As managers using the soils, what do we look at, what do we (want to) see? After decades of regular use of single-super phosphate some farmers and graziers stopped using it when they became aware of the detrimental impact it had on soils and trees, caused by the acidic nature of the fertiliser; use of muriate of potash (potassium chloride) has similar impact and also needs to be avoided. We can learn to use the power of nature rather than fighting it with synthetic chemicals and unproven new technologies in a war we can’t win.
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Organic Farming is surging and Biological Agriculture (Anderson 2000, Zimmer 2006) is emerging as a sophisticated farming system in transition between current and organic. Both benefit from reintroduction and enhancement of humic and soil biological activity, components already fundamental in Biodynamic Farming (ATTRA 2006).
In contrast to the Organic standard, Biological farming allows for minimal use of the most microbe-friendly fertilisers and herbicides with humic additives and molasses or sugar to enhance effectiveness and reduce damage to microbes. This requires ever smaller quantities as the system is balancing and moving towards Organic, a process that occurs much more quickly when actively managed with biological inputs.
A sustainable farming system is a complex ecosystem with non-linear dynamics that can exist in alternate stable states, each state having it’s own threshold for change from one state to another. When a critical threshold is breached, recovery to a sustainable system will become difficult or impossible. For unstable farming systems to again become sustainable, we have to understand ecosystems before we can take the right remedial steps.
Sustainable ecosystems are resilient, having the capacity to absorb disturbance and re-organise over a wide range of conditions before ever reaching a critical threshold. They are characterized by many interactive components within and between scales. Adaptability and transformability are two other characteristics of how ecosystems respond to change. Adaptability is the capacity of ‘actors’ in the system to manage system resilience, while transformability is the capacity to become a fundamentally different system when the existing system becomes unsustainable (Resilience Alliance 2006).The underlying strategies for moving towards sustainable farming systems are conservation of soil, water and energy resources to maximise food production. This goes back to the functioning of ecosystems, the dynamics of interactions between a community and its non-living environment.
Agroecology is an approach in agricultural development which draws on modern ecological knowledge and methods. It is defined as the application of ecological concepts and principles to the design and management of sustainable agroecosystems (Gliessman, 2000). Understanding the functioning of ecosystems requires a ‘big picture’ holistic approach. The knowledge of different groups in the living world and how they interact with other groups is here more important than in-depth knowledge of individual species. Studying the latter, however, and single issues in general, seems to be more popular and advanced.
Unfortunately, we can’t understand a system by combining available knowledge of component single issues. That is, the holistic ‘whole’ is not the sum of reductionist ‘detail’. This also needs to be recognised in simulation modelling of systems.
Symbiosis – the balanced, mutual interdependence of different species – is a protective mechanism in nature, which develops in response to compatible needs. Self-organisation keeps natural biological systems in balance. Interactions between organisms are powerful evolutionary forces. Increased complexity and diversity of species and interactions within the soil foodweb promote balance and higher plant productivity. The whole should be considered as an integrated system being resistant and resilient to change through an abundant diversity of organisms.
Plants depend on beneficial soil organisms to protect them from pathogens, to help them obtain nutrients from the soil, and to break down toxic compounds that could inhibit growth. Soil organisms create a living, dynamic system that needs to be understood and managed properly for best plant growth. If the balance of micro-organisms is wrong, fertilisers and pesticides can’t help recover plant vigour. Understanding soil health requires knowing which organisms occur, which ones are working, how many are present and whether they are the right kinds for the desired plants (Ingham 2006).
Soil health thus requires improvement of biodiversity in paddocks and catchments to enhance natural predation in a functional soil foodweb (FAO 2006). This can be achieved by doubling soil organic carbon (the foundation for a living soil), minimising use of chemicals, and the establishment of shelterbelts for improvement of soil surface microclimate and provision of a ‘home’ for an important part of the soil foodweb. Paddock soil then becomes resistant to change and, being resilient, is able to recover from disturbances caused by extremes in weather or management. Such soils will remain more productive with climate change as living soil organisms can adapt. It will also help slow climate change by sequestering carbon (Leu 2006a, Carbon Coalition 2006).
Further ecosystems improvement may be achieved by managing natural energies with permaculture (PRI 2006), Yeomans’ Keyline Designs (Yeomans 2006) or Natural Sequence Farming (NSF 2006) to fit paddocks into a sustainable landscape. Natural Sequence Farming is a rural landscape management technique aimed at restoring natural water cycles that allow the land to flourish and be less sensitive to drought conditions (Newell 2006). This goes back to the natural balance of water cycles as pioneered by Peter Andrews in conjunction with biological farming principles (Andrews 2006, NSF 2006).
Another strategy in the move towards sustainability and ecosystem protection is reducing the vulnerability of farming to the economic impact of diminishing oil availability (Peak Oil 2006) by decreasing its reliance on petrochemical products.