The influence of a peat amendment and turf density on downward migration of metalaxyl fungicide in creeping bentgrass sand lysimeters

Downward migration of the fungicide, metalaxyl (N-(2,6-dimethylphenyl)-N-(methoxyacetyl)-alanine methyl ester) in irrigated creeping bentgrass (Agrostic palustris Huds) sand lysimeters was studied as a function of two factors: (1) amending sand with peat and (2) density of the bentgrass turf. Based on the determination of metalaxyl in leachates collected at specific intervals following fungicide application, the presence of peat in the sand delayed the downward migration of the fungicide. The percentages of total applied metalaxyl found in the collected leachates generally decreased as turf density and surface organic matter increased. Literature on the subject of the downward migration of metalaxyl in soils is reviewed.