The first hemp crop grown for research purposes to investigate its potential as a ‘mop crop’ to mop up effluent from animal feedlots is about to be harvested by Southern Cross University (SCU).
The crop is a low-THC cannabis variety, meaning anyone who smoked it would not get high, researcher Dr Keith Bolton, from SCU’s School of Environmental Science and Management said.
The one-hectare crop was planted late December at a commercial piggery and grazing farm near Lismore, to test hemp’s ability to soak up effluent produced by the pigs.
“This is the only trial on the NSW north coast of this kind of ‘mop crop’ research, and the first mop crop trial on a feedlot in Australia that we’re aware of,” Dr Bolton said.
Intensive feedlots are a major means of agricultural production worldwide, but getting rid of the sewage produced by the animals is a problem.
“The thrust for this research is the fact that feedlot industries have very significant waste management issues,” he said. “A pig poos as much three people, so the 6,000 sows in this piggery produce as much effluent as the equivalent of a town of 18,000 people.
“So we’re trialing a mop crop approach to effluent management, as well as looking at producing resources that can be used on farms, such as using the hemp to create bedding for the pigs which currently costs the piggery $50,000 a year,” Dr Bolton said.
Effluent is currently irrigated onto pasture crops at the piggery. The three-month trial has shown hemp to be a more effective mop crop, in that it grows quicker and produces bigger plants, soaking up more water and nutrients. The trial also found hemp could tolerate a higher concentration of effluent than normal pastures: a level of 10 times the council-treated human effluent.
From Monday, March 31, they will allow cattle onto the crop in a grazing trial, to test the hemp’s palatability. Hemp is used a fodder crop in many parts of the world eg China and Europe.
“Hopefully they’ll eat most of the foliage and we will harvest the hemp stalks about a fortnight later and convert them to bedding for the piggery,” Dr Bolton said.
The pork industry representative body, Australian Pork Ltd, is funding a three-year PhD scholarship through SCU of $26,000 a year, for Phil Dennison to continue the research. The research is a collaborative project between SCU, Ecofibre Industries Ltd and the pig industry.
NB: any footage or photos MUST NOT reveal the location of the crop, due to security concerns, nor can piggery be identified.
Contact: Sara Crowe, SCU Media Unit, Ph: 6620 3144, or Chris Stewart Ph: 6620 3039 or 0418 431 484.