The Australian Agronomist

The key to the current and future profitability of Australian agriculture could be held in the security of its soils, according to new research conducted as part of the Australian National Soil Research, Development and Extension Strategy. A report detailing the state of Australia’s soils revealed a clear link between inappropriate agricultural practices and soil degradation from the beginning of European settlement to the current day with contemporary farming practices aiding in reducing erosion.

Current advances in agricultural soil management, however could prove pivotal in stabilising and reducing further soil degradation whilst simultaneously improving productivity. According to Andrea Koch, Soil Policy Specialist for the United States Studies Centre at the University of Sydney, there needs to be a clearer link made between soil and agriculture.

“There is a lack of recognition that soil must be treated as a core asset for production” says Koch, reiterating a need for more informed policies regarding soil management. “Most businesses carefully manage and maintain the primary assets that they operate their business on, yet maintaining and improving the soil resource asset is often overlooked on farm and grazing management.”

In order to better manage the condition of Australian soils, five dimensions of soil security must be understood and taken into consideration including:

• Capability: the expected performance and production capability of any given soil.
• Condition: the current state of a given soil relative to its capability (and an outcome of its management).
• Capital: the value of the soil as an economic resource including the goods and services that flow from it.
• Connectivity: the connection of the land manager with their soil within a social dimension as well as the resources and knowledge they possess regarding soil management.
• Codification: the legal frameworks and public policy necessary to support soil security.

Securing soil benefits not only the farmer or landowner but contributes to the current and prospective competitiveness of Australian agriculture. The need for more advanced soil knowledge is therefore critical in order to increase agricultural productivity, profitability and sustainability within Australia.

With the four key markers of soil health used being; soil acidification, soil carbon loss, water erosion and wind erosion, erosion in itself forms the greatest threat to Australia’s soil and greatest preventative factor in the achievement of soil security.

On a paddock-to-paddock scale, unintended changes in soil conditions have ironically come about as a result of strategies to address soil erosion in cropping systems. Further soil management issues have resulted in the form of stratification of nutrients, compaction, herbicide accumulation, localised acidity and aluminium toxicity amongst others.

Better awareness and understanding of the impacts of soil degradation has led to changes in cropping practices from the 1990’s onwards with many farmers now opting towards ‘conservation tillage’ and stubble management. The more recent uptake of retained stubble’ has led to great improvements in erosion with each of the techniques aiding by increasing soil roughness and reducing the effects of water impact and runoff.

In line with the reduction in erosion as a result of such practices, however, comes a misplaced belief by farmers that erosion is no longer a pressing issue. Although conservation tillage or no-till methods have contributed greatly to soil conservation, erosion has by no means been eradicated and vigilant monitoring of soil condition remains crucial. Good soil management involves consistent evaluation, maintenance and improvement measures, the basis of which is a solid foundation of knowledge and proactive public policies.

Whilst highlighting the issues to be addressed surrounding soil security, the study’s authors also offer recommendations to be put in place by Australian Farmers, agronomists and policy makers alike. At the farm-scale, management based agriculture centring on diagnostic and management tools including soil use efficiency (SUE) monitoring and vertical rate guidelines have the potential to take soil security to new levels. As SUE incorporates myriad factors to gain an interpretation of soil condition and land stability including chemical, physical and biological properties, a comprehensive evaluation of soil condition can be made. Further emphasis placed on soil security by State Governments is necessary for the reshaping of public policies which currently omit the serious need for soil conservation.

On a broader scale, the five dimensions of soil security come into play, providing a framework for mitigating soil degradation. The familiar ‘plants down’ approach to soil must be replaced with a ‘soil up’ approach, respecting the role of healthy soil in creating healthy plants and sustainable agricultural practices. Adopting an anecdote of a ‘triage’ system, the most severely eroded and nutritionally deficient soils must be treated the most intensively, — with less dire soil situations treated preventatively. By treating and managing soil as a valuable production asset rather than an infinite resource that can be continually drawn down on, it is possible to reverse degradation and secure Australia’s soils one paddock at a time.

This article was originally published in The Australian Agronomist