Ian farms with his wife Sharon near Stuarttown, NSW. Darrin Doherty put me onto Ian, as Ian is trained in holistic management and has a good understanding of the Keyline principles developed by PA Yeomans in the 1960’s. Ian’s property was currently destocked as a result of the drought but he gave me a good rundown of the Keyline design principles and showed how he puts them into practice on his farm.
Yeomans developed what he called Keyline Scale of Relative Permanence to be used when planning an agricultural landscape and is as follows:
- Land Shape
Climate and land shape are a given and thus need to be considered first. When looking at the land shape, keypoints and thus keylines are identified and the design of the farm revolves around these keylines. Pattern ploughing is a subsoiling technique done relative to the keylines, promoting aeration and water infiltration and runs any excess water away from steep valley or ridges gently outward to the more moderate slopes.
Roads are placed along ridges creating a low maintenance road, avoiding runoff waters and erosion and also providing great vantage of the landscape as you travel across. The success of this technique was obvious as all roads on Ian’s property were great, except one that required maintenance after major rain events as it was placed in a poor location due to the property boundary hindering its placement.
We spent a few hours walking around one of the original Yeoman’s properties near Orange to get some perspective of what PA was dealing with as he developed the Keyline system. All of the original Yeoman’s properties have been sold off, most being developed for housing and none of them are still functioning as farms. This property was owned by a contractor who ran a few horses and wild kangaroos had severely overgrazed the pastures. Nonetheless, the original dams and irrigation and diversion channels were still present so we were able to get an idea of how the system would work on the landscape. Obviously the hills were much more abundant and steeper than the landscape back home but much can be learned from the keyline principles when planning the landscape of our farm properties.
For the most part we can increase the water infiltration capacity of our high organic matter soils to absorb all but very extreme rainfall events but I think we have plenty of opportunities to harvest windblown snow off the landscape at home and increase our effective precipitation. Our farm is on the edge of pothole country so the potholes historically performed that function for us to some extent but there is certainly opportunity to strategically plant tree rows and collect some more snow as long as it is put to good use and doesn’t just water log the system. When perennials are used in the crop rotation they do a good job of intensifying the water use and allow us to capitalize on increased forage growth feeding ruminants.
For more information, an online book called the Geographical Basis of Keyline by J MacDonald Holmes is a good starting point for keyline design principles.