[permaculture] swales vs. complete keyline design?
johnfritz77 at yahoo.com
Mon Aug 31 12:28:01 EDT 2009
As a practical, economic matter, it seems that, for me, incorporating swales on contour makes more sense than to buy a 60 h.p. tractor and keyline plow, or hire someone who has these implements and is adept at using them. The only unknown variable is the efficacy of keyline landscaping, as a whole system,vs. swale earthworks on contour as a stand alone strategy. What would I be losing if I just used swales to retain water in my soil, as opposed to the time and expense of having a complete keyline design adapted to my rolling land? In particular I am thinking about the timeline of energy descent and the availability of a professional keyline design several years out (five, maybe more years) as opposed to obtaining the best swales that I can now afford, even if the contour lines are less than perfectly plotted. One other doubt that I have is the resiliance (sp?) of the plowing done by a keyline chisel plow. I have never seen either a freshly
completed keyline design, nor such a design after several years completion. One thing that is not clear to me is how the chisel plow lines hold up to the natural erosion that would seem to occur over time. Swales seem to have more resiliancy as they are made on gradual sweeping lines that have vegetative protection, whereas keyline chisel plow lines appear to be akin to defiles in the soil and more prone to collapse due to erosion over time...with a resulting need to replow the contour lines. Any corrections to my intuition are welcomed.
John Fritz, NW Arkansas.
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