Myths often told and retold in the ongoing discussions over water quality issues in Iowa typically do not hold up to the scrutiny of science, according to Michael Castellano, an Iowa State University (ISU) soil scientist, dur­ing a seminar last month at the 2015 Iowa Farm Bureau annual meeting in Des Moines.

For example, Castellano said, there is a myth that nitrate problems in Iowa waterways are primarily caused by farmers’ mismanagement of...