Organic farming and the environment
Organic farming reduces the negative environmental impacts of agricultural production. Organic food is produced using sustainable farming methods that imitate natural ecological processes. Organic food production does not disrupt ecosystems with the use of synthetic pesticides, herbicides, fertilisers or GMOs which may be harmful to the environment. Food produced organically instead helps to reduce the impact of chemical run-off (nitrogen, phosphorus and pesticides) from farms[1].
Organic farms have lower Greenhouse Gas (GHG) emissions
Organic farming can help mitigate climate change and lower agricultural greenhouse gas emissions compared to non-organic practices. Synthetic nitrogen fertilisers account for around 67% of all cropping emissions[2]. Nitrous oxide is 265 times more potent than carbon dioxide as a greenhouse gas, remains in the atmosphere for over 100 years and depletes the ozone layer[3].
“43% of GHG emissions from every conventional loaf of bread eaten comes from the synthetic fertilisers used to grow the wheat.”[4]
When synthetic pesticides are made, three main greenhouse gases are emitted: carbon dioxide, methane and nitrous oxide[5]. To create the popular weedkiller Glyphosate, phosphate ore must be mined then refined, further contributing to the emissions produced by non-organic farms. Multiple long-term trials have shown organic farming systems can emit up to 40% less carbon emissions than non-organic systems[6].
Organic farms have higher soil carbon
Organic land also focuses on building healthy soil, which stores considerable carbon and increases drought resilience. More carbon in our soil means less in our atmosphere. Soil erosion, abatement and reparation is a management priority and must be outlined in the Organic Management Plan for organic farms. The Organic Management Plan details how farmers will proactively manage their operation to ensure it remains compliant to the organic standards for certification body approval.
Organic matter is the amount of plant material, bacteria, fungi, and other microorganisms (living or dead) present in a soil sample. The more organic matter in a sample, typically the healthier the soil is. Organic methods such as leguminous (which fix atmospheric nitrogen) crop rotations, cover crops, reduced tillage and compost all contribute to healthy soil.
Organic farms are considered low input systems, with higher nutrient use efficiency compared to non-organic systems[7] for non-renewable resources like phosphorus and potassium; this is integral to future food security. Soil health in organic systems continuously increases over time whilst remaining essentially unchanged in non-organic systems[8].
Organic farms are more resilient to climate change
Soil is the crux of organic agriculture, therefore maintaining best practice soil management is key to long term farm sustainability, both economically and environmentally. Increased soil organic matter has a myriad of benefits. Organic soils can retain higher levels of moisture, making organic farms more drought resilient with 40% higher yields compared to non-organic during drought and climate extremes[9].
“Drought doesn’t cause bare ground, bare ground causes drought.” Allan Savory, Savory Institute.
Drought is defined as prolonged periods of below average rainfall, however, how the land is managed decides what type of effect drought will have on the agricultural system.
Maintaining constant soil cover through under cropping, crimping systems rather than ploughing or harrowing, minimal or no tillage and correct stocking practices to prevent overgrazing all contribute to minimising the true effects of drought. Improved soil health under organic systems can result in 15-20% more water percolation through in soil, replenishing the ground water table and helping organic crops perform well in extreme weather[10].The principles of organic farming are focused on land regeneration. Organic farms can restore life to damaged soil and promote strong levels of biodiversity.
Organic farms have higher biodiversity/richer ecosystems
Organic farms must ensure that a minimum of 5% of their farmland is natural vegetation to enhance farm flora and fauna and ecosystem services. Native areas and borders provide environments for predatory insects like lady beetles and parasitic wasps that control aphids and caterpillars. Ecosystem services work with nature to control pests rather than using harsh pesticides which kill the whole ecosystem and make farms more prone to pest reinfestations.
Synthetic broad-spectrum pesticides that target both beneficial insects and pests are not allowed within organic agriculture. This combination results in an abundance and richness of beneficial insects such as pollinators and pest predators. This increased biodiversity helps fulfill ecosystem services, increasing food sources for pollinators and modulating the potential negative effects of insect infestations[11].
Organic farms have been shown to support 30% more species than non-organic farms and 50% more abundance. Studies have shown that birds, predatory insects, soil organisms, and plants responded positively to organic farming, while non-predatory insects and pests responded negatively[12].
Land use efficiency
Organic systems may have lower yields (tonnes/ha) compared to non-organic systems, especially during initial conversion periods as the soil adapts to the changed practices. However, increased yield per hectare is just one of the outcomes of a complex agroecological system.
Instead of yield, maximum sustainable output per hectare should be prioritised. This is defined as the yield without damaging the land’s natural value. In this age of consumerism where focus is on “cheap” production costs, labour and end products, what are the externalities of this?
Externalities are the true costs to society in a production system. For example, if a farm uses synthetic fertiliser that runs off into the Murray Darling River and causes algal blooms (eutrophication), killing the local wetland ecosystem. This is an externality of the mentality of synthetic fertiliser; which may have provided the farmer with short term yield increases, however, the additional associated costs of the destroyed ecosystem will be paid for further down the track or by somebody else.
