We at Scientific American welcome responses to our articles. A recent blog post by one of our network bloggers, Christie Wilcox—"Mythbusting 101: Organic Farming > Conventional Agriculture"—engendered much discussion online and we received several offers to write responses. This blog post by Jason Mark is the response we accepted. Of course, as our bloggers have editorial freedom, Christie Wilcox may also write her own response to the response. If she does so, I will add the link here.....Edit: Christie Wilcox has responded.


When I saw that Scientific American was carrying a web story by a regular SciAm blogger determined to bust some of the “myths” surrounding organic farming, I was excited. I hoped the article would be something along the lines of Sam Fromartz’s excellent book Organic Inc., a skeptical look at how a well-intentioned effort to protect the environment has turned into a multi-billion-dollar industry. I was quickly disappointed. The article1, by a PhD candidate named Christie Wilcox, was compromised by a slew of elisions and exaggerations. If the intention was to myth-bust, mark this one a fail: The article spread new misconceptions about the methods of organic food production.

As the co-manager of an urban farm2 that uses organic practices, I was annoyed by the distortions in the article. So I’m pleased that the Scientific American editors have dedicated some space for a rebuttal. Here we go, then, point by point.

Busting Myth #1: Organic Farms and Pesticides.

Wilcox starts by explaining, accurately, that “organic farming … still uses pesticides and fungicides to prevent critters from destroying their [sic] crops.” She intends this to be something of a bombshell: the smoking gun in the form of a spray nozzle, as it were. But the shocker fell flat. To the better informed, this is no surprise at all. Yes, organic farmers (including this one) sometimes use sprays to control pests and diseases — sprays that are carefully reviewed to ensure that they do not pose a risk to public health or the environment.

The National Organic Standards Board — a group of 15 farmers, academics, and advocates — advises the Secretary of Agriculture on which substances can be used by organic-certified growers, and which cannot. Recommended substances are then reviewed by a technical panel that examines the scientific research on the substances and makes a final recommendation. The most thorough lists of allowed substances is maintained by the Organic Materials Research Institute (OMRI), an Oregon-based independent non-profit.3 Any approved sprays must either be produced from a natural substance or, if they are synthetic, must be proven to “not have adverse effects on the environment” or “human health.”

Wilcox claims that organic farms “spray their crops with pesticides all the time.” What’s her source for this? “A guy [she] was dating.” In reality, the national organic standards require producers to use ecological methods for pest control — crop rotation, nutrient management, mechanical weeding — before using any spray tactics. And if an organic grower does decided to use a pesticide, the farmer must demonstrate (to their organic certifying agency) that they have exhausted every other means at their disposal.4 Most of the organic farmers I know (and I am friends with dozens) only spray reluctantly, and as a last resort.

(Wilcox’s ex-boyfriend anecdote betrays a confusion about the usage of the term “no spray” commonly used by farmers market vendors. Farmers who cannot afford the costs of the sometimes-onerous organic certification, but who are committed to best organic practices, will often use the term “no spray” at their stands, since they are prohibited by law from saying they are “organic.” This is a colloquial way of communicating that they don’t use synthetic chemicals, not a claim that nothing ever comes out of a spray nozzle on their farms. Imprecise language, maybe, but there it is.)

Which brings us to Wilcox’s next point. She writes: “Why the government isn’t keeping a watch on organic pesticide and fungicide is a damn good question.” Well, actually, the government is — through the highly detailed rules regarding organic certification. 5 Farmers hoping to be certified as organic must keep records covering the “production, harvesting, and handling” of their crops — and maintain those records (including receipts for purchases of any off-farm inputs like sprays) for at least five years. Organic growers also submit to an annual on-site inspection from an organic certifier. Yes, the certifiers are independent, non-government agencies, but the level of scrutiny is intense.

No, the government doesn’t record the use of non-synthetic pesticides on organic farms. And neither does it record the use of synthetic pesticides on individual industrial farms. A national law, FIFRA (the Federal Insecticide, Fungicide, and Rodenticide Act), expressly forbids the EPA from requiring pesticide applicators to report how they use synthetic chemicals6. The only information the federal government collects on pesticide usage is at the aggregate level.

