Keyline Design
Plan the work then work the plan.
What is PA Yeomans Keyline System?
Keyline Design is a method of designing and managing farmland that has been around since the early 1940s. It was developed by Australian farmer P.A. Yeomans. Keyline Design is based on the idea of using the natural contours of the land to improve soil fertility, water retention, and overall farm productivity.
The Keyline System was developed to aid:
- comprehensive whole farm design
- contour cultivation
- water storage in farm dams
- better farm road layout
- quick gravity powered irrigation
- contour strip forests
- subdivision
- healing erosion
- solving salinity
PA Yeomans’ philosophy was that permanent agriculture must materially benefit the farmer and the land.
Properties with a Keyline Design are rendered substantially drought proof for a 5 year period. Any rainfall received during the drought is efficiently used to extend the drought protection.
Keyline is an ordered set of principles, techniques and systems.
When fully utilised, Keyline Design produces strategies and tactics to develop the natural or existing landscape through regeneration and enhancement.
Table of Contents
Who was PA Yeomans?
PA Yeomans (1905 – 1984) was a businessman, mining assayer and engineer turned grazier. He developed a reputation for honesty as a good assay of gold and tin in an industry fraught with charlatans and corruption.
After purchasing a thousand acres of poor land 40 miles west of Sydney, he realised that nobody in agriculture was even aware of the importance of soil life.
Water doctrine was created by the US Corps of Engineers whose purpose was to move troops over land efficiently and so drain any water out of the way as quickly as possible. Saving water for later use was not even considered. The military are not in the agriculture business.
Unfortunately, this shortsighted approach was worshiped by the government of the time (even today). He spent the remainder of his life trying to correct this unmitigated stupidity which did not make him a popular man – no statues here.
As a thinking man, he immediately set to researching and designing possible solutions.
If you treat nature with respect, she will tell you her secrets.
PA Yeomans
The Ethics of Keyline Design
Keyline ethics revolve around care for the land and common sense.
They are best described as “Do No Harm” and “Leave it better than you found it“,
The Origin of Keyline
The Keyline System was a journey over years. It did nor arrive full blown.
After the death of his brother in law who was managing his property, PA as he was known, took over the management. He rapidly realised that property management methods of the time were inefficient and destructive.
His block had shallow soil over shale rock and as a result of rampant erosion, was infertile and poorly watered – a real battler’s block.
Having been a professional mining engineer, he was familiar with managing water flow in the landscape. He sought a way to improve the fertility and usefulness of his land.
He immediately addressed the erosion as the waste of precious soil which deeply offended him both professionally and personally.
His next step was to rip the soft shale in an attempt to increase the soil depth. He discovered the Keyline point where the fall of the slope changed when determining how high on the slope to rip. He drew a line on contour through this point and called it the Keyline.
His tool of choice to break up the shale was a deep ripping plough similar to a heavy chisel plough.
He noticed that when he ripped parallel to the Keyline to avoid erosion, that the plough line often deviated to below the contour due to features of the landscape. Later he noticed that where the line was ripped below contour, water was being directed from the wetter gullies out to the dry ridges.
This was a real bonus as it brought ridge country into production.
He quickly modified his systems to include ripping on a falling line below the contour. This improved his prior discovery and granted him better use of his landscape.
Next followed a series of modifications to his plough to minimise disturbance to the topsoil, but to shatter the subsoil and bedrock. The result is the current Yeomans plough. This plough created greater topsoil depth and improved water dispersion by slowing, soaking and storing runoff.
Having improved his water retention, he turned his attention to improving the performance of the land.
The key aspect was water. Undulating country does not lend itself to traditional irrigation. He developed a system of catchment ditches on contour which linked storage dams. This stored water for later use. He now needed an easy system to deliver it to his slopes.
To avoid pumping over the dam wall he used a lock pipe through the bottom of the dam wall and protected it with baffles. This enabled him to direct water via a channel enabling flood irrigation.
The final component of his system involved mixing his pasture species to use selected legumes to provide ground cover and assist the growth of his pasture and grain crops.
