Benefits in knowing stubble value

According to Birchip Cropping Group's Alison Frischke, stubbles represent a useful feed source in mixed farming systems but need careful management to be best utilised.

"Stubble is only going to be significant feed if the grazing value outweighs the potential disadvantages," she said.

"You need to know when to remove stock when there is no additional liveweight gain to be obtained and know when to start supplementary feeding.

"Most of the value is going to be in the residual grain and green plant growth - there's not a lot in the straw."

Mrs Frischke said growers should aim to maintain 70 per cent groundcover when putting ewes on stubbles, dependent on stubble height.

Another threshold to maintain was 40 kilograms of grain a hectare or 40kg/ha of green material dry matter (equating to 13g in a tenth of a square metre quadrat).

"Once the amount of grain or green feed in the paddock falls below those numbers, livestock are likely to lose weight," she said.

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Lambs require closer to 100kg/ha of grain.

Mrs Frischke said rotational grazing between paddocks was a good tool to maintain those groundcover targets by reducing selective grazing and allowing rested paddocks to recover.

Knowing the feed values of different stubbles and conducting feed tests was also important, she said.

"For lactating ewes and growing wether lambs, high protein feeds are pretty important," she said.

"Green feeds can have 25pc to 30pc protein, 15pc for wheat, 9pc for oats, while leaf and chaff go down to 5pc and can drop off with summer rainfall events."

Mrs Frischke said while some farmers with no-till systems were hesitant to incorporate livestock, trials had shown no measurable changes to water infiltration and storage, and no difference to the following crop or pasture establishment, plus the following grain yield.

"You can often see a visual change in soil structure, particularly in heavier soils, but even Southern Farming Systems didn't record any difference to the following crop," she said.

"You're basically alleviating any compaction by the next tillage pass."

Mrs Frischke said there were no negative effects on soil nutrition and carbon from stubble grazing, provided adequate groundcover was maintained.