Keyline is growing in popularity around the world in both Permaculture circles and without. I think this is a wonderful thing. I have been asked numerous times to explain Keyline, Keyline Design, or the Keyline System many times over the last few years, so I thought I would finally write an article about it. Remember this is just an overview. A whole farm design will incorporate more than just what I will discuss, but this should give a good starting point of understanding for those new to the topic.
The Origin of Keyline
The year was 1944. It was the beginning of December in the farm country about 40 miles west of Sydney, Australia. The land was hot and dry that summer. This was due to a combination of drought and misguided farming practices promoted by the soil conservation departments. Percival Alfred Yeomans (better known as P.A. Yeomans) had purchased about 1,000 acres of poor land the year prior even though he had never farmed before. P.A. Yeomans was previously a door-to-door brush salesman. Then, after completing a correspondence course in mining geology, he became a successful mining assayer, and then an even more successful earth-moving contractor.
Unfortunately, with the land being so dry, a grass fire started. These were not uncommon at that time, but this one proved tragic for P.A. His brother-in-law, Jim Barnes, who was also his farm manager, was out on the land when the fire took off. Even on horseback, he was unable to outrun the fire, and he was killed.
Out of this tragedy, inspiration came. P.A. began to analyze the situation of the dry land with his intellect and experience in mining and earthmoving. He soon determined that the land could be managed in a way to store water on the farm and to keep the soil hydrated. He developed strategies that would not only minimize the risk of racing wildfires but could also build healthy, living, fertile soils.
The Keypoint is vital to the proper implementation of Keyline. In any valley, no matter how small, there is a path down the center of that valley that water will collect and run downhill. Along this central path, the slope of the land will change from convex (where the water is shed or runs) to concave (where the water collects or slows down). You can easily see this point in the illustration. It is important to note that this transition or inflection point from convex to concave is NOT the true Keypoint according to P.A. Yeomans. Many practitioners will use this inflection point as the Keypoint, and I don’t think there is a huge difference, but it is not the same. According to Yeomans, the Keypoint is really the point just a little farther downhill, still along this central path of the valley, where the force of water movement changes from erosive to deposition. Typically, this means the Keypoint is just a bit downhill from the inflection point. On steeper slopes, the Keypoint is close to the inflection point. On more gentle slopes, the Keypoint is farther away from the inflection point.
From a practical standpoint, how do we actually find the Keypoint? Well, there are a number of ways to do this, and it sometimes takes a bit of time. We should start off with a topographic map if available, and this will begin to narrow our search. The more accurate the map (professional topographic survey, RTK GPS, LiDAR, etc.), the faster we will be. But a homemade map using flags and some sort of surveying device (A-frame level, Bunyip level, Laser level, etc.) can also be used. These can still be extremely accurate (just ask the ancient Egyptians!), but they may take longer to create for larger properties. I am not going to get into mapping properties or reading topographic maps now, so if you have questions about this then I would recommend watching some videos on YouTube (seriously).
The inflection point can be found in the valley where the contour lines shift from moving closer together to moving farther apart. This is best seen in the illustration. The Keypoint, as described above, will be found just a bit downhill from this inflection point. This requires actually getting out on the land and making some observations. Typically, when you are at the Keypoint, you may notice more lush grass growth, more organic matter, and/or deeper soil. I emphasize the word “may” because nature doesn’t read our textbooks. There can be a very distinct change, or it can be so subtle that we just can’t tell.
With more experience, it becomes easier and easier to find the Keypoint. I’ve seen Mark Shepard, of New Forest Farm, locate the general location of the Keypoint within just a few minutes of walking the land. It’s not voodoo, it’s experience!
In my opinion, while there may be one, exact, pinpoint Keypoint, in practice and in practical use, getting somewhere close is what matters. As long as you are at or downhill just a bit from the inflection point, you will be in good shape.
As an example, here are images from our farm, the Bauernhof Kitsteiner, in East Tennessee (USA).
Once we have located the Keypoint, then the Keyline is a simple next step. The Keyline is just a line on contour with the Keypoint. See the illustration below. Note that the Keyline truly does not extend all the way to the ridge as there cannot be a Keypoint on the ridge. We will discuss how to handle ridges in a bit.
The first key thing to remember, no pun intended, is that the Keyline is a reference line. I sometimes call it the Keyline reference contour to remind myself that the rest of the system is based on, or referenced to, this contour line. Once we have our Keyline determined and marked, then parallel lines can be drawn on our topographic map. The parallel lines are drawn both above and below (uphill and downhill) of our Keyline.
The second key thing to remember is the relationship between the parallel lines and the land’s underlying topography. This concept is a bit more involved, but it is vital. It is the entire reason Keyline works. The relationship of the lines parallel to the Keyline with the existing topography is why Keyline Design functions.
Now let me elaborate. When we draw our parallel lines on our topographic map, we see that these lines start to cut across our land’s existing topographic contours. The parallel lines will start to transect the land’s contours. Our parallel lines move from uphill in the valley to downhill toward the ridge. Please see the illustration below to see what I mean. The result of this relationship is really important, and I will also elaborate on this in the next section, so stick with me if it’s not clear.
Keyline Plowing (Cultivating)
Drawing lines on a map is great, but not very useful if we don’t do something with it. So let’s talk about using our Keyline to make a difference on the farm and on the land.
To begin, we need to understand how water wants to naturally move in the landscape. Water will always move at 90-degrees to contour (i.e. water always moves downhill). The natural tendency of water is to move from the ridges to the valleys. This is why valleys are green or even boggy in some areas and ridges are dry and therefore can sometimes become eroded.
