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Grazing in North East Queensland

The region | Effects of climate | Managing for drought | Land Management tools |

The region

The cattle grazing industry in the North East Queensland region is rather more diverse and complex compared to others in the tropical savannas. This is because of the variation in soil type, average annual rainfall and rainfall variability, all of which impact on land types, vegetation and pasture communities. It is no surprise then to discover that there is a whole spectrum of cattle grazing enterprises, ranging from traditional, extensive systems in the west of the region, to more intensive, smaller operations on sown pastures in more fertile areas. The region has some of the most fertile soils to be found in the tropical savannas. Operations on these land tracts can be much smaller yet still productive and sustainable. While there are some properties of considerable size running tens of thousands of cattle, on average enterprises in this region are smaller in area compared to others in northern Australia.
 
In terms of grazing management, there are several factors which to some extent set this region of the savannas apart from the rest. These include climatic variability, issues of soil health and stability and costs versus benefits of land clearing.

Effects of climate

Outside of drought events, there is a general climatic variability in terms of total rainfall, and the seasonality of rains. In the south of the region, significant falls of winter rain may occur, but cannot be relied upon. Total rainfall across the region is relatively high and ranges from 1200 mm to 400 mm in the far south west. The majority of the area's rainfall totals falls between 600 and 800 mm per annum.

In December 1999, only 1 per cent of the total area of Queensland was declared drought affected. However, for much of the 1990s, apart from a couple of years of above average annual rainfall, most of this region was declared drought affected. Markets were also depressed over much of this period, which disinclined producers to sell livestock. High stocking rates were therefore maintained on many properties throughout these dry years over the late 1980s and early 1990s, and only recently have rates started to fall to what are considered more sustainable levels (Quirk, M., Ash, A.J., McKillop, G. 1996).

Producers were able to maintain these high stocking rates because of a number of developments which occurred within the industry. Some of the developments included changes in cattle breeds from traditional British shorthorn varieties, to the more resilient and drought tolerant Bos Indicus .

Supplementary feeding, in which herds are supplied with phosphorous and proteins lacking in the native pastures, especially during dry years, increased capacity of animals to consume and utilise available forage. In effect, this meant that land which under drought conditions would have had to be destocked in the past, would continue to be subject to grazing. However, the price for maintaining these high stocking rates was a general, and sometimes severe, decline in land and pasture condition across the region.

Managing for drought

The incidence of drought across this region is between one and two events every 10 years. The regularity of these events, and the strong chance of them occurring even more often, means that producers must factor drought years into their long-term management plans. Some of the ways this is done include: 

  • flexible stocking rates (buying/selling animals depending on land condition)
  • maintaining supplies of hay
  • herd management, i.e. numbers of breeders, timing of breeding (which will mean that calves are not born when there is little food about) weaning and pregnancy diagnosis (which allows producers to cull poorly performing cows)
  • sell normal yearly turn-off in February/March instead of April/May

Many suggest that selling of at least a percentage of the herd is a better long-term strategy for dealing with drought once it has kicked in, rather than supplementary feeding, which may assist in short-term productivity but threaten land/pasture condition in the longer term. (See for example John Bertram's DPI Note on supplementary feeding on the DPI Notes website listed below.)

Land management tools

An important aspect of drought management is monitoring land condition and its response to stocking rates under given climatic factors. Various packages are now available to assist producers in decision-making, which require ongoing monitoring of land and pasture condition. These can be used in combination with herd management and climate prediction packages.

There are also more accurate climate indicators available, such as the SOI (Southern Oscillation Index), which reflect fluctuations in the sea surface temperature, and thus the likelihood of El Nino events. A positive SOI value, for example, may suggest that the chances of average rainfall occurring over the next three months is 70 per cent. A low SOI might change this probability to only 30 per cent.

Late in 1999 SOI readings indicated that chances of higher than usual rainfall were very strong, and indeed the monsoon trough went far further south than usual, dumping plenty of rain as it went. The number of tropical lows, which bring rain to the region over the summer months, was also much higher than usual over the 1999-2000 summer. So although this indicator is not 100 per cent precise, it does provide some indication of what to expect, and as such assists in longer-term property management planning.

Computer programs such as 'Rainman' or 'Droughtalert' can be used to integrate climate information with grazing management strategies. In combination with valuable local knowledge and experience, these tools are improving predictive capacities as well as integrating various aspects of grazing management.