Agricultural nutrient balances as agri-environmental indicators: an OECD perspective

In its policy and indicators work on agriculture and the environment, the O ECD has been addressing a large range of policy relevant issues of concern to countries, including the issue of nutrient use in agriculture. The polic y issue in the case of agricultural nutrient use is to maintain sufficient nutrients to ensure the sustainable use of soil resources to improve crop a nd forage productivity, while reducing surplus nutrients from agriculture f rom causing water and air pollution. It is against this background that the paper describes the overall policy context of the nutrient use issue, in p articular nitrogen use. The paper examines the use of the soil surface nitr ogen balance indicator in the OECD work to analyse national trends in nitro gen use, and examines the data requirements, availability and coverage to c omplete nitrogen balance calculations. A brief overview of the current situ ation and recent trends in national nitrogen balance across OECD Member cou ntries is provided. Finally, the paper discusses the interpretation of tren ds in national nitrogen balances, including consideration of benchmarks and targets, linkages with other agri-environmental issues, such as water qual ity, and also future challenges for quantitative work on nitrogen use issue in agriculture.