Soil Systems Farm

Post Paris – COP21

- how can Australia take action on climate change

The recent UN Climate Change Conference in Paris has left Australia highly castigated for not doing enough. Despite the international back slapping over coming to an agreement that global temperatures should not exceed 2 degrees celsius, there is a chronic shortage of detail on what to do next. In this article, the Organic Federation of Australia Chairman Adam Willson outlines the practical steps Australia needs to implement to dramatically reduce greenhouse gas emissions in agriculture.

Soil is a carbon sink – baselining must begin now
Across the world there has been a dramatic decline in soil carbon levels, in particular colloidal soil humus. Deforestation, reduced pastures and meadows, continuous cropping, over cultivation and excessive use of nitrogen fertilisers have all led to reduced soil carbon levels. This carbon has left the soil as carbon dioxide, one of the 3 primary greenhouse gases, and made its way into the atmosphere and ocean (causing acidification). This process is reversed in agriculture through photosynthesis, where carbon dioxide and water are converted into plant sugars. What is not well known is that 20-60% of the sugars produced make there way to the root and leaf surface feeding local microbiology. In the root zone these root exudates are the primary way carbon is built up in the soil and the more biodiverse the plant species the more root exudates that are produced. This carbon is in addition to the plant carbon found in leaves, stems and roots. In organic farming this process is sped up by soil rotations, pasture phases, correct grazing practices, composting, polycultures, zero till organics and mulching. For example, recent wheat and corn studies carried out in China indicated that yields could be increased and greenhouse emissions reversed when cattle manure replace artificial fertilisers – Liu (2015). In fact the soils went from emitting 2.7t CO2 eq hm2/year to sequestering 8.8t CO2 eq hm2/year.

The building of soil carbon across all farmland must be a National priority because it is a process of sequestering atmospheric carbon, it holds significant amounts of water, reduces erosion across catchments, increases biodiversity, increases nutrient use efficiency and is a key to increasing yields and food quality. With extremes in climate already impacting vast areas across Australia the time for implementing soil carbon building practices is now. To begin this process both the Australian government, the organic industry and conventional counterparts need to immediately start baselining organic carbon in soils. Carbonlink is one Australian company that is developing a soil carbon monitoring process and can measure deeper soil carbon down to 1m – Carbonlink (2015). This data is critical for establishing the effectiveness at which farming practices build soil carbon, biodiversity and resilience across the farming landscape.

Legumes is nature’s sustainable nitrogen source
According to CEH (2013), over 50% of the artificial nitrogen applied to soils in conventional agriculture makes its way to pollute the environment. The water soluble nitrogen infiltrates its way into aquifers to contaminate our water supplies with nitrate, washes downstream with phosphate to kill fish, cause algal blooms, eutrophication and form long term dead zones found at the mouth of most rivers. Excess nitrogen also makes its way into the atmosphere in the form of nitrogen dioxide. This is a serious greenhouse gas that is 300 times more effective than carbon dioxide at heating the atmosphere. Further, Ravishankara (2009) identified that nitrous oxide is now the leading ozone depleting gas in the atmosphere, overtaking Chlorinated Flouro Carbons (CFC’s) that were outlawed by the UN in the 1980’s. In short, the use of artificial nitrogen fertilisers by chemical farming is speeding up the depletion of the ozone layer which will increase skin cancer and significantly reduce crop yields. The argument that world food production requires artificial nitrogen fertilisers needs to be carefully examined with the current destruction of waterways, increase in nitrogen dioxide entering the atmosphere and massive decrease in biodiversity worldwide. It is clearly unsustainable and another reason why consumers should look at the way food is produced when purchasing.

Legumes are nature’s natural way of extracting nitrogen from the atmosphere through a process known as nitrogen fixation. They are found in pasture rotations and green manure crops and are stimulated by the use of quality compost. Legumes are used by organic producers as a primary source of nitrogen and often provide multiple benefits. An example here is the legume Dolichos Lab Lab that not only adds nitrogen to the soil but also reduces weeds in the subsequent wheat rotation by up to 83% – Singh (2004) through a process known as allelopathy (Figure 1). It should be added that legumes are an ecosystem service provided by nature at minimal cost to the producer with little or no negative downside externalities to the environment. This contrasts sharply to chemical farming where the short term production of cheap food doesn’t account for the long term rehabilitation costs of artificial fertilisers polluting waterways, increased eutrophication of rivers and subsequent destruction of our coral reefs.

control 1.1

Figure 1 – Fallowed ground in Autumn with 4,900kg/ha of weeds in between wheat strips – Singh (2004)

 

lablab 2.2

Figure 2 – Fallowed ground in Autumn with 800kg/ha of weeds after a summer Dolichos Lab Lab crop – Singh (2004). The reduction in weeds (83.7%) between the wheat strips is caused by the allelopathic compounds it releases into the ground.