This reveals an unfortunate asymmetry in official recordkeeping. While the government collects national statistics on the spraying of synthetic chemicals, it doesn’t require any usage information from individual farmers; and while the government — via independent certifiers — demands detailed information regarding off-farm inputs used by organic-certified growers, it doesn’t compile that information into any kind of national, publicly available database. The easiest way to correct this inconsistency would be to require the same reporting from both organic and industrial farmers.

Still, given the demands of yearly on-site inspections, it’s fair to say that organic-certified farmers, ranchers, and processors are the most highly regulated sector of the US food system and consent to far more oversight than any industrial farmer. It would make more sense, then, to reverse Wilcox’s question: Why the government requires far less reporting on the production methods of industrial farmers than it does reporting from organic farmers is a damn good question. The burden of proof seems askew.

Wilcox’s real beef appears to be the popular assumption that substances approved for organic farms are safer because they are occur naturally. “Just because something is natural doesn’t make it non-toxic or safe.” Fair enough, I suppose. After all, oleanders and tobacco are natural — and also deadly. I myself occasionally use copper sprays on our farm’s dormant fruit trees during the winter as a fungicide. When I do so, I am careful to wear a bandana around my nose and mouth and make sure I am upwind. No doubt about it: copper, which has been shown to cause liver disease, is nasty stuff.7 (Copper appears on the list of organic approved substances because it’s not synthetic; the Romans pioneered its use in orchards.)

But then Wilcox goes a step too far: “Not only are organic pesticides not safe,” she writes, “they might actually be worse than the ones used by the conventional agriculture industry.” Her evidence for this? A naturally occurring pesticide called Rotenone, which is now banned in the US. Plus one study about aphid control methods in Canada. To use an agricultural term, this is cherry-picking.

In claiming that organic pest controls may be worse than chemical ones, Wilcox perpetuates a false equivalency. She’s suggesting that naturally occurring pesticides pose the same risk as same as synthetic ones. The truth is, they’re don’t.

Just take a look at the EPA’s inventory of the most widely used pesticides, herbicides, and fungicides. 8 The most commonly used insecticide in the United States is Chlorpyfiros. This is an organophostphate pesticide, part of a class of chemicals that, according to three recent independent studies9, can lower children’s IQ by an average of as much as seven points — enough to affect a child’s math and reading skills. The most commonly used fungicide is Chlorothalonil, which the EPA rates as “very highly toxic” to aquatic organisms and which the agency warns is used at levels of concern in potato and peanut production.10

Compare those to natural pesticides. The most commonly used naturally occurring insecticide is Bt, or Bacillus thuringiensis, a bacterium found in soils.11 Bt is effective at killing boll weevils, cabbage loopers, and corn ear worms — and it’s not toxic to humans.12 Two of the other most common OMRI-approved insecticides are neem oil (derived from the seeds of the neem tree) and insecticidal soaps. The active ingredient in insecticidal soaps (which desiccate insects’ exoskeletons) is potassium salts — no danger to people there. Neem is so benign that it appears in some brands of toothpaste. I have yet to see any dental hygiene products containing Chlorpyfiros.

At one point in her essay, Wilcox writes: “What makes organic farming different, then? It’s not the use of pesticides, it’s the origin of the pesticides used.” [Emphasis original.] Exactly. Synthetic pesticides are qualitatively different from natural ones, and it’s the differences that often make the danger. A good example is the distinction between natural pyrethrum and synthetic pyrethroids. Pyrethrum is a naturally occurring insecticide derived from the chrysanthemum; it has been used for at least 200 years. (Napoleon’s armies used it to control lice.) Both the natural compounds and the synthetic versions are moderately toxic to mammals and extremely toxic to aquatic life. Here’s the difference: synthetic pyrethoids have been engineered to be more stable and to resist photodegradation. Whereas phyrethrum will break down in as little as 12 hours, some pyrethoids will remain active for up to 30 days. Their artificial persistence means they are a greater risk to the environment. If the dosage makes the danger, synthetic pyrethoids are more dangerous because they last longer. They are more indiscriminate. What organic farmers see as a virtue — the poison doesn’t work very long naturally — industrial farmers view as a weakness.13

But, for me at least, this is the kicker: all of the top ten synthetic chemicals used in agricultural production are either soil fumigants or herbicides. Organic growers don’t use fumigants such as Dichloropropene (the sixth most commonly used pesticide nationally), a probable carcinogen. Nor, as a rule, do organic growers rely on Glyphosate (most common brand: Roundup) or Atrazine, both of which are endocrine disruptors linked to birth defects14. Instead, organic farmers control weeds with the hula hoe: a proven technology whose most serious impact on human health is the formation of burly calluses.

