Agriculture and the Quality of the Nation's Waters Active
Intensive studies by the USGS National Water-Quality Assessment (NAWQA) Project in agricultural areas provide insight into how agricultural activities have altered the natural flow of water and the way that agricultural chemicals enter streams and aquifers, and in particular how nutrients affect algal and invertebrate communities in agricultural streams.
We all have a connection to agriculture, which supplies a major part of the Nation’s food, feed, and fiber needs. Agricultural chemicals move into and through every component of the hydrologic system, including air, soil, soil water, streams, wetlands, and groundwater.
The results of these NAWQA agricultural-area studies are described in two USGS publications: Agriculture—A River Runs Through It—The Connections Between Agriculture and Water Quality (Circular 1433) and Understanding the Influences of Nutrients on Stream Ecosystems in Agricultural Landscapes (Circular 1437). Find additional publications under the Publications tab and presentations under the Multimedia tab.
Follow the links below to web pages on topics related to agriculture and water quality.
Regional Stream Quality Assessment (RSQA)
Below are multimedia items associated with this project.
Below are publications associated with this project.
Agriculture — A river runs through it — The connections between agriculture and water quality
Environmental and Biological Data of the Nutrient Enrichment Effects on Stream Ecosystems Project of the National Water Quality Assessment Program, 2003-04
Algal and Invertebrate Community Composition along Agricultural Gradients: A Comparative Study from Two Regions of the Eastern United States
Estimating Water Fluxes Across the Sediment-Water Interface in the Lower Merced River, California
Occurrence and fate of pesticides in four contrasting agricultural settings in the United States
Transport and fate of nitrate at the ground-water/surface-water interface
Pesticides in rain in four agricultural watersheds in the United States
Variations in pesticide leaching related to land use, pesticide properties, and unsaturated zone thickness
Using heat to characterize streambed water flux variability in four stream reaches
Pesticide fate and transport throughout unsaturated zones in five agricultural settings, USA
Chemical and toxicologic assessment of organic contaminants in surface water using passive samplers
Simulated fate and transport of metolachlor in the unsaturated zone, Maryland, USA
National, holistic, watershed-scale approach to understand the sources, transport, and fate of agricultural chemicals
- Overview
Intensive studies by the USGS National Water-Quality Assessment (NAWQA) Project in agricultural areas provide insight into how agricultural activities have altered the natural flow of water and the way that agricultural chemicals enter streams and aquifers, and in particular how nutrients affect algal and invertebrate communities in agricultural streams.
We all have a connection to agriculture, which supplies a major part of the Nation’s food, feed, and fiber needs. Agricultural chemicals move into and through every component of the hydrologic system, including air, soil, soil water, streams, wetlands, and groundwater.
Sources/Usage: Public Domain. View Media DetailsThe results of these NAWQA agricultural-area studies are described in two USGS publications: Agriculture—A River Runs Through It—The Connections Between Agriculture and Water Quality (Circular 1433) and Understanding the Influences of Nutrients on Stream Ecosystems in Agricultural Landscapes (Circular 1437). Find additional publications under the Publications tab and presentations under the Multimedia tab.
- Science
Follow the links below to web pages on topics related to agriculture and water quality.
Regional Stream Quality Assessment (RSQA)
The goals of the Regional Stream Quality Assessment (RSQA) are to characterize multiple water-quality factors that are stressors to aquatic life (contaminants, nutrients, sediment, and streamflow alteration) and to develop a better understanding of the relation of these stressors to ecological conditions in streams throughout the region. - Multimedia
Below are multimedia items associated with this project.
- Publications
Below are publications associated with this project.
Agriculture — A river runs through it — The connections between agriculture and water quality
Sustaining the quality of the Nation’s water resources and the health of our diverse ecosystems depends on the availability of sound water-resources data and information to develop effective, science-based policies. Effective management of water resources also brings more certainty and efficiency to important economic sectors. Taken together, these actions lead to immediate and longterm economic,AuthorsPaul D. Capel, Kathleen A. McCarthy, Richard H. Coupe, Katia M. Grey, Sheila E. Amenumey, Nancy T. Baker, Richard L. JohnsonFilter Total Items: 103Environmental and Biological Data of the Nutrient Enrichment Effects on Stream Ecosystems Project of the National Water Quality Assessment Program, 2003-04
In 2000, the U.S. Environmental Protection Agency began the process of developing regional nutrient criteria for streams and rivers. In response to concerns about nutrients by the U.S. Environmental Protection Agency and others, the U.S. Geological Survey National Water Quality Assessment Program began studying the effects of nutrient enrichment on agricultural stream ecosystems to aid in the undeAuthorsRobin A. Brightbill, Mark D. MunnAlgal and Invertebrate Community Composition along Agricultural Gradients: A Comparative Study from Two Regions of the Eastern United States
