LIVESTOCK are proving a powerful tool in efforts to improve pastures on steep hills.

A demonstration site at Warrak, near Ararat, is showing the benefits of deferred grazing in improving perennial grass cover and reducing recharge and salinity.

Research has shown that intensively grazing rundown paddocks during mid to late spring can minimise the growth of annual weed grasses and stop them going to seed.

Stock are then removed to let the native perennial grasses set seed.

This optimised deferred grazing has also been combined with rotational grazing on the trial site.

Host farmer Mark McKew said deferred grazing appeared to have benefits.

"I think the significant results of the trial will be seen in the long term, but plant counts over the last three years showed a slight increase in the number of natives in the innovation (trial) paddock," Mark said.

"The new grazing system makes a lot of sense when we are trying to run low-input native pasture on the hilly country. Years ago, super phosphate was spread by aeroplanes on a regular basis, but I can't imagine that happening again.

"The results have shown we can improve the perennial pasture content and maintain our ground cover and I can see more paddocks on our property doing the same."

The trial is being monitored by Julie Andrew, Evergraze coordinator with the Department of Primary Industries at Ararat.

Julie said onion grass had been sprayed this year to improve the feed value and allow native grasses to further increase.

"The aim is to strategically increase stocking rates to better utilise the increased feed in the innovation paddock and so lift productivity," she said.

Julie said native grasses could survive in low phosphate soils, making them a good species choice on inaccessible slopes where fertiliser application provided little return on investment.

An adjoining 70ha paddock on the McKew farm has been stocked to provide a comparison with deferred grazing.

"So far there has been a marked increase in the perennial coverage showing that regular spelling is beneficial for the recovery of perennials," Julie said.

"Optimised deferred grazing can be used to reduce high levels of annual grasses."