I was having this conversation with a friend the other day, and suddenly realised that although I had the impression that organic food was better for the environment, I didn’t have any studies or data to back up that belief. How shameful of me! So I did a bit of research (thank you Google) and here’s some surprising things I discovered. My findings draw from an excellent article by Hannah Ritchie (1), which is linked below.
What is the definition of ‘organic’?
Organic agriculture is when crops and/or livestock are farmed without the use of synthetic inputs, including:
• Synthetic fertilizers;
• Plant growth regulators;
• Genetically-modified organisms (GMOs).
In contrast, conventional/ industrial farming uses one or more of the above synthetic inputs. But note that organic doesn’t necessarily mean chemical-free or pesticide-free, just that these chemicals and pesticides cannot be synthetically manufactured, with the exception of a small number which have been approved by the National Organic Standards Board in the US. In the UK, farmers get organic certification from one of 9 approved organic control bodies (2).
So instead of synthetic inputs, organic farmers may use the following techniques to for weed and pest control, soil fertility, and increasing yield:
• Planting and tilling techniques such as crop rotation to maintain soil fertility (3);
• Green compost/ animal manure/ bone meal adds nutrients to the soil;
• Livestock are fed organic feed/ graze on land with no synthetic chemical inputs;
• Livestock cannot be given antibiotics except in emergency cases;
• Livestock cannot be given growth hormones;
• Livestock must be raised with access to the outdoors.
So which is better for the environment – conventional or organic produce?
This question is too vague to answer in a meaningful way. There are many different environmental impacts that vary from crop to crop, place to place etc. But an excellent meta-analysis by Clark and Tilman (2017) compares the impacts of organic and conventional farming across 742 agricultural systems, over 90 foods, including cereals, pulses, and oil-crops, fruits, vegetables, dairy, eggs, and meat, and across a range of environmental impact categories, including GHG emissions, land use, acidification potential, eutrophication potential, and energy use.
Have a look at this gorgeous chart from Clark and Tilman:
It's a bit confusing, so here are my summaries of the findings from this graph:
GHGs: Organic and conventional are basically the same
Synthetic fertilisers from conventional farming produce GHGs, and so does manure in organic farming (it produces nitrous oxide, a powerful GHG).
Acidification and Eutrophication: Conventional is usually better than organic
Conventional farming has less acidification and eutrophication potential across all food groups. This is because it uses fertilizers to release nutrients in response to crop demands, meaning nitrogen is only released when required by the crops. In contrast, organic farming uses nitrogen from manure which is more dependent on environmental conditions, such as weather conditions, soil moisture and temperature. This can lead to too much nitrogen in the soil and thus acidification and eutrophication.
Energy use: Organic is better than conventional (except for vegetables)
Organic uses less energy for all food groups except for vegetables. Conventional farming requires the industrial production of fertilizers and pesticides, which is an energy-intensive process. But in the case of vegetables, organic farming uses propane-fueled flame weeding (since they cannot use synthetic herbicides) which increases their energy usage.
But agriculture’s energy usage isn’t a big problem. Globally, agriculture only accounts for 2% of total energy usage, and 0.6% of the UK’s energy usage, so reducing this impact needn’t be a high priority.
Land Use: Conventional is always better than organic
Across all food groups, conventional farming has far higher crop yields and therefore uses far less land than organic farming.
Land use is a big global issue. Agriculture uses 50% of the world’s habitable land, so reducing land use would free up space for rewilding and carbon sequestration in soil.
An interesting side note: 77% of all agricultural land is used for livestock (meat and dairy), but this food only provides us with 37% of global protein supply and 18% of global calorie supply! Compare this to crops, which make up 23% of all agricultural land but produce 63% of our protein and 82% of our calories! So if you want your diet to use less land, eat less meat and dairy!
Which farming approach is better for biodiversity? This is tricky…
Both conventional and organic farming impact biodiversity, but organic less dramatically per unit area due to lower fertilizer and pesticide use.
BUT organic agriculture uses far more land than conventional agriculture.
So should we farm intensively over a smaller area and severely impact that area’s biodiversity? Or should we farm organically and impact biodiversity less severely over a larger area? Scientists remain divided.
So there you have it folks, a quick run-down of the differences between conventional and organic farming impacts. I hope this has been helpful!
(1) Ritchie, Hannah (2017), “Is organic really better for the environment than conventional agriculture?”, in Our World in Data. Available at: https://ourworldindata.org/is-organic-agriculture-better-for-the-environment
(2) Department for Environment & Rural Affairs (2020), “Approved UK organic control bodies”, in GOV.UK. Available at: https://www.gov.uk/government/publications/organic-certification-list-of-uk-approved-organic-control-bodies/approved-uk-organic-control-bodies
(3) Department for Environment & Rural Affairs (2016), “Organic farming: how to get certification and apply for funding”, in GOV.UK. Available at: https://www.gov.uk/guidance/organic-farming-how-to-get-certification-and-apply-for-funding#:~:text=Organic%20farming%20can%20include%3A,to%20control%20pests%20and%20diseases