The potential for legumes to fix nitrogen is directly correlated to the soil nutrition provided by the farmer – Hamilton (2015). Depending on the legume species they have the potential to fix up to 300kg of nitrogen per hectare (600kg of urea equivalent). To do this they need adequate supplies of calcium, phosphorus and trace elements. Compare this to conventional nitrogen production that requires burning a tonne of brown coal to produce a tonne of urea. With over 50% of this nitrogen contributing to degrading our environment surely we need to focus our national agricultural resources on encouraging farmers to grow more high protein legumes with a reduced environmental footprint.

With 2016 being the International Year of Pulses the Federal Government must put in place incentives for growers to increase legumes and reduce the dependence on artificial nitrogen. Legumes in conjunction with appropriate innoculants and nutrition must be promoted as safest natural supply of nitrogen to grow crops and protect the environment. Incentives to get into on farm composting must be encouraged as composting stimulates legumes to build strong root systems – a necessity in this drought ravaged continent.

Agroforestry & Integrated Farming to become the norm
In large areas of Tasmania and many countries within Europe the hills and mountains surrounding agricultural areas are fully forested. The benefit of this foresight is obvious to the untrained eye, forests attract rainfall, they enhance long term water supply and protected stream banks minimise soil erosion. From a medium and long term basis, reforestation of Australia’s hills and mountains adjacent to agricultural land needs to begin in order to rehydrate the landscape – Sheil (2009). These reforested regions need long term protection. Rather than clear felling once mature, these regions should only be selectively logged. Clear felled trees in water catchments has been associated with significant reductions in water supply, up to 30% reduction in water supply from the forests surrounding Melbourne – MWCN (2011).

Geno (2001) in RIRDC’s first major Federal Government report on international integrated farming systems showed that farm production could be increased by developing regional microclimates. Microclimates are small areas within catchments that have similar climatic characteristics protected by agroforestry and trees. Gene (2001) identified that one way of doing this was by implementing an interconnecting series of windbreaks which once fully grown increased yields in pastures and crops by 15-45%. This highlights that farm design plays a significant role in increasing crop and pasture yields and should be prioritised. These microclimates not only boost yields but also increase biodiversity (another major target of Paris COP21). Geno (2001) also described the use of polyculture based farming systems that provide a multiplication effect when certain crops are grown together.

Keyline farming developed in the early 1940’s identified that trees planted on the contour with a slight slope (1:1000) provided a very practical way to establish microclimates in almost all areas of Australia – Yeomans (2008). Further, Yeomans had dams built that could irrigate pastures below the dam or provide firebreaks in extreme conditions. Yeomans’ Yobarnie property in North Richmond NSW is a unique example of long term drought proofing of Australian properties using key line farm principles. Other variations of this theme include introducing perennial crops on contours with slight slopes like Leucena. This provides stock with essential protein rich feed while protecting the grasslands from drying winds. Other perennial legumes could also be established depending on regional suitability. The Ley farming system of a pasture phase followed by grain cropping and green manure crops with livestock could be expanded with the use of these perennial high protein crops.

These are some of the practices that must be supported by the Federal Government. The National Organic Standard mandates that producers protect and maintain at least 5% of the property for native protection. This will probably need to be increased to ensure that farms are protected against the extremes in climate that are forecasted with a 2 degree increase in global temperature. The data collected from the carbon baselining will quickly evaluate what integrated farming systems best suit each catchment and microclimate.

Three founding organic principles  – Law of return, biodiversity and remineralisation
There are three founding organic principles that are applicable to all farming regions of Australia, the Law of return, increasing biodiversity and remineralisation. Failure to focus farm management on building these principles (whether organic or conventional) leads to declining soil health, reduced productivity and increasing susceptibility to climatic extremes.