Benthic algal and invertebrate communities in two Coastal Plain regions of the Eastern United States?the Delmarva Peninsula (27 sites) and Georgia Upper Coastal Plain (29 sites)?were assessed to determine if aspects of agricultural land use and nutrient conditions (dissolved and whole-water nitrogen and phosphorus) could be linked to biological community compositions. Extensive effort was made toAuthorsDaniel L. Calhoun, M. Brian Gregory, Holly S. WeyersEstimating Water Fluxes Across the Sediment-Water Interface in the Lower Merced River, California
The lower Merced River Basin was chosen by the U.S. Geological Survey?s (USGS) National Water Quality Assessment Program (NAWQA) to be included in a national study on how hydrological processes and agricultural practices interact to affect the transport and fate of agricultural chemicals. As part of this effort, surface-water?ground-water (sw?gw) interactions were studied in an instrumented 100-mAuthorsCelia ZamoraOccurrence and fate of pesticides in four contrasting agricultural settings in the United States
Occurrence and fate of 45 pesticides and 40 pesticide degradates were investigated in four contrasting agricultural settings—in Maryland, Nebraska, California, and Washington. Primary crops included corn at all sites, soybeans in Maryland, orchards in California and Washington, and vineyards in Washington. Pesticides and pesticide degradates detected in water samples from all four areas were predoAuthorsG. V. Steele, H.M. Johnson, Mark W. Sandstrom, P. D. Capel, J.E. BarbashTransport and fate of nitrate at the ground-water/surface-water interface
Although numerous studies of hyporheic exchange and denitrification have been conducted in pristine, high-gradient streams, few studies of this type have been conducted in nutrient-rich, low-gradient streams. This is a particularly important subject given the interest in nitrogen (N) inputs to the Gulf of Mexico and other eutrophic aquatic systems. A combination of hydrologic, mineralogical, chemiAuthorsL.J. Puckett, C. Zamora, H. Essaid, J.T. Wilson, H.M. Johnson, M.J. Brayton, J. R. VogelPesticides in rain in four agricultural watersheds in the United States
Rainfall samples were collected during the 2003 and 2004 growing seasons at four agricultural locales across the USA in Maryland, Indiana, Nebraska, and California. The samples were analyzed for 21 insecticides, 18 herbicides, three fungicides, and 40 pesticide degradates. Data from all sites combined show that 7 of the 10 most frequently detected pesticides were herbicides, with atrazine (70%) anAuthorsJason R. Vogel, Michael S. Majewski, Paul D. CapelVariations in pesticide leaching related to land use, pesticide properties, and unsaturated zone thickness
Pesticide leaching through variably thick soils beneath agricultural fields in Morgan Creek, Maryland was simulated for water years 1995 to 2004 using LEACHM (Leaching Estimation and Chemistry Model). Fifteen individual models were constructed to simulate five depths and three crop rotations with associated pesticide applications. Unsaturated zone thickness averaged 4.7 m but reached a maximum ofAuthorsR.M.T. Webb, M.E. Wieczorek, B. T. Nolan, T.C. Hancock, Mark W. Sandstrom, J.E. Barbash, E.R. Bayless, R. W. Healy, J. LinardUsing heat to characterize streambed water flux variability in four stream reaches
Estimates of streambed water flux are needed for the interpretation of streambed chemistry and reactions. Continuous temperature and head monitoring in stream reaches within four agricultural watersheds (Leary Weber Ditch, IN; Maple Creek, NE; DR2 Drain, WA; and Merced River, CA) allowed heat to be used as a tracer to study the temporal and spatial variability of fluxes through the streambed. SynoAuthorsH.I. Essaid, C.M. Zamora, K. A. McCarthy, J. R. Vogel, J.T. WilsonPesticide fate and transport throughout unsaturated zones in five agricultural settings, USA
Pesticide transport through the unsaturated zone is a function of chemical and soil characteristics, application, and water recharge rate. The fate and transport of 82 pesticides and degradates were investigated at five different agricultural sites. Atrazine and metolachlor, as well as several of the degradates of atrazine, metolachlor, acetochlor, and alachlor, were frequently detected in soil waAuthorsT.C. Hancock, Mark W. Sandstrom, J. R. Vogel, R.M.T. Webb, E.R. Bayless, J.E. BarbashChemical and toxicologic assessment of organic contaminants in surface water using passive samplers
Passive sampling methodologies were used to conduct a chemical and toxicologic assessment of organic contaminants in the surface waters of three geographically distinct agricultural watersheds. A selection of current-use agrochemicals and persistent organic pollutants, including polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and organochlorine pesticides, were targeted using the polaAuthorsD.A. Alvarez, W.L. Cranor, S.D. Perkins, R.C. Clark, S.B. SmithSimulated fate and transport of metolachlor in the unsaturated zone, Maryland, USA
An unsaturated-zone transport model was used to examine the transport and fate of metolachlor applied to an agricultural site in Maryland, USA. The study site was instrumented to collect data on soil-water content, soil-water potential, ground water levels, major ions, pesticides, and nutrients from the unsaturated zone during 2002-2004. The data set was enhanced with site-specific information desAuthorsE.R. Bayless, P. D. Capel, J.E. Barbash, R.M.T. Webb, T.L.C. Hancock, D.C. LampeNational, holistic, watershed-scale approach to understand the sources, transport, and fate of agricultural chemicals
This paper is an introduction to the following series of papers that report on in-depth investigations that have been conducted at five agricultural study areas across the United States in order to gain insights into how environmental processes and agricultural practices interact to determine the transport and fate of agricultural chemicals in the environment. These are the first study areas in anAuthorsP. D. Capel, K. A. McCarthy, J.E. Barbash