Beyond “sustainable agriculture”
Eco agriculture
Eco-agriculture (or agro-ecology) is emerging as a both a scientific discipline to investigate the theoretical aspects of production which occurs within the bounds of ecological systems, and as a way for farmers to think about how they may farm by ‘working with nature’ and ‘working with natural processes’.
Lady Eve Balfour’s classic essay (Towards a Sustainable Agriculture--The Living Soil) provides an historical view of the increasing concern for sustainability, and makes the case for an ethical and aesthetic approach to agriculture, as an addition to the economic or agronomic perspective:
http://www.soilandhealth.org/01aglibrary/010116Balfourspeech.html
The idea of agro-ecology is to go beyond the use of alternative practices and to develop agro-ecosystems with the minimal dependence on high agro-chemical and energy inputs, emphasizing the complexity of agricultural systems in which ecological interactions and synergies between biological components provide the mechanisms for the systems to sponsor their own soil fertility, productivity and crop protection (Altieri 2006).
LINK
http://www.cnr.berkeley.edu/~agroeco3/principles_and_strategies.html
A list of the principles of agro-ecology (from The Centre for Agriculture and Sustainable Food Systems) provides some useful checklists for farmers in making decisions about their enterprise.
LINK
http://www.agroecology.org/principles/princlist.htm
Some of the essential properties of agro-ecosystems are productivity (which is the level of output), stability (which is the constancy of output over time) and resilience (which is the ability to recover from stress or disturbance).
Better agriculture will aim to provide these essential properties by optimising:
- energy flow efficiency
- water retention and recycling
- turnover and recycling of organic matter
To do this, an agro-ecosystem must:
- Enhance recycling of biomass and optimize nutrient availability and balance nutrient flow.
- Secure favourable soil conditions for plant growth, particularly by managing organic matter and enhancing soil biotic activity.
- Minimize losses due to flows of solar radiation, air and water by way of microclimate management, water harvesting and soil management through increased soil cover.
- Ensure species and genetic diversification of the agro-ecosystem.
- Enhance beneficial biological interactions and synergies among biodiversity components thus resulting in the promotion of key ecological processes and services. (Reintjes et al. 1992)
There are now university courses available in agro-ecology, for example:
LINK
http://info.anu.edu.au/StudyAt/_Science/Undergraduate/Courses/_SRES2001.asp
What this means Practically
The Sun powers life on Earth. It provides an average of 1,000 watts of energy per square metre to the Earth’s surface. The flow of energy in ecosystems begins when plants capture sunlight for photosynthesis. Sunlight which falls on inanimate objects (such as bare soil) and is absorbed or reflected does not remain in the system for very long, and provides a loss of energy which could be used within the system.
Energy which is captured by plants, by comparison, continues to flow through a number of cycling processes ie food chains. The cycled flow of this energy continues when animals (macro- or micro-) eat plants, when these animals are eaten by others, and when micro-organisms decompose both the plant and animal residues and bodies.
Maximising the total area of plant leaves available to capture sunlight (over the area of the farm and over the whole year) is therefore the key to maximising the total amount of energy available for production.
Water as rainfall, like energy, encounters either plants or bare ground when it falls on the farm. Water which runs off is lost to the system. Water which is intercepted by plants and plant residues (litter, mulch) is retained in the system and able to flow through a number of cycling processes.
For example, the cycled flow of water continues as water which infiltrates the litter and soil is available to build the bodies of plants and the animals that eat them and each other. Maximising the total area of plants and plant litter to intercept rainfall (over the area of the farm and over the whole year) is therefore the key to maximising the total amount of water available for production.
Nutrient cycling is the end result of the processes described in the cycling of energy and water. It is mediated by the activity of soil organisms. The life, death and decomposition of the plants and animals (macro- and micro-) which captures and re-cycles the energy and water also slows and re-cycles the ‘flow’ of nutrients through the system.
The ecosystem processes which are critical to these efficiencies can be seen in any paddock: energy, water and nutrient cycling. In the paddock you can see the amount of plant leaf available to capture sunlight and rainfall; and the degree of nutrient cycling in litter through decomposition.
- Does your pasture have lots of grass leaf to capture sunlight?
- Is there a layer of litter on the soil surface?
- Do you have 100% groundcover, or is bare soil evident?
- Can you push a screwdriver into the soil easily?
- Does a handful of your soil smell like compost?
- If you throw a bucket of water on the ground, does it disappear quickly?
To observe these things you need to be close to the ground, and looking for them:
Picture sourced from Google Images and created by Victorian Department of Primary Industries
www.dpi.vic.gov.au
Rainfall infiltration and soil biological activity can be measured simply using the methods below.
LINK
TO MONITORING SECTION
Regenerative agriculture
Many people are beginning to think that “sustainable” agriculture is just not good enough, and see the concept as implying that we should seek to minimise the damage done by agriculture using current systems and practices. Soil loss by erosion, for instance, could be minimised and it might be hoped that soil loss from agriculture could be limited to natural ‘background’ levels of soil loss.
But many people engaged in “sustainable grazing” are actively managing their grazing enterprises to create soil. For these people, minimising the loss of soil or the degradation of the soil resource is simply inadequate if you are aiming to create new soil and improve soil health. How can new soil be created?
