[permaculture] Dieter's email on clay
diebrand at yahoo.com
Sat Mar 21 05:22:35 EDT 2009
> I used to hate the idea of stealing organic matter from some areas to …
This is one of the central ideas in Natural Farming. On very small and highly fertile fields, which are typical of Japan, it is possible not to use any organic matter (i.e. fertility) from “outside the field”. In most other places, with larger farms and less fertile soil, it is only feasible not to use organic matter from “outside the farm”. For example, when we use manure in the garden, there is a transfer of fertility from the pasture land to the garden. This is sustainable as long as we avoid overgrazing. Traditional farming in most parts of the World has always grown all fertility (all organic matter) on-site. It is only in the last few decades that industrial-scale agriculture has began to be completely reliant on off-site fertility and soil amendments with all its negative consequences. I haven’t had any external input from “outside the farm” in at least 6 years.
>I am somewhat lucky in that I have a few large oaks around and madrone and oak groves
Same here! Most of our 30 acres are covered by cork oaks and madrone. They are ideal for this climate. They get by without water during a summer and recover after a fire.
>The next step would be to scythe large areas of grass for mulch, but this seems less effective.
Try it anyways! Sometimes the effect is only felt after a year or two.
>Isn't fire a concern at your site?
Half of our property burnt down once in the last 10 years, but a neighbor burnt down completely twice in the same time. And even when we are not directly affected, we often have to evacuate when a fire front approaches. The only safe place in a fire is on a ploughed field. When a fire approaches, people often load all their belongings onto trailers and drive them into the middle of a ploughed field. Many farmers plough a strip of land around the house or around the farm. Still, you won’t find an inch of bare soil on our property because bare soil is dead soil. The terrible quality of soil in this region is due to the combined effects of high temperatures (humus depletes quicker with high temperatures) and the constant plowing used in dry-land farming. Bare ploughed soil backing in the scorching sun loses all life and nutrients oxidize in contact with the air.
When we deal with fire risk we need to find the right compromise between the extremes of removing all combustible materials (i.e. all vegetation), on the one hand, and leaving tons of the stuff laying around everywhere, on the other hand. For example, when you cut the grass to less then 6 inches during the dry season, a fire will just burn through without doing much damage. Placing a few large flat stones around the trunk of your fruit trees can also help. Mulching plots of land you want to improve, while leaving only the stubble in other places also reduces fire risk. If you have too much organic matter for mulching, use some for heap composting at least during the dry season because it is easier to keep a compost heap wet. Thin out shrub and wood land: cut and shred the shrubs in regular intervals, cut the lower branches of trees. There should be a few meters of free space between the grass and the lower branches of trees. Around the house and on
access roads, I use gravel and stone mulches, stone walls, stone gardens, etc. A stone or gravel mulch protects the clay soil just as well as does an organic mulch. Where I have covered the access roads with gravel, the middle strip and road sides produce so much grass and weeds that I can mulch part of our garden with it. There is far less growth in places where I haven’t put any gravel yet. Lastly, avoid fire accelerating plants (pine trees, eucalyptus, etc.) and select fire retarding plants (cistus, oaks, etc.). Unfortunately, most succulents don’t grow on heavy clay.
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