I am proud to take part in Blog Action Day Oct 16, 2011 www.blogactionday.org

Today marks Blog Action Day 2011 — an annual event that unites the world’s bloggers around the same issue. This year’s topic? FOOD. Cool Green Science asked Joe Fargione, lead scientist with The Nature Conservancy’s North America Region, to share his thoughts on a food topic we’re often asked about: is organic food better for the environment? Here Joe explains the trade-offs between buying organic foods and using less land through conventional farming practices.

Growing crops has several impacts on the environment. Crop production takes land, water and other inputs which can include synthetic fertilizers, herbicides and pesticides (all of which can be either synthetic or natural). Let’s discuss each in turn.

Organic crops do generally have lower yields and therefore require more land. This has been shown in randomized experimental designs and on real farms. In 2008 the United States Department of Agriculture conducted its first ever survey of organic producers, collecting data on acreage and production from over 20,000 organic farms.

The results of this survey were published in 2010, allowing a comprehensive, crop by crop, comparison of yields between conventional and organic production for the first time. The data are conclusive: comparing 62 crops – from almonds to watermelons – conventional yields are 10%-360% higher than organic yields.

There are a few (four) exceptions: organic tomatoes, sweet potatoes, canola and hay are higher yielding than their conventional counterparts.

This means that if all of our crops were organic, they would take substantially more land. For example, if all of the corn grain, winter wheat and soybeans in the United States were grown organically, it would require about 93 million more acres of farmland, a 30% increase in total crop acres.

Of course, if you want to reduce the amount of land required to produce your food, you can always eat less meat or buy grass-fed meat. Grain-fed meat production requires a lot of land – over a third of all cropland in the United States is used to produce livestock feed and forage – so eating less meat means using less land. And grass-fed beef, bison or other free-ranging livestock require grasslands for grazing, and these grasslands often provide habitat for lots of species – its own form of habitat preservation.

For water use, I’m not aware of studies comparing conventional and organic farming. But since organic certification doesn’t require lower water use, I see no reason to expect any difference between water usage in organic versus conventional crops. Similarly, both conventional and organic methods can cause soil erosion that contributes to sediment pollution in rivers. One of the best solutions to sediment pollution is no-till farming. But organic farmers have traditionally used tillage as a form of weed control, making it difficult for them to switch to no-till farming.

Organic crops use manure fertilizes, which unlike synthetic fertilizers, contain organic matter that helps build soils. But both organic and synthetic fertilizers can contribute to run-off of nitrogen and phosphorus into streams and rivers. Synthetic fertilizers tend to cause more nitrogen pollution to surface and groundwater, whereas manure application tends to cause more phosphorus pollution to surface waters.

It should be noted that both types of fertilizers can be applied responsibly by using the correct amount of fertilizer at the correct time and using tillage practices and buffer strips that slow runoff and reduce the loss of nutrients from farm fields. One challenge particular to manure fertilizers is that the ratio of phosphorus:nitrogen is high compared to the demands of the crop, so that if you add enough nitrogen you are likely to add too much phosphorus.

When it comes to toxic pesticides, organic farming is the clear winner. In a comprehensive nationwide USGS study of 186 streams and over 5,000 shallow wells, pesticides (or their byproducts) were detected in every stream and more than half of shallow wells in agricultural and urban areas. Conventional agriculture used 877 million pounds of pesticides in 2007, the last year for which data are available.

Pesticides kill significant numbers of birds and other non-target species each year. In addition, these pesticides are generally not good for anything that lives in or drinks water.

For example, the European Union ranks pesticides according to their impacts to aquatic organisms; essentially all of our conventional pesticides are considered either harmful, toxic, or very toxic to aquatic organisms. Encouragingly, conventional agriculture has doubled the proportion of pesticides that are only “harmful or toxic” from 20 to 40% between 1999 and 2007 (reducing the proportion of “very toxic” pesticides from 80 to 60%). And the total amount of pesticide that is used every year decreased by 8% between 1999 and 2007, even though food production has increased. But on balance, conventional food can’t compete with organic food when it comes to environmental impacts of pesticide use.

Life is full of tradeoffs, and this is no exception: Organic foods require more land, but don’t use synthetic pesticides.

CSA vegetables

(Graphic courtesy of Blog Action Day. Image: CSA vegetables. Source: thebittenword.com via a Creative Commons license).

