es062147h_si_001.pdf (259.42 kB)
Enrichment of Heavy Metals in Sediment Resulting from Soil Erosion on Agricultural Fields
journal contribution
posted on 2007-05-15, 00:00 authored by John N. Quinton, John A. CattHeavy metal pollution of soil and water is often associated
with industry, but in this paper we demonstrate that
water erosion on agricultural soil which has received
only agrochemicals has enriched sediment metal
concentrations to toxic levels which breach many accepted
standards for soils and sediments. Eight 0.1 ha erosion
plots with different cultivation treatments were monitored
over a 6 year period for surface runoff, soil loss, and
Cr, Cu, Pb, and Ni concentrations. Mean concentrations
of these heavy metals were up to 3.98 times higher in the
sediment than in the parent soil and in some erosion
events the sediment had 13.5 times the concentration of
metals in the soil. All the sediment heavy metal concentrations
were significantly correlated (p < 0.01) with the clay
and silt sized fractions of the sediment and with carbon
content. The erosion was a highly selective process enriching
the detached material in silt, clay, and organic carbon.
This was particularly true in smaller erosion events. Sediment
metal concentrations tended to follow the shape of
runoff hydrographs, although the pattern changed from
storm to storm.