Scientific trials test grazing regimes aimed at coping with variable rainfall
Almost 30 years of scientific data has provided the data “bones” for change in North Queensland grazing management regimes.
Beginning in 1997, led by Department of Primary Industries Principal Scientist Dr Peter O’Reagain and John Bushell, a team of scientists has collected data on pasture condition as well as the production performance of the cattle.
Five grazing regimes have been trialled, each in duplicate across 10 paddocks of about 100ha each at the Lyons’ family property Wambiana Station south of Charters Towers.
Dr O’Reagain said the strategies to cope with the huge variability of rainfall — and therefore, grass — typical in North Queensland were largely developed by graziers.
“The strategies we trialled were not developed by scientists in a laboratory,” he said.
“They were strategies learnt by producers across many generations.”
The initial trial strategies were:
- heavy set-stocking at 5ha per adult equivalent (AE);
- moderate set-stocking at around the long-term carrying capacity of the country of 10ha per AE;
- moderate stocking with wet season spelling;
- flexible stocking rate varying from 4ha per AE to 20ha per AE; and
- flexible stocking rate and wet season spelling.
Dr O’Reagain said the heavy set-stocking trial was replaced in 2023 with a regenerative regime of short-duration grazing combined with big mobs of cattle and long rest periods to try to repair the degradation of pasture caused by the heavy set-stocking trial.
The grazing trials at Wambiana were a highlight for Collinsville and district graziers on a four-day bus trip through the Upper East Burdekin.
They were taken through the trial paddocks with frequent stops to explain strategies in relation to the pasture condition and animal production in different paddocks.
The trial is aided by a Grazier Advisory Committee (GAC) to ensure decisions about cattle numbers, spelling and fire were made in line with industry standards.
Genalpine Station grazier Barry O’Sullivan was pleased to learn the GAC included experienced graziers Jamie Gordon (Mt Pleasant, Bowen) and Fran Lyons (Basalt River, Charters Towers) as well as other prominent names in the industry including host landholders Michael and Michelle Lyons, and Roger Landsberg and Martin Holzworth.
Dr O’Reagain said the trial reported biannually to Meat & Livestock Australia (MLA).
The trial was funded by MLA through a donor company project.
He said the trial showed three key factors to successfully managing variable rainfall in northern grazing enterprises:
- determining a stocking rate well within carrying capacity each year;
- allowing significant rest periods for pasture; and
- making early decisions to adjust stock numbers to match forage availability.
Dr O’Reagain said the five strategies were based on common practice in the north.
The visiting graziers were particularly interested in the problem of encroaching currant bush and its effect on the pasture.
Dr O’Reagain was peppered with questions about forage budgeting, stocking rates and the condition of paddocks after a heavy wet season.
“It’s a really positive thing that there are experienced people from the industry involved, particularly with the short durection grazing treatment,” Glenalpine grazier Barry O’Sullivan said.
Dr O’Reagain said the trial had been a very positive experience for the scientists and had been important in training numerous students and agency staff.
“It’s been really good for us to see it happening in front of our eyes,” Dr O’Reagain said.
“It’s been a really positive thing for us.”
Department of Primary Industries Principal Scientist Peter O’Reagain explaining what’s happening in one of the pasture trial paddocks at Wambiana Station. Listening are NQ Dry Tropics Senior Grazing Field Officer Brad Martin, left, and Glenalpine grazier Barry O’Sullivan.
The ‘change’ journey packed with lessons that keep coming after the first step
Fran and Damien Lyons have been on a journey moving their Basalt River grazing business from a set-stocking operation to a regenerative grazing system.
The couple took over management of the property in 2017 after some tough drought years from 2012-2015.
They were convinced changing the grazing system could deliver benefits including, most importantly, reducing stress.
But they didn’t know how they had to change, so the first step was education and they attended field days and courses and looked for mentors.
Using what they had learnt, they started pasture budgeting, initially by estimating kilograms of dry matter per hectare but quickly swapped to estimating stock days per hectare.
At the same time, they started ensuring rest for paddocks was a part of the grazing regime.
From baby steps at the beginning, they managed to move from grazing all of the property all of the time down to about 20 per cent of the property at a time while the remainder was rested.
That took four or five years and Fran stressed to the BBB graziers that it was important to move at a manageable pace.
“There’s no set recipe,” she said.
Getting fencing and infrastructure in place was a matter of doing what you could when you could. Seeing the result of a change always motivated them to do more.
Fran said at the start of their transition, they mobbed up where they could, and were very careful about investing in infrastructure, doing a cost-benefit analysis before making a decision.
She said they could see tangible results in the mix of plants in their paddocks.
“As the pasture declined, it followed a set successional order, from desirable perennials to undesirable perennials, annuals, broad leaves and, eventually, bare ground,” Fran said.
As the pastures improved in response to the graze and rest regime, the plants returned in reverse order, including the undesirable perennials before the desirable plants were dominant.
She said there were a number of lessons they learnt during their journey including that whether a low rainfall year became a drought is entirely within the grazier’s control.
“The absolute key to not running out of grass is pasture budgeting,” she said.
She said healthy pastures also reduced the need for weed control.
Seeds — good or bad — needed sunlight, moisture and soil to germinate. If the ground cover is sufficient, there simply isn’t room for any “invasive” species.
Fran told the group any step towards the principles of resting pasture and matching stocking rate to carrying capacity would improve landscape health.
This bus trip was hosted through the Landholders Driving Change (LDC2) project, funded by the Queensland Government through the Queensland Reef Water Quality Program.