The Benefits of Keyline
- Improved soil structure and fertility – By deep ripping, Keyline Systems can help activate the physical and chemical properties of the soil, making it more fertile and productive.
- Increased water retention, distribution and infiltration – By creating water-holding basins and channels, Keyline Systems increase the amount of water available and improve infiltration rates.
- Increased biodiversity – Keyline Systems encourage the growth of different plant species and can improve the habitat for wildlife and beneficial lifeforms.
- Increased productivity and yields – Yield is directly related to soil quality.
- Resilience – Keyline Designed land is better able to withstand climate extremes such as drought and flooding leading to long-term sustainability.
The Challenges of Keyline
- Initial Cost – Implementing Keyline Design can be costly if significant earthworks are required. This expense is quickly returned however.
- Time – Creating a Keyline system can be a time-consuming process if significant earthworks are involved.
- Regulatory considerations – Regulatory considerations need to be taken into account when implementing Keyline Design. Permits may be required for earthworks, or there may be restrictions on how much water can be diverted or stored.
What does Keyline Cover?
- Erosion Management
- Water Management
- Short Duration Flood Irrigation
- Pasture Management
The basic principle of Keyline Design is to use the topography of the land to create a series of interconnected water-holding basins and channels. This allows water to be stored and moved more efficiently across the farm, improving soil moisture levels and reducing the risk of waterlogging or erosion.
One of the key features of Keyline Design is the use of a “keyline,” which the highest contour for earthworks, as it provides the most efficient way to move water across the property. By following the keyline, earthworks can be constructed to create a series of water-holding basins and channels that can be used to irrigate crops and improve soil fertility.
Keyline Design Tools
- Scale of Permanence
- Keyline contour as the focus of the design
- Linked dams on contour
- Irrigation ditches
Scale of Permanence
Yoemans developed a Scale of Permanence for the land. From the most permanent, to the least was:
- Climate
- Land-form
- Water Supply
- Roads and Access
- Trees
- Structures
- Fences
- Soil
The scale is accurate. Mountains can be moved, but it is rare and expensive. Roads usually outlast Trees – look at the Roman roads. Trees regularly outlast sheds and fences. Soil can be modified within one to three years.
When making long term plans, consider this scale the best guide available and address each level in top down order either as a constraint or modification.
Keyline Management tools
- Surveying for level
- Yeomans ploughing
- Grain / pasture / legume companion planting
- Short duration flood irrigation
Plan the work then work the plan.
P.A. Yeomans
Find the Keyline
There is a point in the slope of a valley where the shape of the ground changes from convex to concave – most easily identified by your heels as you are walking directly downhill. This is the key point.
A line on contour passing through the key point is called the keyline. This line should be marked in the landscape, usually by a row of trees, a road or a water collection ditch between dams.
The keypoint will also usually indicate the high water mark for the highest dam site on the slope.
Keyline Ploughing
The main feature of a Yeomans’ Keyline Plough is that it does not greatly disturb the topsoil zone and its micro-life. In particular, this retains the mycelial network which feeds the root network of trees and pasture.
When the land is ripped slightly below contour using a Keyline Plough, water is encouraged to travel from the wetter valley bottom to the dry ridge line. This enables the normally dry ridges to produce better pasture.
Another benefit of Keyline Ploughing is to increase the depth of the soil. Normally an area is ploughed each year for three years, increasing the soil depth and allowing water and air to infiltrate. The newly opened subsoil is thus activated allowing colonisation by soil micro-life and mineral mining for pasture species.
In Summary
In addition to water management, Keyline Design emphasizes the importance of soil health and biodiversity. By increasing the amount of organic matter in the soil and creating a more diverse range of plant species, Keyline Design can help improve soil fertility and create a more resilient system.
Keyline Systems are a sustainable farming approach that takes into account the natural features of the land and seeks to work with them.
Prior to devoting my time to Properly Organic and Designer Acres, I served as a contracted super tech in the bleeding edge of satellite imagery, business management and accounting software, then telecommunication software bringing SMS and Mobile Application Protocol into Australia. I then decided to return to the land. I quickly discovered that apart the shape of the bales and the colour of the tractors little had changed.