Just got back from hearing a terrific lecture by David Montgomery, author of Dirt: the Erosion of Civilizations and had to share. I'm putting it here, because 1) the book might be good for the book club to take on and 2) it connects so well with what we are reading now.
Here's a few of his main points:
The erosion of soil due to plow based agriculture has lead to the demise of many civilizations from ancient Greece in the bronze age on. Plow-based agriculture erodes away 1.5 mm/yr of soil, no-till agriculture about half of that. Leaving native vegetation, about .01 mm/ yr of soil erodes away which nicely balances the .01 mm/yr rate of soil production. 1.5 mm/yr of erosion may not sound like much, but that means that the typical .5 -1 meter thick of original hillslope soil is totally destroyed in 500 - 1000 years, which not coincidentally is the life span of most major civilizations.
What to we need to do to prevent soil erosion from being the demise of our civilization:
*reduce subsidies for conventional erosive farming
*increase support for no-till practices
*promote practices that increase soil organic matter to sequester carbon and increase soil fertility.
He points out that 50% of the life of this planet exists below ground and the rest of us totally depend on that 50%.
By working on creating soil and soil fertility (by use of compost and biochar) we address the issues of climate change, public health, and feeding a hungry world!
Any of this sounding familiar, gang? I feel sort of like God is talking to me! Some times when the Universal Spirit has a message for you, it starts coming at you from all directions. Now I just need to figure out what (other than building my own soil), I'm supposed to be doing with this message. The Gospel of Dirt -- shout it from the rooftops!
"A nation that destroys its soil, destroys itself." FDR 1937 (the dust bowl years)