Management of native grass trials – a burning issue

Rural Solutions SA has reintroduced native grasses along the South Eastern Freeway to enhance biodiversity, minimise management costs, reduce exotic grass fuel loads and improve overall aesthetics.

The business manages a number of native grass trial sites along the South Eastern Freeway at Bridgewater and Verdun.

The challenge at these sites is to maintain healthy stands of summer-active native grasses that will provide a green sward over the summer months without the need for watering.

To achieve these objectives, a controlled management burn was undertaken by Rural Solutions SA consultants on the South Eastern Freeway in Winter 2008.
Fire is one method used to promote the growth of Kangaroo Grass (Themeda australis) by replenishing soil nutrients and suppressing competition from introduced weed species.

The response of Kangaroo Grass and other exotic species following the burn will be closely monitored and this information will be used to guide the future management of this native grass species.

Kangaroo grass has sprouted vigorously following the 2008 burn and stands out as one of the few green grass patches along the freeway during the Summer months.
This observation may indicate an opportunity to use native grasses as fire breaks instead of the commonly used scorched earth approach.

Follow-up management such as slashing and spot-spraying of invasive grasses (e.g. Phalaris and Cocksfoot) will ensure that the kangaroo grass has a competitive advantage over the weeds during the summer growing season.

A range of other management techniques is also used by Rural Solutions SA at these grass trial sites. In particular, sculpture mowing is a novel approach used to suppress weeds and enhance native grasses (see video).

As well as its practical advantages, this technique gives the sites an attractive appearance of evenly-spaced parallel rows.
For further information contact Dr Stuart Collard.