Our goal with Keyline is to try to evenly disperse water over our landscape. This means we need to try and change the tendency of water to move from ridge to valley, and instead have it move from valley to ridge. We will not, without massive earthworks, be 100% effective in this. And we do not want to be. We don’t want to desiccate our valleys. We just want to move some of the excess water from our more wet spots to our dry spots.
They way we do this is with a subsoiler or the Keyline Plow which, in my opinion, is really just a fancy subsoiler (I know some will disagree with this!). A subsoiler is an implement that attaches to a tractor. This tillage tool was designed to break up the hard pan, i.e. the dense layer of subsoil that is often man-made when we repeatedly run tractors back and forth over the land. Use of the subsoiler results in deep furrows that loosen the soil, beak up compacted areas, and shatter the hard pan. But it does not turn the soil. This minimal disruption of the soil layers helps preserve the natural soil stratification and soil biology which is integral to farm health.
In our Keyline System, we use a subsoiler (or Keyline Plow) to follow our parallel lines we created on our map. The deep furrows in the landscape therefore are running parallel to our Keyline. As on our map where the parallel lines transect the land’s existing topographic contours, our subsoiler’s furrows also transect the land’s topographic contours, and our furrows move from uphill in the valley to downhill toward the ridge. If we imagine our furrows as miniature canals, we can now start to see the magic of the Keyline system. When it rains, water will fill these little canals and flow from uphill in the valley to downhill toward the ridge, instead of moving straight downhill into the valley.
In reality, a drop of water that falls in the center of the valley is not going to travel all the way toward the ridge. The water will be absorbed into the soil well before it reaches the ridge. However, it will move toward the ridge a few millimeters or a few inches or more depending on the saturation of the soil. If every drop of rain moves a few inches toward the ridge, then we will have a net result of more hydration toward our ridges instead of away from our ridges.
The other benefit of Keyline plowing is that it gets oxygen down into the soil. We disrupt the anaerobic conditions (low oxygen) of compacted soil. When oxygen can get deeper into the soil, and the soil can stay routinely moist with our Keyline design, then the beneficial soil life can move deeper and deeper into the soil. It can also start to move into the subsoil as well. When beneficial soil life gets into the subsoil, then the subsoil will turn into topsoil. This is how we can create topsoil from the top down!
The idea with Keyline plowing is to get the subsoiling (cultivation) down as deep as you can go, within reason. Oftentimes, the first pass can only be made to a depth of a few inches although a good goal is 8 inches (20 cm). We want to get deep, but we may be limited by the soil condition or the power of the tractor we are using. If you keep breaking shear pins (the pins attach to the frame being pulled by the tractor, and these break before the subsoiler itself does – pins cost a lot less than a subsoiler shank!) than you are probably too deep. If you are using a smaller or weaker tractor, then the subsoiler will not move or will move very slow. If you can only get 2-4 inches deep (5-10 cm) on your first pass, you can immediately run a second pass in the same furrow to try to get deeper, again with a goal of about 8 inches.
The frequency of Keyline plowing will vary depending on the soil’s progress, the goals of the farm, the budget, and a number of other factors, but most landscapes will not need to be cultivated more than three times if the fields are otherwise properly managed (this is where I will unabashedly recommend Holistic Management as a tool to manage our land). These two to three subsoil plowings can take place once a year, but may also be done in early spring and late autumn of the same year, again depending on the soil and environmental conditions.
I also know that Mark Shepard will also run his subsoiler close to his treeline to act as a root trimmer. He does this early in the trees’ lives, before the roots get too large, to prevent the roots from growing out into the fields. Also, since his fields are all set up on the Keyline system, he is staying on his Keyline parallel lines when he does this.
The above diagram shows how to handle ridges. Basically, the tractor will follow the lowest contour at the ridge that will be subsoiled (cultivated). The pattern will work back uphill from there, blending into our lines parallel to our Keyline (i.e. the parallel lines that follow the Keyline Contour Relationship) as we transition from ridge back to valley.
Keypoint Dams (Ponds)
(store water high in the landscape)
In Keyline Design, we want to store water as high in the landscape as possible, but we only need to do this when appropriate. Although I really do think ponds benefit most landscapes from, at a minimum, an ecological and aesthetic perspective, not all valleys need ponds, and not all landscapes need ponds. It just depends on your goals. The benefit of water high in the landscape means that we can use gravity to move the water. Multiple ponds means less, or at least shorter, infrastructure to move the water from its source. Gravity systems may be more costly upfront, but they are more passive and enduring over time.
There are many types of ponds/dams that can be built, again depending on the landscape and our goals. Without going into too much detail, the first type of pond often associated with Keyline Design is the Keypoint Dam.
The Keypoint Dam is located in the valley along our Keyline as depicted in the diagram above. Multiple Keypoint Dams may be built, one in each valley. Water channels may also be built that collect water and transport it to the ponds. The water channels may also transport water from one pond to the next (with a very gentle slope at 1:300-400+) while also allowing irrigation to occur.
There is more to placing a Keypoint Dam than just having a valley, and there are also many other types of dams/ponds that can be built. In addition, there is more to the entire Keyline Design System or Plan (roads, trees, buildings, etc.) than presented here, and I will share more about that in the future. For now, I hope this article serves its purpose by providing an introduction to the basics concepts of Keyline.
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Photo References (other than the photo of P.A. Yeomans, all color photos are mine. Please ask if you’d like to use them!):