Soil Health Position


Introduction

Soil is one of the earth’s most important natural resources. Healthy soils are central to delivering agricultural resilience, mitigating climate change, meeting emission reduction targets, securing human health, food and water security, biodiversity, and economic growth.

The USDA Natural Resources Conservation Service defines soil health as “the continued capacity of soil to function as a vital living ecosystem that sustains plants, animals, and humans”[1].

Healthy soils underpin human existence. When soils fail, civilisations fail. Reduced soil quality and function impacts our economy, environment, and every aspect of life. This is exacerbated by a changing climate that is bringing more frequent and intense climatic events like drought, bushfires, and storms[2].


Soil Health and Organic Agriculture

Since the dawn of farming, most agricultural soils have lost from 30% to 75% of their original soil organic carbon[3]. Anthropogenic modernisation of farming practices, such as synthetic nitrogen fertilisation, tillage, monocropping, and yield based management systems, have accelerated the depletion of soil carbon stocks and atmospheric load of N2O and CO2[4]. Soil organic matter is a key component of arable soil, which is essential for long-term productivity of agriculture. It contains Nitrogen (N), Phosphorus (P), Carbon (C) and other nutrients indispensable for growing plants, acts as an energy reservoir for the soil microbiome[5], and has a priming effect on the global carbon cycle[6].

A significant tenet of organic agriculture is to build soil fertility by increasing the levels of organic matter in the soil. This is primarily achieved by:

  1. Using photosynthesis to convert carbon dioxide.
  2. Using management techniques that convert plant materials into soil organic matter.

Organic agriculture focuses on building healthy soil, which stores considerable carbon and increases drought resilience. Carbon performs many crucial functions such as acting as a reservoir of plant nutrients, binding soil particles together, maintaining soil temperature, providing a food source for microbes, binding heavy metals and pesticides, influencing water holding capacity and aeration, and more[7]. The amount of carbon stored in the soil can be a measure of soil health. Soil health in organic systems increases over time while the non-organic systems remain essentially unchanged.

To control weeds, organic farmers use cover crops, green manure, crop rotations and underplanting to reduce pressure. Plant residue is then incorporated into the soil with natural compost, increasing the soil organic matter. Synthetic pesticides have been shown to enhance pathogenic microbial species in the soil, impair plant defence systems and reduce uptake of nutrients by crops[8].

Chemical fertilisers pollute ground water sources[9], require extensive fossil fuels for production and reduce the soil viability. They can therefore increase the chance of pest outbreaks on crops[10] and jeopardise soil microbial communities reducing soil fertility[11], compared to organic systems.

A healthy beneficial microbe population in soil allows nutrients to remain available to plants for longer and reduces the incidence and severity of disease[12]. The effects of good soil health and organic management is translated into the final product. Organic plant-foods contain higher concentrations of nutritionally desirable phenolics, antioxidants and mineral micronutrients with lower concentrations of nutritionally undesirable chemicals (pesticide residues, cadmium, and Fusarium mycotoxins)[13].

Australian Organic Limited identifies soil health as the pinnacle of organic agriculture. Chemical fertilisers and synthetic pesticides are negative for soil health. AOL will continue to support and promote organic agricultural systems that build soil organic matter and will advocate for best practice of this within the industry.

Naturally enhancing soil health is at the heart of organic production.


Australian Government

A key soil policy from the previous Australian Government is the National Soil Package, a $214.9 million funding package to implement the National Soil Strategy (The Strategy). The Strategy is set to run from 2021-2041 and has the potential to be the guiding document for how the Australian Government approaches soil health for years to come.

The vision statement of the strategy highlights the following:

“Australia’s soil is recognised and valued as a key national asset by all stakeholders. It is better understood and sustainably managed, to benefit and secure our environment, economy, food, infrastructure, health, biodiversity, and communities – now and in the future”[14].

AOL supports the implementation of this soil package as a positive step forward in the recognition of soil health and its importance to biodiversity and agriculture. AOL looks forward to working with government to incorporate organic farming practices as part of this implementation.

The continued growth of organic farming across Australia provides an opportunity to combine the stated vision and goals of the strategy with this growth.

There are three broad goals in the strategy:

  1. Prioritise soil health
  2. Empower soil innovation and stewards
  3. Strengthen soil knowledge and capability

Organic operators rely on soil quality for the nutritive needs of plants/crops given synthetic fertilisers are not allowed within organic production. Organic operators fulfil the goals of the soil strategy through the natural agricultural processes required for organic production such as ground cover, cover crops, rotations, and increased soil organic matter. They prioritise soil health, develop innovative ways to maintain stewardship of the land and help strengthen our understanding of soil capability under organic farming conditions.

