Free Standard AU & NZ Shipping For All Book Orders Over $80!
Register      Login
The Rangeland Journal The Rangeland Journal Society
Journal of the Australian Rangeland Society
Shopping Cart: ( empty )
You are here: Home > Journals > RJ > RJ07058
RESEARCH ARTICLE
Contents Vol 30(3)

Safe pasture utilisation rates as a grazing management tool in extensively grazed tropical savannas of northern Australia

L. P. Hunt
+ Author Affiliations
- Author Affiliations

CSIRO Sustainable Ecosystems, Tropical Ecosystems Research Centre, PMB 44, Winnellie, NT 0822, Australia. Email: Leigh.Hunt@csiro.au

The Rangeland Journal 30(3) 305-315 https://doi.org/10.1071/RJ07058
Submitted: 23 August 2007  Accepted: 3 April 2008   Published: 5 September 2008

Abstract

The concept of safe pasture utilisation rates is frequently promoted as a tool for use in setting livestock numbers in perennial grass pastures in northern Australia’s tropical savannas to achieve a grazing intensity that is ecologically and economically sustainable. However, recommended pasture utilisation rates have been defined and applied in several ways, and this has led to some confusion among managers, researchers and advisers about their appropriate use. In order to reduce this confusion, this paper reviews the ecological basis and use of safe pasture utilisation rates as a management tool, concentrating on two common ways (i.e. strategic and tactical) in which they are applied. The main objective of both approaches is to limit the intensity of grazing of perennial grasses during the growing season when they are most sensitive to defoliation. When used in a strategic way, safe pasture utilisation rates provide an indication of long-term safe stocking rates that will avoid pasture deterioration in most years. Alternatively, they are used in a tactical sense to adjust stocking rates to track forage production, usually on an annual basis. Using the tactical approach, stocking rates are set at the end of the growing season in order to use a ‘safe’ proportion of the standing forage available at that time during the subsequent 12 months. Thus, stocking rates for one growing season are based on the quantity of forage available at the end of the previous growing season. In areas with high year-to-year variability in pasture growth this may lead to overgrazing during the growing season. This paper concludes by suggesting several strategies to better manage pasture utilisation levels under a tactical management approach to ensure that palatable perennial grass populations persist in the long term. A call is also made for researchers and land management advisers to be clear in the way recommended safe pasture utilisation rates are defined and intended to be used.

Additional keywords: defoliation, grazing intensity, perennial grasses, rangelands, stocking rates.


Acknowledgements

I thank Peter O’Reagain and Mick Quirk for helpful discussions. Peter, Mick, John McIvor, Jeff Corfield, Alan Andersen, Peter Johnston and an anonymous referee provided constructive comments on an earlier draft that substantially improved the manuscript. Robyn Cowley kindly provided the GRASP pasture growth data.


References


Archer S. , and Smeins F. E. (1991). Ecosystem-level processes. In: ‘Grazing Management: an Ecological Perspective’. (Eds R. K. Heitschmidt and J. W. Stuth.) pp. 109–139. (Timber Press: Portland, OR.)

Arndt W. , and Norman M. J. T. (1959). Characteristics of native pasture on Tippera clay loam at Katherine, N.T. CSIRO Australia Division of Land Research, Regional Survey Technical Paper No. 3, CSIRO, Canberra.

Ash A., McIntosh P., Cullen B., Carberry P., Stafford Smith M. (2007) Constraints and opportunities in applying seasonal climate forecasts in agriculture. Australian Journal of Agricultural Research 58, 952–965. (accessed 10 March 2008).

Ebersohn J. P. (1973). Environmental limitations and their role in stability of low rainfall grazing lands and grasslands. A case history and view point. In: ‘Proceedings. 3rd World Conference on Animal Production’. pp. 2(d): 6–8. (World Conference on Animal Production: Melbourne.)

