Soil is a dirty word. Pejorative even. Soiled clothes; soiled himself; soiled reputation. Usually washed clean with water. Both soil and water are vital for growing food, hence fundamental for life, but Australia is the poorest continent for both.
As you might expect, given our old degraded soils and high levels of drought, Australian design is renowned for many responses to these issues, think water tanks or Permaculture. Less well known is a pioneering system to improve both, called Keyline design.
In a period when talk of soil conservation held sway, thought of by scientists such as Dr H. H. Bennett as a resource which only declined and not replaced, Australian inventor P.A. Yeomans developed ‘Keyline’ - a two-part system to reverse the idea: to make more soil. The idea is deceptively simple: open up the soil with particular deep ploughing, and then control water flows into those furrows.
Percival Alfred Yeomans was born in 1905 and trained as a mining engineer and gold assayer, and in practice developed a keen sense of hydrology, as well as designing equipment for his engineering work. When his brother-in-law, a farmer, died in a grass fire Yeomans assumed the management of a large tract of land that he named Nevallan in NSW.
Wanting to improve the farming he came to understand the value of promoting the growth of more soil deep down without fertilisers. This is quite different to the usual tradition of turning the soil over, exposing more minerals to the air, but eventually depleting the whole of the soil of its value.
Instead the Keyline system leaves the upper layers of soil intact and makes fresh quality soil from the inert, poor quality soils below. This it does using single deep plough, developed from the American idea of a ‘chisel plow’, into a narrow tine to pull the soil apart without turning over the topsoil. The narrow and deep incisions induce water and air deep into the ploughed soil where, together with organic material, it quickly improves.
But how to get the sparse water into those newly created furrows? This is where the most ingenious second part of the Keyline system comes in, making water appear to run uphill.
On a farm, water will run down from a ridge to the gully at right angles to the contour, increasing in speed and energy causing erosion and degrading the area. Ploughing along the contour will only increase the damage. In the Keyline system a point is picked between the steep and shallower parts of a valley called the ‘Key Point’. A contour is established from that point known as the Keyline. Deep plough lines run parallel to that contour, higher up the slope.
Those parallel cuts will increasingly run out and slightly down towards the ridges, the water being channelled by gravity into areas where the least amount of water normally gathers. The water that falls near the valley, normally forming a stream, now runs to the ridge, seemingly uphill.
This has three beneficial effects; firstly, it slows down the run of the water, reducing erosion; secondly, it distributes water more evenly over the land, particularly into areas which normally have less water penetrating into the soil from rainfall; and thirdly, along the Keyline contour, it allows the water to enter the soil, together with air, to promote extra depth of soil.
In this system the ideal position for dams is along the Keyline contour, much higher than the usual position, so a series of small dams holding water, ensuring a constant water supply can be that can be then fed down the furrows in drier times.
Yeomans not only invented the idea of Keyline, but a number of designs to go with it, notably the Yeomans Plow, and the Bunyip, a type of level to assist in establishing the Keyline. He also had a few ‘bon mots’ including that one should “feed the soil, not the plants” and “plan the work and then work the plan”.
Yeomans’ ideas have been carried on since his death in 1984. His sons Ken and Allan promote the work, the latter publishing a book called ‘Priority One’ in 2005, carrying the ideas forward into 21st century issues of climate change and food security. His concepts underpin much of author David Holmgren’s (and Bill Mollison’s) early research for the far more well-known system of Permaculture.
Now expounded in more than 120 books, Permaculture is now seen as absolutely essential in mitigating climate change, capturing more CO2 into the soil, promoting more organic farming, with better quality soils, and therefore better and more easily produced food, with less need for artificial fertilizers.
P. A. Yeomans should be far better known than he is. Throughout his life he was considered somewhat of a crank, even though University of Sydney undertook research that established the veracity of his claims for the system, and Keyline Design is now part of the agricultural course curriculum of university and colleges; and has been adopted by farmers around the world.
Although he received the Prince Phillip Design Award in 1974, he never received an Australian Honour, particularly poignant given the recent awards to careerists for just doing their job, or worse, politicians whose work has been so counterproductive. As we strive in Australia to make better soils and use our limited water better, P. A. Yeomans work will become increasingly appreciated.
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