Letter From The Editor - Issue 69 - June 2019

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  Science Fact-ion by Randall Hayes
April 2018

Don't You Dare Call it 'Dirt'

“I believe in the future of agriculture,
with a faith born not of words but of deeds . . .
in the promise of better days through better ways,”
-- creed, Future Farmers of America

The FFA was a big thing where I grew up in Kentucky. Those iconic blue corduroy jackets with the gold embroidery were at least as common in my high school as the letter jackets the jocks wore. I was never a member, but my younger brother was, and one of my favorite cousins still teaches agriculture there and runs the local chapter. The organization these days is training roughly 650,000 young people for 210 different careers, with the overall goal of feeding 9 billion Earthlings by 2050.

Although my personal contributions to that goal are currently limited to a few fruit trees and berry bushes in my suburban yard, I'd like to use this Earth Day column to address a specific issue: soil science. Space farming and the future of food more generally have been hot topics lately, and I'll defer to that coverage.

My family's immediate agricultural tradition goes back a couple of generations. As soon as my grandfather saved up enough money, he quit mining coal and started farming (not soon enough to avoid the blacklung, but that's another story). Ironically, although the tools were different, the mindset was more or less similar. American farmers at the time were essentially mining the soil for food, not feeding the soil in a symbiotic partnership. That's how my dad still thinks of it, despite nearly a century of no-till evangelism from the Soil Conservation Boards set up by the feds during the Dust Bowl. In fact, as soon as the contract for maintaining a riparian buffer along the creek ran out, he and my brother opened the fence to allow their cattle into the woods to “clean them up.”

That mental model of farmer as dirt-miner is slowly changing as we learn more about soil. It's such a short, simple word for an intricate 3-dimensional system containing three phases of matter: solid mineral particles of different sizes, a liquid phase of chemicals dissolved in water, and a complex mixture of gases, prevented from equilibrating by being separated into lots of little pockets distributed throughout the matrix. Soil science has exploded in the past couple of decades, once we realized that under the right circumstances, the stuff is alive.

There can be more species below ground than above. Root-chewing insects and nematode worms are a big component of that diversity, but there are many others. Fungi coat and even interpenetrate the root hairs of plants, trading minerals for sugar sent down from the plants' leaves. Bacteria, many of whom are still unidentified because they won't grow on simple solid agar plates in an incubator, are down there doing something called quorum sensing—passing chemical messages back and forth to coordinate their political and genetic campaigns for dominance. All of this was hard to see until a Scottish group invented a transparent polymer substrate that would mimic enough of the properties of soil to simulate an almost-natural root zone. Now they can watch it all happen with light and fluorescent optical probes, like Avatar in the lab.

David Montgomery is a geologist who won a MacArthur fellowship for promoting awareness of the soil conservation crisis through numerous books and a movie called Dirt (a word that drives soil scientists crazy, apparently). In his book Growing a Revolution, he cuts through all the hubbub about GMOs vs organic farming, or meat vs. vegan, to lay out three underlying synergistic elements of sustainable agriculture.

1) Minimum disturbance of the soil. Plowing is like having an earthquake in your city every year. You can survive, but you end up living in tents because there's no advantage to building long-term structures. Complex subsurface soil ecosystems can store huge amounts of carbon for us in the bacterial biofilms that coat the particles, for free, if we will just stop disrupting them. Estimates range widely up to 9 gigatons a year.

2) Keep the soil covered. Bare dirt bleeds water into the air, and without water, the soil community dies, releasing even more carbon into the atmosphere. Mulch, whether dead material like leaves and wood chips, or living “green mulch” in the form of cover crops, prevents this. Even gravel and rocks are better than nothing.

3) Rotate crops unpredictably to prevent diseases and pests from establishing a rhythm. This vastly reduces the amount of chemical inputs necessary to produce food, which slows the evolution of resistance in the verminous species, preserving those chemicals for emergencies.

