This thread was a response to questions about how to build soil. I look at the big picture what helps soil grow & end with a discussions about how towns & cities might be designed to help.
So there’s so much to cover in how to repair things. I’m going to do a slow thread on how the designed and built environment can be directed to soil building and climate repair.
1st thing to think about is what is soil? For brevity i’m going to say soil is the culturing of weathered rock with a food web of microorganisms that leads to making rock nutrients solvable &stores them along with organic carbon. (Soil scientists i know i’m over-simplifying)
I’m talking about aerobic souls formed with oxygen rather than anaerobic. Wetlands souls are amazing and do good. But there are reasons to focus in aerobic for now. (I’m a huge fan of wetlands and pond systems too)
Too much water and too much compaction removes oxygen. The system switches to anaerobes that live by yanking Oxygen off of soil nutrients, making them smell bad and able to leave the soil. They also produce alcohols that prevent plant roots from growing.
So this kind of soil needs: enough air, water, contact with plants (that feed it with sugars and proteins made with photosynthesis and CO2 exuded from their roots.)
Rock weathers into subsoil without a lot of big life, when plants interact with it they build living subsoil through their roots and the accumulation of organic matter on top.
Living soil is protective. So it actually protects the subsoil from some of the processes that speed up formation. Which is why in natural conditions it can settle into a very slow rate of production.
We have been running civilizations in the use of this built up soil. Turning it killing fungi and structure to get bacterial blooms that feed out Annual crops.
This leads to Erosion rates more similar to mountain systems then the low lands where the soil formed. We are burning through our soil to grow and crash quite a few civs
You have to understand. The buffering capacity of our plants souls* could have handled the CO2 from fossil fuels. Only what we used fossil fuels for was to increase erosion, change the balance of water runoff, deforest, and plow over the grasslands every April. 8/?
*Sorry about the autocorrect to soul. Lol
I have to be off-line for a spell but I’ll continue with a discussion about how we design to accelerate that soil building process. Including some references in case studies
So i want to introduce a few puzzle pieces. The first is the work of this man PA Yeomans. He was a mining geologist who retired and starting thinking about soil care from a Geomorphologist POV
When he set off to tend his land, the Australian gov provided soil conservation literature focused on contour plowing. Based on the view that soil is precious(it is) but that it’s impossible to speed its production (it’s not)
The main problems with contour based design can be seen from this image by PA. On land contours are not parallel. This slows water but it drains ridges and concentrates water in valleys. Overdrying and overwriting soil at the same time. Can even blow out.
PA developed a way of understanding topographic features to organize landscapes so that: water is infiltrated, spread, extra collected stored as high as possible to re-hydrate during dry times. He realized this could be used to organize everything on broad acre farmland
This prob is too dense for Twitter. But imagine land as big ridges between streams and they have smaller ridges and valleys. Imagine the inflection point in those smaller valleys where the land nicks in like a clavicle * in the pic 13/
PA called them keyponts and they are : the highest water concentrating point in land, where soils thicken, & any line parallel to this on the land concentrated water above but spreads water below
Now he had a way to organize features. First he placed ponds at those points. Collection drains could be set to collect overland flow and move it into those ponds. Then any roads could follow those drains with minimal impact actually helping water collection.
And bellow, the land could be plowed with a subsoiler that sharpers the subsoil without turning the soil. And he would plow down on ridges and up on valleys which means water spreads.
PAs land:
And here in red are plow lines (or how to organize and water receiving element such as tree rows to spread water along ridges)
Roads, buildings, pasture, agroforestry- whatever could be designed. Roads can also be placed along ridges, Trees get planted along ridges & in valleys and along streams with complete connectivity. And humans move out of valleys to ridges, leaving valleys for soil and wildlife.
This planning process is like adding sourdough starter to flour and sugar and adding just enough water. The subsoil can be reached by water, roots, inoculated by microbes. you can rapidly add feet of topsoil. Keyline farms are amazing. They stop flashy creeks & can repair land
And it should be viewed as appropriate for where people live and farm. Ag land not the giant ranges that could be bison prairies.
So there is more. PAs last book was on how these design methods could be applied to cities and towns. That towns could extend along ridges,roads could direct water into Catchment which could water yards then agricultural & reforested lowlands. He called it “the city forest”
The City Forest by P.A. Yeoman hosted on SoilandHealth.org
Library Rules and Copyright Notice
Think about what this would mean. Human settlements designed so they are collectors of water, human labor, and even humanure, directed towards the generation and care of soils and forestry.
So let’s talk examples. Frederick Law Olmstead designed a number of Stormwater collecting parks Into towns. One of the most famous being Boston’s Emerald Necklace. /24
His son John Charles did something similar when he designed Portland Oregon’s water collecting neighborhood of Lauralhurst. Before the current Stormwater system, Laurelhurst Park was the detention basin.
Next step in the journey Is Davis California in the 80s where Mike Corbett designed village homes a neighborhood designed to handle Stormwater by soaking it in Swales and orchards rather then management systems
https://en.wikipedia.org/wiki/Village_Homes
Here’s a video of Mollison touring the place in the 1990s. https://youtu.be/v_05oRQxssQ I’ve heated that they have managed several very large storm events that flooded their neighbors. All while building the soil and restoring the water table.
Village Homes with Bill Mollison (improved audio)
So:,remember this and this question: what if we really looked for a city that took this approach?
