon footprint. The UK has a long history of hemp cultivation starting from Roman times, and it was an economically significant crop until the start of the 20th Century. For much of this time, it was such an economically important crop for rope and sails in the shipbuilding trade that there were subsidies available to encourage farmers to grow it. Under Henry VIII it was even required that every farm grow a quarter of an acre of hemp for every 60ac cultivated. Hemp has over 25,000 uses, with applications for all parts of the plant. These include food, construction, textiles and bioplastics. It is also environmentally beneficial to grow. Hemp produces a lot of biomass in a short period of time, allowing it to sequester an estimated 15t of CO2 per hectare. This makes it an important tool in the race to Net Zero. Its deep root system (the taproot can go down to 2m) improves soil structure and brings up nutrients from lower in the soil profile. It has low input requirements and reduces herbicide requirements thanks to effective weed shading. Finally it takes up heavy metals in the soil, enabling its use in phytoremediation to deal with soil pollution.
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Hemp seed is the easiest market for cereal growers to switch to since it can be harvested using a combine harvester. Seed varieties are usually shorter at 1.5-2m (vs. 2-4m for other varieties). Finola is popular among UK growers because it has been bred to flower automatically 120 days after sowing, rather than being triggered by a change in day length; this allows an earlier harvest in mid-September. Hemp seed is nutritionally dense with high levels of omega oils and protein. It is pressed for oil, made into hemp milk, sold as whole hemp hearts which can be added to cereal or smoothies, and processed into protein isolate used in vegan meat-alternatives. Hemp oil can be extracted using cold press equipment similar to that used for oilseed rape. There are also several UK companies who produce hemp oil and seed products such as Good Hemp.
Stem Hemp stem consists of long outer bast fibres and a woody core which is broken up into ‘shiv’. These are separated through a process called ‘retting’ allowing the plant to break down slightly in the field followed by decortication which uses physical processes to separate the fibre and shiv. These products are used for construction, animal bedding, paper, kindling, bioplastics and textiles.
Building Hemp is used to make ‘hempcrete’ a more sustainable alternative to concrete, made by mixing hemp shiv with lime. This results in a construction material used in walls with a timber frame or sprayed for insulation. As well as the carbon sequestered while the plant grows hempcrete buildings lock up additional carbon as they cure with total carbon ISSUE 15 | OCTOBER 2021