The first principle is “The Law of Return” which means there must be a recycling of organic matter component to every farming operation. For grazing operations this means that pasture management must aim to continually build soil carbon and increase species diversity. Each plant species has different root exudates helping to recycle nutrients deep down in the soil profile. The over grazing of pastures in the catchments leading into sensitive  regions like the Burdekin and Great Barrier Reef must not continue. This has caused gully erosion which is highly expensive to restore – ABC (2015). I have also seen rehabilitation of active gullies using cell grazing which may be another solution. Burning of grasslands on farms must also be outlawed as soil carbon is a critical solution to stopping sediment flow into our river systems. For cropping operations green manure crops, pasture rotations and the use of on farm produced compost will help to recycle farm organic matter, builds nutrients in the soil and as a result increases nutrient use efficiency. For perennial crops the use of mulches, compost and inter row pastures helps the recycling of nutrients thereby reducing plant stress and farm costs – see Andre Leu case study Benjamin (2004). These practices benefit all of Australian farming, are critical for natural resource management and could easily be monitored using a National carbon baselining programme that Carbonlink is developing.

Biodiversity is the second critical component of successful farming. The wider the selection of plant species the less single point sensitive the operation is to pests and diseases. The key to this principle is monitoring and record keeping. One beef farmer I met had a botanist visit him once a year in January to measure plant species and link it to dry matter production. During the 15 years that he implemented cell grazing his dry matter production increased from 800 to 3000 kgDM/ha. With a rough conversion of 6-10kgDM giving 1kg beef, this management change was highly profitable. During the same period the number of plant species increased from 15 to over 70. With the increases in plant species there will also be a corresponding increase in the number of bees, butterflies and birds. This is what is referred to as ecosystem services and in organic production, rotations in cropping operations add to this biodiversity. The key here is benchmarking and using botanists, entomologists or ornithologists to improve farm data baselines. This contrasts to chemical farming where biodiversity and the ecological services provided by this biodiversity are compromised by increased chemical usage through the use of GM technology. These chemicals also have detrimental public health outcomes. One example is the increasing use of glyphosate where at even low doses it has been linked to human kidney and liver damage – Mesnage (2015).

The final founding principle of organic farming is remineralisation. This means that each soil type is unique in its chemistry and you can’t expect to produce the same food from different regions using the same method of applying artificial nitrogen fertiliser. For grazing operations that are based around native grasses this means you need to have a diverse selection of plant species and the grazing periods must be adequate to ensure plants are not grazed out opening the farm to weed infestations. For introduced pasture species and crops, natural forms of nutrients will need to be added to the fertility programme in order to reach optimum quality and yields. This is very important as many of Australia’s soil types are very poor and require macro and trace elements to produce quality food. By increasing plant diversity and optimum nutrition, the range and amount of root exudates increases leading to more carbon sequestration and healthier crops and pastures. It is an important issue for both organic and chemical farmers.

The Federal Government needs to look at these 3 founding organic principles because it is these issues that help reduce farming costs, builds valuable soil carbon, minimise the use of nitrogen fertilisers, address downside externalities and help mitigate climate change. Like all organic farming practices these principles have multiple flow on effects – Magdoff (2004). For example, green manure crops and compost provide benefits to the soil well past the current crop cycle and financial year.

Agricultural zones and food security
The USDA has developed a Plant Hardiness Zone Map – USDA (2015) to identify which plants grow best in each area. This is a very handy piece of information because you can quickly identify what crops, legumes and cover crops (green manure crops) are suitable to a particular area. In Australian, the Department of Agriculture and Water Resources needs to develop a similar on line mapping service so that sourcing relevant information is quick and easy. At the moment if I want to find a legume/crop that is suited to a particular region you need to search the world literature for legumes grown at the same latitude.

Coupled with this Plant Hardiness Zone Map there should be a map identifying the Australian soil types. Using a national website all state and federal agricultural research could be linked to these maps by both soil type and location. This makes it easy for any farmer or researcher to access information. By the Federal Government assisting the development of this website, farmers can contribute to data baselining thereby speeding up the adoption of the most effective climate mitigating agricultural practices.

Coupled with this on line information, the Federal Government will need to begin the process of protecting existing high value prime agricultural land. This will need to be mapped and a strategy for protection drawn up to include Local, State and Federal duristriction. It is not an easy subject to deal with but we can’t continue loosing valuable fertile soil whilst at the same time trying to produce high quality food on marginal soils. The loss of highly fertile Ferrasol soils on the coast and Vertisols inland will impact on food security and loss of agricultural productivity.

