Waikato couple Dave and Anne Jordan have been trialing the growing and harvesting of industrial hemp for both oil and fibre.
Hemp cultivation dates back to the beginnings of recorded history. Its first use was as food for humans and animals. For centuries hemp was a significant agricultural crop producing fibre, paper, clothing, lighting fuel and medicine.
Technological advances have made possible a large variety of foods that can be made from the seeds. The leaves and stalks have been used to produce a range of products from medicine to construction material.
Growers also say hemp removes more CO2 from the air than trees, and is pest, weed and drought resistant. They say the crop uses a lot less water and can reach maturity in as little 90 days.
Dave and Anne started off with a dream to create an industry in New Zealand based on hemp. The couple has been working towards harvesting hemp for textile use as well as oil. They say there are no limits to the use of hemp, from creating bio-fuel to improving the soil for future crops. Dave says the crop can also be used to remediate contaminated soils.
While they help to develop a local industry, the couple sell imported hemp seed oil for skin care and related products. At present they can’t sell it for human consumption in New Zealand but hemp seed oil has been promoted for its health-giving properties elsewhere. The oil contains essential fatty acids (EFAs) Omega 6 and Omega 3 which are important for the proper functioning of the immune system, brain health, wound healing and for insulating nerves. The oil is said to have a strong anti-inflammatory effect and is effective in reducing symptoms of PMT, eczema and acne.
Rules surrounding the growing of industrial hemp were relaxed in NZ in 2006. The new regulations – the Misuse of Drugs (Industrial Hemp) Regulations 2006 and the Misuse of Drugs Amendment Regulations 2006 – reflected the low drug content of hemp, which was previously subjected to the same strict controls as those placed on illicit cannabis.
The new licensing system covers only industrial hemp, which refers to varieties of cannabis with a THC content generally below 0.35 per cent and not higher than 0.5 per cent. In varieties grown for use as a drug, THC levels can reach as high as 20 to 30 per cent.
The relaxation of rules followed a trial cultivation of industrial hemp to determine its potential as a commercial crop and the level of control that would be appropriate for such cultivation. That scheme was extended to allow the continued cultivation of hemp while the new regulations were being developed.
In 2003, Cabinet approved the recommendation to develop a regulatory scheme to control activities relating to industrial hemp. As at January 2017 the New Zealand Government hasn’t yet approved it for human consumption. In March 2016 ministers asked FSANZ (Food Standards Australia and NZ ) to prepare a proposal on how low-THC hemp could legally be designated as a food. A call for submissions was sent out in July 2016 for consideration by April 2017.
Proponents say hemp is an ideal rotation crop helping to break up and condition the soil for following crops due to its long root structure that penetrates deep into the soil when fully matured, helping to aerate the soil.
The crop needs a similar level of care to other commercial crops – with moderate fertiliser requirements and little or no pesticides. Industrial hemp is frost tolerant. And while not pest free – the crop can be regarded as hardy and tolerant.
Birds were a problem pest in early trials in Canterbury – but those growers say those problems can be overcome by keeping crops away from stands of trees or shelter belts.
Early trial work has shown that planting in a stale seed bed is important because of the lack of herbicides that can be used in establishing the plant. Hemp should not be planted until soil temperatures reach at least 6 – 8°C, in the first month or so. The seedlings need reliable rain or irrigation but once they are established these requirements drop dramatically due to the dense canopy enabling water retention and the deep taproot seeking out the water table.
In 2004 trials, yields of over 820kg of seeds per hectare were achieved. Growers involved in those trials say that cultivars need to be selected for seed or fibre and a dual purpose or multi purpose cultivar for New Zealand conditions is some way off. Under favourable growing conditions Dave expects to harvest one tonne of seed, three tonnes of fibre and six tonnes of hurd (or leaf fibre) per hectare.
Dave says part of the problem in New Zealand is the lack of purpose-built machinery to harvest. Currently many growers are hand harvesting but Dave has been testing, importing and developing suitable machinery to enable mechanical harvesting for greater efficiency.