Role of buffer zones in controlling pesticides fluxes to surface waters

Buffer zones may be a useful tool to limit water contamination by pesticides, in complement of a reasonable use of pesticides and agricultural good practices. Different kinds of buffer zones exist, for example vegetative filter strips, humid woods, constructed wetlands. Their efficiency depends notably on dominant hydrological processes: surface runoff, deep infiltration, lateral subsurface flow, tile drainage flow. This article presents the orders of magnitude of different kinds of these elements, and insists on the necessity of a sound diagnosis at the catchment or the hill slope scale in order to optimize the design of a set of buffer zones in a given area.