Its the soil stupid!

Posted August 1st, 2007 by Sylvia S Tognetti and filed in Grounds for optimism

I’ve often been known to say “there is no magic bullet.” Now I might have to take that back. Blogging has been light over the past few weeks because I have been immersed in a couple of papers, one of which I’m still finishing so I’ll be brief – but the paper is on ecosystem services associated with soil and water management practices. Of all the elements in the ecosystem that interact to sustain life, soil and water are the ones that can actually be managed. Managed properly, soil stores and regulates the flow of water and sediment – and thereby, reduces agricultural water use, stores carbon, reduces the need for artificial fertilizer inputs, and, of course produces forests, food and other vegetation which add to the carbon storage…. and has the highest concentration of biodiversity. It gave me the sense that perhaps soil could be managed to store even more carbon and increase food production, etc.

Turns out somebody has already been there and done that – possibly thousands of years ago, in the Amazon, by producing “biochar” or “Terra Preta”- a form of charcoal that is produced from burning and smoldering waste biomass under low oxygen conditions (i.e., pyrolysis), thereby removing 20-50% of the carbon in spite of the emissions produced. This was then used to enhance the soil, which dramatically increased agricultural production in the nutrient poor soils of the tropical rainforest, and reduced nutrient leaching. I had sort of heard about some of that. Differences in the soil around human settlements in the Amazon have been observed for some time but the implications for mitigating climate change and for producing clean energy while sequestering carbon have only started to be explored in the past few years. Seems it also suppresses nitrous oxide and methane emissions from soil. Although more research is needed to quantify the benefits and to develop applications and production capacity, what mostly seems to be missing is the availability of credits for carbon stored in soil, at a price sufficient to create an economic incentive to do it, which would spur implementation, and provide all of those multiple benefits on the side. Senator Salazar is sponsoring an amendment to the senate version of the Farm Bill to provide $100 million in research funding. Recent developments along with some background and links can be found in this ES&T article .

Of course, it took a geographer to pull a lot of the information together. Although there were a number of researchers who laid the groundwork, one of the background papers that I found in the links, by William Denevan, says it was Nigel Smith who, in 1980, published this landmark article in the Annals of the Association of American Geographers that is frequently cited and influential. All of the claims now being made would sound ludicrous if they did not come from a string of articles in the peer-reviewed literature. It even restores some of my degraded optimism about the future – in spite of the herd of elephants in the room….

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