Well, here's Siena Italy which started as a number of little settlements and converged in the hills of Tuscany: that big public square is the Piaza Del Campo- built in the key point of the landscape, The roads collect water into drains and reservoirs under the piazzas.
Link to tweet with 3 Images here
28/ if you look at the landscape you see how this hilltown stayed on the uplands and collected water to irrigate the lowlands.
Link to tweet with 4 Images here
Underground passages for water, the 'fountain of the earth' sits at the keypoint, and the lowland valleys are irrigated and saved for soil...
On their blog, HeenanDoherty has a posted a paper originally posted here in all its glory ie with pictures and format. I made an attempt to contact HeenanDoherty via a comment On their blog, to no avail – the page would not let me comment. I have republished AN EXTRACT below. And have created a PDF document from the original source here. To download this worthy paper, go here. SOURCE: …
Vancouver Island folks! I just found out about this great (free!) workshop happening in Victoria on November 24 (short notice, I know) about Keyline design. Did I mention it's free? You just have to register on their site.
"We are discovering a new Australia! As yet, few Australians have seen it." - P. A. Yeomans
Percival Alfred Yeomans is a greatly underappreciated figure in Australia's history. This is the conclusion to which I have come while reading "The Challenge of Landscape" in preparation for a course in regenerative agriculture in West Sussex this week. Yeomans developed a system of landscape development which dramatically and quickly improves even very poor agricultural land by considering and working with landscape pattern. Within permaculture, the keyline system is often misunderstood or treated vaguely as simply a water harvesting technique, amongst other things. Like permaculture, however, keyline is principally about design --- "... from pattern to detail."
As a mining engineer, Yeomans came to farming with a unique outlook. He poured over maps, particularly contour maps, with the idea that there must be some pattern which would allow him to work cooperatively with nature's forces. Allan Yeomans, his son, writes in the introduction to "The Challenge of Landscape":
"He discovered that a contour line, that ran through that point of a valley, where the steepness of the valley floor suddenly increased, had unique properties. Starting from this line, and cultivating parallel to it, both, above the line, and below the line, produced off contour furrows, which selectively drifted water out of the erosion vulnerable valley. He named this contour "The Keyline". The entire system became "The Keyline System"."
Water is primary within the Keyline System but only because it is the first thing over which we may exercise some significant influence in what Yeomans calls "The Keyline scale of relative permanence of things agricultural." What is more succinctly known as "The Keyline Scale of Permanence" includes:
Climate
Land shape
Water supply
Farm roads
Trees
Permanent buildings
Subdivision fences
Soil
One of Yeomans' most important insights in comparison to his agricultural contemporaries was the recognition that soil can be built quickly. With something of a prophetic ring, he announces:
"Soil will improve until Australian soil everywhere is richer and deeper than nature has ever provided."
Nevertheless, soil is last on the Keyline scale because, though most important, it is the least permanent. Yeomans sees soil improvement and fertility in general as a function of other more permanent factors with which we must first work:
"If the effect of climate on soil is fully understood, I believe we have a basic knowledge that will enable us to increase the fertility and productivity of any natural soil ... While there are many ways of worsening the soil climate to reduce fertility of soil, and we have no doubt employed them all, there are, in my opinion, as many ways of improving the soil climate and increasing fertility ... The fertility of good soil can be destroyed before a line of fenceposts will rot. A poor soil can be changed into a highly fertile soil in about a tenth of this time."
This rapid improvement is achieved through adressing the items on the scale over which we have control in turn, beginning with the foundation of water:
"With full water control from Keyline planning, the farm environment improves, the soil improves; the pasture, crops and stock improve in health and their numbers may increase many fold with the growing capacity of the property."
Keyline, then, while emplyoying amazing techniques for slowing, speading and sinking water into the landscape, is not just a technique. It is a system of planning or design for increasing fertility through harvesting sunlight while facilitating sensible placement of agricultural elements in accordance with their relative permanence. We'll get into the geometry and detail of keyline in future posts --- for now, here are some links with great information about Keyline design:
I have been lax in my posts. My intention has been to post each week on a Tuesday but I have been working very long days on the farm and getting little time for writing.
So, excuses aside, I have decided to make a less-than-substantial post which points to some resources I have recently created on the back of other people's generosity.
Next week, I am going to be attending to course on regenerative agriculture with Darren Doherty. As far as I can tell, the course follows essentially the Keyline Scale of Permanance. Some of the key texts in the 'recommended reading' list are three which Steve Soloman of the fantastic Soil and Health Library has made available with the permission of Alan Yeomans --- one of the sons of the indomitable Percival Alfred Yeomans, the author of these three works.
I wanted to be able to read these books on my e-reader, so using 'wget', a GNU / Linux command line tool, I downloaded the full illustrated HTML and, using Calibre, an open source e-book manager, I converted the texts to .epub format, a free and open standard for e-books.
Just in case anyone else finds illustrated HTML as frustrating as I do, I am making the .epub versions of the books available here:
The City Forest
The Keyline Plan
The Challenge of Landscape
Thanks again to Alan Yeomans for giving permission for the Soil and Health Library to host these important works. If you appreciate them, why not buy a hardcopy of Yeomans' classic work "Water for Every Farm" to show your gratitude.
If you're interested in the idea that free e-books could improve sales of hardcopy books, check out Cory Doctorow's book 'Content', available as a free e-book or audio book on his site craphound.com.
