From decision-support to compliance tool: the social dimensions of Overseer and the implications for farm nutrient management

An increase of public and scientific pressure resulting in recent reforms of New Zealand’s National Policy Statement for Freshwater Management (NPS-FM) has instigated a reliance on Overseer to regulate nutrient losses from agricultural land. Overseer was previously used as a qualitative tool for farmers to assess fertiliser requirements for the following season, but has now changed to a quantitative, compliance tool in use by a number of regional councils. Understanding farmers’ perceptions of this new approach is vital to its effectiveness as a management technique. This research presents an analysis of fifteen semi-structured interviews of farmers and farm consultants from two locations in the Bay of Plenty: The Rangitāiki Plains, who use Overseer for decision-support, and the Rotorua Lakes, who use Overseer for compliance. This research has found that the role of numbers, power and authority, model credibility, perceived fairness, social identity, and the relationship to data production were significant to farmers’ perceptions of Overseer. The perceptions farmers have of Overseer is a key influence in their acceptance of nutrient regulation and adoption of sustainable nutrient management practices. By taking the focus away from individual’s technical understandings of scientific knowledge, this research has attempted to explore the social identities that characterise public responses to regulations. Trust and credibility emerged as key themes in the development of perceptions to the use of Overseer by farmers, shaped by the working relationships between farmers and council staff, council scientists, private consultants, members of the public, and industry representatives. It was found that when considering Overseer, many farmers focus on contextual factors surrounding its use, rather than the practicalities of the model itself. This shows that continued efforts to improve the scientific accuracy of Overseer will not resolve issues of distrust between farmers and Overseer.