Why soil testing is not enough: A mixed methods study of farmer nutrient management decision-making among U.S. producers

Understanding farmers' nutrient management decision-making is critical to minimizing nutrient loss to water resources. This research examines farmer decision-making in the United States surrounding nutrients (primarily nitrogen and phosphorus) and water quality among 105 farmers in Missouri, North Carolina, and Ohio. Data were collected between 2015 and 2016 using a mixed-methods approach of in-person farmer interviews and accompanying quantitative surveys with demographic and Likert ranking questions. This work presents findings regarding 1) how farmers made decisions, 2) who and what they consult with when making decisions, and 3) how their views on local water quality and regional pollution impact their choices. Farmers reported many resources for information when making nutrient management decisions including yield data, market prices, weather, product availability, prior experience, risk management/avoidance, university research reports, soil and tissue sampling, and social networks. Location also shaped how farmers made nutrient management decisions both because of differences in the structure and types of professional and informal support available to farmers as well as how individuals perceived the severity of local water problems. Younger farmers saw more room for improvement in their nutrient management practices while older farmers were more likely to be satisfied with current practices and decisions. Ultimately, our findings suggest we need to tailor programs and education to regional economic, social norm, and environmental contexts with recognition that past experiences and long-term knowledge shape how farmers receive new interventions. Constructing multifaceted approaches to address these diverse conditions is a critical step in improving water quality when it comes to nutrient management choices.