Soil scientist goes myth-busting about feeding the world with fewer chemicals

Three big myths that impede our ability to restore degraded soils and feed the world using fewer chemicals are tackled in an essay in The Conversation, an online publication covering the latest research.

The essay, written by David R. Montgomery, has been reprinted in Scientific American (HERE).

Montogmery is a Professor of Earth and Space Sciences at the University of Washington in Seattle, where he is a member of the Quaternary Research Center. Wikipedia

One of the biggest modern myths about agriculture he now confronts is that organic farming is inherently sustainable,

It can be, but it isn’t necessarily.

Montgomery then addresses other issues which he says must be recognised to restore degraded soils to feed the world using fewer agrochemicals.

He embarked on a six-month trip to visit farms around the world to research his forthcoming book, “Growing a Revolution: Bringing Our Soil Back to Life.

The innovative farmers he met showed him that regenerative farming practices can restore the world’s agricultural soils.

In both the developed and developing worlds, these farmers rapidly rebuilt the fertility of their degraded soil, which then allowed them to maintain high yields using far less fertiliser and fewer pesticides.

Their experiences, and the results that I saw on their farms in North and South Dakota, Ohio, Pennsylvania, Ghana and Costa Rica, offer compelling evidence that the key to sustaining highly productive agriculture lies in rebuilding healthy, fertile soil.

But the journey also led Montgomery to question three pillars of conventional wisdom about today’s industrialised agrochemical agriculture:


Not so. He cites a recent UN Food and Agriculture Organization (report which says family farms produce over three-quarters of the world’s food. The FAO also estimates that almost three-quarters of all farms worldwide are smaller than one hectare – about 2.5 acres, or the size of a typical city block.

Of course the world needs commercial agriculture, unless we all want to live on and work our own farms. But are large industrial farms really the best, let alone the only, way forward?


While mechanisation can provide cost and labor efficiencies on large farms, bigger farms do not necessarily produce more food. Large farms excel at producing a lot of a particular crop – like corn or wheat – but small diversified farms produce more food and more kinds of food per hectare overall.


The most extensive yield comparison to date, a 2015 meta-analysis of 115 studies, found that organic production averaged almost 20 per cent less than conventionally grown crops, a finding similar to those of prior studies.

But the basis for claims that organic agriculture can’t feed the world depend as much on specific farming methods as on the type of farm.

Moreover about a quarter of all food produced worldwide is never eaten. Each year the United States alone throws out 133 billion pounds of food, more than enough to feed the nearly 50 million Americans who regularly face hunger.

So even taken at face value, the oft-cited yield gap between conventional and organic farming is smaller than the amount of food we routinely throw away.

In the upshot, Montgomery says he no longer sees debates about the future of agriculture as simply conventional versus organic.

He now sees adopting farming practices that build soil health as the key to a stable and resilient agriculture.

And the farmers he visited had cracked this code, adapting no-till methods, cover cropping and complex rotations to their particular soil, environmental and socioeconomic conditions.

Whether they were organic or still used some fertilizers and pesticides, the farms I visited that adopted this transformational suite of practices all reported harvests that consistently matched or exceeded those from neighboring conventional farms after a short transition period.

Another message was as simple as it was clear: Farmers who restored their soil used fewer inputs to produce higher yields, which translated into higher profits.


Organic not the only ingredient in recipe for sustainable food production

A new UBC study published in Science Advances finds organic thinking alone is not necessarily better for humans and the planet.

Organic is often proposed a holy grail solution to current environmental and food scarcity problems, “but we found that the costs and benefits will vary heavily depending on the context,” said Verena Seufert, a researcher at the Institute for Resources, Environment and Sustainability (IRES).

Seufert and her co-author, Navin Ramankutty, Canada Research Chair in Global Environmental Change and Food Security at UBC, analysed organic crop farming across 17 criteria such as yield, impact on climate change, farmer livelihood and consumer health.

It is the first study to systematically review the scientific literature on the environmental and socioeconomic performance of organic farming, not only assessing where previous studies agree and disagree, but also identifying the conditions leading to good or bad performance of organic agriculture.

Two factors that are top of mind for many consumers are synthetic pesticide use and nutritional benefits of organic. Seufert and Ramankutty argue that in countries like Canada where pesticide regulations are stringent and diets are rich in micronutrients, the health benefits of choosing organic may be marginal.

“But in a developing country where pesticide use is not carefully regulated and people are micronutrient deficient, we think that the benefits for consumer and farm worker health may be much higher,” said Ramankutty, professor at IRES and the Liu Institute for Global Issues at UBC.

Another important measure of the sustainability of farming systems is the yield of a crop. To date, most studies have compared the costs and benefits of organic and conventional farms of the same size, which does not account for differences in yield.

Previous research has shown the yield of an organic crop on average is 19 to 25 per cent lower than under conventional management. Seufert and Ramankutty find that many of the environmental benefits of organic agriculture diminish once lower yields are accounted for.

“While an organic farm may be better for things like biodiversity, farmers will need more land to grow the same amount of food,” said Seufert. “And land conversion for agriculture is the leading contributor to habitat loss and climate change.”

The findings suggest that organic alone cannot create a sustainable food future. The authors nevertheless conclude it still has an important role to play. Buying organic is one way that consumers have control over and knowledge of how their food is produced since it is the only farming system regulated in law.

“We need to stop thinking of organic and conventional agriculture as two ends of the spectrum,” said Seufert.

Instead, consumers should demand better practices for both so the world’s food needs can be met in a sustainable way.

‘Organic’ milk is poorer in iodine than conventional milk

Milk from organic farms has a lower concentration of elements like zinc, iodine and selenium than milk produced by conventional farming methods.

A news item from the Alpha Galileo Foundation says the discrepancy is due to the absence of mineral substances in the diets of the cows reared.

Researchers are quoted as saying animals on organic farms should have their diets supplemented with natural sources of iodine such as seaweed, because it is an important element for children and pregnant women.

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