We investigate in a hydrologic-economic integrated model framework, how different incentive instruments aiming at regulating the emission of no-point source pollutants (herbicides) do heva an impact on cultural practices. Based on multiparametric programming techniques, two combined tools are considered by the decision model: (i) positive and negative quality-based differentiation of the price of the products and (ii) positive differentiation and tax on the polluting inputs. Non-linear responses are observed, with a favorable environmental effect at the farm level when positive differentiation of the price is noticeable. However, this favorable response at the farm level results into poor performances at the watershed level, because the described incentive design does not include location-based devices.
