Does Spending More Green On Groceries Really Help the Environment?

Author:  Wear Emma
Date:  August 2005

Spotted recently at a grocery store: a huge stand of strawberries, $2.50 a pint. Yet five lonely baskets of fruit, isolated in the far corner of the display, went for $3.99 a pint. Why so much more for fruit that looked pretty much the same? A closer look at the labels showed the difference: the more expensive berries were organic.

Figure 1. The USDA certified organic logo.

Figure 1. The USDA certified organic logo.

Organically-grown produce has become a common sight not only in supermarkets, but also in the news. Whenever a new study about pesticide residues on produce is published, the media highlights organic farmers who tout their produce as healthier for both humans and the environment. No surprise there; after all, the USDA's definition of organic farming is food production based on "practices that foster cycling of resources, promote ecological balance, and conserve biodiversity."


But does organic farming truly live up to these goals? How much impact can farming methods really have on the surrounding ecosystems? And do its benefits justify the extra cost at the grocery store?

To Spray or Not to Spray.

Organic farming is best known for using natural alternatives to pesticides, such as natural predators and rotating crops. Strawberries are a good example of the impact of organic farming. Conventionally grown strawberries, most of which come from California, require more pesticides per acre than any other crop grown in the state – over 9 million pounds statewide, or nearly 8 pounds per acre, in 2003.

"[Organic farming] has reduced by maybe hundreds of tons the introduction of toxic suspected carcinogens into the environment," says Bob Scowcroft, executive director of the Organic Farming Research Foundation.


Similarly, a study funded by the USDA's Sustainable Agriculture Research and Education program found that water draining from organic farms in Illinois contained lower levels of nitrate, chloride, and atrazine (an herbicide that can cause cancer after prolonged exposure) than water from conventional farms.

Figure 2. Mixed cropping, where two different species of crops are grown in the same field. Mixed cropping controls soil quality and weeds, like undersowing. (Photo Courtesy of HDRA)

Figure 2. Mixed cropping, where two different species of crops are grown in the same field. Mixed cropping controls soil quality and weeds, like undersowing. (Photo Courtesy of HDRA)

Chemicals from farms can affect an entire natural ecosystem, not just the parts that contact the fields or even just the areas where pesticide drifts reach. Pesticides can cause bird species to disappear from farms, both by killing them directly and by eliminating the invertebrates and plants upon which they feed; runoff in surface water can kill fish. Organic farming can help alleviate such losses by reducing the amount of toxic substances. In addition, fertilizing fields with organic manures encourages the invertebrates that serve as food for wildlife like birds.

But pesticides can, in specific circumstances, directly benefit the environment. For example, in New Zealand, pesticides can help prevent erosion by controlling the population of rabbits, an introduced species. Similarly, limiting the number of non-native opossums on the continent can help protect naturally occurring plants.

Other Organic Alternatives

However, there is more to organic farming than eliminating pesticides and applying manure. Farmers use a variety of methods to produce healthy crops. According to Scowcroft, such practices contribute to organic farms' ability to use less water, absorb more carbon from the environment, and contribute lower levels of nitrates to groundwater runoff.

One such method is cover crops: plants that do not produce a profit, but which organic farmers grow along with profitable species to maintain soil quality and prevent weeds. For example, in undersowing, shorter grasses and cover plants are grown under taller cereal grains. These plants can help native insect and bird species to survive in the middle of farm fields.

Another method is rotating crops, which gives different species opportunities to breed and feed. Crop rotation is also part of a system that prevents soil erosion, keeps fields fertile, and prevents silt from accumulating in waterways.

The Harvest of Opinions

According to a review of organic standards in the United Kingdom, organic farms preserve at least 50% more biodiversity than conventional farms. Organic livestock farms especially conserve close-to-natural habitats.

Scientists at the Research Institute of Organic Agriculture in Switzerland compared organic and traditional farming on their fields for more than twenty years. While their organic fields yielded about 20% fewer crops, those crops were healthier, even though the farmers invested less fertilizer and energy in them. In addition, soil in the organic fields had more beneficial nutrients and more organisms living in it.

Yet the finding that organically grown plants produce less food than their conventionally grown counterparts is the reason that Robert Reese of the Illinois Department of Agriculture describes organic farming as "a double-edged sword." Fewer substances are introduced into the environment, but, with additional labor requirements, farmers still spent about as much money on organic as on traditional farming, and in return they have lower crop yields.

Taking that idea a step further, Dennis Avery, director of the Hudson Institute's Center for Global Food Issues, argues that large-scale organic farming would lead to wildlife habitat destruction, at least compared with the use of modern methods that allow farmers to use less land. Or, as the CGFI's website says: "Growing more per acre leaves more for nature."

Reese sees future farming as "a balance between the two [systems]," without excessive levels of fertilizers and pesticides, but with the benefit of more advanced technology and management practices to increase crop yields. In the meantime, he believes that both farming systems offer specific benefits, and that organic farming can particularly help "people sensitive to chemicals."

So can paying nearly twice as much for organic groceries really save the world? The evidence suggests that, at the scale at which it is currently practiced, organic farming does benefit the environment.

"It's more of an investment in the environment," says Scowcroft. "You may only be able to put seventy cents into organic every week, but that helps, too."

But comparisons between organic and traditional farming are few, and propaganda for both sides of the issue is far more prevalent than solid data. Until more research is done, buying organic has to be a personal value judgment – which is more valuable: possibly helping the environment over the long term, or sticking with the grocery budget for the week?

Further Reading

A guide to various sustainable farming practices, including how they affect the environment.

Grocery Store Wars, an advocacy video from the Organic Trade Association.