Sowing forage ryecorns and grazing cereals into established lucerne stands is giving Upper South East sheep producers Rodney and Paul Bartlett greater ability to turn off lambs free of grass seeds.
Last year, some of their crossbred lambs grazing Scope CL barley and Southern Green and Vampire ryecorns achieved impressive daily weight gains of about 450 grams.
Even better, it was at very high stocking rates, from weaning in July to sale time in early October.
The Bartletts, Tolcain, Sherwood, are hosting one of two Meat & Livestock Australia producer demonstration sites in the Seed Free Lamb project.
Their previous approach to grass seeds, like many, was to winter clean or spraytop their lucerne paddocks to reduce seedset of unfavourable grasses such as barley grass, silver grass and brome grass.
But Rodney says this has gradually become less effective, with 80 per cent of the barley grass population in one paddock found to be resistant to paraquat, the most common herbicide used to control grasses in lucerne.
“We were also wasting a lot of feed that we could have been grazing,” he said.
So, they jumped at the chance to participate in the Seed Free Lamb project, which is supported by the SA Sheep Industry Fund.
It is testing two alternatives, using ryecorns for high quality feed and superior weight gains or Scope CL barley, which contains Clearfield technology to enable in-crop control of grass weeds.
In early May, after the season break, they sprayed the ryecorn and barley area with 170g/ha of diuron, 17g/ha of Sharpen, 1.5 litres/ha of Treflan and 1.6L/ha of paraquat.
A few days later, 11ha of Scope CL barley and 14.5ha of Southern Green forage ryecorn and 13ha of Vampire forage ryecorn were sown, with the ryecorn sown into the paddocks with a lower weed burden.
The Scope supported 160 lambs from early August and was then crash grazed with 800 lambs for five days in early September to keep it at a manageable level.
Another 320 lambs were put on the Scope for five days in early October before being sold at 22 kilograms carcaseweight.
The two ryecorn strips supported an even higher stocking rate with 640 lambs for a month from early August and then 882 from mid-September to early October.
The Bartletts run a 2000 head self-replacing Merino flock and another 1700 Merinos mated to Poll Dorsets for prime lamb production.
They have been so impressed with the results they are feeling confident enough to delay a portion of the lambing of their prime lamb flock to May.
“We will also be able to put our ewes on these paddocks to keep grass seeds out of the wool and our Merino lambs grass free,” he said.
Seed-free stands help to increase lambing window
MANY Upper South East producers are forced to lamb in late March and April to ensure the lambs reach marketable weights before grass seeds become an issue.
But Seed Free Lamb project coordinator Felicity Turner is hopeful the project will give producers the confidence to lamb a month or two later, better aligning the feed on offer with the requirements of pregnant and lactating ewes.
Mrs Turner has calculated the additional cost of oversowing ryecorn or grazing cereals into lucerne stands – about $55 a hectare for ryecorn, based on sowing it at 60kg/ha, and $46.35/ha for the Scope CL barley – and believes the economic benefits are well worth it.
“The ryecorn on the modified soil was really effective in outcompeting some of those grass weeds that lead to seed problems, so if we can establish it early we could see it was starting to reduce visually the barley grass component,” she said
“And with the Scope, if we get a really good season we can lock it up for grain.”
In the coming season, the project, run through the MacKillop Farm Management Group, will expand to eight farms, all taking a different approach.
They will undertake full paddock trials using Scope barley, the forage ryecorns or even vetch as a green manure crop.
“The ultimate aim is also to clean up paddocks to fill the gap for our lambs to then utilise the stubbles,” she said.
