A physical and social analysis of how variations in no-till conservation practices lead to inaccurate sediment runoff estimations in agricultural watersheds

Abstract

Although agricultural influence on sediment runoff is well known, determining what sources of sediment contribute most to stream impairment has remained challenging in agricultural watersheds across the world. Therefore, methods to distinguish the sources of sediment in streams are warranted, particularly methods that incorporate information on anthropogenic practices that affect sediment runoff. In this study we examined how variations in conservation practices contributed to unidentified sources of sediment in an agricultural watershed, where 49% of sediment was sourced from agricultural fields that were assumed to have little erosional runoff. We found that variations in the way no-till agriculture is practiced significantly affected estimates of erosion in the watershed and also led agency managers to overlook sources of sediment in the watershed. In doing this research, we provide a methodological framework that may be useful to researchers who are attempting to identify sources of sediment erosion in watersheds impacted by variations in agricultural conservation practices.