The 'Dairy Nitrogen Fertiliser Advisor' - a method of testing farmers' fertiliser decisions against a meta-analysis N-response function

Abstract

Decisions about using N fertiliser rely typically on rules based on expected average pasture responses to N applied, a flawed criterion from the perspective of production economic theory. In this paper, the rationale for a web-based tool called the ‘Dairy Nitrogen Fertiliser Advisor’ (the ‘N-Advisor’) is presented. The tool uses marginal analysis to inform dairy farmers and their advisors about how a range of N applications applied to a particular paddock for a particular grazing rotation add to profits. The tool contains response functions for each Australian state and season derived from a metaanalysis of experiments in pasture yield response to nitrogenous fertiliser undertaken across Au..