Next steps for the Federal Government
As outlined above, there are practical ways in which the Australian Government can reduce green house gas emissions. These include the following;

  1. We need to begin baselining of soil carbon on farmland as this will enable the verification of soil carbon fluxes which can be traded. Maybe the Federal Government could help direct Landcare funds into evaluating what farming systems build soil carbon (taking these greenhouse gases out of the atmosphere). Using multiple paired farm studies across different catchments the data could be correlated to the economics of the farm. Financial institutions may also wish to be financially involved as it is in their interest to find the most profitable and sustainable farming methodologies.
  2. The Federal Government also needs to direct Landcare funds towards promoting the use of legumes and identifying what parameters maximise nitrogen fixation. This should be linked to soil type, location and baselining of soil carbon.
  3. Agroforestry and integrated farming implementation could also be part of the overall baselining strategy within Landcare. We need to find out quickly what farming systems build soil carbon and increase profitability. Landcare needs to evolve into a baselining and data collection service that is available on-line to every producer and researcher. A simple annual membership of $20 may provide a way to fund this service to farmers, students and researchers across Australia. Another way is to identify the financial savings that organic farming practices make towards natural resource management (less nutrient movement, less erosion, less damage to the reefs and fishing resources) and target this money towards farm based extension and research.
  4. The Federal Government could consider research tax breaks or funding grants to help the development of small farm programmes. Like the US, educational institutions could be given tax incentives or grants to help educate new entrants on how to set up and manage profitable small farms. These small farms are important for local employment and reduce the need for food to be transported large distances (as refrigeration is a large emitter of greenhouse gases in agriculture). ATTRA is a US Department of Agriculture programme that provides farming businesses with on-line services, links to National field days and weekly updates. It has played a significant role in expanding the number and profitability of small to medium sized farms in the US and encouraging youth to get involved in farming.
  5. The Federal Government could also direct research incentives and provide startup seed funding to develop solar cool rooms, solar irrigation, solar desalination and battery storage for farmers. This is hi tech research that has clear benefits to the farming community and environment.

Australia has the opportunity to lead the region in adopting low greenhouse gas agriculture, mitigate climate change and provide the market with chemical free nutritious food. Bellamy’s Organics is one billion dollar ASX company that has shown that Australia is well regarded with producing high quality and trusted organic food for babies. There is a lot of potential for many more Australian companies to export organic food. With small investments, joint funding projects and shifting of priorities in existing funding the Federal Government can provide tangible solutions and incentives leading into 2016 and beyond.

References
ABC (2015) How sediment is killing the Great Barrier Reef

http://www.abc.net.au/news/2015-11-23/unsoiling-the-great-barrier-reef/6963598

Benjamin (2004) Organic Farming Is it for you? A learning guide. QDPI publication

Carbonlink (2015) – Carbon Baselining
http://www.carbonlink.com.au/carbon-baselining/

CEH (2013) One Nutrient World: the challenge to produce more food and energy with less pollution. Centre for Ecology and Hydrology. Viewed 10 October 2015, http://www.unep.org/gpa/documents/publications/ONW.pdf

Geno (2001) Polyculture Production – Principles, Benefits and Risks of Multiple Cropping Land Management Systems for Australia – RIRDC
https://rirdc.infoservices.com.au/downloads/01-034

Hamilton (2015)  Boron deficiency in pasture based on subterranean clover (Trifolium subterraneum L.) is linked to symbiotic malfunction

http://dx.doi.org/10.1071/CP14300

Liu (2015) Mitigating greenhouse gas emissions through replacement of chemical fertilizer with organic manure in a temperate farmland

http://link.springer.com/article/10.1007/s11434-014-0679-6#/page-1

Magdoff (2004) Soil Organic Matter in Sustainable Agriculture

https://books.google.com.au/books?id=djZpKk4k8HoC&q=Brady+and+Weil#v=snippet&q=Brady%20and%20Weil&f=false

Mesnage (2015) Transcriptome profile analysis reflects rat liver and kidney damage following chronic ultra-low dose Roundup exposure

http://www.ehjournal.net/content/14/1/70

MWCN (2011) Science explaining logging water loss 
http://melbournecatchments.org/learn-more/impact-of-logging-on-melbourne-water/

Ravishankara (2009) Nitrous Oxide (N2O): The dominant ozone-depleting substance emitted in the 21st Century. Science 326, 123-125.https://www.sciencemag.org/content/326/5949/123.figures-only

Sheil (2009), How Forests Attract Rain: An Examination of a New Hypothesis.

http://bioscience.oxfordjournals.org/content/59/4/341.full

Singh (2004) Increasing phosphorus supply in subsurface soil in northern Australia. II. Economic and environmental sustainability for the dryland cropping system

USDA (2015) USDA Plant Hardiness Zone Map

http://planthardiness.ars.usda.gov/PHZMWeb/

Yeomans (2008) Water For Every Farm: Yeomans Keyline Plan

 

 

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