By John Muir, Agronomist | August 2025
The iHemp NSW Field Trip on September 11, 2024, visited the University of Sydney’s Narrabri Research Station and a cotton farm in Moree as part of the annual winter crop field day. Among the many crops on display, hemp emerged as a standout feature for the 300 guests in both field observations and presentations.
Included in one of Narrabri’s many alternate winter species dryland cover crop projects, hemp had been sown in addition to the AgriFutures summer sown irrigated crop variety trials. Traditionally a summer crop, hemp often struggles to establish in high air/soil summer temperatures. Recognising this, Professor Guy Roth, Director of Northern Agriculture from the Sydney Institute of Agriculture, extended sowing dates into winter – and the results were surprising.
As part of the broader winter green manure /cover cropping program preceding dryland summer cotton, the trial featured a mix of cereals, brassicas, legumes, and hemp. All crops were sown no-till, into 5 tonnes per hectare of wheat stubble on June 22.
Around three months later, on September 11 – following a frosty winter – the field day showcased an unexpected standout leader: hemp. By 60 days after sowing, the HFA Ruby variety had reached mid-flowering, stood approximately 0.75 meters tall, and had achieved an estimated biomass of 3 tonnes per hectare.
Hemp’s frost tolerance in its vegetative stage proved advantageous. As long as flowering occurs after the winter frost, hemp can fill and finish, just like a winter crops, into spring and completing grain fill before the hot, dry summer sets in.
The trial yielded over 500 kg/ha of grain, despite a significant portion of seed shattering prior to harvest. Like canola, hemp is indeterminate and tends to have uneven maturity, making timely harvest critical. Even with some losses, at a market price of $3,000 per tonne, the return equated to approximately $1,500/ha.
This result is just the beginning. With further improvements in genetics, agronomy, and environmental understanding, the potential for winter-sown hemp in southern Australia is immense. And new trials are already in this year including dryland winter commercial crops in NSW to South Australia.
Further Information:
For additional insights, refer to the April 2024 extract of a presentation at Australian Industrial Hemp Conference, written by John Muir, Polish breeder of Henola and Don Telfer DPIRD WA, and AgriFutures Knowledge Hub.
