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    Serial Blind-Spot For Organic Advocates
    By Steve Savage | June 13th 2013 10:54 PM | 13 comments | Print | E-mail | Track Comments
    About Steve

    Trained as a plant pathologist (Ph.D. UC Davis 1982), I've worked now for >30 years in many aspects of agricultural technology (Colorado State...

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    Researchers affiliated with the Institute of Organic Agriculture in Switzerland and the Institute of Agricultural Sciences in Germany published a meta-study in which they conclude that organic farming methods lead to higher rates of carbon sequestration in soils.  This work was well done and published in a well respected journal, PNAS.  Unfortunately the ramifications of the paper are being badly misinterpreted by environmental and food bloggers who are organic advocates.  The scientific authors make no claim that their analysis is a full, net carbon footprint measurement, but it is being interpreted that way by others.  Building up soil carbon is a very good thing to do, and organic methods were the state-of-the-art method for doing that from around the 1920s to the 1960s.  However there are newer and better ways to improve soil quality on farms, and they don't have the huge carbon footprint problem that is common in organic - emissions of the potent greenhouse gases methane and nitrous oxide which have 21 and 295 times as much greenhouse gas effect as carbon dioxide respectively.

    All forms of farming including organic can lead to soil emissions of these gases, particularly the nitrous oxide.  Those are best managed by the new farming methods I mentioned above.  The issue that is problematic for organic are emissions of those gases associated with composting.  To borrow a line from Al Gore - this is "an inconvenient truth" about organic.  This inconvenient truth is that any significant adoption of the compost-use feature of organic farming would be an environmental disaster.

    I have written about this a few times before, but because of the misinterpretation of this study I want to reiterate that this is a clear-cut issue where organic is problematic. The common failure to recognize this very important issue leads to misguided policies and people believing that they are doing something very "green" when in fact the opposite is true.

    I have done quite a bit of carbon footprint analysis regarding agriculture over the years as part of my paying job as a consultant.  That has given me the opportunity to read extensively from the scientific literature on this topic and on life cycle assessments (LCAs) in general.  From that work I came across a body of literature concerning greenhouse gas emissions during composting (I'll put a list of papers at the end of the post).  The goal of composting is to keep things aerobic (with oxygen), but inevitably, even in the best managed composts there are micro-sites that are anaerobic (no oxygen) and under those conditions some microbes generate methane or nitrous oxide.  The numbers are not small.  In one typical study of this type the carbon footprint of the finished compost ranged from 1,769 to 2,167 pounds of CO2 equivalents per ton.  Since compost is applied at rates such as 4 to 10 tons per acre, that means 7-22,000 lbs of CO2 equivalents for each organic acre.  The middle of that range is like driving a 25 mpg car 13,982 miles or fertilizing 12.9 acres of corn at 200 lbs of synthetic nitrogen/acre.  It would be equivalent to growing, handling and transporting 9,641 lbs of bananas from Costa Rica to Germany.  This is a major reason that it is a good thing that organic remains such a small part of agriculture.

    The Serial Blindspot

    The false assertion that organic is better from a climate change perspective keeps coming up over and over again.  In this case it was through misinterpretation of a good paper.  The more problematic examples have been claims from generally credible organic groups - the US's Rodale Institute and the UK's Soil Association.  Each organization has published white papers claiming that organic is a solution to climate change.  In both analyses, the authors completely ignore the issue of greenhouse gas emissions from composting as well as other parts of organic farming (e.g. there are even more emissions once the compost or manure is incorporated in the field).  I've corresponded with the authors in both cases and they have not been able to dispute my points.

    Why Does This Matter?

    So, what sort of policy and thinking problems arise from the promotion of this false impression about organic?  One example would be the US government spending money to encourage more farmers to adopt organic practices.  Another would be the many consumers who spend more believing that they are doing the green thing by buying organic (There are also several other reasons that is not true).  Another would be other consumers who unnecessarily feel guilty because the don't want to spend so much.

