Application of nitrogen and phosphorus criteria for streams in agricultural landscapes.

摘要: Efforts to control eutrophication of water resources in agriculturally dominated ecosystems have focused on managing on-farm activities reduce nutrient loss; however, another management measure for improving quality is adoption environmental performance criteria (or ‘outcome-based standards’). Here, we review approaches setting nutrients, summarize developed Canada ‘ideal’ and ‘achievable’ streams agricultural watersheds, consider how such could be applied. As part a ‘National Agri-Environmental Standards Initiative’, the Government committed development non-regulatory standards that establish total P (TP) N (TN) concentrations protect ecological condition streams. Application four defining ideal using only chemistry data resulted values TP TN spanning relatively narrow range within given ecoregion. Cross-calibration these chemically derived with information biological recommendations would likely aquatic life from adverse effects eutrophication. Non-point source modelling was then conducted specific watershed estimate achievable standards, i.e. chemical conditions attained currently available recommended practices. Our research showed that, taken together, short-term ultimate used set policy targets should, if realized, lower Canadian improve biotic condition.