Ethan Roland of Carbon Farming Tennessee and Gaia Northeast presented this talk at the 2010 Northeast Organic Farming Association’s Winter Conference. Read more and download a resource sheet at www.regenerativedesigns.wordpress.com.
2009
Quantifying Carbon in the Forest and Soil
A question from a Permaculture Design Course student came in the other day:
Does anyone have some quick reference to equivalent measures of green house gas reductions per tree? Especially for the urban context?
Basically biomass equations are often used to estimate the amount of carbon a tree can sequester at any given size which often increases with age to a certain peak. The equations are derived from humans actually harvesting and weighing real trees by species, in numerous studies. Scientists literally cut up a tree, weigh it, combust the carbon and weigh it again. br It’s obviously a lot of work. So, for north America, there is fairly good data by species already in existence. All one needs to do is look up the species in a table (U.S. Forest Service’s national Forest Inventory and Analysis data set is commonly used for the US) and make some conversions to CO2 equivalents from biomass tons/ac to get a general idea of how much carbon a certain tree may be sequestering. Here’s a slideshow from Winrock International on the subject of soil carbon sequestration.
Remember most of science is a compilation of statistics, and there is no real way to know exactly what is going on in a complex ecological system, only our best attempts to use good scientific methods to get as close an approximation as possible with given technology and resources.
In the tropics, there are many more species so it can be more difficult to find a biomass equation so you may have to do the initial ground work as well, but starting with a good search of existing research is a good place to start (try searching for biomass equations in www.googlescholar.com).
One of the equations I’ve used is called the Jenkins equation, but there are many, and they give you different results. That’s science for you. For developing carbon projects where you are looking to sell carbon credits, the general good practice is to use a conservative estimate, then actually do your own baseline and long term monitoring – this gives you a better idea how much carbon you actually have on your site, and that is the number you ultimately use to sell the carbon you’ve sequestered, depending on the agreement you’ve reached with your buyer (this ends up being a cost/bennefit analysis – the estimates with the biomass equations help you determine how much carbon you may have to sell, if it’s a lot, then you assess if the monitoring study costs will be adequately covered to make them worth your while rather than using a more conservative estimate using a biomass equation, etc.)
Here are some good links: http://www.nasa.gov/centers/ames/news/features/2009/Trees.html – a general description of new remote sensing methods to determine carbon
http://files.harc.edu/Sites/HoustonRegionalForest/Events/CarbonWorkshop/ScienceWinrockInternational.pdf – a powerpoint that describes the science behind carbon sequestration
http://www.fs.fed.us/ccrc/topics/urban-forests/docs/construct%20WBE%20gen%20equations%20gtr_nc230_096.pdf – comparison of some biomass equations for US species
Here are a couple of references which will have even more references cited (first one includes a couple of authors who won a nobel prize for their carbon science work):
Brown Sandra, David Shoch, Tim Pearson and Matt Delaney 2004. “Methods for Measuring and Monitoring Forest Carbon Projects in CA.” Winrock International: Arlington VA, for the Regents of California/ California Institute of Energy Efficiency.
Halpern, Charles B, Miller, Eric A., Geyer, Melora A. 1996. Equations for predicting aboveground biomass of plant species in early successional forest of the western Cascade Ranges, Oregon. Northwest Science. 70(4): 306-320
2009
Brad Lancaster shares his Abundance!
We come screaming into the third module of the Carbon Farming Course with the arrival of Brad Lancaster. Author of Rainwater Harvesting For Drylands and Beyond, he is one of the worlds experts on integrated water management, and we are all thrilled to have him here in Tennessee teaching us.
We flew through an overview of the water issues facing us today, and quickly got into action building a simple and practical rain garden. Brad started out by making sure all of us knew how crazy the current water situation in the world is.
- 97% of all water on this planet is salt water.
- Of the other three percent
- 75% is locked up in glaciers and other ice
- 13% is held in deep aquifers (too deep to tap without immense expense)
At the same time, over half the worlds population has inadequate access to clean drinking water or have to walk over three hours to get it. And the demand for fresh water is growing very quickly while we watch our wells and shallow aquifers dry up.