Are organic practices perfectly pristine? No. But are they preferable to synthetic chemicals? Certainly. Organic growers are, in general, better stewards of soil health, water quality, and public health than industrial farmers who are reliant on synthetic chemicals.

Busting Myth # 2: Organic Foods and Nutrition

According to Wilcox, “science simply cannot find any evidence that organic foods are in any way healthier than non-organic ones.” Wrong. A number of studies have found intrinsic differences between crops produced organically and those produced industrially. Other studies have not. The fairest way to explain the situation would be to acknowledge that the evidence is mixed.

A 2007 study by researchers at University of California-Davis, for example, found that organic tomatoes had nearly twice as much flavonoids as industrial tomatoes.15 Flavonoids such as quercetin, kaempferol, and naringenin have been found to reduce cardiovascular disease. The UC-Davis study suggested that industrial tomatoes may have fewer of the metabolites because they are over-fertilized. When researchers at Washington State University compared organic strawberries and industrial ones, they found that the organic berries had significantly higher antioxidant activity (8.5 percent more), ascorbic acid (9.7percent more), and total phenolics (10.5 percent more) than industrial berries.16 Finally, a January 2011 study published in the Journal of Dairy Science found that milk from cows raised organically in the UK had higher levels of beneficial fatty acids.17 The study’s author, Gillian Butler, believes the difference between organic milk and non-organic milk has to do with whether cows are allowed to graze freely on grass.

In short, the jury is still out on the question of whether organic foods are more nutritious. Further research is needed to resolve the issue. To definitively say, as Wilcox does, that “organic foods are not better for us” just promulgates another myth.

Busting Myth #3: GMOs and Organic Crop Yields

In attempting to burst the bubble of her third “myth” — the claim that organic methods are better for the environment — Wilcox pursues two separate arguments: First, that genetically modified foods are an overall environmental good; and, second, that crops yields in organic systems can’t compete with industrial yields. Both of her arguments are flawed.

Pay special attention to Wilcox’s language. She writes that GMOs “might” reduce or eliminate the use of chemical pesticides; she trumpets the “potential” of GMOs to increase farm yields and increase crops’ nutrition value. As Tom Laskaway put it in a riposte at the environment news site Grist.org, this is where Wilcox goes from “science to science fiction.”18 None of the wonderful crop features she trumpets have actually made it to market. So far, genetically modified crops have failed to match many of the promises of their backers. That’s a big deal. If you’re going to praise something, it better work as you say.

Then Wilcox accuses organic proponents of “hypocrisy” for opposing the development of Bt-enhanced crops. According to Wilcox, it’s unreasonable for growers to apply Bt on their crops but oppose its insertion in the genome of plants. She writes: “Ecologically, the GMO is a far better solution.”

This is a narrow interpretation of ecological thought. Yes, some self-identified ecologists support GMOs because they believe GM technologies can reduce the use of chemical herbicides and pesticides. Other self-identified ecologists oppose them. This just shows that ecology — like economics — is a science that allows for many different interpretations.

“When we try to pick out anything by itself, we find it hitched to everything else in the universe,” John Muir famously wrote, in what is probably the most concise summation of ecological thinking. One of the main reasons that many ecologists have resisted GMO technology is because it’s reductive: it assumes that we can isolate a certain plant or animal trait and embed it in another plant or animal (even from a different kingdom) to get a certain outcome. Ecologists caution that we don’t yet understand all of the interconnections at a genetic level, and so it’s wiser (and safer) not to mess with them.

In her complaints against critics of GM technology, Wilcox once again slips into a false equivalency, suggesting that there’s no distinction between spraying Bt and placing it directly into the plant. I have to disagree. There are major differences — both in terms of direct and indirect environmental consequences — between applying an insecticide by hand and manipulating the genetic code of a plant to embed that insecticide in its very DNA. At the very least, there’s a difference of scale; if there weren’t, there would be little sense in doing the genetic manipulation in the first place.