Everist S. L. (1964) The Mitchell grass country. Queensland Naturalist 17, 45–50. open url image1

Galt D., Mendez G., Holechek J., Joseph J. (1999) Heavy winter grazing reduces forage production: an observation. Rangelands 21, 18–21. open url image1

Gardener C. J., McIvor J. G., Williams J. (1990) Dry tropical rangelands: solving one problem and creating another. Proceedings of the Ecological Society of Australia 16, 279–286. open url image1

Hart R. H., Bissio J., Samuel M. J., Waggoner J. W. (1993) Grazing systems, pasture size, and cattle grazing behaviour, distribution and gains. Journal of Range Management 46, 81–87.
| Crossref | GoogleScholarGoogle Scholar | open url image1

Hodgkinson K. C. , and Mott J. J. (1987). On coping with grazing. In: ‘Grazing-Lands Research at the Plant–Animal Interface’. (Eds F. P. Horn, J. Hodgson, J. J. Mott and R. W. Brougham.) pp. 171–192. (Winrock International: Morrilton.)

Hodgkinson K. C. , and Müller W. J. (2005). Mortality model for a perennial grass in Australian semi-arid wooded grasslands grazed by sheep. In: ‘Pastoral Systems in Marginal Environments’. (Ed. J. A. Milne.) p. 108. (Wageningen Academic Publishers: Wageningen.)

Holechek J. L. , Pieper R. D. , and Herbel C. H. (2004). ‘Range Management: Principles and Practices.’ 5th edn (Pearson Prentice Hall: New Jersey.)

Johnston P. W., McKeon G. M., Day K. A. (1996) Objective ‘safe’ grazing capacities for south-west Queensland Australia: development of a model for individual properties. The Rangeland Journal 18, 244–258.
| Crossref | GoogleScholarGoogle Scholar | open url image1

Jozwik F. X. , Nicholls A. O. , and Perry R. A. (1970). Studies on the Mitchell grasses (Astrebla F. Muell.). In: ‘Proceedings 11th International Grassland Congress’. pp. 48–51. (University of Queensland Press: St Lucia.)

Landsberg R. G. (2002). Applying grazing management principles in the northern savannas. In: ‘Shifting Camp – Proceedings 12th Biennial Australian Rangelands Conference’. Kalgoorlie, WA. (Eds S. Nicolson and D. Wilcox.) pp. 248–252. (Australian Rangeland Society: Northam, WA.)

McIvor J. G. (1981) Seasonal changes in the growth, dry matter distribution and herbage quality of three native grasses in northern Queensland. Australian Journal of Experimental Agriculture and Animal Husbandry 21, 600–609.
| Crossref | GoogleScholarGoogle Scholar | open url image1

McKeon G. M. , Brook K. D. , Carter J. O. , Day K. A. , Howden S. M. , Johnston P. W. , Scanlan J. C. , and Scattini W. J. (1994). Modelling utilisation rates in the black speargrass zone of Queensland. In: ‘Clean Country, Clean Product, Clear Profit. Working Papers. 8th Biennial Australian Rangelands Conference’. Katherine, NT. pp. 128–132. (Australian Rangeland Society: Cottesloe, WA.)

McKeon G. M., Day K. A., Howden S. M., Mott J. J., Orr D. M., Scattini W. J., Weston E. J. (1990) Northern Australian savannas: management for pastoral production. Journal of Biogeography 17, 355–372.
| Crossref | GoogleScholarGoogle Scholar | open url image1

MLA (2003). ‘Grazing Land Management Workshop Notes.’ (Meat and Livestock Australia: Sydney.)

Mott J. J., Bridge B. J., Arndt W. (1979) Soil seals in tropical tallgrass pastures of northern Australia. Australian Journal of Soil Research 17, 483–494.
| Crossref | GoogleScholarGoogle Scholar | CAS | open url image1

Mott J. J., Ludlow M. M., Richards J. H., Parsons A. D. (1992) Effects of moisture supply in the dry season and subsequent defoliation on persistence of the savanna grasses Themeda triandra, Heteropogon contortus and Panicum maximum. Australian Journal of Agricultural Research 43, 241–260.
| Crossref | GoogleScholarGoogle Scholar | open url image1

Mott J. J. , Williams J. , Andrew M. H. , and Gillison A. N. (1985). Australian savanna ecosystems. In: ‘Ecology and Management of the World’s Savannas’. (Eds J. C. Tothill and J. J. Mott.) pp. 56–82. (Australian Academy of Science: Canberra.)