Nutrient leaching
Globally, farmers apply around 115 million tonnes of nitrogen to non-organic crops every year. However, only around 35% of this is used by the plants, leading to 75 million tonnes of nitrogen run-off into rivers, lakes and natural environments annually[13]. 56% of phosphorus fertiliser is also not used by the crops and may also become an environmental pollutant[14]. Excess nutrient run-off can cause eutrophication and lead to low water oxygen and high toxicity in waterways. This can have adverse environmental effects on marine animal and plant life. The majority of nutrients for organic plants are taken up via humus colloids in the soil rather than water soluble synthetic fertilisers. This releases nutrients to the plant slower, lowering the chance of nutrient leaching and eutrophication downstream and environmental degradation.
Conclusion
The premium you pay for organic produce is invested in minimising the potential externalities of the agricultural food system. When you next shop, think, “what are the hidden environmental costs of buying non-organic, unbranded products versus certified organic equivalents?” Every choice you make as a consumer goes toward creating a more sustainable future.
Always remember to look for a certification mark such as the Australian Certified Organic Bud logo to make sure your organic purchases are authentically organic.
[1] Tuomisto, H.L.; Hodge, I.D.; Riordan, P.; Macdonald, D.W. Does organic farming reduce environmental impacts? A meta analysis of European research. J. Environ. Manag. 2012, 112, 309–320.
[2] Hanqin Tian et.al.: A comprehensive quantification of global nitrous oxide sources and sinks. Nature, 2020. Summary Doi.org/10.1038/s41586-020-2780-0.
[3] S. Solomon, D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.). IPCC (2007) Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press. Cambridge, United Kingdom 996 pp.
[4] Bowles, Liz (2021) Opinion: Agro-ecology holds the key to fighting climate change. Farmers Weekly, 2021. Available at: https://www.fwi.co.uk/news/opinion-agro-ecology-holds-the-key-to-fighting-climate-change.
[5] Heimpel GE, Yang Y, Hill JD, Ragsdale DW. Environmental consequences of invasive species: greenhouse gas emissions of insecticide use and the role of biological control in reducing emissions. PLoS ONE. 2013;8(8):e72293. Available from: https://doi.org/10.1371/journal.pone.0072293.
[6] Moyer, J, Smith, A, Rui, Y and J, Hayden. 2020 Regenerative Agriculture and the Soil Carbon Solution. Rodale Institute, September 2020. Available at https://rodaleinstitute.org/education/resources/regenerative-agriculture-and-the-soil-carbon-solution/.
[7] Tilman, D.; Cassman, K.G.; Matson, P.A.; Naylor, R.; Polasky, S. Agricultural sustainability and intensive production practices. Nature 2002, 418, 671–677.
[8] Rodale Institute (2022). Farming Systems Trial. Available at: https://rodaleinstitute.org/science/farming-systems-trial/.
[9] Moyer, J, Smith, A, Rui, Y and J, Hayden. 2020 Regenerative Agriculture and the Soil Carbon Solution. Rodale Institute, September 2020. Available at https://rodaleinstitute.org/education/resources/regenerative-agriculture-and-the-soil-carbon-solution/.
[10] Rodale Institute (2022). Farming Systems Trial. Available at: https://rodaleinstitute.org/science/farming-systems-trial/.
[11] Fuller, R., L. Norton, R. Feber, P. Johnson, D. Chamberlain, A. Joys, F. Mathews, R. Stuart, M. Townsend, and W. Manley. 2005. Benefits of organic farming to biodiversity vary among taxa. Biology letters 1(4):431. http://dx.doi.org/10.1098/ rsbl.2005.0357; Attwood, S., M. Maron, A. House, and C. Zammit. 2008. Do arthropod assemblages display globally consistent responses to intensified agricultural land use and management? Global Ecology and Biogeography 17(5):585-599; Gabriel, D., I. Roschewitz, T. Tscharntke, and C. Thies. 2006. Beta diversity at different spatial scales: plant communities in organic and conventional agriculture. Ecological Applications 16(5):2011-2021. http://dx.doi.org/10.1890/1051-0761(2006) 016[2011:BDADSS]2.0.CO;2; Batáry, P., A. Báldi, D. Kleijn, and T. Tscharntke. 2011. Landscape-moderated biodiversity effects of agri-environmental management: a meta-analysis. Proceedings of the Royal Society B-Biological Sciences 278(1713):1894-1902. http:// dx.doi.org/10.1098/rspb.2010.1923.
[12] Bengtsson, J., J. Ahnström, and A. C. Weibull. 2005. The effects of organic agriculture on biodiversity and abundance: a meta-analysis. Journal of Applied Ecology 42(2):261-269. http://dx.doi.org/10.1111/j.1365-2664.2005.01005.x.
[13] Ritchie, H., Roser, M. (2013) “Fertilizers”. Published online at OurWorldInData.org. Retrieved from: ‘https://ourworldindata.org/fertilizers’ [Online Resource].
[14] Ritchie, H., Roser, M. (2013) “Fertilizers”. Published online at OurWorldInData.org. Retrieved from: ‘https://ourworldindata.org/fertilizers’ [Online Resource].