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

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Stites, W. Articles by Kraft, G. J. Search for Related Content PubMed Articles by Stites, W. Articles by Kraft, G. J. Agricola Articles by Stites, W. Articles by Kraft, G. J.

Groundwater Quality Beneath Irrigated Vegetable Fields in a North-Central U.S. Sand Plain

Central Wisconsin Groundwater Center, Univ. of Wisconsin-Stevens Point, 1900 Franklin St., Stevens Point, WI 54481.

^* Corresponding author (wstites{at}coredcs.com).

ABSTRACT

The dramatic expansion of irrigated agriculture since about 1970 in the north-central USA has been accompanied by NO₃ and pesticide pollution of groundwater. The expansion has been concentrated in areas with sandy soils and shallow water tables, such as the Wisconsin central sand plain. In some parts of this sand plain, most wells contain detectable pesticide residues and NO₃-N concentrations that exceed the 10 mg L^–1 U.S. drinking water maximum contaminant level (MCL). To evaluate the effects on groundwater quality of this agricultural system, we monitored solutes 23 times during a 2-yr period in the upper 3 m of the aquifer beneath and immediately upgradient of four irrigated vegetable fields. Groundwater beneath fields had significantly greater concentrations of most solutes and lower pH than upgradient groundwater. Especially pronounced were Ca, Cl, K, Mg, and NO₃ differences, with concentrations 5 to 26 times greater under fields. Nitrate N concentrations averaged 21 mg L^–1 under fields, compared with 1 mg L^–1 upgradient. Pesticide residues were ubiquitous beneath fields, and generally persisted for many months after application. Pesticide concentrations often exceeded Wisconsin preventive-action limits (PALs), but seldom exceeded federal MCLs. Even when agricultural management approximated best management practice (BMP) recommendations, the NO₃ concentration beneath these fields approached double the MCL, indicating a need for new approaches to control agricultural groundwater pollution.

This article has been cited by other articles:

				L. G. Bundy and T. W. Andraski Recovery of Fertilizer Nitrogen in Crop Residues and Cover Crops on an Irrigated Sandy Soil Soil Sci. Soc. Am. J., April 11, 2005; 69(3): 640 - 648. [Abstract] [Full Text] [PDF]

				W. Stites and G.J. Kraft Nitrate and Chloride Loading to Groundwater from an Irrigated North-Central U.S. Sand-Plain Vegetable Field J. Environ. Qual., July 1, 2001; 30(4): 1176 - 1184. [Abstract] [Full Text] [PDF]