The effects of denitrification parameterization and potential benefits of spatially targeted regulation for the reduction of N-discharges from agriculture.

Diffuse nitrate leaching from agricultural areas is a major environmental problem in many parts of the world. Understanding where in a catchment nitrate is removed is key for designing effective land use management strategies that protect water quality, while minimizing the impact on economic development. In this study we assess the effects of spatially targeted nitrate leaching regulation in a basin with limited knowledge of the complexity of chemical heterogeneity.

Application of the re-circulating tracer well test method to determine nitrate reaction rates in shallow unconfined aquifers.

Five re-circulating tracer well tests (RCTWTs) have been conducted in a variety of aquifer settings, at four sites across New Zealand. The tests constitute the first practical assessment of the two-well RCTWT methodology described by Burbery and Wang (Journal of Hydrology, 2010; 382:163-173) and were aimed at evaluating nitrate reaction rates in situ. The performance of the RCTWTs differed significantly at the different sites.