Burdekin beef producers contribute about100 million export dollars annually to theregion’s economy, but the industry’s future isthreatened by soil and nutrient erosion.

The Burdekin Catchment delivers an average ofone ton of soil per hectare per year to streamsand rivers, just over twice the national average.For the most part this is a result of the moreintensive tropical rainfall.

As part of its commitment to the beefindustry’s long-term sustainability, Meat &Livestock Australia is working with CSIROand the Queensland Department of PrimaryIndustries to identify sources of erosion andpatterns of sediment transport within theBurdekin River Catchment.

Patterns of Erosion andSediment Transport in the

Burdekin River Catchment

Patterns of Erosion andSediment Transport in the

Burdekin River Catchment

Muddy streams and rivers mean that soilsand nutrients are disappearing and thereforethreatening the long-term viability of the beefindustry. As soils erode, so too do theproduction foundations of the beefindustry.

This brochure indicates erosion hot spotsacross the Burdekin River Catchment. It ispart of the research effort currentlyunderway to develop recommendations thatwill help industry and communities tackle theissues at their source.

Gully erosion• Gully erosion varies throughout the

catchment with hotspots in central areaswhich feature moderately steep slopes.

• In areas where gully erosion is prominent,there is more sediment yield than fromareas of hillslope erosion.

• Soil washed from gullies tends to movedirectly into streams and rivers.

Erosion begins here

Hillslope erosion• Moderately hilly areas, where ground cover

is low, are likely to show signs of erosion.• Soil loss rates are generally less than

twenty tonnes per hectare per year, butsome hotspots are predicted to lose up toone hundred tonnes per hectare per year.

• Soils eroded from hillslopes tend to bedeposited before reaching the waterways,although the finer clay particles tend toleave the landscape.

• It is the fine soil fraction that has anegative effect on local pasture productionthrough the loss of associated soil organicmatter and nutrients.

• Moderate hillslope erosion can becorrected through appropriate grazingmanagement, but severe erosion demandscomprehensive rehabilitation.

Kilometres

Low ground cover at the head of anerosion gully in the Fanning River subcatchment of the Burdekin River -indicators of high erosion risk.

Gully erosionhotspots in the

Burdekin River Catchment

KilometresHillslope erosionhotspots in the

Burdekin River Catchment

Where do sediments go?

Sediment exported to the coast• 2.4 million tonnes of sediment are transported to

the sea each year and may add to the potential riskof smothering nearshore reefs and sea grass beds.

• Fine sediments also supply nutrients that have thepotential to change the ecological balance ofnearshore communities.

• Most of the exported sediments arriving at theriver mouth come from the Upper Burdekin andBowen rivers.

• Predictions for the Burdekin River Catchmentindicate that delivery of sediment to the ocean mayhave increased by up to six times since Europeansettlement.

A tributary of the Burdekin River at low flow showingextensive bed deposits of sand. These can be a naturalfeature of semi-arid rivers but in some reaches can also leadto the filling of pools vital for river life.

Sediment plume from the Burdekin River after a cyclone event (photo supplied by GBRMPA)

Permanent, undisturbed waterholes and intact riparian vegetation areimportant to maintain healthy rivers in the Burdekin catchment

(photo supplied by Damien Burrows, ACTFR)

River-bed deposition• Only 13% of the sediment delivered to

streams is transported as far as theBurdekin River mouth.

• Much of the coarse sand and gravel(called bedload) is stored in floodplains,streambeds, dams and weirs.

• Riverbed diversity is reduced as pooland cobble beds are filled with bedloadand no longer provide suitable habitatfor fish and other river species.

Is erosion a problem in the

Burdekin?

• About 85% of sediment delivered to the coastcomes from grazing land.

• Highly localised hotspots generate the bulk ofthe sediment, with 95% of the sediment comingfrom 13% of the catchment.

• Hillslope and gully erosion are the primemanagement issues.

Further reading

Prosser, I.P., C.J. Moran, H. Lu, A. Scott, P. Rustomji, J. Stevenson, G. Priestley,C.H. Roth and D. Post, 2001: Regional patterns of erosion and sedimenttransport in the Burdekin River catchment. MLA Occasional Paper, Meat andLivestock Australia: Sydney.http://www.clw.csiro.au/publications/technical2002/

The good news…..

• Since 1997, substantial investment bylandholders and governments has resultedin the infrastructure necessary forimproved grazing land management in theBurdekin Catchment.

• Burdekin graziers, CSIRO and QDPI havedeveloped management practices that aremaintaining sufficient ground cover toenable production and avoid erosion.

• Regulated grazing in riparian areas resultsin dramatic improvement in water quality,according to research by the AustralianCentre for Tropical Freshwater Research(James Cook University).

• The information provided in this brochureis helping landcare groups and stateagencies identify the key hotspot areas totarget for funds from NHT and NAP.

• Further research arising from thepartnership between Meat & LivestockAustralia, CSIRO and QueenslandDepartment of Primary Industries isdeveloping more specific guidelines tomanage soil erosion at the property level.

Contacts

Dr Christian Roth,CSIRO Davies Laboratory,TownsvillePh: (07) 47 538569 Christian.Roth@csiro.au

Dr Ian Prosser,CSIRO Black Mountain Laboratories, CanberraPh: (02) 62465830 Ian.Prosser@csiro.au

Mr Bob Shepherd,DPI Charters TowersPh: (07) 47 546100 Bob.Shepherd@dpi.qld.gov.au

Copyright © 2002 CSIRO Land and WaterProduced by the CL&W Communication Group, May 2002

C S I RO

Photographs supplied by CSIRO Land and Water except where otherwiseindicated.

Example of a well managed native pasture with the cover levels required tomaximise rainfall infiltration for better production and minimise soil and waterloss. (Photo supplied by Taoufik Ksiksi, DPI).

What does this mean for beefproducers?

The simplest answer to address soil erosion is ismanaging soil cover, because:

Practices that graziers are adopting to combat acceleratedsoil erosion, improve pasture condition and maintain groundcover, include:

• Conservative stocking rates• Rotational wet season pasture spelling• Appropriate use of fire• Fencing riparian areas• Man-made stock water points• Fighting woody weeds• Intensive land and grazing management.

Other techniques to rehabilitate severely degraded land andreduce gully erosion include:

• Contour ripping and seeding• Shallow water ponding on flat land• “Crocodile seeding”.

Further reading

Ash,A., Corfield, J. and Ksiksi,T. 2001.The Ecograze Project: developing guidelinesto better manage grazing country, CSIRO, Davies Laboratory,Townsville.

Moregroundcover

=More

rainfallinfiltration

=Moregrass =

Less runoffand

erosion=

BETTERBEEF

PRODUCTION