The utilization of edge-of-field monitoring of agricultural runoff in addressing nonpoint source pollution

While basin-scale studies and modeling are important tools in relating land uses to water quality concerns, edge-of-field monitoring (EOFM) provides the necessary resolution to spatially target, design, and evaluate in-field conservation practices for reducing nonpoint source pollution from agriculture. This paper introduces this special issue of the Journal of Soil and Water Conservation, a collection that provides an overview of EOFM on agricultural lands. The issue describes the transition of EOFM from a mainly research endeavor to on-farm monitoring of the environmental impact and performance of agricultural practices and addresses topics such as (1) disconnect between large-scale loading estimates and the prevalence of sound nutrient management practices; (2) obstacles in identifying the causes, sources, and solutions to agricultural nonpoint source pollution; (3) progress evaluation at the watershed scale; (4) need for additional multiscale studies to better understand the fate and transport continuum and establish linkages between EOFM and in-stream water quality; (5) history of EOFM and recent advances; and (6) alternative methods to determine whether EOF results are acceptable. The increased attention on agricultural runoff has concurrently raised awareness of the need for EOFM. It is at the field scale that data are needed to better understand the fate of sediment and applied nutrients and inform adaptive management to mitigate offsite losses. This special issue compiles the latest scientific information related to utilizing EOFM to evaluate and address agricultural nonpoint sources, and provides a glimpse of EOFM in the future.