Kentucky State University
Dimethoate Residues in Soil and Runoff Water Under Three Management Practices
Institution
Kentucky State University
Faculty Advisor/ Mentor
George Antonious
Abstract
Dimethoate [O, O-dimethyl-S-(N-methylcarbamoyl-methyl) phosphorodithioate] is a broad-spectrum systemic insecticide currently used world-wide and on many vegetables in Kentucky. Dimethoate is a hydrophilic compound (log KOW = 0.7) and has the potential of off-site movement from the application site into runoff and infiltration water. The persistence and dissipation pattern of dimethoate residues were studied in soil and water under field conditions. Following foliar application of Dimethoate 4E on broccoli foliage at the rate of 0.47 L acre-1, dimethoate residues were monitored in soil, runoff water collected down the land slope, and in infiltration water collected from the vadose zone. The study was conducted on a Lowel silty loam soil under three soil management practices: 1) soil mixed with municipal sewage sludge, 2) soil mixed with yard waste compost, and 3) no-mulch rototilled bare soil used for comparison purposes. The main objective of this investigation was to study the effect of mixing native soil with municipal sewage sludge or yard waste compost, having considerable amounts of organic matter, on off-site movement of dimethoate into runoff and infiltration water following spring rainfall. Runoff water and dimethoate residues in runoff water from the no mulch treatment were higher than sewage sludge treatment. Dimethoate residues in the 10-15 cm top soil were greater (0.27 Fg. g-1 dry soil) in soil mixed with sewage sludge than yard waste and no mulch soil (0.085 and 0.19 Fg. g-1 dry soil, respectively).
Dimethoate Residues in Soil and Runoff Water Under Three Management Practices
Dimethoate [O, O-dimethyl-S-(N-methylcarbamoyl-methyl) phosphorodithioate] is a broad-spectrum systemic insecticide currently used world-wide and on many vegetables in Kentucky. Dimethoate is a hydrophilic compound (log KOW = 0.7) and has the potential of off-site movement from the application site into runoff and infiltration water. The persistence and dissipation pattern of dimethoate residues were studied in soil and water under field conditions. Following foliar application of Dimethoate 4E on broccoli foliage at the rate of 0.47 L acre-1, dimethoate residues were monitored in soil, runoff water collected down the land slope, and in infiltration water collected from the vadose zone. The study was conducted on a Lowel silty loam soil under three soil management practices: 1) soil mixed with municipal sewage sludge, 2) soil mixed with yard waste compost, and 3) no-mulch rototilled bare soil used for comparison purposes. The main objective of this investigation was to study the effect of mixing native soil with municipal sewage sludge or yard waste compost, having considerable amounts of organic matter, on off-site movement of dimethoate into runoff and infiltration water following spring rainfall. Runoff water and dimethoate residues in runoff water from the no mulch treatment were higher than sewage sludge treatment. Dimethoate residues in the 10-15 cm top soil were greater (0.27 Fg. g-1 dry soil) in soil mixed with sewage sludge than yard waste and no mulch soil (0.085 and 0.19 Fg. g-1 dry soil, respectively).