Tasmania produces ~80% of the total Australian hemp seed production, and approximately 1400 ha of hemp was grown in Tasmania in 2018.
Hemp provides an excellent option for short summer gaps in the cropping sequence, and goes from sowing to maturity in around 90 days. There is also anecdotal evidence to suggest that their fibrous roots can improve soil structure and function. However, at the moment it is not possible for Tasmanian farmers to make >$2000/ha gross margin as at the moment only the seed is harvested and utilised - the vegetative parts are left in the paddock and burnt.
It is possible that hemp could be used as a forage crop exclusively, or as a dual purpose crop (such as canola) for both forage and seed, or forage and fibre. However, there has been no research regarding the nutritional value of hemp for animal feed in Tasmania, except for a current honours project that focusses only on one variety.
This project is investigating the effects of genotype, grazing time and environment on the nutritional value (fibre, protein, minerals etc) of five genotypes. Growing these crops in two locations across the state and over two years will provide scientifically robust data regarding the nutritional value.
Using two simulated grazings (performed by manually cutting the plants) will enable the project to give information to growers about when the best grazing time is to suit their priorities regarding seed yield and forage production.
Dr Beth Penrose, a lecturer in pasture science at the Tasmanian Institute of Agriculture (TIA), is in the final stages of the two-year research project.
Currently, industrial hemp is grown for seed and/or for fibre to make foods, cooking oils, health and beauty products, textiles and building products. However, often only part of the plant is used which limits the profitability of the crop.
“Hemp is a relatively new crop in Australia and its potential as an animal feed hasn’t been fully explored. We’ve been working for a few years with research students and with a larger research project looking at the potential of using industrial hemp as a forage crop for livestock,” Dr Penrose said.
“Up until now, this is the only research that has been conducted regarding the nutritional value of hemp for animal feed in Tasmania.
“The current research is looking at five varieties of industrial hemp, and assessing the effects of genotype, grazing time and environment on the nutritional value. We also want to find out the impact that grazing has on the yield of hemp seeds, and whether it could potentially increase the yield and the overall value of the crop.”
TIA works closely with the Tasmanian Hemp Association (THA) who are supporters of research to drive development of the industrial hemp industry. The current research trial is supported by funding from Agrifutures Australia and the THA.
Dr Beth Penrose is a researcher and lecturer at TIA with a particular interest in improving soil and plant nutrition for human and animal health. She joined TIA in 2017 from Nottingham University in the UK.
A webinar on the potential use of industrial hemp as a forage crop for livestock, and the challenges that need to be overcome for industrial hemp to become a mainstream forage crop was recorded on the 10th March, 2022.
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