As with so many of the things I write about, our social and moral relationship with soil has not caught up with the rapidly expanding science. We still use words like dirt and filth interchangeably with evil. Our mental models of physical and moral contamination overlap. People who are plagued by disease must have done something to deserve it. It's been suggested that the “plague of fiery serpents” from the Bible refers to the guinea worm, a crippling infection that was so painful that victims might easily have assumed they were being punished by their God. Moreover, studies have shown that people who grow up in disease- and parasite-filled environments, where being dirty has real life and death consequences, tend to be more politically and religiously conservative, as well as more cautious about any intimate contact with nature. In other words, disgust is a feature, not a bug.

The opportunities in a changed mindset are enormous, both ecologically and economically. My entrepreneurial colleague Shawn Gagne and his team at the Greensboro firm Urban Offsets are building public/private carbon markets to monetize living trees. Schools and cities are making money off the carbon their trees are storing, which encourages them to take better care of their trees, and to plant more of them. In 2016, voluntary carbon markets accounted for 64 million tons of CO2, at a value of 191 million dollars. As mentioned above, though, that's only a fraction of what is possible. According to some estimates, 80% of terrestrial carbon is in the soil ecosystem below the surface. We could save our civilization and get rich at the same time—or maybe just eat well and be happy, like tech-savvy Hobbits.

Unless, of course, owning land becomes so valuable that we revert to feudalism, like the post-apocalyptic martial arts adventure show Into the Badlands, except the barons and their private armies of “clippers” would be wearing snazzy blue corduroy jackets, and the “cogs” would be farming organic beets and arugula instead of opium poppies. They'd probably have to change the creed . . . or maybe not. Language, like soil, can have complex structure, and multiple layers of meaning.

Randall Hayes, Ph.D., spent his childhood enslaved by a herd of dairy cattle, until he escaped the swollen udders of his piebald overlords into the wilds of academia and business. And he's never going back—DO YOU HEAR ME, COWS? NEVER!!!





Or ten billion. Future demographics is not an exact science.


Lots of authors have dealt peripherally with food production. A new source for me (yay!), stumbled across because of a surprising hole in coverage in Clute's encyclopedia, which has more articles on authors named Farmer than articles about farming.


Future Tense is a collaboration between Slate, New America, and Arizona State University. This particular archive currently holds 18 interesting articles.


In my home dialect, “blacklung” is one word.


I actually went to one of these board meetings last month. It was more interesting than you might think. They oversee local grant programs and run educational contests and such.


There are several societies publishing several journals, but the ones I found seem to have paywalls. The Public Library of Science (PLoS) does not.



super-quick overview

A PubMed search for “quorum sensing in soil bacteria,” limited to reviews and free full text, gave me 25 results, which is a lot more manageable than the 235 I started with.


More recent and more general review article on “The Emergence of Consensus.” Not limited to bacteria.


If it's not Scottish, it's CRAP!”


Check out Pandorapedia.

Montgomery, D.R. (2017) Growing a Revolution: Bringing Our Soil Back to Life. WW Norton & Company, New York, NY.

Logsdon, G. (2017). Letter to a Young Farmer: How to Live Richly without Wealth on the New Garden Farm. Chelsea Green Publishing, White River Junction, VT.

Chapters include The Economic Decentralization of Nearly Everything; The Rise of the Modern Plowgirl; Big Data and Robot Farming; and others. Seriously, much food for SF thought.



Jimmy Carter, ex-president and public health hero—or possibly genocidal maniac, from the worm's point of view.


Tybur is an evolutionary psychologist who has published a lot of the work on this issue over roughly the last decade.


Valerie Curtis has been writing about this issue for more than a decade now.


Trees are just another example of “invisible assets,” like the economist de Soto describes in The Mystery of Capital.




Note: like most Wikipedia articles, this has massive spoiler potential. If you care.

Read more by Randall Hayes

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