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)
Nutrients and Eutrophication
Agricultural Contaminants
Pesticides and Water Quality
Estimated Annual Agricultural Pesticide Use
Below are publications associated with this project.
Agriculture — A river runs through it — The connections between agriculture and water quality
Understanding the influence of nutrients on stream ecosystems in agricultural landscapes
A conceptual framework for effectively anticipating water-quality changes resulting from changes in agricultural activities
Holistic assessment of occurrence and fate of metolachlor within environmental compartments of agricultural watersheds
Integrating seasonal information on nutrients and benthic algal biomass into stream water quality monitoring
Contrasting nitrogen fate in watersheds using agricultural and water quality information
Effects of hydrology, watershed size, and agricultural practices on sediment yields in two river basins in Iowa and Mississippi
Trends in pesticide use on soybean, corn and cotton since the introduction of major genetically modified crops in the United States
Effect of variable annual precipitation and nutrient input on nitrogen and phosphorus transport from two Midwestern agricultural watersheds
Data worth and prediction uncertainty for pesticide transport and fate models in Nebraska and Maryland, United States
Low transient storage and uptake efficiencies in seven agricultural streams: implications for nutrient demand
Pesticides in Mississippi air and rain: A comparison between 1995 and 2007
Fertilizer consumption and energy input for 16 crops in the United States
- 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.
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.
Map of the agricultural areas across the United States whose results are summarized in USGS Circulars 1433 and 1437. - 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.Nutrients and Eutrophication
Like people, plants need nutrients, but too much of a good thing can be a problem. Nutrients, such as nitrogen and phosphorus, occur naturally, but most of the nutrients in our waterways come from human activities and sources—fertilizers, wastewater, automobile exhaust, animal waste. The USGS investigates the source, transport, and fate of nutrients and their impacts on the world around us.Agricultural Contaminants
About 40 percent of the land in the United States is used for agriculture, and agriculture supplies a major part of the our 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.Pesticides and Water Quality
Pesticides are chemicals designed to kill pests, including insects (insecticides), weeds (herbicides), and fungi (fungicides). The USGS assesses the occurrence and behavior of pesticides in streams, lakes, and groundwater and the potential for pesticides to contaminate our drinking-water supplies or harm aquatic ecosystems.Estimated Annual Agricultural Pesticide Use
These tables, maps, and graphs provide estimates of U.S. agricultural pesticide use suitable for evaluating national and regional patterns and trends of annual pesticide use. - Multimedia
- 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: 103Understanding the influence of nutrients on stream ecosystems in agricultural landscapes
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 long-term economic,AuthorsMark D. Munn, Jeffrey W. Frey, Anthony J. Tesoriero, Robert W. Black, John H. Duff, Kathy Lee, Terry R. Maret, Christopher A. Mebane, Ian R. Waite, Ronald B. ZeltA conceptual framework for effectively anticipating water-quality changes resulting from changes in agricultural activities
Agricultural activities can affect water quality and the health of aquatic ecosystems; many water-quality issues originate with the movement of water, agricultural chemicals, and eroded soil from agricultural areas to streams and groundwater. Most agricultural activities are designed to sustain or increase crop production, while some are designed to protect soil and water resources. Numerous soil-AuthorsPaul D. Capel, David M. Wolock, Richard H. Coupe, Jason L. RothHolistic assessment of occurrence and fate of metolachlor within environmental compartments of agricultural watersheds
Background: Metolachlor [(RS)-2-Chloro-N-(2-ethyl-6-methyl-phenyl)-N-(1-methoxypropan-2-yl)acetamide] and two degradates (metolachlor ethane-sulfonic acid and metolachlor oxanilic acid) are commonly observed in surface and groundwater. The behavior and fate of these compounds were examined over a 12-year period in seven agricultural watersheds in the United States. They were quantified in air, raiAuthorsClaire E. Rose, Richard H. Coupe, Paul D. Capel, Richard M. WebbIntegrating seasonal information on nutrients and benthic algal biomass into stream water quality monitoring
