Buying organic food may not always be better for the planet or for human health than cheaper options grown with artificial pesticides, according to researchers.
Birds and bees tend to be more abundant on organic farms but the benefits may be cancelled out because they produce an average of 19 to 25 per cent less food per acre than conventional farms. This means that more land is needed to produce the same amount of food — and land conversion for agriculture is one of the greatest threats to wildlife, researchers at the University of British Columbia said.
Organic farms tended to use less energy and produce lower emissions, but “when lower organic yields are taken into account, greenhouse gas emissions might actually be higher under organic management”.
The authors of the study, published in Science Advances, said: “We don’t know whether organic agriculture provides any benefits for biodiversity if lower organic yields are taken into account.”
Organic farms tend to cause less nitrogen and phosphorus pollution of water systems, but the lower yields could mean that nitrogen loss per unit of food produced is higher than on conventional farms.
The authors argued that in countries like Canada, where pesticide regulations are stringent and diets are rich in micronutrients, the health benefits of choosing organic may be marginal. They said organically grown food probably contained slightly more micronutrients but it was not clear whether this provided “any actual health benefits to consumers”.
The team analysed organic crop farming across 17 criteria including yield, impact on climate change, farmer livelihood and consumer health. “Organic is often proposed as a holy grail solution to current environmental and food scarcity problems, but we found that the costs and benefits will vary heavily depending on the context,” said Verena Seufert, one of the authors.
They concluded that organic farming is not the only solution to providing a sustainable source of food for an ever-growing global population, but does have an important role to play. “We need to stop thinking of organic and conventional agriculture as two ends of the spectrum. Instead, consumers should demand better practices for both so that we can achieve the world’s food needs in a sustainable way,” said Ms Seufert.
The study, which involved a review of the scientific literature on the environmental and economic performance of organic farms, also found that they were highly dependent on animal manure from conventional farms and added: “It is not clear whether we would have enough organic fertilizers to feed everyone in the world with organic food.”
Organic food is more expensive and “therefore less accessible to consumers with low income”, they said.