    I think the most absurd example is San Francisco's much touted food waste recycling program .  Sending food waste to a landfill is definitely bad, but the best solution is for people to grind it up in their disposal, send it into the sewage system, and for the treatment plant to convert it to renewable, carbon-neutral energy using an anaerobic digester (most advanced sewage treatment districts do this now).  But perhaps the San Francisco sewage system can't handle that volume.  In any case, what they do is to drive heavy trucks up and down the famously steep hills of the city collecting the scraps.  Then they drive the heavy loads 50 miles to a composting facility in Vacaville.  There they generate the trace gases in the process I've described above.  Then they load the heavy compost back into trucks and haul it 50 to 100 miles to organic vineyards who then claim to be doing something sustainable.  That is pretty absurd.

    I'm sure this won't be the last time that people will make unfounded climate change mitigation claims for organic.  It won't be the last time I try to explain why they are not true.

    You are welcome to comment here and/or to email me at savage.sd@gmail.com   I tweet a bit @grapedoc.  Organic farm image from wikimedia commons.  Composting in the UK image also from wikimedia commons.

    References:

    Hao, X., Chang, C., Larney, J., Travis, G. 2001Greenhouse gas emissions during cattle feedlot manure composting. Journal of Environmental Quality 30:376-386.


    Osada, T., Kuroda, K., Yonaga, M. 2000 Determination of nitrous oxide, methane, and ammonia emissions from swine waste composting process.  Journal of material cycles and waste management 1:51-56


    Hellebrand, H.1998. Emission of nitrous oxide and other trace gases during composting of grass and green waste. Agric. Engng Res. 69:365-375 


    Sommer, S., Holler, H.2000. Emission of greenhouse gases during composting of deep litter from pig production – effect of straw content. The Journal of Agricultural Science 134_327-335


    Hao, X., Chang, C., Larney, F. 2004. Carbon, nitrogen balances and greenhouse gas emission during cattle feedlot manure composting.  Journal of Environmental Quality 33:37-44


    Jackel, U., Thummes, K, Kampfer, P. 2005Thermophilic methane production and oxidation in compost. FEMS Microbiology Ecology 52:175-184. (looking for microbes which might help reduce the methane emissions from composting)


    Hellmann, B., Zelles, L., Palojarvi,A, Bai, Q. 1997.  Emission of climate-relevant trace gases and succession of microbial communities during open-windrow composting.  Applied and Environmental Microbiol 63:1011-1018









    Comments

    Bonny Bonobo alias Brat
    Steve, I'm confused because this Pesticide Action Network Europe Climate Change and Agriculture fact sheet disagrees quite a bit with what you are saying here. They say that 'agriculture is a major contributor to climate change. According to the International Panel on Climate Change it accounts for up to 12% of all man-made greenhouse gas emissions.' However they then go on to say :-

    'How does agriculture contribute to climate change? The use of synthetic nitrogen fertilizer is the biggest contributor to climate change in agriculture owing to the potent greenhouse gas N2O (nitrous oxide). Enteric fermentation (methane from cows and sheep) is the second largest source because cows and sheep digestive tracts produce CH4(methane) through anaerobic fermentation.'

    'A major agriculture-related source, and on an even larger scale, is land conversion. For the most part,extensive grasslands (6m hectares a year) and forests (7m hectares) are converted to crop land. The loss of CO2 into the atmosphere above ground (trees and plants) and underground (soil organic matter) is enormous. Peat soils in particular carry huge loads of soil organic matter which is released under crop growing over subsequent decades'.

    They then say that agriculture can help reduce climate change:-
    'The only way to halt the release of climate gases caused by land conversion is to halt land conversion and forest destruction.This means our consumption, especially in the rich countries, must be reduced to curb pressure on newly converted land. Meat consumption must be slashed because meat production draws heavily on feed production which consumes huge areas of land (eg soybeans and corn). First generation biofuel production must also be abandoned as it combines huge land-use and offers no real carbon gain.'

    They say that the Fourth Assessment of the IPCC (2007) recommends mitigation measures on:-
    • crop rotation and design
    • nutrient management
    • livestock growing
    • maintaining fertile soils

    'The manufacture and application of pesticides represents a tiny proportion of fossil fuel use and
    greenhouse gas emissions in farming, compared with fertiliser use. But reducing our reliance on
    synthetic fertilisers in European farming and replacing them with animal manure, compost, green
    cover crops and more legumes in crop rotation would also help reduce our reliance on pesticides.
    This is because increasing the soil’s organic matter from natural sources increases the number of
    beneficial micro-organisms in the soil, which helps crops cope better with disease-causing organisms.'

