Mass Balance and Swath Displacement Evaluations from Agricultural Application Field Trials

Spray drift is an ongoing concern for any agricultural application and continues to be the focus for new developments and research efforts dealing with drift reduction, best management application practices, and new decision support systems for applicators. Typically, field trials conducted to evaluate and compare these new technologies and methods lack sufficient in-swath and near downwind data resolution to allow for an accurate mass balance from the in-swath spray portion and furthermore to determine both the effective swath width of the application and the swath displacement resulting from sprayer travel line or meteorological conditions, or both, present at the time of application. Both are critical in defining the fraction of the applied material that is considered spray drift versus in-swath deposition. This work presents an exploration into a modified sampling protocol and analysis method designed to allow for a detailed examination and determination of the effective spray swath width and the lateral downwind swath displacement to provide a better understanding of data collected during spray application trials, ultimately providing applicators with improved guidance on how to best compensate for swath displacement.