Keyline is a method of land development that was devised by PA Yeomans in the late 1940s. The term “Keyline” refers to a point where the gradient of a slope changes. It is below this point that the landscape lends itself to the methods of water transfer and retention. The Keyline plan is based on the natural topography of the land.
Combined with this are the tree belts, either planted or left standing during the process of clearing. The tree belts provide shelter to the pasture and stock. Even the infrastructure, fences & tracks, can be designed into the developed areas.
While there are principles to follow, make your own valuation of the land form, the plant species on it and the soil types. Do not try to turn rock into soil, be flexible, leave the trees in those poorer soil areas and concentrate on the more fertile soils.
Be aware of the native species of grasses and support them in their natural environment. Recent consecutive years of drought have shown that for certain areas, the native grasses have had the greatest resilience and supported stock were introduced species have not.
In order to create the best principals of water redirection & retention the soils need to be ploughed in a specific pattern. This method of ploughing runs on a “modified” contour, where the modification requires that the pattern falls in height from the wetter gullies to the dryer ridges. This means that with rainfall the water is not running directly to the lowest point (gully) but will tend to move laterally towards the ridges.
Because of the increased costs of tilling soils it is important to calculate the financial and environmental benefits of the process. Because of the vast amounts of rock at the soil surface on Knockalong, we find that the structure of the soil is excessively disturbed and so we choose areas with greater fertility and less rock.
The document “The Geographical and topographical basis of keyline” By Prof J. MacDonald-Holmes, (modified and saved as a PDF file), gives a detailed description of the basis of Keyline. It originated from the link http://www.yeomansconcepts.com.au/basis-of-keyline.htm
Information on related products etc. can be found at “Yeomans Plow”.