Monday, February 14, 2011

"Organic" Food, Part III

In previous posts I've addressed whether "organic" foods contain more nutrients or fewer toxins  than conventionally-grown foods.[1] The only claim made by "organic" farming left to consider is its impact on the environment versus conventional farming methods. This can be broken down into four sub-claims: that "organic" farming is better for the soil, produces less pollution,  increases biodiversity, and is sustainable. Let's see if it's true.

The third claim: Is "organic" farming better for the environment?
  • The first sub-claim: Is "organic" farming better for the soil?
"Organic" farming methods tend to be less damaging to soil fertility than conventional methods. First, the nitrogen and phosphorus added in manure and  urine is mostly contained within organic molecules—e.g. nucleic acids, proteins, and fats. Plants must wait for these compounds to be broken down by soil microbes before they can absorb them and use them.[2] Thus repetitive applications of manure and urine increase the total amount of nitrogen and phosphorus over time. Secondly, conventional farmers usually only apply nitrogen, phosphorus, and potassium (abbreviated as NPK); and to a lesser degree calcium, magnesium, and sulfur. Thus over time micronutrients (boron, chlorine, copper, iron, manganese, molybdenum, and zinc) are depleted from the soil. Only when crops start showing obvious deficiencies, do farmers apply other fertilizers. Micronutrients are naturally reapplied to "organic" farm soil in manure (including green manures) and are thus depleted less quickly. They are also depleted less quickly because of smaller harvest yields. So in general "organic" farming methods are less harmful to soil quality—simply because they're less efficient overall. And when you consider the environmental impact based on yield instead of based on acreage that benefit disappears.[3]

The answer: No.
  • The second sub-claim: Does "organic"" farming produce less pollution?
Run-off of nitrogen and phosphorus from agriculture is a contributor to the eutrophication (mouse-over for definition) of rivers, lakes, and even the ocean. This includes synthetic fertilizers used in conventional farming as well as the manures that "organic" farmers use to amend their soils. However, the pollution from manure is one-fifth that of chemical fertilizers applied at the same rate.[4] However, a recent report by the United Kingdom's Department for Environment, Food and Rural Affairs found that certain "organic" products produced more carbon dioxide, contributed more to eutrophication, required more water input, and used more energy (e.g. electricity, fossil fuels, etc.).[5] "Organic" farms also tend to burn more fossil fuels due to the use of mechanical equipment for tilling and weed removal.[6]

The answer: No.
  • The third sub-claim: Does "organic" farming increase biodiversity?
Evidence suggests that "organic" farming methods increase both animal numbers and number of species for plants, birds, mammals, invertebrates, and microbes.[7] In particular, the increase in earthworms seems to contribute positively to nutrient availability in "organic" farming systems. For a good overview of the impact of "organic" farming methods on farm biodiversity, see this Wikipedia article.

The answer: Yes.
  • The fourth sub-claim: Is "organic" farming sustainable?
"Organic" farms in developed countries enjoy protection from the conventionally-grown farms around them. Fewer total pests, fungi, and weeds in the area means they also have fewer pests, fungi, weeds—without having to do anything for it! (This also explains why they pick up synthetic pesticides even though they aren't the ones applying them.) Because their pest, fungi, and weed management is less effective, a higher percentage of food is produced that is "unsellable"—i.e. people won't buy it because it's scarred, damaged, discolored, etc. Sometimes, but not always, these can be sold to be used as ingredients for processed foods, such as crackers, sauces, etc., where the consumer doesn't see the condition of the food before processing. However, more of this food goes to waste.[8] I assume, however, that this unused food is composted, so it's not a total loss. This reduction in overall yield means that were "organic" farming to be implemented worldwide, even more land would have to be converted to agriculture. With the loss of the protection of widespread pest management, yields would drop even further, requiring even more land for crops. Which means damaging the environment. The way it is currently practiced, "organic" farming cannot produce enough food to feed the world population.[9]

The answer: No.[10]

The overall answer: No.[11]


[1] These posts can be read here (nutrients) and here (toxins).

[2] Incidentally, this is when those same nutrients leach out into the water supply.

[3] Tuomistoa, H. L. et al. (2012) "Does organic farming reduce environmental impacts? – A meta-analysis of European research." J Environ Manage, 112: 309–320.

[4] Kramer, S. B. et al. (2006) "Reduced nitrate leaching and enhanced denitrifier activity and efficiency in organically fertilized soils." Proc. Natl. Acad. Sci. USA, 103 (12): 4522–7.

[5] Foster, C. et al. (2007) "Environmental Impacts of Food Production and Consumption: A Report to the Department for Environment, Food and Local Affairs." (.pdf) Manchester Business School, Defra, London.

[6] Trewavas, A. (2001) "Urban Myths of Organic Farming." (.pdf) Nature, 410: 409–410.

[7] Invertebrates include insects, spiders, earthworms, and mollusks (slugs and snails). Microbes include bacteria, fungi, and nematodes. See Hole, D. G. et al. (2005) "Does Organic Farming Benefit Biodiversity?" (.pdf) Biological Conservation, 122: 113–130. doi:10.1016/j.biocon.2004.07.018

[8] Many of the high yields reported for "organic" farms have been inflated or misrepresented. See"organic-abundance"-report-fatally-flawed/. According to the paper cited in [6], "organic" yields are typically 50–70% of conventional yields. See also

[9] There is currently only enough manure produced each year to feed about one-fifth of the world population using "organic" methods. See However, this manure would have to be produced "organically", which would require that the animals consume only wild  browse or "organic" feed. The "organic" feed would require "organic" manure. And so on. This manure shortfall could be offset by using 'night soil', but that is fraught with danger (nor is it allowed under current "organic" standards).

[10] "Organic" farming methods have also been reported to stress aquifers—not good for the environment. See

[11] For a rebuttal to the concerns I've raised in these posts about "organic" farming, see "Organic Food and Farming: Myth and Reality" (.pdf). Note that it was prepared by the Soil Association and Sustain, two UK-based thinktanks which encourage "organic" farming methods. While some of their arguments are sound, many are emotionally based, appealing to the perception of what "organic" farming should be, not the reality of what it is. See also "Is Eating Organic BS?" (Part I and Part II), an article by a raw-food vegan which reviews an episode of Penn and Teller: B.S.! which offers some of the same rebuttals I've mentioned here. Note that he dismisses the idea that "organic" food tastes better than conventionally-grown food.

Image attribution:

Mountain wildflowers are by Alex Lovell-Troy, available at

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