Implications of Nutrient Fate and Transport Following Nanopesticide Applications in Agricultural Field Plots in Central Kentucky.

The potential benefits of nanopesticide use over standard pesticides include more precise application at reduced application rates, lower premature degradation, and decreased direct impacts to target organisms. However, field scale investigations of the fate and transport of common nanopesticides such as copper (II) hydroxide and imidacloprid combinations, remain limited. A field study evaluating nano-scale copper (II) hydroxide (Cu), standard imidacloprid (I), nanoimidicloprid (NI), and nano-scale copper (II) hydroxide and imidacloprid (CuNI) compared to control (C) plots was conducted using thirty 14.6 m² field plots to determine the impacts of nanopesticide applications on nutrient cycling and quantify the persistence of copper (II) hydroxide in soil and surface runoff during the growing season. Soil samples were taken at the beginning and end of the growing season, while water quality runoff samples were collected following eleven rainfall events. Ammonium concentrations in runoff decreased in CuNI plots by 1.74 mg N/L, while total nitrogen concentrations in runoff increased by 1.29 mg N/L in Cu plots compared to CuNI plots. Runoff orthophosphate concentrations decreased in CuNI treatments compared to all other pesticide treatments by 1.37, 1.32, and 1.30 mg P/L in Cu, I, and NI plots, respectively. Significant increases in soil copper concentrations were also observed in all plots receiving Cu. These findings emphasize the potential biogeochemical implications of using these nanopesticides on nutrient cycling in agroecosystems.