Conservation, Demonstration Sites, Irrigation, Land, News, Rehabilitation, Soil Biology, Soil Conservation, Structure, Water Harvesting — by Craig Mackintosh PRI Editor December 19, 2009
One of the most influential people in sustainable agricultural systems development is the late P.A. Yeomans. Yeomans went against the contemporary fertility-in-a-bottle school of thought to develop ‘keyline’ concepts of land management that work in harmony with natural land features (working with contours), to maximise water harvesting in the landscape, minimise soil erosion and build lasting soil fertility. His observations and practice led him to design and develop the keyline plow, a deep chisel plow that maximises water infiltration and soil aeration – setting up conditions that soil macro and microorganisms can flourish in – but that doesn’t overturn the soil, with its associated destruction of soil structure and life, as other plows do.
The ABC just ran an interesting spotlight (video – or transcript here if you prefer) where we learn that one of Yeomans’ properties, ‘Yobarnie’, in Richmond, north of Sydney, is facing ‘development’ that would turn this important historical demonstration site into a housing estate. In the 1950s and ’60s the site attracted busloads of people on weekend tours where observers could see the transformation his methods effected and learn about their implementation.
Yeomans’ methods, which have heavily influenced permaculture design systems, are increasingly seen today as having tremendous potential to not only increase agricultural productivity but also to have a significant impact on reducing atmospheric CO2 concentrations through increasing soil carbon levels.
It’s a sad day when such a site, with not only such historical significance, but also present relevance, would be paved over.
For good measure, here’s a YouTube clip of Darren Doherty showing the before and after effect of a single keyline plowing on his property.
- Keyline Plowing with Compost Tea Application
- The Keyline Plan by P. A. Yeomans
- The Challenge of Landscape by P. A. Yeomans
- The City Forest by P. A. Yeomans