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Comments

  1. I am disappointed to find this article lacking in some key respects in its discussion of organic farming. It seems to assume that organic farming shall replace a conventional farming model in scope, in that food should continue to be grown on huge scales and by large, mechanized operations. Organic farming in small-scaled, family and community-oriented farms is much more efficient than any giant-scale farming operation, because you are using human labor that responds to specific conditions in micro climate (aka – the gardener/farmer can go out and check the soil, only watering when needed). In addition, small-scale farming can be done on spaces that are otherwise unusable for other things such as development (for example, hillsides or other infrastructure in cities). This could greatly improve the efficiency of land and create economies of scale in local markets while making up for any need for additional land to produce the same amount of produce as is being churned out by conventional, oil-intensive farms. We need a MUCH more in-depth and nuanced analysis to make the conclusion that this author has made.

  2. I’m for bio-dynamic as the preferred method of farming. Second is organic combined with eating less which would cure a lot of other ills in this country. We could also use better planning in terms of human population.

  3. How would compare organic vs conventional when it comes to preserving biodiversity of crops. I find conventional farm crops are of only a few varieties, while organic farms have more of a diversity of crops. Also, when you compare the two are you comparing large corporate farming operations or smaller family type farms? There is a huge difference in the way these two types of farms operate. Corporate farms that are organic or conventional tend to be more harmful to the environment due to use of more land, pest controls,etc. Would smaller, better managed farms of both kinds contribute less damage to the environment?

  4. This article is missing a huge point on the use of organic versus synthetic fertilizers. Synthetic fertilizers use the haber Bosch process that uses a large amount of fossil fuels to turn nitrogen into bioavailable forms that the plants can use. So organic farming is not just about using less pesticides, but also about using less nonrenewable fuels.

    Also genetic engineering is not mentioned at all.

  5. I am assuming the estimated difference in yield is based on mono-cultures and yield by weight rather than nutritional value. Organic poly-cultures produce greater nutritional value per unit of land than do mono-cultures, while building soil faster, especially if mushrooms are included in the poly culture. It would be interesting to see what the estimated difference in land use would be with these factors in mind.

  6. Who wrote this ~~ someone from Monsanto? We’re being poisoned to death by agribusiness, and you say that duh well it takes more land to remain unpoisoned? Good grief. Do you think we’re all a bunch of numchucks?

    I’ve heard that agribusiness is buying out all the little organic businesses. Apparently it’s also bought out the Nature Conservancy.

  7. Why stop at organic food? Yes, it is more widely available and accessible now than ever but let’s continue to educate on even more ecological food production strategies that are also becoming more available throughout the U.S. through farmers markets, community gardens, and community supported agriculture groups. Small-scale agriculture requires intensive management practices that actually increases yields/acre. And many of these small scale farmers don’t use synthetic chemicals either, even if they’re not certified organic. Furthermore, locally-grown and distributed food does not require nearly the amount of the gasoline that is necessary to transport conventional products all around the world. Organic ag had its day when people used drastically different methods from conventional ag, but now they are basically one in the same. If we are really looking for food that doesn’t decimate our environment to produce it, we need to move away from large-scale, corporately controlled monocultures entirely.

  8. Organic foods require more land, but don’t use synthetic pesticides — I disagree, ever heard of the method that promises higher yield without the need to eat up more land? Perhaps you should read this: http://www.rodaleinstitute.org/20040401/Hamilton

    I rather feel uncomfortable at how this article was written. There are several methods of organic farming available. I’m sorry, but this article is disappointing.

  9. A recent study released by the International Journal of Biological Sciences found that Monsanto’s GM Corn causes liver and kidney damage in lab rats. Monsanto only released the raw data after a legal challenge from Greenpeace, the Swedish Board of Agriculture, and French anti- GM campaigners. I’m sure the corn is fine to feed to our cattle or eat ourselves though. Right? You can take action by staying informed and spreading the word at http://geneticallyengineeredfoodnews.com

  10. WTF! Are you out of your mind?
    Organic farming is better for the whole plant, people animal and earth. How can you even suggest that agribusiness is a beter option as we can all see that it screws up everything? It is not healthy, it’s bad for environment….even the taste is not good.

  11. My father is an organic farmer. I’m glad we’re getting healthy foods without any cost.

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