Opportunity for a hemp-food industry comes with challenges

In April 2017, Federal and state food ministers agreed that low-THC hemp seeds were fit for human consumption.  The decision is likely to take effect by the end of 2017.

This news comes as a great relief to the Industrial Hemp WA Association (iHempWA), which was set up in 2015.  Just two months prior to the ministers’ decision, iHempWA held a field day supported by the Regional Landcare Facilitator to discuss how to grow hemp at a commercial scale.  The event showed that WA growers have a lot of work to do if they want to compete at a commercial scale.

In Western Australia, the Industrial Hemp Act defines hemp as cannabis, the leaves and flowering heads of which do not contain more than 0.35% of tetrahydrocannabinol.  As of February 2017, approximately 30 licenses had been approved for fibre or seed using approved seed sources.

Like the rest of Australia, the hemp industry in WA has been impeded by legislation, the lack of long-term markets, poor agronomic understanding, inefficient harvesting methods and a lack of processing plants.  In 2011, only an estimated 185.5 hectares of hemp was planted in Australia.

Hemp (Cannabis sativa) is a fast growing annual that can grow to five metres with a deep tap root.  It is a summer plant that doesn’t tolerate frost or waterlogging, and is generally grown under irrigation.

Hemp has many potential markets:  Hemp has many potential markets from the three most commonly harvested parts of the plant:  The outer fibre (bast), the inner fibre (hurd) and the seed.

The main seed producer in WA is Glenn Ossy-Orley, chair of iHempWA.  The field day included a visit to his Nannup property to look at his small crop.  Glen said that one of the issues with producing hemp is that plant parts must be tested for THC content.  His THC has been rising for the past few years, and if his crop goes over the 0.35% threshold, he won’t be able to sow the seed from that crop.  It is an issue that Murdoch University is currently researching.

The increase in THC could be caused by plant stress, according to one of the main speakers at the field day, Colin Steddy.  Colin runs The Hemp Corporation (THC) and has been trying to develop an industry for over ten years.  Colin said that growers need to test their soils and deal with any nutritional and pH constraints, and get their irrigation right to reduce plant stress.

“If you haven’t got your soil right to start off with, one strike against you. If you haven’t got enough water, two strikes against you. So, it’s a lot to do with management practice. You put too much water on it and waterlog it for too long, your THC will go the wrong way.”

Colin’s comments were mirrored by agronomist Anthony Quinlan, who was also at the event.

“There’s a misconception that people think it will grow in poor soil without anything.  It will grow, but for commercially viability it’s got to be treated like a corn or wheat crop and treated accordingly with inputs.  If you know your pH is at 4.5, don’t plant.”

The event also featured a visit to first-time grower Gail Stubber’s property.  While Gail was commended for her first crop, the lack of markets meant that she wasn’t planning to sell any hemp products.

“I think most of it will be composted this year because, at the moment, we don’t have a processing mill, and if we don’t have a processing mill I don’t have a market.  It does make a good compost. My soil is sand and it needs carbon.”

Colin has spent a lot of time in NSW with Vacy hemp grower Bob Doyle.  Colin said that Bob was interested in using hemp in rotations because its dense planting and high shade is ideal to break weed cycles.  For fibre crops, a plant density of 250 plants per metre squared is desirable, while for seed crops the aim is more like 30 to 70 plants per square metre.  But while hemp’s fast growth rate helps it to outcompete other plants, controlling existing weeds prior to sowing is still essential.  Colin also says that Bob deep rips the soil to allow the hemp tap root to grow deep.

Harvesting is yet to be refined in WA, but a forage harvester has been used in NSW.  For seed, Colin says a conventional harvester can be used, but needs to be driven slowly and would require an even height.

While most attendees at the event were interested in growing hemp for food, another use discussed was construction.  Gary Rogers from Hemp Homes Australia described how he had built the first hemp house in WA.  The house consists of a timber frame encased by a 200mm wall of hempcrete, a mixture of hemp hurd and hydrated lime.  Hempcrete has good insulation properties resulting in reduced need for heating and cooling, and is a good way to store carbon dioxide fixed by plants.

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