Which decision support tools for the environmental management of nitrogen?

Which decision support tools should be developed to help agricultural stakeholders manage nitrogen in an environmentally friendly way? This paper presents the limitations of current decision support tools with respect to the implementation of a four-step quality spiral. PLAN: planning technical actions that satisfy both economic and environmental constraints. The priorities are to develop decision tools at the farm and the regional levels, and to estimate the indirect effects of nitrogen on the environment due to its interaction with pesticides. DO: implementation of technical actions. The design of decision support tools must integrate more information about the way in which farmers and their advisors will use the tools. CHECK: efficiency of the "PLAN/DO" steps must be evaluated on different scales. The priority is to propose and validate environmental indicators. ACT: definition of new priorities for the next loop. Research is required on diagnosis tools for tracing back the causes of environmental problems.