O’Connor T. G. (1993) The influence of rainfall and grazing on the demography of some African savanna grasses: a matrix modelling approach. Journal of Applied Ecology 30, 119–132.
| Crossref | GoogleScholarGoogle Scholar | open url image1

Orr D. M. , Bowly P. S. , and Evenson C. J. (1986). Effects of grazing management on the basal area of perennial grasses in Astrebla grassland. In: ‘Rangelands: a Resource Under Siege’. (Eds P. J. Joss, P. W. Lynch and O. B. Williams.) pp. 56–57. (Australian Academy of Science: Canberra.)

Orr D. M., Evenson C. J., Lehane J. K., Bowly P. S., Cowan D. C. (1993) Dynamics of perennial grasses with sheep grazing in Acacia aneura woodlands in south-west Queensland. Tropical Grasslands 27, 87–93. open url image1

Partridge I. (1992). ‘Managing Native Pastures: a Grazier’s Guide.’ (Department of Primary Industries, Queensland: Brisbane.)

Partridge I. (1993). ‘Managing Southern Speargrass: a Grazier’s Guide.’ (Department of Primary Industries, Queensland: Brisbane.)

Partridge I. (1996). ‘Managing Mitchell Grass: a Grazier’s Guide. Information Series QI96009.’ (Department of Primary Industries, Queensland: Brisbane.)

Partridge I. (1999). ‘Managing Grazing in Northern Australia: a Grazier’s Guide. Information Series QI99026.’ (Department of Primary Industries, Queensland: Brisbane.)

Post D. A. , Bartley R. , Corfield J. , Nelson B. , Kinsey-Henderson A. , Hawdon, A., Gordon, I., Abbott, B., Berthelsen, S., Hodgen, M., Keen, R., Kemei, J., Vleeshouwer, J., MacLeod, N., and Webb, M. (2006). Sustainable grazing for a healthy Burdekin catchment. Project NBP.314 Final Report, Meat and Livestock Australia, Sydney.

Richards J. H. (1984) Root growth response to defoliation in two Agropyron bunchgrasses: field observations with an improved root periscope. Oecologia 64, 21–25.
| Crossref | GoogleScholarGoogle Scholar | open url image1

Richards J. H., Caldwell M. M. (1985) Soluble carbohydrates, concurrent photosynthesis and efficiency in regrowth following defoliation, a field study with Agropyron species. Journal of Applied Ecology 22, 907–920.
| Crossref | GoogleScholarGoogle Scholar | open url image1

Roe R. , and Allen G. H. (1945). Studies on the Mitchell grass association in south-western Queensland. 2. The effect of grazing on the Mitchell grass pasture. Bulletin No. 185, Council for Scientific and Industrial Research, Melbourne.

Scanlan J. C. (1983) Changes in tiller and tussock characteristics of Astrebla lappacea (curly Mitchell grass) after burning. Australian Rangeland Journal 5, 13–19.
| Crossref | GoogleScholarGoogle Scholar | open url image1

Scattini W. J. (1973). A model for beef cattle production from rangeland and sown pasture in south-eastern Queensland. PhD Thesis, University of California, Berkeley, USA.

Spies P. , and Partridge I. (2006). ‘Managing for drought in grazing lands. Natural Resources and Water Facts, Land Series.’ (Department of Natural Resources and Water, Queensland: Brisbane.)

Stafford Smith M. (1996). Management of rangelands: paradigms at their limits. In: ‘The Ecology and Management of Grazing Systems’. (Eds J. Hodgson and A. W. Illius.) pp. 325–357. (CAB International: Wallingford, UK.)

Thurow T. L. (1991). Hydrology and erosion. In: ‘Grazing Management: An Ecological Perspective’. (Eds R. K. Heitschmidt and J. W. Stuth.) pp. 141–159. (Timber Press: Portland, OR.)

Tothill J. C. , and Gilles C. (1992). ‘The pasture lands of northern Australia. Occasional Publication No. 5.’ (Tropical Grasslands Society of Australia: St Lucia, Qld.)