    'Excessive use of synthetic fertilisers often produces lush crop foliage which attracts more pests and
    diseases, leading farmers to apply more insecticides and fungicides. Managing soil fertility more
    carefully and cutting back hard particularly on nitrogen-based fertiliser, can help produce a healthier,
    more robust crop, resulting in a virtuous circle.'

    'A study by Niggli et al, ‘Low greenhouse gas agriculture’, published by the FAO, May 2009, shows that full transition to organic agriculture would completely re-balance all of agriculture’s negative climate change effects. The potential of, eg, leguminous inter cropping (saving 140 megatonnes of nitrogen per year) is far greater than the complete industrial production of nitrogen (90-100 megatonnes per year). No tillage is another important mitigation measure.'

    What do you think about what they are saying? Is that study by Niggli et al at all credible?
    My latest forum article 'Australian Researchers Discover Potential Blue Green Algae Cause & Treatment of Motor Neuron Disease (MND)&(ALS)' Parkinsons's and Alzheimer's can be found at http://www.science20.com/forums/medicine
    Thank you Helen, for your reasonable response. Steve's article does not speak truth.
    RC

    sdsavage
    Niggli did not factor in the composting emissions which, on a per acre basis, are far larger than any of these other sources.  Yes, nitrous oxide can be major depending on a whole host of factors, but organic has the same issue - just often later in the season when the nutrients are being mineralized after the crop is needing them.  Methane from paddy rice culture is also very big and from enteric fermentation.  The best thing is to develop well aerated soils which is best done with no-till and cover cropping.  The use of controlled wheel traffic is also key - auto-steering of the equipment so that no wheel ever goes over most of the field area.  Then if the nitrogen is placed in that well aerated zone and particularly if it is precision variable-rate applied, nitrous oxide can be seriously reduced.  Also, conventional farmers have the option of applying nitrification inhibitors that further reduce it.    The carbon footprint of making the nitrogen can be eliminated with new technologies coming out to use something like wind power at the farm level to run the Haber-Bosch method on a small scale.   Legumes are great, but if they are tilled into the soil (as is done in organic when they grow a "green manure crop," then there are major methane and nitrous oxide emissions.
    This is a very complex area and one has to read scores of papers to get the whole picture.  I look to people like Rattan Lal of Ohio State, a soil scientist and a Nobel Prize winner for his work on the carbon footprint of agriculture.  Also there is a multi-stakeholder sustainability metric organization called Field To Market which has used the extensive USDA crop statistics database and used peer reviewed models to estimate GHG and other parameters for major US crops:

    http://www.fieldtomarket.org/news/2012/field-to-market-releases-national...


    What it shows is steady progress in the reduction of GHG, energy, water and other measures over time on a per bushel basis.  There is still much room for progress because not all farmers are using those ideal practices I mentioned.  However, the biggest barrier to doing so is that even though they make good economic sense in the long run, most farmland is rented on an annual cash basis.  Making a 5-7 year investment in soil improvement isn't practical if you know that any year you might be out-bid for a given field.  That is why the key lies with educating the owners of the land that it would be in their long-term interest to make leases designed to build soil quality.  Those owners are mostly city-dwelling folks whose families once owned the farmland.  They mostly just let a property management company handle things and pay not attention except to getting their check!
    Steve Savage
    Helen

    Simplest answer is that PAN is not an science entity, they are a political change activist entity.

    sdsavage
    Scott,Yes, that is true.  A veneer of science does not a scientist make
    Steve Savage
    Steve,

    It seems misleading to apply statements such as "The false assertion that organic is better from a climate change perspective keeps coming up over and over again" to the entirety of Organics in lieu of providing commentary addressing that some implementations of Organic methodologies can indeed yield such Carbon emissions. I appreciate that you referenced no-till and cover cropping, practices widely used by the Organic farmers in my area, but it seems you may have overlooked reference to Aquaponics in the other methods and linked articles you've suggested. Solely looking at the issue of Climate Change, it appears that an Organic methodology is in fact better than commercial implementations as I've yet to find someone capable of adequately dismissing the benefits of such systems in their reduction/balance in impact with regards to Carbon, or the fact that such methodology also uses significantly less water than commercial agriculture. I'm happy to rectify my views if you've convincing evidence otherwise.

