Submitted to: Soil and Water Conservation Society
Publication Type: Abstract Only
Publication Acceptance Date: 7/22/1997
Publication Date: N/A
Technical Abstract: At the watershed scale, the impact of agricultural chemicals on stream water quality is not a simple function of land-use. The interaction of soils, hydrology, climate and the chemical properties of the contaminant, control transport to the stream. In this study, water samples were collected from 95 streams throughout northern Missouri in 1994 and 1995. Sampled watersheds range in area from 40 to 7880 sq. mi. Different water quality problems exist in the Central Claypan Region (CCR) than in the Deep Loess Hills (DLH). During post-plant sampling, streams in the CCR (poorly drained soils) had consistently higher atrazine concentrations than did DLH (well drained soils) streams, even though treated acreage is significantly higher in the DLH. However, nitrate concentrations were higher in DLH streams than CCR streams. Greater percolation in the DLH leads to more nitrate transport to ground water which then discharges to the streams. Runoff events are less common in the DLH, but transport of chemicals attached to sediment may be significant for these highly erodible soils.