A critical physical geography of no‐till agriculture: Linking degraded environmental quality to conservation policies in an Oregon watershed.

A variety of agricultural conservation trends have gained and lost favour throughout the years, with farm bills in the United States often influencing which conservation practices are implemented. This paper explores the consequences of a set of conservation techniques loosely defined as "no‐till agriculture," focusing on their implementation and adoption since 1985, at which point such approaches began to be explicitly encouraged under US Farm Bill soil conservation mandates. We begin by noting a core contradiction that has characterized these approaches in the Fifteenmile Watershed of Wasco County, Oregon, where despite high rates of farmer enrollment in no‐till programs, both no‐till agriculture and sustained tillage have led to the increased use of herbicides and sustained sediment runoff. Using a critical physical geography framework that integrates intensive physical field data collection, spatial analysis, social surveys, and interviews, we address the biophysical and social factors collectively driving changes in herbicide use and variable erosion estimates. We draw particular attention to how farm bill support for no‐till has enrolled farmers in a vaguely defined and underregulated conservation practice that may ultimately undermine environmental quality. Key Messages: No‐till has been broadly used to describe many conservation tillage practices, which has led to inaccurate erosion estimates.Variations in no‐till practices have coincided with unprecedented increases of herbicide.Processes of neoliberalization have influenced the sustainability of no‐till. [ABSTRACT FROM AUTHOR]