The "huge potential" of legal cannabis crops is being explored by East Anglian farmers - who are also calling for regulatory changes to unlock the versatile plant's full commercial value.

The industrial hemp variety of the plant is estimated to have up to 50,000 uses, including cooking oil, dietary supplements and biofuels from its seeds, and ropes, textiles and construction materials from the strong fibres of its stem.

Its cultivation in the UK is increasing, but farmers are currently not able to take advantage of the growing market for cannabidiol (CBD) products, widely promoted as having health benefits without the effects associated with the illegal cannabis drug.

UK farmers can grow industrial hemp for its fibres and seeds, as long as they obtain a Home Office licence which ensures the plants contain no more than the legal limit of 0.2pc of tetrahydrocannabinol (THC) - the highly-restricted psychoactive substance which creates a "high" for recreational drug users.

But despite these restrictions the lucrative leaves and flowers which produce CBD must still be destroyed - putting growers at a disadvantage to other countries which can lawfully make use of the whole hemp plant.

One Norfolk grower experimenting with the crop is John Barrett, who farms at Hill House Farm in Hedenham, near Bungay, and is director of farming company Sentry.

He will soon be planting 20ha of hemp plants for this season, which he hopes to extend to 200ha in future years.

“Hemp is a crop with a great future – in a market that needs developing," he said.

"We as an industry need to collaborate more on the market for it, and collaborate with the end user. And the key has to be for us as growers to be part of that chain so we don't give away our added value.

"I think there is huge potential for the crop. There is a multitude of different uses for the fibre, and we can harvest the seed to either market that directly as a heathy food or you can crush it and extract the hemp oil in the same way as oilseed rape oil, which a lot of people in Norfolk are doing.

"But for the CBD element you need to harvest the leaves and the flowers, not the seeds and stalks.

"That is the bit we are not allowed to do. But it is definitely where we want to be in the longer term, so we need that legislation to be opened up."

Mr Barrett said hemp grew well in dry soils and offered an alternative break crop to "widen our rotation away from traditional crops".

  • The uses and market for industrial hemp and medicinal cannabis will be discussed at an online Agri-TechE event called: "From Farmer to Pharma – and Beyond" on Wednesday, May 12. For more details see the Agri-Tech E website.