So with all these important issues around water, how do we in the US deal with water. Well, we go through a huge amount of expense to purify, and pipe drinking-quality water to all the people in municipalities. Great! We have cleaned it so that we can drink it. The only catch to this is that 30-50% of all that cleaned, chlorinated and fluorinated water then gets used for irrigation on our gardens! (Not so good for the soil food web.) And a further 30% gets used for (clean water necessary) activities such as a place to put our urine and feces. Interesting strategy, huh? It gets even crazier than this. We then flush the feces away, sending it often miles away to be processed at high expense once again.
Brad comes from Tuscon, Arizona, where he has created an oasis of sorts right in an urban neighborhood. He said that all this cleaning and pumping of water uses over 42% of all Tuscon’s electricity! 42%! That’s huge. There must be some way to change this crazy situation. If only we could get water from some other source, or at the very least, use less. Well, Brad showed us how we can do both of those things.
We do have another source of water, its called RAIN! Unfortunately, most people look at rainwater as an inconvenience that needs to be dealt with and moved away as quickly as possible. Brad showed us that coming off a very modest size roof we can have tens of thousands of gallons of clean usable water for free! Or at least for the minimal expense of setting up a rain catchment system.
Lancaster helped craft legislation in Arizona that allows people to use rainwater very effectively, both off their roofs and the storm-water running down the streets. He is quickly growing an urban oasis in a climate that most people would think would be more suitable to cacti and tumbleweed. Visit his website, and see pictures of this amazing transformation:
And now other communities are following suit as well. Portland, Oregon has saved $58 million with their Green Streets initiative, reducing runoff by over 98% in affected areas and helping to restore the salmon habitat in the streams. In Seattle, Washington there has been an effort to transform Vine Street. You can see what they have done at:
Its not just about the water, Brad explains. These projects, as well as home-based projects, do a lot more than save water. By saving water they save huge amounts of energy in the pumping and cleaning. Using our gray water, or catching storm-drain run-off also makes more productive systems out of our homes and cities, while providing food and beauty for those of us who live in them. By shading the streets with trees (that grow from storm drain water) we also reduce the “heat island” effect that comes from having so much exposed asphalt, while at the same time reducing the stress on the storm drain system, reducing polluted waters entering our streams and saving the tax-payer money fixing problems caused by erosion. Multi-functional, interconnected and positive feed-back loops that benefit us and our communities in many, many ways.
To finish out the day, and to bring the knowledge home, Brad led the group in putting in a rain garden at the Eco-village Training Center, here at The Farm. We identified a downspout from the roof of the main building, and calculated the amount of water it would put out in a year
16 feet x 32 feet x 3.83 feet rainfall per year x 7.48 = 14,667 gallons per year
That just off of less than a quarter of the roof space on this one building! Over 14,000 gallons is plenty to cause a bit of erosion if not utilized correctly, and plenty to grow a small flourishing garden. That is exactly what we did, or at least we got started. We laid out a design that we thought would work for the space provided and the community of people that live here, and put it into action. The final step will come when Eric Toensmeier, one of the authors of Edible Forest Gardens, starts teaching on Thursday.
2009
Keyline Design – Day 5
Tennessee has a lot of ticks. At least that is my conclusion after spending the last 3 days in freshly bushhogged fields. Big ones and small ones, that fortunately seem to take longer than 8 hours to attach themselves to a human body. Besides, a shower feels great after working in the field all day (and doing a tick scan in the process.)
Today a lot of Keyline design, and why it takes Darren 6 days to get the information across, came clear. The difference between Keyline design and contour subsoil plowing, for example.
We spent the morning working on soil samples and marking contours on a small (13 acres) pair of fields at 4-foot contours, with a couple of drains running across the 8-acre section. This level of complexity on such a small parcel made the Keyline design a challenge. We took GPS readings along each of the middle contours and brought the data back in to plot it on a map of the property so as to be able to analyze the map to design a plow line to duplicate in parallel throughout the field.
