Farms that have achieved healthy soils look and smell good, with dung beetles present in pastures and no slugs or snails in crops. Plants growing on such farms have less disease and insect damage, less frost damage (high sugar content or ‘brix' in plant sap), have great root systems, and taste better. For example, canola and lucerne having no to minimal insect damage without pesticides after commencement of biological farming. Animals show the most extraordinary health (e.g. lack of foot rot, bloat, pink eye, mastitis), fertility (e.g. +25% lambing), and longevity. They need less fodder and graze for shorter periods compared with available conventional feed systems. Think of what could happen to humans if we ate such food!
Biological farming can reduce fertiliser use by up to 50% and eliminate fungicides and insecticides within three years of commencing. Such personal statements about achieved outcomes are available in company newsletters and articles in rural magazines but independent quantification is rare (Stapper 2004). Most methods haven't been proven scientifically, failures are experienced if methods or conditions are not right, and are therefore rubbished by many.
Improved soil biological activity becomes visible through the presence of earthworms and many ‘creepy crawlers'. Common soil problems have been alleviated such as acidity, salinity, compaction, water logging and wind erosion (no dust behind sheep). Water-holding capacity has been improved, which shows, for example, on irrigated farms through a 2-3 day extension between irrigations. The retention of water also seems greatly improved as topsoil remains moist longer. Improved soil organic carbon manifests itself through many factors, but the overall benefit can be great. For example, one study in NSW quantified the value of soil organic carbon as $116 per one percent increase, resulting from better water holding capacity and nitrogen availability (Ringrose-Voase et al. 1997).
As in current systems, not all inputs are always effective. Success in biological systems depends on many factors working together. Soil organic carbon formation from roots and stubble, for example, requires not only the presence of microbes but also availability of important nutrients as the C:N:P:S ratio of organic carbon is similar across the world (Kirkby et al. 2006). Something can fail if a catalyst is missing. Nevertheless, when everything connects, we can get responses beyond expectation as synergies (‘1+1=3') start to occur. We are, however, on the right track. An organic farmer from the UK, a Nuffield Scholar having visited the USA regularly, stated in February 2006: "I have seen some truly exceptional farmers who are light years ahead of anything I saw in America, particularly where it really counts, in the practical application and making it work on farm."
Lal (2006) found that enhancing soil quality and agronomic productivity per unit area through improvement in the soil organic carbon pool will increase food production in developing countries, with numerous ancillary benefits. Adoption of recommended management practices on agricultural lands and degraded soils would improve soil quality including water holding capacity, cation exchange capacity, soil aggregation, and susceptibility to crusting and erosion.
Many have studied the impacts of farming methods on environment and food production. For example, studies have shown reduced nitrate leaching and enhanced denitrifier activity and efficiency in organically fertilised soils (Kramer et al. 2006). Impacts of herbicides on rhizobium survival and recovery with reductions of up to 60% in nitrogen fixation have been reported by Drew et al. (2006). Organic agriculture often is a proven good producer of food with yields comparable to those of conventional agriculture both in poor (Parrott and Marsden 2002) and rich (Maeder et al. 2002) countries. Gala (2005) and Leu (2006b) provide detailed accounts of studies from many countries.
With acquired knowledge, NPM is becoming successful in poor and rich countries in a move away from petrochemicals. India, for example, with three-quarters of farmers on less than 1.4 ha, is increasingly going back to traditional knowledge, which, combined with current knowledge and logistics, is leading to productive, profitable systems (Rupela et al. 2006, CSA 2006)
Organic technologies have been developed over about 6000 years to feed mankind while conserving soil, water, energy and biological resources. We are now able to increase yields for these low-input systems by using our breeding knowledge and methods to select higher yielding varieties adapted to local conditions (e.g. to improve harvest index). Among the benefits of organic technologies are higher soil organic matter and nitrogen, lower fossil fuel energy inputs, yields similar to those of conventional systems, and conservation of soil moisture and water resources – the latter being especially advantageous under drought conditions (Pimentel et al. 2005).
Cuba is the first country to develop agroecological systems nationwide – as a result of the disintegration and collapse of the Socialist Bloc and tightening of the US trade embargo which prevented access to petrochemicals. Cuba successfully turned to self-reliance, organic farming, animal traction, biofertilisers and biological pest-control, while retaining agricultural productivity – a remarkable paradigm shift (Funes et al. 2002).
The road to sustainability
While ‘sustainable agriculture' has been defined in many ways, it is fundamentally a process of social learning, not led by a science that overemphasises production and neglects maintenance functions within agroecosystems. Hill (1998) sees this blind spot as one of a number of indicators of our undeveloped and distressed psychosocial state. Habits, perception and assumptions determine what we see and want to see, and correlation is not cause. This realisation is another aspect of the change that will be required in our paradigm – the way we learned to see the world.
How do we find the road to a sustainable agriculture producing healthy food in a healthy landscape? How do we turn our ‘Clean and Green' image into reality? Minerals and microbes are the key, in both soil and human health. Over the past 60 years, mineral density of foods has declined to less than half of former levels (Bergner 1997, McCance and Widdowson 2000). We need to increase it again through improved production systems, and keep it available with proper food processing, so that good nutrition returns to the way our foods are grown, processed and prepared. Real medicine must start with the patient's diet and, ultimately, the nutrition on the farm (Anderson 2000, 2004). Worthington (2001) and the Soil Association (2002) found genuine differences in nutrient content of organic and conventional crops – improvements which could be even greater if all organic crops are actively managed with microbes and minerals. Farmers and graziers need to be paid for such quality.
Active management of the soil foodweb, remineralisation, and substantial increase of soil organic carbon are essential to reaching ecologically sustainable production systems and a (less-un)sustainable agriculture. Such a system produces healthy food with good taste and structure (i.e. availability calcium and silica), and extended shelf-life.
Trees are important as shelterbelts in a dry, wind-swept continent. There are examples in many districts where farmers have converted a proportion (say 10%) of their property to trees and wetlands (often from say 0.5%), resulting in improved productivity through improved water use efficiency and decreased sensitivity to droughts. This will especially be the case when appropriately combined with Natural Sequence Farming which rehydrates the landscape and makes soils healthy when following Peter Andrews' principles that include biological farming (Andrews 2006). Healthy, living soils will be able to adapt to a changing climate.
Organic-biological farming methods seem promising on a landscape and catchment scale, as they result, through minimizing the use of synthetic chemicals, in farming systems that stimulate biodiversity, stabilise the soil, and balance the hydrology, thereby reducing off-farm impacts. It is important to mix and match such systems with landscape changing initiatives such as permaculture (PRI 2006), Keyline Design (Yeomans 2006) and Natural Sequence Farming (Andrews 2006, Newell 2006, NSF 2006) – thus increasing the knowledge intensity in farming.
In most districts today, there are properties applying sustainable practices as outlined above. These practices have been achieved with persistence by the manager – through trial and error, under financial pressure, and on fragile soils in our highly variable climate. It is now the task of science, using participatory research, to connect up these ‘dots' in the landscape using appropriate concepts and principles. A typical agricultural manager is both time poor and cash poor – thereby, of necessity, readily following advise from (trusted) outsiders. Action research is needed to develop indicators that conceptualise farmer knowledge of natural resource management. This, in turn, will feed the required information-exchange networks, allowing knowledge to be transferred in time and space to achieve and maintain soil health, optimise production and minimise risk to achieving profitable farms in sustainable rural communities.