Soil Erosion
In a message dated 9/25/99 5:10:55 AM EST, johnsaia@dnai.com writes:
<< Actually, it is believed that much of the loss of soil in the islands
(created by
construction of earthen dikes in marsh area about 100 years ago), is due to
sinking
of the ground, as the "soil" dried as the water has been removed. >>
Of course, the loss of 25 vertical feet of soil is not all due to wind
erosion. Certainly subsidence due to shrinkage and to draw-down of the
subsurface water table have also contributed. Perhaps the most destructive
practice to contribute to the loss of soil on these islands, however, has
been the burning of the corn and sunflower stubble in the fields every Autumn
prior to plowing. On most California farmland, this has no other effect than
to return nutrients to the soil more quickly and make it easier to plow. In
the islands, however, this practice not only burned off the stubble, but also
the top inch or two of soil every year. I believe that it is this latter
practice, more than any other single factor, that has contributed to the loss
of soil. In recent years, I have, however, seen more farmers in the Delta
plowing in corn stubble without burning, so perhaps they are getting the
message.
Kurt Mize
Stockton, California
USDA Zone 9