With the variety of contours in the field, eyeballing a representative plow line to try to be compatible with most of the variety proved easier on the map than on the field. We took the data generated by GPS and computer and translated it into points in the field and found that in the center it just didn’t look right. In the end, we decided that instead of planting a row of trees across the plow line in the center of the field, we would recommend that the owner plant a diagonal treeline in the valleys and that it made sense to keyline the 3 remaining sections of the field and leave the targeted treed section alone because it would tend to accumulate water anyway.
This goes along with Darren’s position with respect to Keyline plowing – that one do the plowing and wait to see the result and changes in the water cycle on the property before taking action and doing land planning for the property – the results of keyline plowing on the water cycle may be unpredictable.
Net result of all of this is the learning that not every field is a trivial design example, and that perfect applications of the toolset are rare, and that other tools from other disciplines such as Permaculture may be necessary to help in decision-making in real life.
2009
Carbon Farming Course 2009
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2009
Keyline Design Day 4
The process of assembling the Keyline plow was not intuitively obvious. The tool has a lot of flexibility, with spacings of the shanks, locating the coulters relative to the shanks, adjusting the wheel depth and mounting the seeders. Everything about the coulters was adjustable – depth of cut, camber, angle wrt the shank, etc. We left everything loose to be torqued down after moving it to where it would be used.
Weather was hot, dry and sunny this morning when we went out to mark the field for Keyline plowing and do the soil analysis. One of the students, who has worked with the NRCS and state Agriculture department, shared her expertise with all of us on how to do the soil analyses. We wanted to be able to measure bulk density and soil carbon to be able to show the level of carbon sequestration in the subsoil and also how the soil is uncompacted as a result of keyline plowing. Both measurements will provide a coarse measure, not up to standards of selling carbon credits, but fine for our purposes..
Digging holes in the hard rocky clay that lies beneath the scant 4 inches of topsoil was no picnic. WIth no auger, we used Pickaxes, Mattocks, shovels and rock bar, a tool that looks a giant nail with a flat blade on the pointed end. After digging the holes for soil samples, we took a soil compaction sample and filled a bag from each hole to send out for the other tests.
Another team was simultaneously working on flagging the keyline with the help of the laser level, and yet another was mapping out locations of the soil test holes relative to semi-permanent landmarks (large trees) which will enable us to do tests from nearby locations in subsequent years to compare to quantify the effect of the Keyline plowing. We triangulated the holes with two trees each, and a coarse map labeled with species.
When we finally got around to using the plow, we saw dramatically the effects of overgrazing, rocky soil and soil moisture in two ways – the pattern left behind by the plow, which was not as smooth as normal, and the toll taken on the plow.. The rocky soil meanwhile quickly claimed a couple of shear pins and sent its owners in search of 3/4 inch 10/20 steel stock. The coulters quickly came off – they did not work well in the extremely rocky soil.
I was able to maintain attention throughout Darren’s software demo (loading the waypoints and drawing the landscape features into the Aerial/topo) because of Darren’s colorful language. The Australian slang (well bugger that bit…, he’s a tool, sheep’s clacker, etc.), combined with the stories from his travels, provided subtle and not-so-subtle entertainment. Listening for these odd terms mitigated the soporific effect of watching him work with software from my position in a back-row seat. The course registrants are split between property owners looking to implement Holistic Management and Keyline Design on their properties, and not necessarily looking to develop more accurate topo maps as sales tools, and Permaculture Practitioners looking to deepen their skillsets with an eye towards working with larger properties and incorporating grazing strategies for large animals with clients looking to preserve grasslands. The GIS/GPS information addressed more the latter group with software and hardware recommendations for developing great sales tools for implementation plans.
2009
Keyline Design day 3
It started out cloudy and started raining hard by 9:30, postponing our plans to go out and survey for plowing tomorrow. Since the Keyline plow is most effective in soils that are neither very dry nor very wet, we will need to dig down into the soil to see how wet it is tomorrow before we use the tool.
