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Organic farming can feed the world — until you read the small print

By Mark Lynas

Picking organic basil. Photo by Organic Farming Research Assocation

A Europe-based research team made headlines last week with its conclusion that organic farming can feed the world after all. However, few people took the time to read the small print in their paper, which shows that the researchers' conclusion depends on several highly questionable assumptions.

"A worldwide conversion to organic farming can contribute to a comprehensive and sustainable food system, if combined with further measures," read the lead of the press release issued by the Research Institute of Organic Agriculture, whose staffers — led by Adrian Mueller — made up most of the co-authors of the accompanying paper, “Strategies for feeding the world more sustainably with organic agriculture.”

Mueller et al. use a food systems computer model to assess the environmental impacts of a theoretical conversion of world agriculture to 100 percent organic. This shows, based on estimates culled from the existing scientific literature, that global organic conversion would lead to a 16-33 percent increase in land use, with a corresponding 8-15 percent increase in worldwide deforestation.

So how do the authors achieve their headline conclusion? By combining a worldwide conversion to organic agriculture with a heroic parallel worldwide conversion to vegetarianism, allowing them to assume (in some scenarios) a 100 percent reduction in land-area competition from animal production. This is combined with a similarly heroic 50 percent reduction in global food waste.

The flaws in this logic are readily apparent. It is like arguing that smoking is good for your health if you reduce your exposure to other carcinogens sufficiently to offset the higher chance of cigarettes giving you lung cancer. Well, OK, but wouldn't it be better to not smoke and also avoid the other carcinogens too?

In other words, what the researchers actually show is that 100 percent conversion to organic can only feed the world if two — frankly impossible — other conditions are met. That gives a very different headline from the one they chose to lead their study with.

The problem is that however desirable vegetarianism might be both environmentally and for human health, global consumption of animal products is going up not down as developing countries achieve higher standards of living. And the food waste issue is incredibly complex and intractable. Just think how much food each one of us throws away and why.

A better option would surely be to retain the yield and land-use improvements of conventional agriculture, and combine these with efforts to reduce waste and increase vegetarian diets in order to spare even more land for nature. With habitat loss being the major cause of biodiversity declines, this is surely the most environmentally-friendly approach.

But the Mueller et al. paper carries another — potentially even more fatal — flaw, one that the authors do not sufficiently address. Most of the literature on which their model is based assumes the continued existence of what I call “laundered nitrogen,” which seriously biases existing assessments of organic vs. conventional crop yield gaps.

This happens because the vast majority of existing organic crops depend on imported nitrogen “laundered” from animal manures. This nitrogen is ultimately derived from artificial fertilizers used to grow crops to feed the animals on conventional farms. In a worldwide organic scenario envisioned by the researchers, this would not be possible, so the nitrogen scarcity would be critical.

This would lead to worldwide famine. In one of the few attempts to quantify this impact properly, Vaclav Smil concluded that only about half the current world population can be supported without the Haber-Bosch process for artificial nitrogen fixation. Mueller et al. do show a substantial “nitrogen deficit” for a 100 percent organic planet, but argue that this is a good thing because it reduces greenhouse gases and pollution of water systems.

Organic farms benefit from 'halo effect'  in controlling pests. Photo by Genetic Literacy Project

A similar challenge applies for synthetic pesticides, which are noisily avoided in organic farming. To my knowledge, none of the published studies account for the “halo effect” of existing synthetic pesticide use, which helps protect neighboring organic farms from severe pest outbreaks by area-wide suppression of pest populations.

The same goes for diseases. Currently the biggest threat to global harvests is probably wheat rust, a devastating fungal disease of wheat. Rust is now controlled by the application of fungicides. Without these chemicals huge outbreaks of rust would likely occur, and the spores would travel great distances on the winds, quickly affecting harvests globally.

Organic farmers can use non-synthetic pesticides such as copper and sulphur-based compounds (which can, in fact, be more toxic than their synthetic alternatives, though that's a different story), but these products would struggle to prevent worldwide food shortages.

As with nitrogen, most existing assessments of organic farming productivity, as the Australian agricultural scientist David Connor has written, "confuse yield of individual crops with that of production systems." In reality, as Connor argues, a 100 percent organic planet would either mean halving the world's population or doubling cropland use. Famine or environmental devastation — you decide!

Ironically, organic practitioners have rejected what might be the only way of getting out of this conundrum. As Michael Le Page has pointed out in New Scientist: "This divide will become ever greater in the future, because the organizations that set the rather arbitrary standards for what counts as 'organic' have firmly rejected the technology showing the greatest promise for reducing farming emissions: genetic modification."

The examples are many and obvious. Blight-resistant potatoes, now available in Canada and the US and close to becoming available elsewhere, allow for blight control with less fungicide applications. Insect-resistant Bt crops, which have been around for decades, have led to big drops in insecticide applications.

GMOs have therefore likely already done far more to reduce pesticide use than organic farming — while not having the drawback of lower yields — although I'm not aware of anyone having published an explicit comparison.

And developments in prospect could help even more. Here at the Alliance for Science we have already written about how boosting photosynthesis with genetic tweaks could drastically increase crop productivity, and how researchers are aiming for staple non-legume crops that could fix their own nitrogen.  

Organic organizations have unfortunately also come out against new gene editing techniques, although bizarre organic standards allow the use of seeds developed using the much blunter instruments of radiation or chemical mutagenesis.

In a logical world, organic and conventional farms would be able to cross-fertilize and learn from each other while benefiting from scientific innovations such as genetic modification. Regrettably, the polarizing effect of the organic label continues to be a hindrance rather than a help in the search for more sustainable agriculture.

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