Benthic chlorophyll a (BChl a) and environmental factors that influence algal biomass were measured monthly from February through October in 22 streams from three agricultural regions of the United States. At-site maximum BChl a ranged from 14 to 406 mg/m2 and generally varied with dissolved inorganic nitrogen (DIN): 8 out of 9 sites with at-site median DIN >0.5 mg/L had maximum BChl a >100 mg/m2.AuthorsChristopher P. Konrad, Mark D. MunnContrasting nitrogen fate in watersheds using agricultural and water quality information
Surplus nitrogen (N) estimates, principal component analysis (PCA), and end-member mixing analysis (EMMA) were used in a multisite comparison contrasting the fate of N in diverse agricultural watersheds. We applied PCA-EMMA in 10 watersheds located in Indiana, Iowa, Maryland, Nebraska, Mississippi, and Washington ranging in size from 5 to 1254 km2 with four nested watersheds. Watershed Surplus N wAuthorsHedeff I. Essaid, Nancy T. Baker, Kathleen A. McCarthyEffects of hydrology, watershed size, and agricultural practices on sediment yields in two river basins in Iowa and Mississippi
The specific sediment yield (SSY) from watersheds is the result of the balance between natural, scale-dependent erosion and deposition processes, but can be greatly altered by human activities. In general, the SSY decreases along the course of a river as sediments are trapped in alluvial plains and other sinks. However, this relation between SSY and basin area can actually be an increasing one wheAuthorsGustavo Henrique Merten, Heather L. Welch, M.D. TomerTrends in pesticide use on soybean, corn and cotton since the introduction of major genetically modified crops in the United States
BACKGROUNDGenetically modified (GM) varieties of soybean, corn and cotton have largely replaced conventional varieties in the United States. The most widely used applications of GM technology have been the development of crops that are resistant to a specific broad-spectrum herbicide (primarily glyphosate) or that produce insecticidal compounds within the plant itself. With the widespread adoptionAuthorsRichard H. Coupe, Paul D. CapelEffect of variable annual precipitation and nutrient input on nitrogen and phosphorus transport from two Midwestern agricultural watersheds
Precipitation patterns and nutrient inputs affect transport of nitrate (NO3-N) and phosphorus (TP) from Midwest watersheds. Nutrient concentrations and yields from two subsurface-drained watersheds, the Little Cobb River (LCR) in southern Minnesota and the South Fork Iowa River (SFIR) in northern Iowa, were evaluated during 1996–2007 to document relative differences in timings and amounts of nutriAuthorsStephen J. Kalkhoff, Laura E. Hubbard, Mark D. Tomer, D.E. JamesData worth and prediction uncertainty for pesticide transport and fate models in Nebraska and Maryland, United States
BACKGROUND Complex environmental models are frequently extrapolated to overcome data limitations in space and time, but quantifying data worth to such models is rarely attempted. The authors determined which field observations most informed the parameters of agricultural system models applied to field sites in Nebraska (NE) and Maryland (MD), and identified parameters and observations that mostAuthorsBernard T. Nolan, Robert W. Malone, John E. Doherty, Jack E. Barbash, Liwang Ma, Dale L. ShanerLow transient storage and uptake efficiencies in seven agricultural streams: implications for nutrient demand
We used mass load budgets, transient storage modeling, and nutrient spiraling metrics to characterize nitrate (NO3−), ammonium (NH4+), and inorganic phosphorus (SRP) demand in seven agricultural streams across the United States and to identify in-stream services that may control these conditions. Retention of one or all nutrients was observed in all but one stream, but demand for all nutrients wasAuthorsRich W. Sheibley, John H. Duff, Anthony J. TesorieroPesticides in Mississippi air and rain: A comparison between 1995 and 2007
A variety of current-use pesticides were determined in weekly composite air and rain samples collected during the 1995 and 2007 growing seasons in the Mississippi Delta (MS, USA) agricultural region. Similar sampling and analytical methods allowed for direct comparison of results. Decreased overall pesticide use in 2007 relative to 1995 generally resulted in decreased detection frequencies in airAuthorsMichael S Majewski, Richard H. Coupe, William T. Foreman, Paul D. CapelFertilizer consumption and energy input for 16 crops in the United States
Fertilizer use by U.S. agriculture has increased over the past few decades. The production and transportation of fertilizers (nitrogen, N; phosphorus, P; potassium, K) are energy intensive. In general, about a third of the total energy input to crop production goes to the production of fertilizers, one-third to mechanization, and one-third to other inputs including labor, transportation, pesticideAuthorsSheila E. Amenumey, Paul D. Capel