biochar? carbon gardening?

Daphne brought up biochar as the most stable way to sequester unwanted atmospheric carbon. As a nice side effect, it also improves the soil. And Tony explained that my tasty lettuce gardens don't hold onto much carbon very long, but if I added more wetlands, that would. Hmm, carbon gardening - that's new to me. I had to do more research.

The main focus of recent Climate Change Conferences is to reduce emissions, but then, there's a secondary discussion: what to do with the carbon that's already in the air? Biochar is one proposal.

Solutions for the "What to do with it" problem have been divided into biological and chemical approaches. NOFA recommends tying CO2 up in plant/compost cycles. This has the advantage of using a free energy source: the sun. The disadvantage is that we have only the earth's surface for this activity.

Biochar (pyrolyzed organic products that sequester CO2) production is also considered a "biological approach". (I'm not sure why as it doesn't use the sun to do the pyrolyzing, it uses fossil fuel. It just make use of organic products.) Biochar has the advantage of great potential capacity as it can be buried, However, the scale it's used on currently is relatively minuscule.

There are also spectacularly varied chemical methods of capturing CO2 that are being proposed — "from direct air capture using resins, to the use of crushed olivine (a mineral that absorbs CO2 as it weathers) to seed beaches, to new forms of carbon-negative cement-making."

But back to the biochar, it's currently having an impact agriculturally as a soil amendment that revitalizes tired soils. It's not effective everywhere (negative issues include price, affects on soil microbes, and the large volumes that are needed), but in many places it is improving crop production. Like Daphne's garden! (Is that how she grew those beautiful sweet potatoes?)

As far as expanding biochar production to the point where it can impact atmospheric CO2, critics are concerned that land used to grow plant material could displace food crops, they sorry and about socioeconomic effects, and they worry about what eventually happens to biochar in soils - when it does breakdown. They worry that sufficient research has not yet been done.

I like the rational view of Stephen Joseph, a biochar researcher from Univ of New South Wales in Australia, "Biochar probably won’t save the world from climate change, nor is it going to be the key to increasing agricultural productivity everywhere. But used wisely, it is a tool that may help in both situations.”

Personally, I this I'll to stick with NOFA's very biological approach and traditional methods: Cover everything I can with plants (more lettuce!! more clover!!), compost everything I can on site, and use my chickens to enhance my composting. I'm also growing locally - in my backyard - and reduce driving to the grocery store. I hope my little micro-farm is at least a transient a part of reducing atmospheric CO2.

Sources:
NY Times (July 24, 2015) A Third Way To Fight Climate Change
BloombergBusiness (June 8, 2015) Scientists Are Coming Up With 'Last Ditch' Remedies for Climate Change
PBS (July 3, 2015) The Coal That’s Good for the Climate

Since I'm a new NOFA member I was reading through their literature. I like this one about Soil Carbon Restoration.

"Much discussion has focused on how to deal with greenhouse gas emissions and resulting weather extremes. Most analysts believe we must stop burning fossil fuels to prevent further increases in atmospheric carbon. [But we} must also find ways to remove carbon already in the air....

"...where can we put carbon once it is removed from the air? There is only one practical approach -- to put it back where it belongs, in the soil.

So here's a list of things vegetable gardeners can do to put carbon back in the soil:
- Plant nitrogen fixing cover crops and living row paths
- Heavily mulch weeds instead of pulling
- Incorporate no-till or shallow till practices
- Replace pesticides and fungicides with diverse beneficial organisms
- Incorporate perennials in our garden
- Compost your garden and kitchen waste
- Recycle biomass with livestock (grazers, browsers, compost to poultry)

And things yard-owners can do:
- Plant lawns with diverse species: deep rooted grasses and nitrogen fixing species like clover
- Incorporate multi-layer, perennial, diverse plantings
- Compost, rather than burn, yard waste
- Minimize pavement and unproductive mulch
- Grow nitrogen fixing trees and perennials
- Maintain diverse forested buffers and perimeters

I think we've all heard about the importance of doing most of these things since we know good soil health is important for our crops. Soil health is also important for the earth. More info is at the NOFA site (NOFA Carbon Soil Restoration).

NOFA

I just signed up for NOFA's winter one-day conference Saturday, Jan 16 in Worcester MA. Anyone else going? Has any been to these before? I just signed up as a new member. It looks fun. NOFA is the Northeast Organic Farming Association. I met a board member the other day and he told me they had lots of programs and resources for organic home gardeners.