An index approach to assess nitrogen losses to the environment

Nitrogen (N) losses from agriculture are negatively impacting groundwater, air, and surface water quality. New tools are needed to quickly assess these losses and provide nutrient managers and conservationists with effective tools to assess the effects of current and alternative management practices on N loss pathways. A new N-Index tool was developed in spread-sheet format, allowing prompt assessments of management practices on agricultural N losses. The N-Index tool was compared with experimental field data and shown to estimate the effects of management practices on N loss pathways (probability, P < 0.001). The N-Index correctly assessed the nitrate nitrogen (NO3-N) leaching losses when tested against measured NO3-N leaching data and atmospheric N losses collected over multiple years (annual basis) and locations. The N-Index tool was developed with international cooperation from several countries and there is potential to use this tool at the international level. (C) 2007 Elsevier B.V. All rights reserved.