AOL believes the best way to help integrate organics into the strategy is through the development of improved research capability. This would allow a clear understanding of the advantages of organic farming on soil health, which would in turn provide the catalyst for future policies that would benefit organic operators, as well as non-organic operators looking to become organic in Australia.

A draft National Soil Strategy Action Plan 2022-2027 (the action plan) was released for consultation on 26 September 2022 by the Department of Agriculture, Fisheries and Forestry (DAFF). AOL took the opportunity to provide a submission to this process to help the Department understand the importance of soil from an organic perspective, as well as the opportunities that exist for the Department and Government to promote the benefits of organic farming for soil health.

Before the release of the action plan, set for early 2023, the Commonwealth Interim Action Plan, highlights the measures in place while the action plan is being developed[15]. While there is room for more specific policies around the use of organic farming techniques to improve soil health, AOL supports the government‘s approach to increasing the number of programs dedicated to understanding and improving soil health.

The next stage will be to expand this to understand how different farming techniques affect soil health, including organic farming. It remains to be seen if the programs announced in their current form will be able to adequately separate findings between the impact of organic versus non-organic farming on soil health.


Research

As concern grows for the availability of farming land across the world, more research is being conducted on how to improve soil health and maintain viable crop production. Research into improving farming techniques and increasing utilisation of the soil is the next step in understanding how organic farming techniques can help better understand these issues.

Internationally, a study of Europe’s soils found only 30-40% of European soils were considered healthy[16]. The Soil Association in the UK has produced a report highlighting concerns around soil health and has offered several suggestions to help monitor soil health. These include[17]:

  1. Monitoring soil health on farms
  2. Increasing the amount of plant and animal matter going back onto fields
  3. Improving soil life by reducing tillage and chemicals
  4. Covering up bare soil with continuous plant cover
  5. Bringing more trees onto farmland
  6. Reducing soil compaction from machinery and livestock
  7. Designing crop rotations to improve soil health

Coincidentally, this report also highlighted the need for a Soil Strategy for the United Kingdom.

In the United States, the Rodale Institute has completed research on soil carbon and regenerative agriculture through its Farming System’s Trials, designed to compare regenerative farming principles such as[18]:

  • Diversifying crop rotations,
  • Planting cover crops,
  • Green manures and perennials,
  • Retaining crop residues,
  • Using natural sources of fertiliser, such as compost,
  • Employing highly managed grazing and/or integrating crops and livestock,
  • Reducing tillage frequency and depth and,
  • Eliminating synthetic chemicals

These trials have shown positive results, including:

  • Crop yields up to 40% more in times of drought.
  • Earning potential between 3-6x for organic farmers.
  • Using 45% less energy.
  • Release 40% fewer carbon emissions

These are promising developments that could allow for an improved understanding of Australian soil health and the effectiveness of regenerative and organic farming techniques in Australian conditions. The announcement in December 2021 of a collaboration between PWC, the Macdoch Foundation and the National Farmers Federation to conduct a research program to identify links between natural capital (such as soils) and farm profitability is one such positive example[19].

This is an important first step towards understanding the benefits of protecting soils in an Australian context as well as the advantages of organic farming practices. AOL is supportive of this project, and hopes the initiative provides opportunities for organic farmers to demonstrate their management practices and the opportunities they provide for soil health.

Rodale Institute research on soil carbon and regenerative agriculture has yielded positive results.


Summary

Regardless of evolving agricultural technology, maintaining soils for agricultural use will be important as the planet faces the ever-increasing environmental challenges of the 21st century. Data from countries such as the United States show the use of organic practices have helped improve farm yields and the resilience of soils against increased climate volatility.

In Australia, the development of a National Soil Strategy is an opportunity to build on the understanding of the role of organic farming in improving soil health. Organic farming practices have significant potential in the implementation of the strategy, and AOL will work with the Government to incorporate the benefits of organic farming into this strategy.

AOL will continue to support and promote organic agricultural systems that build soil organic matter and will advocate best practice for this within the industry, avoiding the use of chemical fertilisers and synthetic pesticides that are negative for soil health.



