Dirt: The Erosion of Civilizations by David R Montgomery

[rainbowgardener]

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)

[Toil]

looks like a cool book! book club or no I want to read it.

[gixxerific]

Good to hear you had some newly found insight Rainbow.

I will be going to see a movie called Dirt this week. not sure if it of the same person, I can't get on my other PC due to it's sucking nature.

[Toil]

well you could write to your legislator and tell him/her that we need to stop dumping subsidized crops on foreign markets in the name of "aid", and instead fund biochar facilities so people have fuel and food.

[cynthia_h]

In August 2008, I started a (very short) thread on an article in NatGeo, "Where Food Begins," which focused on soil. The thread is at

http://www.helpfulgardener.com/forum/v ... hp?p=50333

It has good links to the article, which itself contained excellent photos of subsurface plant roots, and bunches of other info highly relevant to *this* thread.

Cynthia H.
Sunset Zone 17, USDA Zone 9

[cynthia_h]

And, regarding agricultural subsidies, here's a blog at sfgate.com which *sigh* linked to a cool graphic on "why a salad costs more than a burger at McDonalds":

http://www.sfgate.com/cgi-bin/blogs/gre ... y_id=58726

hmmm....

Cynthia

[Toil]

the pyramid graph was very vague.

Was federal grazing land included as a subsidy? The costs cleaning up water supplies polluted by fertilizer runoff (borne by local agencies most likely)? Was the corn subsidy treated as a beef subsidy, and if so, what percentage goes to beef? and on and on.

externalized cost is the problem, via subsidy or otherwise. We need to pay at the register, not with the well being of future generations.

Not helpful to say the least, when it comes to looking at subsidies. But it did make for a nice visual.

I maintain: pull out the corn subsidy, and beef prices will rise enough to modify behavior.

Then we can talk about subsidizing spec crops like broccoli and lettuce.

This kind of talk makes fish look good, until you realize eating anything from the sea is even worse! At least on land we stay away from tigers an bears (mostly). In the sea we stick to predators mostly. And the death of soil has put even more pressure on the sea.

pork and chicken, that's what I say! They can turn waste into meat very efficiently.

[Swivel]

The destruction and erosion of our lands is very sadening. When thinking of agriculture there needs to be more of an emphasis on biodiversity and ecological pertection when planting and pertecting our crops. Whats good for the land can be good for the crops, whats good for the crops can be good for us. Soil dwelling organisms and fungi help to keep the land fertile and the best way to pertect these organisms is to use the least invasive gardening possible. We must think long term or else the land ends up virtually useless, then where wiill the crops end up? On the same land packed with synthetic fertilizers thus further disterbing the delicate land and ecosystem.

I have yet to read the teaming with microbes book, but it is on my purchase and to do list.

[rainbowgardener]

Nice post! You will enjoy the Teaming with Microbes book and find it very in tune with your way of thinking!

[The Helpful Gardener]

Great suggestion; I am bumping this book to the top of my list. It jibes well with everything I have been reading of late, and certainly dovetails with the concepts of Jared Diamond's books Guns, Germs And Steel, and Collapse; How Societies Choose To Fail Or Succeed, which I hold in very high regard...

I have said it here a number of times; tilling destroys soil. Interesting to see the concept as a central theme for a book...

HG