HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (10) Citing Articles via Google Scholar Google Scholar Articles by Bishop, P. L. Articles by Bloomfield, J. A. Search for Related Content PubMed PubMed Citation Articles by Bishop, P. L. Articles by Bloomfield, J. A. Agricola Articles by Bishop, P. L. Articles by Bloomfield, J. A. Related Collections Surface Water Quality Best Management Practices Phosphorus Watershed-Scale Studies Other Models

TECHNICAL REPORTS

Surface Water Quality

Multivariate Analysis of Paired Watershed Data to Evaluate Agricultural Best Management Practice Effects on Stream Water Phosphorus

^a Bureau of Water Assessment and Management, New York State Department of Environmental Conservation, 625 Broadway, 4th Floor, Albany, NY 12233-3502
^b Department of Natural Resources, Fernow Hall, Cornell University, Ithaca, NY 14853
^c School of Civil and Environmental Engineering, Hollister Hall, Cornell University, Ithaca, NY 14853-3501

^* Corresponding author (plbishop{at}gw.dec.state.ny.us)

Received for publication May 18, 2004. Quantification of the effects of management programs on water quality is critical to agencies responsible for water resource protection. This research documents reductions in stream water phosphorus (P) loads resulting from agricultural best management practices (BMPs) implemented as part of an effort to control eutrophication of Cannonsville Reservoir, a drinking water supply for New York City. Dairy farms in the upstate New York reservoir basin were the target of BMPs designed to reduce P losses. A paired watershed study was established on one of these farms in 1993 to evaluate changes in P loading attributable to implementation of BMPs that included manure management, rotational grazing, and improved infrastructure. Intensive stream water monitoring provided data to calculate P loads from the 160-ha farm watershed for all runoff events during a two-year pre-treatment period and a four-year post-treatment period. Statistical control for inter-annual climatic variability was provided by matched P loads from a nearby 86-ha forested watershed, and by several event flow variables measured at the farm. A sophisticated multivariate analysis of covariance (ANCOVA) provided estimates of both seasonal and overall load reductions. Statistical power and the minimum detectable treatment effect (MDTE) were also calculated. The results demonstrated overall event load reductions of 43% for total dissolved phosphorus (TDP) and 29% for particulate phosphorus (PP). Changes in farm management practices and physical infrastructure clearly produced decreases in event P losses measurable at the small watershed scale.

Abbreviations: ANCOVA, analysis of covariance • BMP, best management practice • CI₉₅, 95% confidence interval • MDTE, minimum detectable treatment effect • post-BMP, post-treatment period • pre-BMP, pre-treatment period • PP, particulate phosphorus • STP, soil test phosphorus • TDP, total dissolved phosphorus • WAP, Watershed Agricultural Program • WFP, Whole Farm Plan

This article has been cited by other articles:

				L.T. Ghebremichael, T.L. Veith, J.M. Hamlett, and W.J. Gburek Precision feeding and forage management effects on phosphorus loss modeled at a watershed scale Journal of Soil and Water Conservation, September 1, 2008; 63(5): 280 - 291. [Abstract] [PDF]

				Z. M. Easton, M. T. Walter, and T. S. Steenhuis Combined Monitoring and Modeling Indicate the Most Effective Agricultural Best Management Practices J. Environ. Qual., August 8, 2008; 37(5): 1798 - 1809. [Abstract] [Full Text] [PDF]