Darwin is a major port for the live export of cattle
Pastoral properties in the Darwin-Kakadu region are generally on a smaller scale than those in adjacent tropical savanna regions. The larger properties are in the south and west of the area. Management strategies differ markedly on smaller properties and many of these are experimenting with forms of diversification, with the aim of better weathering market fluctuations. Family owned properties still constitute the majority of leases in this region, although corporately owned enterprises may occupy a larger area.
Compared to other areas of the savannas, this region is undergoing fairly rapid development in the primary production sector. Areas around Darwin which may have traditionally been used for cattle grazing are increasingly being converted to more intensive agricultural uses. The Katherine-Daly region has also been identified as having agricultural potential, which could well see cattle grazing becoming part of farming systems which incorporate various complentary enterprises. Intensification of the industry in this region is contributing to an ongoing reduction in the age of turnoff and increases in carrying capacities and breeding rates.
While beef cattle aimed at the live export market is the major focus of most producers in the region, the grazing of buffalo is also becoming significant.
In addition, production of hay for feed at export cattle depots, for manufacture into pellets for feed on the live export boats and for the recreational horse market is also a growing earner for farmers in the Darwin/Kakadu region.
This region receives an annual average rainfall of between 850 and 1600 mm, mostly concentrated in the December to March period. However, variability from year to year, and between monthly averages, is very high. For example, yearly rainfall totals have reached 2500 mm on the coast. For pastoralists, the major concern is not so much the total volume of rain, but rather when it will start raining, and stop—in other words, the length of the growing season, and how much surface water will remain at the end of the wet season and into the dry.
The Darwin-Kakadu region also has abundant natural permanent surface water. Large areas of the coastal plains are under water in the wet season, which necessitates the removal of stock from these areas to the uplands. Producers must have at least 35 per cent of their property above the reach of these waters to maintain full production potential on such country. Wetland areas are nutrient-rich and on drying produce very good forage for livestock.
The majority of pastoral properties are situated on the red and yellow earths of the Katherine District, Daly Basin, and coastal uplands.
Some properties contain areas of solodic soils on shallow floodplains associated with the upper reaches of the Mary, Adelaide and Finniss River systems, which have little grazing value in their natural state. As a consequence of the demand for hay in the Darwin region several properties grow Cavalcade and Bundey crops on these soils. A few properties contain, along with coastal uplands, areas of fertile black cracking clay soils on the coastal floodplains.
Grazing in Kakadu
Prior to the eradication program initiated in 1979 when Kakadu National Park was proclaimed, water buffalo (Bubalus bubalis ) had been causing extensive damage in the area, and on floodplains along the breadth of the Top End, by breaking down natural levees and allowing salt water intrusion. They also trampled native aquatic plants, many of which are important food sources for water fowl.
More than 100,000 buffalo were removed between 1979 and 1990. However, traditional owners expressed concerns that buffalo, which have considerable value as a food resource, should not be eliminated entirely. The Park Director in 1989 gave consent for the Gagudju Association to operate a small herd of domesticated buffalo as a food source for traditional owners. Impacts of this project continue to be monitored. The remaining feral buffalo are still being removed, generally with the use of contractors in order to facilitate a financial return for traditional owners.
Cattle have been removed progressively from the Park during the buffalo eradication program, although small numbers still occur on higher ground in the south of the Park. (Kakadu National Park Management Plan, 1999).
Potential development areas
The Northern Territory government is supporting the development of some 440 000 hectares, via 40 or 50 new subdivisions, in the Katherine-Daly region. These are envisaged to provide opportunities for mixed farming which would include native and sown pasture grazing, dryland crop rotation and ley pastures. With this initiative the NT government predicts a doubling in the number of store weaners produced in the territory, via the adoption of improved pastures on a broad scale.
In addition to traditional systems of improved pasture, NT Department of Business, Industry and Resource Development experiments suggest there is much potential to increase productivity via ponded pastures. In this system the drainage of water from low lying areas is controlled. Levee banks are built and 'paddocks' then drained in rotation to ensure that good improved feed is available until the end of the dry.
These systems however continue to be controversial. This is in part a result of the pasture species required. Para grass (Brachiaria mutica), olive hymenachne (Hymenachne ampexicaulis) and aleman grass (Echinochloa polystachya ) are all very useful and productive ponded pasture species, and yet all have the potential to become costly weeds in Top End floodplain environments. Para grass is already widespread in many wetlands of the Darwin/ Kakadu region. A further concern raised about ponded pastures is their impact on estuaries. Decreased freshwater runoff could impact on the primary productivity of these systems and limit, for example, the migration of juvenile barramundi (Finlayson et.al 1997: 19). In addition "ponded pasture species have the potential to suppress the distribution and abundance of food plants . . ." which local wildlife, birds in particular, may rely on." (Whitehead et al 1992 ).