Spatial Variability of Pesticides in Field Soils: Methods for Data Analysis and Consequences

The spatial variation of measured pesticide concentrations is often a complicating factor in interpreting the results from field studies. This is particularly true when the study objective is quantitative evaluation of pathways of pesticide loss (leaching, degradation) or efficacy. The variation can result from a lack of uniformity in pesticide or water application (an extrinsic factor) or from spatial differences in various physical, chemical, and biological processes (intrinsic factors) that act to transport and transform pesticides in the field. Most research attention to date has not focused on the spatial variation of these basic processes, but rather on the total spatial variation (extrinsic plus intrinsic) in the measured concentrations of residual pesticide.