Today, we're speaking with geologist David Montgomery, co-author with Anne Bikle of a new book called "What Your Food Ate." Very interesting title. David is professor in the College of the Environment at the University of Washington and earlier had been awarded a MacArthur fellowship. You may already be familiar with him through his acclaimed book called "Dirt: The Erosion of Civilizations." Dr. Montgomery has long argued that the root of good health begins with dirt, a factor that we ignore at our peril.

Interview Summary

 

Well, I really admire your work, and this work in this area is so important. We've recorded a number of episodes around the issue of regenerative agriculture, and it's been impressive how much interest there is in this topic, which I think, only a few years ago, wasn't very well known to most people but now is becoming more part of the general discussion, which I see as a very positive development. Let's begin with your interest in dirt. So what is the condition of the Earth's dirt?

 

Well, sad to say, not very good in terms of our agricultural soils in particular. That's something as a geologist, that's what got me interested in soils is looking at the long history of human interaction with our landscapes and soils and ended up writing a history of farming about how it had degraded farmland around the world over the course of centuries. The short answer is that we have degraded something between about ¼ to 1/3, probably, of the world's potentially viable agricultural land to the point where it's not terribly useful for agriculture. The UN's 2015 Global State of the Soil report concluded we are losing about a third of a percent a year of our ability to grow food on this planet due to ongoing soil loss and degradation. So the physical erosion of the soil and the degradation of its fertility as manifests through the loss of soil organic matter. And, that 0.3% a year number doesn't sound like a big deal on a year to year basis. But think about that over the rest of this century, and it adds up to almost another 1/3 of the world's farmland taken out of production at a time when we really need all hands on deck or all acres on deck, as it may be, to feed the world as our population keeps growing. So, we face a fundamental challenge this century of how to sustain agriculture on a degrading resource base. Our other choice is to think about trying to improve, enhance and restore the soil. That is where regenerative agriculture comes in and where my interest has really grown beyond just looking at the sad experience of past civilizations that degraded their land. And to thinking about possible solutions that will allow humanity to continue intensive agriculture to feed the world well into the future.

 

So what are some of the factors that have driven the erosion and the degradation?

 

One of the biggest factors that contributed to the loss of topsoil in societies around the world was tillage, the act of plowing. That seems a little odd to hear at first because isn't that something that farmers do? It helps to provide weed control. It helps to prepare a seed bed for planting, but it also leaves the ground bear and vulnerable to erosion by water and wind until the next plants come in, whether it's a crop or whether it's weeds. If you leave the ground bare and vulnerable, you get the erosional situation like we saw in the Dust Bowl where great clouds of dust blew off the American Midwest when we plowed up the plains when the next drought came in. The same kind of thing happened in slower motion in societies in the past, mostly in response to rain rather than wind, but erosion that proceeded faster than the rebuilding of the soil gradually stripped off the top soil from regions around the world that people depended on to grow their food. And in the modern world, we can actually degrade soil faster with the combination of tillage, the over application of synthetic nitrogen fertilizers, which also contri

Id. d’épisode : 1000578040778

GUID : fe8979a1-1ee3-4287-8658-b51b194c7e2d

Date de publication : 1/9/2022 à 15:09:07