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Conference Program & Abstracts

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Third International Conference in China

"Meeting the Nitrogen Management Challenge: Arresting the Nitrogen Cascade"
AAAS 2003 Symposium, February 15, 2003
(PowerPoint presentations attached)

Of the biogeochemical cycles, the nitrogen cycle has been altered the most by human activity. Human fixing of reactive nitrogen now exceeds that of all natural processes. Because of nitrogen's complex chemistry and the fact that it is often the limiting nutrient in both terrestrial and aquatic ecosystems, the effects altering the nitrogen cycle are often surprising and severe. The majority of anthropogenic reactive nitrogen comes from the production of ammonia for agricultural fertilizer that provides 40% of current global food production. Additional nitrogen sources include livestock, fossil fuel and biomass combustion, chemical production and waste management. From an ecosystem perspective, the multiple chemical and biological transformations of nitrogen produce a cascade of impacts that move among the atmosphere, soils and water.

The nitrogen cascade will be utilized as the organizing principle for examining human alterations of the nitrogen cycle, the consequences for ecosystems and the economy. New strategies and opportunities for improved nitrogen management will be the goal of the symposium. The timing of the AAAS meeting lies midway between the second and third triennial, International Nitrogen Conferences, and will allow an assessment of trends. In addition to summarizing what is known about the biogeochemistry of the nitrogen cycle, critical issues such as the excessive release of nitrogen in China, Europe and North America, and its under availability in Africa, Latin America and other parts of Asia will be addressed. Finally, an economic analysis of the nitrogen cycle and the implications for management and policy intervention will be provided.

Papers (PowerPoint)
Contact webmaster at esa.org for the files below.


"Impacts of the Nitrogen Cascade on Ecosystems"
This presentation will set the context of the nitrogen cascade and the multiple effects that each molecule of reactive nitrogen introduces into the ecosystem and the economy. Specific examples of nitrogen damage will be documented. The description will be quantitative in nature and will present a model that will be utilized by the other speakers.
    James Galloway
    Dept. of Environmental Sciences, University of Virginia

"Fertilizer Use in Theory and Practice"
This presentation will demonstrate how nitrogen fertilizer is used and what are the motivations for current practices that often involve excessive or inappropriate use. It will also compare proposed alternative cultivation practices and their implications for nitrogen management.
    Ken Cassman
    Agronomy Department, University of Nebraska

"Opportunities for Managing Fertilizer Use"
There are multiple ways in which nitrogen is lost from agroecosystems. Reducing these losses while maintaining the opportunity to increase system productivity is the challenge that must be met for the efficiency of nitrogen use to be improved. An understanding of the nitrogen cascade can provide insights as to where intervention to reduce adverse impacts might be more effective. Altering nitrogen use patterns also has implications for the fertilizer industry that will need to be addressed.
    Paul Fixen
    Potash and Phosphate Institute

"Livestock and Reactive Nitrogen"
Animal agriculture contributes substantially to the quantity of reactive nitrogen in the environment. For every unit of nitrogen contained in the protein of animal products, 3 to 10 units of reactive nitrogen are lost to the environment. Improving the efficiency of feed N utilization by animals can be achieved by feeding protein closer to requirements and increasing production per animal to enable a reduction in animal numbers for the same level of food production. Animal diets can also be optimized to enable selection of crops that can be produced with lower losses to the environment. Techniques are available to reduce N losses from manure collection, storage, and application, but unless these techniques are used in concert, the losses may only be transferred from one location to another without having an overall impact. Opportunities do exist to reduce N losses on individual farms, but it is a challenge to develop and implement programs that will provide incentives to farmers.
    Richard A. Kohn
    Animal & Avian Sciences, University of Maryland College Park

"Effective Regulatory Strategies for Controlling NOx Emissions from Power Plants"
Over the last two decades, there has been an increasing emphasis on reducing emissions of NOx from existing industrial, combustion infrastructure in the US, including electricity-generating plants. Power plants in the US emit more than 5 million tons of NOx per year (about one fourth of US emissions). Other major sources include large industrial boilers, cement plants, large diesel engines and combustion turbines. The regulatory and technology history of NOx control in the US has been characterized by weak requirements in the early 1970s and 1980s (from no control to about 30 percent reductions). This was followed by rapid development, innovation, and application of advanced technology capable of reducing emissions by over 90%. The "policy confusion" of whether NOx control was counterproductive ("the so called " NOx disbenefit issue") delayed the effective regulatory drivers till about 1994. The more recent "multi pollutant "approaches of addressing all types of emissions from combustion ( NOx, SO2, mercury, carbon dioxide, primary fine particles including toxic trace metals) in an integrated manner will be described including their cost and implementation benefits as well as policy hurdles. Finally, this presentation will give results from a recently completed NESCAUM report on the relationship between environmental regulation and technology innovation in the area of combustion controls from power plants and automobiles. The major finding of this report, that innovation in the US has consistently occurred, not before, but after regulatory drivers with well defined targets and deadlines were put into place, has serious implications for the future direction of NOx controls.
    Praveen Amar
    Northeast States for Coordinated Air Use Management (NESCAUM)

"The Economics of the Nitrogen Cycle"
There has been relatively little economic analysis of the nitrogen cycle and the alteration to it. This analysis will identify some of the major economic implications of different portions of the nitrogen cascade to suggest where intervention might be most cost effective. A second analysis will utilize economic comparisons to provide and economic set of criteria for choosing among mitigation strategies.
    William Moomaw
    The Fletcher School of Law and Diplomacy, Tufts University

Ecological Society of America  
American Society of Agronomy USDA Agriculture Environmental Protection Agency
  Crop Science Society of America Dutch Ministry of Housing.. The Fertilizer Institute
  Soil Science Society of America USGS National Oceanic and Atmospheric Administration