List of References


[1] United States Department of Agriculture 2012 ‘Farming in the 21st Century a practical approach to improve Soil Health’ Natural Resources Conservation Service, https://www.nrcs.usda.gov/sites/default/files/2023-04/Farming_in_the_21st_Century_expanded_version.pdf.

[2] Australian Government 2021, National Soil Strategy, Commonwealth of Australia, Canberra, viewed 20 October 2021, https://www.awe.gov.au/agriculture-land/farm-food-drought/natural-resources/soils#national-soil-strategy.

[3] Lal, R., Follett, R. F., Stewart, B. A. & Kimble, J. M. Soil carbon sequestration to mitigate climate change and advance food security. Soil Sci. Dec. 2007 172, 943–956 (2007).

[4] Lal, R. Soil carbon sequestration to mitigate climate change. Geoderma 123, 1–22 (2004)

[5] Hasanaliyeva, G.; Chatzidimitrou, E.; Wang, J.; Baranski, M.; Volakakis, N.; Pakos, P.; Seal, C.; Rosa, E.A.S.; Markellou, E.; Iversen, P.O.; et al. Effect of organic and conventional Production Methods on Fruit Yield and Nutritional Quality Parameters in Table Grapes and Wine made from three traditional Cretan Grape Varieties; Results from a Farm Survey. Foods 2021, 10, 476.

[6] Jones, R.L.; Norris, F.A. Factors affecting degradation of aldicarb and ethoprop. J. Nematol. 1998, 30, 45–55.

[7] Van Bniggen, A.H.; Termorskuizen, A.J. Integrated approaches to root disease management in organic farming systems. Aust.Plant Pathol. 2003, 32, 141–156.

[8] Martinez, D.A.; Loening, U.E.; Graham, M.C. Impacts of glyphosate-based herbicides on disease resistance and health of crops: A review. Environ. Sci. Eur. 2018, 30, 2.

[9] Tal, A. Making conventional agriculture environmentally friendly: Moving beyond the glorification of organic agriculture and the demonization of conventional agriculture. Sustainability 2018, 10, 1078.

[10] Kim, J.J.; John, K.M.; Hae-Kyung, M.; Jin, K.; Enkhtaivan, G.; Kim, D.H. Morphological and biochemical variation of Chinese cabbage (Brassica rapa spp. Pekinensis) cultivated using different agricultural practices. J. Food Compos. Anal. 2014, 36, 12–23.

[11] Ansari, R.A.; Mahmood, I. Optimization of organic and bio-organic fertilizers on soil properties and growth of pigeon pea. Sci.Hortic. 2017, 226, 1–9.

[12] Haghighi, R.S.; Critchley, N.; Leifert, C.; Eyre, M.; Cooper, J. Individual and interactive effects of crop type and management on weed and seed bank composition in an organic rotation. Int. J. Plant Prod. 2013, 7, 243–268.

[13] Rempelos, L., Baranski, M., Wang, J., Adams, T. N., Adebusuyi, K., Beckman, J. J., … & Leifert, C. (2021). Integrated Soil and Crop Management in Organic Agriculture: A Logical Framework to Ensure Food Quality and Human Health?. Agronomy, 11(12), 2494.

[14] Australian Government 2021, ‘National Soil Strategy’ Commonwealth of Australia, https://www.awe.gov.au/sites/default/files/documents/national-soil-strategy.pdf.

[15] Australian Government 2021, Commonwealth Interim Action Plan, Commonwealth of Australia, Canberra, viewed 15 November 2021, https://www.awe.gov.au/sites/default/files/documents/commonwealth-interim-action-plan-national-soil-strategy.pdf.

[16] Veerman et al (2020) ‘Caring for soil is caring for life’ (independent report written for the European Commission), https://op.europa.eu/en/web/eu-law-and-publications/publication-detail/-/publication/32d5d312-b689-11ea-bb7a-01aa75ed71a1.

[17] Payton, Louise, 2021 ‘Saving Our Soils: Healthy soils for our climate, nature and health’, UK Soil Association.

[18] Moyer et al 2020 ‘Regenerative Agriculture and the Soil Carbon Solution’ Rodale Institute, https://rodaleinstitute.org/wp-content/uploads/Rodale-Soil-Carbon-White-Paper_v11-compressed.pdf.

[19] National Farmers Federation, ‘Generational study to help shape farming for the future’, Media Release, accessed 9 December 2021, https://nff.org.au/media-release/generational-study-to-help-shape-farming-for-the-future/.