Solute transport in eroded and rehabilitated prairie landforms. 2. Reactive solute.
The impact of varying soil, landscape, and climate conditions on the off-site transport of pesticides must be determined to develop improved pesticide management practices. This study quantified the rate of S-metolachlor dissipation after fall and spring application in eroded and rehabilitated landforms in which topsoil was moved from the lower slope to the upper slope. Fall-applied metolachlor provided no control of annual grasses because approximately 80% was removed from the root zone during the winter and early spring, presumably by leaching and runoff. S-Metolachlor dissipated in the spring with a DT(50) of 24-29 days. These results suggest that fall-applied metolachlor may not provide economic weed control and presents an increased risk of water contamination. Although landscape position and bulk soil movement within the landform had a large impact on soil properties, no significant differences in metolachlor dissipation between different landscape positions and between eroded and rehabilitated landforms were observed.
Papiernik
Sharon K
SK
North Central Soil Conservation Research Laboratory, Agricultural Research Service, U.S. Department of Agriculture, Morris, Minnesota 56267, USA.
Koskinen
William C
WC
Yates
Scott R
SR
D000081:Acetamides / Q000032:analysis*; D010575:Pesticides / Q000032:analysis*; D012621:Seasons; D012987:Soil / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis*; D014872:Water Movements
D000081:Acetamides; D010575:Pesticides; D012987:Soil; D012989:Soil Pollutants; C051786:metolachlor