GIS information and mapping is available with varying quality throughout the US, from MYTOPO.com, MAPINFO.com, NRCS.gov, and state and county GIS websites. These can be used to down load maps (not available through Google’s free service, and the premium service is very expensive without sample information.) Once downloaded, these maps can be enhanced with software and a graphics tablet to provide site maps and topographic information. A GPS receiver can be used to get 3 registration points to to link the map to your footsteps on the property. To get to 2-foot contour resolution, it is generally necessary to survey the property.
Darren’s shared worksheets used with clients are useful both for those in the class who want to use the information for consulting as well as those wanting to use the information learned in the class on their own properties. These documents are available on Google Documents from a link on Darren’s website. These provide good checklists of what to look for on your own or your client’s land, such as categories of vegetation, soil chemical analysis and organic content, inventory of land and chattel, water sources and uses, services needed, caveats, etc.
Afternoon was Georgia-like weather, but a little more humid. Clear, sunny, and moist. The rain evaporated quickly, hanging in the air as humidity. Surveying for a pond site, drain to increase watershed for the pond, and an additional drain to provide a spillway well in front of the dam consumed our afternoon, using a quicksite level, laser level, staff and laser receiver. We dug into the rocky clay soil down to about 1 meter, going through 3 layers in the process, with the roots of the overgrazed field going down only about 4-5 inches, and the clay below was dry even after the morning’s torrential rain. Keylining the fields will hydrate the field and regenerate life in the soil, allowing the roots to grow deep and develop drought tolerance.
2009
Keyline Design with Darren – day 2
We began with a review of some of the literature available and not available (Darren is a collector of Yeomans memorabilia) describing the products and techniques of the Yeomans company products. His recommendations are 1) The Challenge of Landscape, written by PA Yeomans in 1966, available at http://www.soilandhealth.org/01aglibrary/010126yeomansII/010126toc.html 2) The Geographical Basis of Landscape, by J. McDonald Holmes, available for free download from the Yeomans company website here: http://www.yeomansconcepts.com.au/basis-of-keyline.htm and 3) the 1994 version of Water for Every Farm, still in print.
PA Yeomans’ (The Founder of the Yeomans Company and co-inventor of the Yeomans (Keyline) plow) developed a superlative example of water use with his products and theories, Yobarnie, outside of Sydney. This 760 acre property held 558 acre-feet of water in a dry area, and he drained the holding ponds each year. The property was sold a few years ago for $40.2 million, and subdivided into 2000 homesites, some of which are on the bottoms of what were formerly lakes. The provision of water and removal of effluent from the newly-developed site does not take advantage of the site water, but each is pumped 50 km. The sheer madness of such decision making is difficult to understand.
We went out into the woods to follow up on Keypoints and Keylines in a more physical sense. We drove in the first stake at the keypoint, the confluence of two slopes into a third order catchment, and then used quicksite levels to mark contour lines around the valley downstream from the keypoint. This represented the water level of the catch basin. At the suggestion of one of the students we marked in between the stakes with fallen logs, giving a very visual representation of the pond surface, should we follow up and build it.
Fallen logs, if oriented uphill/downhill, will decompose and do nothing to help retain detritus on the forest floor, but if oriented across the slope instead will slow downhill flows and catch organic matter in heavy rainfall situations. The logs along the contours defining the potential pond served two purposes as we had oriented them.
After lunch we discussed the Keyline plow itself, and Darren showed a video of his own plow in use on a second pass after a couple of months. The surgical nature of the cuts and clean way the roller closed the slit in the soil elicited oohs and aahs from the group, and he played the video 4 times before moving on. A ‘farm-porn’ video that beats any tractor catalog.
The remainder of the afternoon was spent on examples of water retention and diversion earthworks, including some larger-scale works done in a project in Vietnam, and some of the earthworks created by PA Yeomans decades ago. He wrapped up the day with a few representative prices for various services, such as Keyline plowing per acre. The beauty of using the Yeomans Keyline plow is that you can use it once or a few times and accrue benefits for many years or decades afterwards. Its use positively changes the character of land and its water cycle, and applied on a large enough scale will have a positive impact on stabilizing atmospheric carbon. I am anxious to get this done on my own farm as soon as I can.
