Hydrologic Controls on Nitrogen Cycling and Nitrate Transport Through the Vadose Zone of a Subsurface Artificially-drained Dryland Agroecosystem in the Palouse Basin of Eastern Washington

Hydrologic Controls on Nitrogen Cycling and Nitrate Transport Through the Vadose Zone of a Subsurface Artificially-drained Dryland Agroecosystem in the Palouse Basin of Eastern Washington
Author: Christopher Joshua Kelley
Publisher:
Total Pages:
Release: 2015
Genre: Dry farming
ISBN:

Advances in the application of stable isotopes to address environmental issues have led to new understandings of biogeochemical cycles for both natural and agricultural systems. Of particular concern, is understanding nitrogen cycling in agricultural systems due to potential losses of reactive nitrogen to aquatic and atmospheric domains. Research in this area is timely because of growing concern about climate change and coastal eutrophication. The overarching concept for this research is that nitrogen cycling and pathways for nitrogen losses are substantially regulated by soil hydrologic conditions, with the premise that water availability and residence time in the soil are the key factors controlling nitrogen cycling in agricultural systems. The focus is on an artificially-drained dryland agricultural system, but the links between soil hydrology and nitrogen cycling developed here will be similar to irrigated and non-artificially drained agricultural systems.

Sources, Fate, and Transport of Nitrogen and Phosphorus in the Chesapeake Bay Watershed

Sources, Fate, and Transport of Nitrogen and Phosphorus in the Chesapeake Bay Watershed
Author: Scott W. Ator
Publisher: Geological Survey (USGS)
Total Pages: 27
Release: 2011
Genre: Chesapeake Bay Watershed
ISBN: 9781411332621

Spatially Referenced Regression on Watershed Attributes (SPARROW) was used to provide empirical estimates of the sources, fate, and transport of total nitrogen (TN) and total phosphorus (TP) in the Chesapeake Bay watershed, and the mean annual TN and TP flux to the bay and in each of 80,579 nontidal tributary stream reaches. Restoration efforts in recent decades have been insufficient to meet established standards for water quality and ecological conditions in Chesapeake Bay. The bay watershed includes 166,000 square kilometers of mixed land uses, multiple nutrient sources, and variable hydrogeologic, soil, and weather conditions, and bay restoration is complicated by the multitude of nutrient sources and complex interacting factors affecting the occurrence, fate, and transport of nitrogen and phosphorus from source areas to streams and the estuary. Effective and efficient nutrient management at the regional scale in support of Chesapeake Bay restoration requires a comprehensive understanding of the sources, fate, and transport of nitrogen and phosphorus in the watershed, which is only available through regional models. The current models, Chesapeake Bay nutrient SPARROW models, version 4 (CBTN_v4 and CBTP_v4), were constructed at a finer spatial resolution than previous SPARROW models for the Chesapeake Bay watershed (versions 1, 2, and 3), and include an updated timeframe and modified sources and other explantory terms.

Clean Coastal Waters

Clean Coastal Waters
Author: National Research Council
Publisher: National Academies Press
Total Pages: 422
Release: 2000-08-17
Genre: Science
ISBN: 0309069483

Environmental problems in coastal ecosystems can sometimes be attributed to excess nutrients flowing from upstream watersheds into estuarine settings. This nutrient over-enrichment can result in toxic algal blooms, shellfish poisoning, coral reef destruction, and other harmful outcomes. All U.S. coasts show signs of nutrient over-enrichment, and scientists predict worsening problems in the years ahead. Clean Coastal Waters explains technical aspects of nutrient over-enrichment and proposes both immediate local action by coastal managers and a longer-term national strategy incorporating policy design, classification of affected sites, law and regulation, coordination, and communication. Highlighting the Gulf of Mexico's "Dead Zone," the Pfiesteria outbreak in a tributary of Chesapeake Bay, and other cases, the book explains how nutrients work in the environment, why nitrogen is important, how enrichment turns into over-enrichment, and why some environments are especially susceptible. Economic as well as ecological impacts are examined. In addressing abatement strategies, the committee discusses the importance of monitoring sites, developing useful models of over-enrichment, and setting water quality goals. The book also reviews voluntary programs, mandatory controls, tax incentives, and other policy options for reducing the flow of nutrients from agricultural operations and other sources.

From the Corn Belt to the Gulf

From the Corn Belt to the Gulf
Author: Joan Iverson Nassauer
Publisher: Routledge
Total Pages: 273
Release: 2010-09-30
Genre: Law
ISBN: 113652536X

Nutrients from farms in the Mississippi River Basin are the leading cause of the Gulf of Mexico‘s 'Dead Zone,' a 5,000 to 7,000 square mile region where declining oxygen levels are threatening the survival of marine life. From the Corn Belt to the Gulf explores how new agricultural policy can help alleviate this problem, and at the same time improve water quality overall, enhance biodiversity, improve the quality of life for the people who live and work in Corn Belt communities, and relieve downstream flooding. The themes of the book are the far-reaching environmental impacts of Corn Belt agriculture, including associated economic and social effects at multiple spatial scales - and the potential for future agricultural policy to address those impacts through changes in agricultural landscapes and practices. We know that the environmental 'footprint' of Corn Belt agriculture extends beyond farmland and adjacent lakes and streams to groundwater, rivers, cities downstream, into the Gulf of Mexico, and, ultimately, to global oceanic and atmospheric systems. And we acknowledge that agricultural policies, including commodity support payments, have economic impacts at the national and international levels. Pressing negotiations with America‘s trade partners, along with increasing societal attention to both the costs and environmental effects of current agricultural policy, are creating momentum for policy change. From the Corn Belt to the Gulf presents innovative, integrated assessments of the agriculture and ecological systems in the Mississippi River Basin along with studies of local Iowa agricultural watersheds. Contributors from multiple academic and professional disciplines discuss how agricultural policies have contributed to current environmental conditions, and, in what the authors term 'alternative futures' for agricultural landscapes, envision how new policy can help achieve more beneficial patterns.