On a more practical level, organic farmers have opposed Bt GMOS because they worry that its large-scale deployment could lead to Bt resistance among pests. This is a well-grounded fear. Just look at the history of Roundup Ready corn, soy, and cotton. Farmers in Missouri — the home base of Roundup manufacturer Monsanto — are beginning to report the appearance of glyphosate-resistant weeds.19 To help farmers cope with the new “super weeds,” Monsanto has launched a new herbicide, Warrant. So much for the claim that GMOs will reduce chemical use.

I thought Wilcox’s defense of GMOs on ecological grounds was especially odd given that twice earlier in the essay she acknowledges organic agriculture’s value in reducing crop monocultures. I will leave it to others to argue the concerns about GMOs’ possible impacts on human health or the risk of GMOs spreading into other crops. As a small farmer, my biggest worry about GMOs is how they lead almost inevitably to further concentration of food production: call this a concern of political ecology. The skills needed to genetically modify seeds are so specialized (and the investment required so immense) that only a handful of massive firms can take it on. Compare that to the thousands — or, globally, the millions — of seed dealers and seed savers who use traditional plant breeding techniques. GMOs are dangerous, I think, because they encourage a kind of monocropping of the global food system. They also contribute to real monocrops out in the fields: According to USDA figures20, 94 percent of soybeans and more than 70 percent of corn and cotton planted in the US contain the Roundup-resistant gene. This is the very antithesis of the biodiversity Wilcox says she values. (For more on the dangers of monocropping and the importance of biodiversity, see: Phytophthora infestans and the Irish potato famine.)

Speaking of biodiversity: Wilcox’s second claim is that organic agriculture “isn’t more green than conventional” because it can’t compete on crops yields, and therefore will require more land, which will cause more forest loss and habitat destruction. This is an echo of the canard that organic agriculture will never be able to feed the world. As with the science over the nutrition of organic foods, the evidence is more mixed that Wilcox admits.

Wilcox cites a single study to make her case that organic farms underperform industrial ones. As agriculture writer Tom Philpott has pointed out, Wilcox neglected to share with Scientific America readers that the study’s authors attributed the lower yields, in part, to the fact that “inputs of fertilizer and energy was reduced by 34 to 53%.”21 Given industrial agriculture’s complete reliance on fossil fuel inputs and the eventual depletion of fossil fuels, organic agriculture’s energy savings should be considered an environmental and food security asset.

More frustrating is that Wilcox completely ignored other studies that show organic methods competing with and excelling over industrial practices. The Rodale Institute in Pennsylvania has been conducting what it calls the “longest running, side-by-side comparison of conventional and organic agriculture.” Its 27-year trial has shown that corn yields on organic plots are equivalent to the yields on non-organic plots.22 Perhaps most significant, the corn yields in the organic fields were 31 percent higher in years of moderate drought, probably because organically farmed soils are better at retaining water.

A recent report by the United Nation’s Special Rapporteur on the Right to Food confirmed some of the Rodale findings.23 The report, which studied farming methods in 57 countries, concluded that small farmers using ecological methods could double food production in 10 years. The study found that farmers currently using agro-ecology methods have increased their yields by an average of 80 percent and in some countries have boosted harvests by 116 percent.

Here’s the hitch: Agro-ecology, which is centered on building soils through compost, is very labor intensive. The challenge of feeding the world isn’t — as Wilcox assumes — a question of needing more land. Rather, we need more farmers using land more efficiently.

I’ll acknowledge that as a matter of public policy recruiting more farmers is going to be difficult. The global demographic trend is toward urbanization, not a return to the countryside. But it’s misleading to suggest, as Wilcox does, that organic methods cannot “rival the production output of conventional farming.” The emerging evidence doesn’t support Wilcox’s conclusion.

The most dangerous myth to be found in Wilcox’s essay is the idea that organic practices are incapable of producing enough food to feed the human population.

Busting Myth #4: You Don’t Have to Choose

Wilcox ends on a gentler, accommodationist note. “What bothers me most,” she writes, “is that both sides of the organic debate spend millions in press and advertising to attack each other instead of looking for a resolution. … The biggest myth when it comes to organic farming is that you have to choose sides. Guess what? You don’t.”

No, I supposed you don’t have to choose between organic and industrial food. But here’s the great thing about the free market: you get to choose. At least three times a day you get to make a choice about what you want to put in your body.

