Scale of Permanence
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The scale of permanence is a tool developed by farmer and engineer PA Yeomans in the 1950s as part of a strategy for farm planning he called keyline design. The scale was the backbone of his system for whole farm planning, and was originally dictated as:
- Climate
- Landshape
- Water Supply
- Roads/Access
- Trees
- Structures
- Subdivision Fences
- Soil
It defines the features of the land from the most permanent to the least. We would have difficulty changing the climate quickly ourselves, but can modify the soil in 2-3 years. Trees do tend to outlast sheds and other structures. Once established, roads rarely change their path.
Keyline is a set of principles, techniques and systems, which form the logical basis for a practical plan for the sustainable development of rural and urban landscapes.
Table of Contents
A permanent design
Base your design system upon the Scale of Permanence.
Climate and landform are effectively permanent. As you progress downwards through the list, each aspect becomes more flexible, malleable and amenable to change. This makes more options available. Top down design does not create as much work as bottom up which if changed, must be totally changed.
Aim for a permanent and sustainable farm design. Constantly updating and renewing a design on the land becomes expensive rapidly – both in outlay and in lost production.
Climate
Climate is one of the relatively fixed features of a landscape. It can change, but does so very slowly – and usually in a repeating cycle.
Mankind is fooling itself if it thinks it can make more than minimal change to climate – warming or cooling. The quantities are just so vast that our production of greenhouse gasses is minimal compared to that produced and stored by nature.
Do not be misled by the mouthings of activists, politicians and bought scientists using the current changes to hide their agenda.
We have finished global warming, global weirding (the random effects between warming and cooling trends) is nearly complete and we are now entering the global cooling phase. This is part of a regular cycle – consider the warmer times either side of the little ice age.
Landshape
It is possible to add or remove a mountain with our machinery, but it is rarely done. Like climate, landshape does change gradually. Overall it is a given.
The shape of the landscape has a large effect on the micro-climate of an area.
The shape,of valleys and hills controls the direction and strength of the local winds. This also directs the fire risk, the flow of hot and cold air, the pooling of cold air in the frost zones etc
Aspect determines the quantity and quality of solar radiation received at the ground. Is the light direct from the sun or is it scattered? Is it reflected off a snowfield or a large body of water?
Contour determines the availability and location of run-off water. It also modifies airflow. When planning a property, consider the effects of slope assisting or hindering movement of goods and livestock. Make gravity your friend.
Water Supply
Water supply has two aspects:
- existing water features like creeks and rivers
- added features like dams and drains
When adding dams, consider joining them with shallow ditches on contour. Thus when one dam fills, its overflow will be directed to another, thus saving the most of the available run-off. Traditionally run-off has been regarded as a nuisance to be removed as safely and quickly as possible – not a smart move in a dry country, Clever controls can reserve the water for when it is most needed – a most important feature of property improvement.
Keyline dams are usually fitted with a lockpipe which is a horizontal pipe and tap under the wall to make stored water available without the need of a pump.
Roads/Access
Under the Keyline system, roads and access are on contour where possible and up the centre line of a ridge where not.
The contour based road is a non eroding water trap and used to catch run-off for dam supply. Roads up a ridge line rarely erode as they mark the watershed. Water runs off to either side rather than down the road.
Trees
Trees are strategically placed above a road or on-contour drain. When near a road, care is taken not to shade the road and keep it wet leading to ruts.
Timber can act as a windbreak to spoil the flow of hot drying air and redirect the down-slope flow of cold air – often pooling it until it can be warmed by the sun. They can also act as shelter belts and camps for livestock.
A camp will naturally collect animal manure and allow it to be broken down organically then washed down-slope to fertilise the hill.
Structures
Structures have varying lifespan, depending on how they are built and used. They must be functional to last. Otherwise they will be moved or replaced. A useful stone shed is almost permanent, however a timber and corrugated iron hay shed is usually a ruin inside 70 years. When repaired, it is effectively replaced.
Most sheds serve two purposes:
- shelter / storage
- water collection
Subdivision Fences
Fences are like sheds, their life is determined by their utility and construction.
Changing trends in livestock management can cause them to be moved. If they are built of stone they will last until someone needs a ready stock of stone for some other structure.
Timber and wire fencing must be maintained constantly – the wire breaks and the timber rots.
Soil
Soil is ephemeral. It can be destroyed in 3-5 years and repaired in the same time.
The use of a Keyline plough can build soil at a rate of inches per year. A disc plough can break the soil structure and allow it to blow or wash away as quickly.
The value and structure of a soil is usually determined by the amount of micro-organisms it contains. These days that is measured by the amount of encapsulated carbon.
Avoid breaking and turning the soil layers which results in compaction and erosion. Instead consider no or low till systems like chevron rollers and cross T drilling. At all cost protect the soil life unless you are considering broadacre hydroponics as your cropping system. Inputs are expensive – biology is much less so.
Author’s Note
Consider the sustainable aspects of Regenerative and Biological agriculture. They are generally more productive and less expensive to manage,
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.