    -christopher gillespie

    Hank
    There is no way organic food is even close to environmentally responsible. In order for it to come close, you have to cherry pick results. The drop in yield is 25% if we are lucky and 34% when accurately compared. Much of the emissions-related work in all food is identical so growing 25% more is simply 25% more environmental damage.

    Organic food is fine for what it is, I buy it too, but growing organic uses less water?  What?? There is no difference at all in the water requirement of an organic carrot versus a regular carrot, modern farming just allows food to be grown in what were once poor agricultural areas and that sometimes takes more water, but that is not a global warming, or even an environmental, problem. We're not running out of water.

    Making vague, unsubstantiated claims about how superior your beliefs are and then demanding data to refute it isn't really a constructive argument.
    Hank
    You'll forgive me if I don’t write a new article debunking this nonsense yet again but you'd spend 5 seconds Googling for some confirmation bias and declare it all invalid anyway. 
    Hank,

    You make me laugh with your spurious conjecture.

    Steve provided a blanket statement on Organics that was Fallacious, and you did not adequately come to his defense. There is no need to cherry pick results as you claim, proper implementation of techniques enough to suffice.

    If you aren't deliberately attempting to misrepresent what I've said, you appear to have misunderstood Aquaponics entirely; Such methodology utilizes about a tenth of the water of commercial agriculture. As for your belief that water usage doesn't play a part in affecting climate, you're underestimating the situation. Water doesn't just show up where you need it in a limitless supply; It has to come from somewhere. Georgia has been experiencing such drops in the levels of Lake Lanier that we've been eyeballing the water supply of Tennessee for awhile; The same can be said for many regions looking to their neighbors around the world. Ever been to Las Vegas? Every hotel room has a note about limited water. The time, effort, and expenditure to transport water in one form or another is further hastening change in climate through emissions, be it to pay for pipe construction, truck transport, or elsewise. If we instead used 1/10th of the current water usage to produce our food, most people would look at that math and call it a good thing.

    So what do we have as far as Organics? A closed system, that uses less water while ALSO not requiring a bunch of fertilizers. Aquaponics also doesn't need to poison large swaths of land with runoff, and it can be deployed anywhere, including Urban environments; It can even be utilized in conditions that aren't otherwise amenable to growth through implementation indoors with Shipping containers or warehouses, such that food can be produced locally for every human settlement. Food grown locally like this is great because there isn't the additional transport cost and loss of nutrients that would otherwise be seen in several days of movement across country.

    Were someone to otherwise read Steve's commentary, it does appear pretty sound overall. However, the fact that he applies his assertions en masse to Organics begs the clarification lest he misrepresent the Organic movement and himself. I already made a point of recognizing that not all Organic methodology is perfect, but this article otherwise neglects proper representation of the fact that Organic is better than 'traditional' Commercial means for the environment when more properly applied.

    sdsavage
    Christopher,I'm sure you are aware that there are some in the hard-core organic camp who don't consider aquaponics to be really organic because there is no soil.  In fact there are some organic greenhouses that intentionally expose themselves to the pest potential of soil just to satisfy that ideological demand.

    There are a great many greenhouse operations that do not require the use of any pesticides because they are sufficiently sealed-off from pest populations.  Most don't call themselves organic and thus are able to use the most cost-effective forms of soluble fertilizers.  Like the operation you describe, they are extremely efficient in utilization of land, water, fertilizer and labor time.  Many use waste head and LED lighting to be highly energy efficient.


     It is a wonderful solution for the production of certain crops of high enough value and long enough harvest span to justify the capital expense.  That is great and it is a rapidly expanding part of ag.  It will not; however, ever be the way we produce foods like staple grains, pulse crops, and animal fodder and feed.  For those crops, Organic still only represents something like 0.2% and the food companies that use them are increasingly sourcing them from seriously sketchy sources in China etc. 

    Steve Savage
    Hank
    Right, I gave up replying to him. Anyone who has a pet cause they are advocating and puts blinders on about its viability is being silly. I am constantly impressed by your patience, however.
    Thor Russell
    A bit off topic, but talking of water its been in the news lately that fish farming is expanding massively lately. Does anyone have any idea of its long term potential and perhaps ability to displace/reduce stress on growing animals for food on land? This doesn't seem to be mentioned that much in "how do we feed people in 2050" type articles.
    Thor Russell