2009
Keyline Design with Darren – day 1
Darren Doherty was accompanied by his wife and partner in Australia Felix Permaculture, Lisa, and two of his three children, Pearl, 9, and Zane, 8, who after being present at several of his classes are now certified in Keyline design.
The first session involved introductions and personal objectives and then we immediately dove into assembling the Yeomans plow that was brought to class by one of the class participants. Darren explained the basic use, theory and subtleties of using each of the implements (coulter to split the soil in front of the plow, the plow and how it functions and the seeder). He also explained some of the other implements available such as one for cutting off root crowns of weeds, that attach to the plow itself.
Darren’s intro focused on benefits of Carbon Farming, the relationship of Keyline Design to Holistic Management, water holding capacity as a function of soil carbon, carbon sequestration in temperate climates vs. tropical climates, some of the shortfalls in the carbon trading systems, and much more.
After lunch Darren went through a review of Holistic Management and spoke at length about its relationship to Keyline Design. He has an extensive and in-depth knowledge about both topics, and spoke at length about analysis techniques for measuring soil organic material, formulas for conversion of CO2 to organic soil carbon and the like. He shared all of his materials, including a Powerpoint slideset, yet we still were writing furiously keeping notes of all the useful information.
Late afternoon session – Darren covered a number of his design examples, using them to introduce new concepts and review some concepts from Permaculture, many of the class attendees have taken a PDC in the past. Some of the Keypoints included the definition of a Keyline, where to use a swale vs. a Keyline plow, cost and labor savings of the keyline method and thus its greater applicability to broad acreage, etc.
One key takeaway is that with Keyline plowing, your master plan may have to be thrown out – water sometimes comes up in unexpected spots because it it difficult to predict where underground flows will occur, therefore it’s impossible to pre-plan for everything up front, incremental design and implementation can be more practical. If you are going to do Keyline planning, you may want to postpone doing more extensive land planning until you see the results from the keylining. This is consistent with the Permaculture recommendation that you first spend a long time observing the land before planning.
2009
Holistic Management Land Planning
Day 6 – Land Planning
In the first half of the day today we began by reviewing the original course expectations of the individual participants, and nearly all were already met. We still needed to cover a few more subtle considerations, such as placement of gates and tuning rotational schedules to minimize transit distances, toxic plants, places where snow piles up in drifts or remains, grazing considerations for tropical environments (a couple of attendees are from Central and South America), etc. We dug into these immediately, and followed up with the second half of the case study from yesterday.
After completing the case study for winter forage, in which we learned the basics of storage of forage in place and how to manage grazing patterns during the non-growing season , we moved on to going through some materials on examples from one of Kirk’s more innovative clients from a location in Canada with a 60-day growing season. Kirk showed two sets of slides with photos of his client’s implementations of water systems, fence systems and land planning systems for optimization of fence length, water system capital costs, manure distribution, etc. These real-world systems, put together to meet his own customized needs, showed enormous creativity.
Another field visit followed lunch. Cynthia Rohrbach and Elizabeth Barker took us on a tour of one of the meadows left over from the fingers of the plains that remained in Tennessee after the bison were all killed off. It was host to an amazing variety of plants with diversity found nowhere else in the state. Sumac berries, Rattlesnake Master, and a huge number of flowers and grasses would have provided the bison with, as Joel Salatin would say, a veritable salad bar.
When we returned to class from the meadow, Darren Doherty, who will teach the Keyline design course starting Tuesday, joined the discussion. The interaction of Kirk and Darren together was particularly valuable in their discussion of how the two methodologies fit with one another and how one might apply both on the same property with a couple of sequences, depending on existing land use. All of my current questions and anxieties were addressed by this interaction, at least until I gain more experience or learn more in the coming days.
Here’s most of our class at the second field day:
Thanks Kirk for an excellent start to the Carbon Farming Course! Our blogging team will pick up again on Tuesday for the Keyline Module with Darren Doherty.
