
Note: all soil erosion and sediment yield values are given in 1,000s of metric tons per year.
Soil conservation practices reduced soil
erosion ("Sources") from 441,000 metric tons/year
during
the 1853-1938 time period to 117,000 tons/year
after 1975 (a 73% reduction),
but the sediment yield
to the
Mississippi River remained virtually unchanged. Why? Coon
Creek adjusted to the reduction
in
soil erosion by meandering and eroding sediment stored in its valley bottom.