Sustainable Grazing in Cape York

Grazing management

Cape York has management issues which are quite different to those experienced by graziers elsewhere in Northern Australia. Because many of the properties are only marginally productive, many graziers in Cape York must engage in off-farm employment such as fencing, mustering or supplying tourist facilities. It also means that there is very little capital available for property development.

Overall the very low stocking rates mean severe land degradation and changes in pasture composition experienced elsewhere have not occurred on a large scale in the Cape. However, preferential grazing has certainly caused localised degradation. As the majority of properties have very limited internal fencing and watering points, the distribution of cattle is very difficult to control.

Fire management

The region is currently experiencing an increase in tree density, possibly associated with increased stocking rates and the lack of fires. The reduction in fires may be related to the lower annual rainfall in some areas, or it may reflect the increasing time spent by many working off the farm. Fire on Cape York is used as part of herd management, although the principle reasons for its use can change from one year to the next, or from one region to another. For example, fire is used in the north to clear the tall sorghum grasses to make visibility better during mustering. In other regions it may be used to encourage green pick, or to combat weed infestations. However, the use of fire as a management tool on Cape York may decrease if properties in Cape York continue to change hands at the current rate. Research has shown that producers with little experience in the north Australian environments are often reluctant to use fire at all (CYPLUS 1995).

Weeds and feral animals

Introduced plants and animals are a major threat to the industry. Feral pigs and horses are common in Cape York and have major impacts. Pigs carry an array of parasites and can also act as vectors for diseases such as foot and mouth. Pigs, feral dogs and dingoes all attack and kill calves. In some areas of Cape York, such as the lower Mitchell, feral pigs are considered to be in plague proportions. Crocodiles are also a problem in this area, and are known to take both cattle and plant horses. Feral horses compete with cattle for both food and water, can destroy fences and upset musters. While there are control programs in place over the much of the region, limited infrastructure and the large property sizes makes implementation difficult.

Weeds also have the potential to become major threats to both the productivity and the ecological integrity of systems on Cape York. Rubbervine ( Cryptostegia grandiflora ) for example has infested 80 percent of the Mitchell River catchment (Mitchell and Hardwick 1995). This plant inhibits growth of native flora, provides a harbour for feral animals and limits cattle access to watering holes. Other weeds of concern include Hyptis (Hyptis sauveolens ) which can be found over most of the region, water hyacinth (Eichhornia crassipes) around Kowanyama and the Rutland plains, lantana (Lantana camara) and sicklepod (Cassia obtusifolia). These tend to invade disturbed areas such as cleared country and roadsides, but are less of a concern in undisturbed areas. In addition there has been an increased density of native woody vegetation over much of the region, which may be an outcome of stocking levels and resultant decreases in fire frequency and intensity.

Traditional production system

There are a few production systems currently in use on Cape York. The first and probably still the most common, is known as the traditional system. This system continued to resemble feral cattle hunting up until the 1970s when the BTEC (The National Brucellosis and Tuberculosis Eradication Campaign) program required producers to improve property infrastructure, and thus facilitate cattle control.

In this system all cattle are run on native pasture so weight gains are low. While supplementary feeding in the wet season can improve animal productivity, this is difficult to achieve because the cattle tend to be distributed over such large areas.

The parameters of production are limited by ecological and financial factors. Cattle mortality rates are high as are the costs of mustering while efficiency is low. "Feral" herds or "bush cattle" are common because of the inefficiency of mustering and low branding rates. Infrastructure remains minimal and financial returns relatively low. On a more positive note this system has less environmental impact than other more intensive ones, and yet its sustainability is increasingly in doubt (McKeague 1992). This traditional system requires very large tracts of land to be viable. Queensland Department of Primary Industries studies have shown that no matter how large the area, the economic sustainability of such leases is still very questionable. Given that these properties rarely earn much surplus income, opportunities for intensification for those graziers running traditional systems are few.

Improved production system

The alternatives are improved systems, or systems using improved pastures. In the former, cattle are also run on native pastures, but supplementary feeding is undertaken. This results in improved carrying capacity of the land which allows herd size to be reduced. Weight gain is also improved, mortality is decreased and since cattle congregate around the licks, mustering is easier. More property infrastructure is required (fencing and water) but profitability can be substantially higher.

The other far more intensive system is using improved pastures. Capital input here is far greater, as clearing, fertiliser, regrowth control measures and greater infrastructure are all necessary. Carrying capacity in this system however can reach 1 head per 1.5ha. Once the pasture is established this system offers easier herd management and very productive output. Yet the costs of establishing such systems can be prohibitive for the majority of producers in Cape York. This system is used by some smaller property owners in the Cooktown hinterland, although several larger owners are attempting to combine some elements with the traditional grazing system. A report commissioned by CYPLUS in 1995 estimated that more than fifty percent of land currently being grazed in Cape York was suitable for some form of pasture improvement. In addition, compared to other pastoral regions Cape York has a particularly long and reliable `green season', that is, the period of time during which cattle running on native pasture can be expected to gain weight, This fact could put graziers running cattle on improved pastures at considerable advantage. However, for many graziers in the region there is not available capital to intensify systems even minimally. Some see subdivision of leases as necessary to make property sizes more manageable and efficient, and to attract more capital to the area. (McKeague 1992)

Pasture communities

The Cape York region tends to be dominated by tallgrass pasture land communities, which change to short and midgrass pastures along the extensive coastline. Eight local pasture units (LPU) occur in the seven main pasture land communities. These are noted below and are detailed in Tothill, J. C. & Gillies, C. (1992). Monsoon tallgrass ( Schizachyrium spp). and other tall grasses cover most of the Cape York region. The LPU are found on northern flooded alluvial plains, tropical plains and low hills.

Cape York Pasture Communities are dominated by Monsoon tallgrass ( Schizachyrium spp) shown in mauve.

Broken patches of monsoon perennial tallgrass pasture lands are located across the central sectors. Native sorghum ( Sorghum plumosum ) is associated with loamy, alluvial and black soil types in high rainfall zones. The tip of Cape York and much of the eastern coast of the peninsula support tropical/subtropical perennial heathland pastures.
 
Broken patches of eucalypt open forest and woodland, of paperbark teatree, is associated with Aristida-Chrysopogon pastures. These occur along the southern coastal sectors. Coastal communities of perennial saltwater couch ( Sporobolus virginicus ), without top feed (palatable shrubs and trees), are located in the west.

Marginally inland and southwards, following the coast from Cape Melville, lie small patches of tropical/subtropical perennial tallgrass pastures of blady grass ( Imperata cylindrica ). Black/bunch spear grass ( Heteropogon contortus ) is another tropical/subtropical tallgrass perennial pasture, which occurs around Cape York's south-east boundary.