Environmental Engineering Reference
In-Depth Information
We need more information about the water-using capacity of various
types of vegetation and on experimentation with new farming systems that
are adapted to the temporal and spatial variability of the Australian climate.
Crop and pasture species have not been designed with the control of
natural resource degradation in mind. Most plant breeding programs gener-
ally focus on grain yield and quality, pest control and other limitations. Few,
if any, have focused on the role of crop and pasture species in controlling
deep drainage and nitrogen leakage. Studies have highlighted that the breed-
ing, selection and bioengineering of crops and pastures have considerable
potential to help ameliorate dryland salinity and acidification by designing
crops and pastures to minimise the leakage of water and nutrients past the
root zone.
Developing new farming operations that do not harm the natural
resources and environment, while generating enterprise incomes that can
support sustainable communities, must be an urgent goal for Australia.
Next steps for science, people and institutions
To understand how Australia's rural industries might move towards ecologi-
cal sustainability, we first need to identify the scientific and technological
issues that must be solved. We have flagged some in this chapter.
The very leaky nature of Australian agro-ecosystems lies at the root of
nearly all land and water degradation concerns. To match farming and land
use patterns to landscape and ecosystem function, we desperately need new
biophysical solutions that can plug leaky systems and capture the water and
nutrient for productive purposes. The irony of Australian agriculture is that,
while the shortage of both water and nutrients greatly restricts yield, the fun-
damental cause of both salinity and acidification is the loss of valuable water
and nutrient beneath the crop or pasture. A key strategy for science and
technology, therefore, is to build productive agro-ecosystems that leak much
less water, nutrient and carbon to the landscape in which they are located.
This requires that the soil/plant/animal agro-ecosystems be studied in an
integrated way and as part of the larger-scale ecological and hydrological
processes that operate over the landscape. Solutions must incorporate these
functions at a range of scales, including paddock, hill slope, catchment,
whole landscapes and regional basins. The landscape designs will need to
integrate sustainable production and maintenance of biodiversity for the
catchments and regions. Any revegetation program must have multiple
