Reef Rescue Forum in focus

Land managment improvement in the grazing industry

Reef Rescue R&D projects working with the grazing industries are focused on reducing sediment and pesticide load in runoff by improving land management. CSIRO's Scott Wilkinson and DNRM's Mark Silburn talked about the impact of improved practices on water quality outcomes. Monitoring practice change using data from 1986 to 2010, combined with the GRASP model, the researchers have shown, for example, that to decrease the level of sediment in runoff by 20%, requires a 20% increase in groundcover.

In other Reef Rescue R&D projects addressing the major issues to improve grazing practice, Andrew Brooks from Griffith University said gullies had been identified as the major type of erosion in the Cape York region, resulting in a revision of sediment load estimates. He said several options were available to manage gullies but whether these are feasible at the landscape scale is uncertain. Undoubtedly, the best management option is preventing gullies developing in the first place.

In a discussion of 'D' condition land rehabilitation techniques, Trevor Hall from DAFF said that while results from mechanical intervention were positive, the costs still need to be quantified.

In a project investigating the effect of land use changes on nitrogen loads, Craig Thornton from DNRM has looked at nitrogen in runoff from pasture legumes. The results will provide additional data to improve catchment models. In a ground-breaking study, Craig and his colleagues have also measured the movement of tebuthiuron in pasture. This information is particularly valuable because until now there has been no data on tebuthiuron breakdown into dissolved and particulate forms.

Groundcover is an important indicator of grazing land condition. Terry Beutel from QDAFF spoke about a project to develop better techniques for groundcover monitoring and mapping in GBR catchments. This project is being undertaken in collaboration with a team of remote sensing experts in DNRM and DSITIA under the Paddock to Reef Program who are also completing burnt area mapping, gully mapping and predictive models, land use mapping and higher resolution crop mapping and monitoring.