For me, at least, the choice is clear. I want to eat food that I know doesn’t involve the use of chemicals that harm ecosystems and have been linked to human health impacts. I want to eat food that is GMO-free, if for no other reason than I don’t want to support the further concentration of the food system. I want to eat food that I believe is more nutritious (I’m waiting for the research to catch up), because as a farmer I know that healthy soils make for the healthiest plants.

Other people will make other choices, of course. But at the very least they should be well informed when making decisions. Unfortunately, Christie Wilcox’s article did more to spread myths than it did to dispel them.



[1] https://blogs.scientificamerican.com/science-sushi/2011/07/18/mythbusting-101-organic-farming-conventional-agriculture/

[2] Since 2006, I have been a part-time co-manager at San Francisco’s Alemany Farm, a three-acre fruit and vegetable garden. While we practice ecological farming, what some call agro-ecology, we are not organic certified, as it does not make sense for a farm of our size. http://www.alemanyfarm.org.

[3] Lists of allowed substances can be downloaded here: http://www.omri.org/omri-lists.

[4] Reporter’s interview with Lindsay Fernandez-Salvador Program Director, Organic Materials Review Institute.

[5] The complete regulations, including requirements for reporting, can be found here

[6] An overview of FIFRA can be found here: http://www.epa.gov/agriculture/lfra.html. The language governing individual reporting is in section 11 (d).

[7] http://pmep.cce.cornell.edu/profiles/extoxnet/carbaryl-dicrotophos/copper-sulfate-ext.html

[8] http://www.epa.gov/opp00001/pestsales/07pestsales/usage2007_2.htm#3_4 The most recent data available is from 2007. Perhaps the most interesting piece of this document is that it’s an “estimate.” As noted earlier, the government does not keep firm records on synthetic pesticide usage.

[9] http://e360.yale.edu/feature/from_the_fields_to_inner_city_pesticides_affect_childrens_iq/2404/

[10] www.epa.gov/oppsrrd1/REDs/factsheets/0097fact.pdf

[11] http://www.sciencedaily.com/releases/2006/09/060926072327.htm

[12] http://extoxnet.orst.edu/pips/bacillus.htm

[13] http://extoxnet.orst.edu/pips/pyrethri.htm and http://www.livingwithbugs.com/permethrin_pyrethrum.html

[14] For details on Atrazine, see Tyrone Hayes, et al: Atrazine-Induced Hermaphroditism at 0.1 ppb in American Leopard Frogs (Rana pipiens): Laboratory and Field Evidence. For Glyphhosate, see http://www.ncbi.nlm.nih.gov/pubmed/19539684: Gasnier, et al, Glyphosate-based herbicides are toxic and endocrine disruptors in human cell lines.

[15] http://ltras.ucdavis.edu/res/nutrition

[16] http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0012346

[17] http://www.sciencedaily.com/releases/2011/01/110116214603.htm

[18] http://www.grist.org/organic-food/2011-07-21-in-defense-of-organic

[19] http://www.stltoday.com/business/article_b503aada-7f4e-5ded-86d4-8eb0703ef7bb.html

[20] http://www.ers.usda.gov/data/biotechcrops/

[21] For the Philpott rebuttal, see: http://motherjones.com/tom-philpott/2011/07/organic-agriculture. For the original study, see: http://www.sciencemag.org/content/296/5573/1694

[22] http://www.rodaleinstitute.org/fst

[23] http://www.srfood.org/index.php/en/component/content/article/1174-report-agroecology-and-the-right-to-food

Related at Scientific American:

- Christie Wilcox - Mythbusting 101: Organic Farming > Conventional Agriculture

- David Ropeik - Food Fight: why are we so passionate about what enters our bodies

- Marie-Claire Shanahan - Science Education and Changing People’s Minds: Writing to convince

- Bora Zivkovic - Blogs: face the conversation

- Christie Wilcox - In the immortal words of Tom Petty: “I won’t back down”

- Pamela Ronald - Genetically engineered crops – what, how and why

- Janet D. Stemwedel - Environmental impacts of what we eat: the difficulty of apples-to-apples comparisons.

- Erin Prosser - Nutritional Differences in Organic vs. Conventional Foods: and the Winner is…

- Katherine Harmon - Going Organic Cuts Poultry Farms’ “Superbug” Bacteria in Single Generation

- Bora Zivkovic - Books: Michael Pollan – The Omnivore’s Dilemma

And more at Passions of Food—Special Day at #SciAmBlogs.