ARS | Publication request: CURRENT TOPICS IN AGRICULTURAL HYDROLOGY AND WATER QUALITY: INTRODUCTION

Submitted to: Journal of the American Water Resources Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 25, 2005
Publication Date: April 5, 2005
Citation: Williams, J.D., Koplin, D.W. 2005. Current topics in agricultural hydrology and water quality: Introduction. Journal of the American Water Resources Association. 41(2): 243-244.X

Technical Abstract: Current Topics in Agricultural Hydrology and Water Quality: Introduction John D. Williams and Dana W. Koplin1 The journal is pleased to present a select group of papers originally presented May 2003 in Kansas City MO at the AWRA Spring Specialty Conference - Agricultural Hydrology and Water Quality. When the organizers first conceived the idea of a specialty conference focused on agricultural hydrology, the intent was to bring together policy makers, specialists, and researchers from around the world who deal with the management of lands dedicated to agricultural production. The conference was a success, with 200 oral papers and posters presented, from 32 states and 9 countries. The papers presented here address a broad range of topics, not unusual for an industry that has evolved and grown exponentially in the last few decades. For example, commercial fertilizers and pesticides have increased production and reduced labor, but they also appear in increasing frequency and concentration in associated water bodies. Industrial-scale confined animal feeding operations are replacing animal production on small farms and ranches, concentrating formally non-point sources of animal waste and pharmaceuticals. The papers in this issue of JAWRA identify some of these problems, and provide some insight into how problems such as these can be solved. Dr. Brian Haggard and co-authors representing three USDA-ARS laboratories and the University of Arkansas report results from a rainfall simulation experiment to evaluate management of poultry litters to reduce runoff of nutrients and xenobiotics found in poultry litters (on page ##). Based on the author's findings, producers can reduce concentrations of phosphorus and ß17-estradiol by treating the pelleted litter with alum. Professor Kathleen Miller with the research staff of the Montana Bureau of Mines and Geology, on page ##, reports on the imazamethabenz-methyl, (U.S. trade name Assert®), contamination of an aquifer used for drinking water by three public water supplies and more than 400 private wells in Montana. The contamination has been traced to irrigation practices in the area. After examining three commonly used irrigation techniques, the author reports that the degree of Assert contamination is controlled by: (1) hydraulic loading rates of each irrigation method, (2) Assert persistence in soil, (3) hydraulic characteristics of the aquifer, and (4) adsorption/desorption of Assert onto clay particles and organic matter. Co-authors Dr. Alan Stueber, Southern Illinois University Edwardsville, Edwardsville, Illinois, and Dr. Robert Criss, Washington University, St. Louis, Missouri, on page ##, show the relative contributions of karst groundwater and treated wasted water to water quality in a small Illinois stream. Although the karst water dominates stream flow 11:1, the wastewater originating from outside the small stream contributes the majority of Na, K, Cl, NO_3, F, P, and atrazine found in the stream. On page ##, Dr. Doug Boyer, USDA-ARS Beaver, West Virginia, evaluates the success of the President of the United States Initiative for Water Quality and Environmental Quality Incentives Program (EQIP) management of grazing systems on the quality of water flowing into karst systems. These results demonstrate the difficulty in identifying and treating non-point sources of water pollution while at the same time trying to meet other landuse objectives. Although the author presents evidence that highly focused grazing prescriptions might improve forage production on a farm, the end result might just as likely result in increased contamination of surface water draining into the underlying karst aquatic system. Christopher Blattel and co-authors, Southern Illinois University, Carbondale, Illinois, page ##, evaluate the capacity of native giant cane and hardwood riparian forest buffers to reduce orthophosphate or dissolved reactive phosphate before it contributes to surface flow. Although vegetation in buffers removed some dissolved reactive phosphate, their findings do not support early reports of higher effectiveness in similar systems. The authors list a number of conditions that could have contributed to the discrepancies, providing guidance for further research on the subject. Beginning on page ##, Bill Battaglin and four coauthors from the U.S. Geological Survey, are the findings from a regional survey of stream contamination in the Midwestern United States by 21 herbicides and herbicides transformation products. The focus of the survey was the relative occurrence of glyphosate and its primary transformation product, AMPA, to other herbicides found in streams after pre-emergent, post-herbicide, and harvest herbicide applications. Dr. John Westra, Louisiana State University, Baton Rouge LA, and coauthors from the University of Minnesota and the U.S. Geological Survey, in Saint Paul MN, on page ##, demonstrate the economic, physical, and biological consequences of implementing best management practices on watershed scales. Comparing cold and warm water systems, they demonstrate that best management practices reduce producer incomes 1 to 2 percent, and are beneficial to fish communities in the cold water system but not the warm water system. This exercise can be used to focus funding on implementation of best management practices where they will be most economically efficient. Dr.'s A. Bakhsh and Ramesh Kanwar, Iowa State University, Ames, Iowa, report on page ## their research investigating the spatial relationships of NO3-N leaching loss to soil and landscape attributes using cluster and discriminant analysis and geographical information system (GIS) technology. They successfully used this combination of tools to select soil type, elevation, and subsurface drainage as factors necessary to identify field locations with low, medium, and high levels of leached NO3-N. This information can be used to manage fertilizer inputs and to reduce the costly loss of commercial fertilizer and the concomitant contamination of surface and groundwater. Dr. M. Srinivasan, USDA-ARS, University Park PA, and coauthors from Cornell University, Ithaca, NY, on page ## compare two models to identify runoff areas that can be managed to control phosphorus contamination. The soil and water assessment tool (SWAT) and the soil moisture distribution and routing (SMDR) model were tested. Although each model performed certain tasks well, the authors also show where improvement can be made. They conclude that SMDR has the capability to represent a watershed as grids and may allow targeted management of phosphorus sources, unlike SWAT's use of hydrologic response units. The guest editors thank the reviewers and authors who made the extra effort to move their papers through the peer review process. Thanks to the Journal for providing a venue for the subject matter, and AWRA, organizers, and participants who originally made the 2003 Spring Specialty Conference a success. Thanks, finally, to the AWRA agricultural hydrology technical committee for their efforts bringing attention to the important role of agriculture in the management of water resources.