LINK
http://creatingnewsoil.blogspot.com
The notion of agricultural practices being used to restore and enhance ecological processes has been gaining attention overseas:
LINK
http://www.newfarm.org/features/0802/regenerative.shtml
and in Australia:
LINK
http://www.regional.org.au/au/stipa/2001/p-13.htm
The essential elements of regenerative agriculture are restoring and improving ecosystem functions and processes (such as energy capture, moisture infiltration and retention, nutrient cycling) by using farming methods which mimic or enhance natural processes.
Carbon Farming
The Carbon Coalition is an Australian group whose members see soil biomass as a natural carbon sink and the basis for an agriculture which is good for both production and the environment.
They identify deep-rooted plant species in agriculture as one of the most effective strategies for locking up carbon to reduce global warming. Soil biomass is a natural carbon sink and could be used to create carbon credits which can be traded alongside those currently traded for forests.
The Carbon Coalition website has information on forums and events being held around Australia, and includes articles on soil carbon and grazing management in Australia, and links to sites related to soil carbon from Australia and other countries.
Dr Christine Jones, whose work features prominently on the Carbon Coalition website, maintains a website concerned with carbon sequestration in pasture soils which has technical presentations from the Carbon Forums held around Australia.
LINK
http://www.amazingcarbon.com.au
Natural Sequence Farming
Peter Andrews, a grazier and horse breeder from Bylong in the Upper Hunter Valley in NSW developed Natural Sequence Farming over 30 years and has implemented what he believes to be a sustainable farming system on ‘Tarwyn Park’.
“Natural Sequence Farming (NSF) is a rural landscape management technique aimed at restoring natural water cycles that allow the land to flourish despite drought conditions. NSF offers a low-cost, widely applicable method of reducing drought severity and boosting productivity on Australia’s farms and landscapes. The technique is based on ecological principles, low input requirements and natural cycling of water and nutrients to make the land more resilient.”
“Stream incision had…. lead to a total disruption of the natural fertility cycle, leading to a chronic decline the overall health of the landscape. He also observed that, under natural conditions, the interaction between fluvial and biological processes would combine to maximise the efficiency of nutrient and water use as well as carbon cycling. He argued that this would actually lead to a growing of that landscape as sedimentation would far exceed erosion and carbon sequestration would far exceed carbon loss.”
The quote above is from the Natural Sequence Farming website:
LINK
Permaculture
Permaculture was conceived in the 1970s by Bill Mollison and David Holmgren as a practical approach to establishing a permanent agriculture based upon working with the observed patterns and processes of nature.
David describes it as: 'Consciously designed landscapes which mimic the patterns and relationships found in nature while yielding an abundance of food, fibre and energy for provision of local needs'.
Permaculture has grown worldwide since the 1970s. Three Permaculture books are available: the introductory Permaculture I and II, and the Designers Manual. Training courses are available in Australia which cater for practitioners or designers.
The Permaculture website has details of current courses and links to articles of interest:
LINK
Permaculture Hunter Region can be contacted on 02) 4944 9943
Biodynamic farming
Biodynamic farming practitioners understand that a healthy, well-structured soil, rich in humus and high in biological activity is a prerequisite for any sustainable agricultural system.
Biodynamic practitioners seek to understand and work with the life processes as well as enhance their understanding of the mineral processes used in conventional agriculture. Healthy soil is a prime basis for healthy plants, animals and people.
Biodynamic farming practices are of an organic nature, not relying on bringing artificial fertilisers on to the farm, although some organic or natural mineral fertiliser may be necessary during the establishment phase.
The biodynamics website listed below has information, courses, events and links:
LINK
Organic Farming
Organic farming is farming without the use of additives which are synthetic: ie not naturally occurring. Such additives include fertilisers, herbicides, pesticides and hormones manufactured by humans.
Prior to the relatively recent invention of such additives, all agriculture was organic.
The links below provide information on organic practices, organic produce certification agency, education and events:
National Association of Sustainable Agriculture Australia
PO Box 768 Stirling South Australia 5152
Phone: 08 8370 8455 Fax: 08 8370 8381
LINK
Organic Federation Australia
452 Lygon Street East Brunswick Melbourne 3057
Phone: 03 9386 6600 Fax: 03 9384 1322
LINK
Hunter Organic Growers Society
Phone: 02 4938 5308
Kooragang City Farm
PO Box 292 Wallsend NSW 2287
Phone: 02 4955 5758 Fax: 02 4955 5791
LINK
www.newcastle.edu.au/kooragang
Biological Farmers of Australia
LINK
The NSW Department of Primary Industries
Provides an introduction to what's required for sustainable organic farming, in an Australian context, with information about aspects of setting up an organic farm.
It covers terminology; why farm organically? is organic farming a threat to conventional farming? who keeps organic farmers honest? why does NSW Agriculture support organic farming? how does organic farming differ? tactics; farming without chemicals; markets; converting to organic farming; and first steps into organic farming.
LINK
http://www.agric.nsw.gov.au/reader/organic-services/nsw-ag-organic-farming.htm
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