Water Quality Monitoring (1988 to 1991) At The Iowa Academy of Science's Parish Farm, Grundy County, Iowa

Authors

Brenda K. Nations, IDNR-Geological Survey Bureau
George R. Hallberg, IDNR-Geological Survey BureauFollow

Document Type

Research

Keywords

Water Quality, Nitrate-nitrogen, Pesticides, Non-point Source Pollution, Parish Farm, Grundy County

Abstract

In May 1988 sampling was initiated to evaluate water quality in relation to management practices at Parish Farm, which is owned by Iowa Academy of Science. Initial results showed tile-line effluent to have high concentrations of nitrate-nitrogen (N0₃-N). Twelve monitoring wells were installed over a one year period to analyze shallow groundwater at the farm. The wells, tile lines, and surface water were sampled monthly, through October, 1991, and the water analyzed for N0₃-N and some pesticides. N0₃-N concentrations varied, related to landuse and management of adjacent areas. Greater N0₃-N concentrations were detected from row-cropped areas than in the restored wildlife-vegetation buffer strip and prairie areas. The greatest concentrations (up to 79 mg/L) were associated with greater amounts of fertilized corn in the cropping sequence. Concentrations of pesticides were dependent on various factors such as chemical properties, season, hydrologic events, and patterns of use. Atrazine was the pesticide most often detected and was present in 46% of the samples. Seven agricultural pesticides used on the farm were detected in water samples with a maximum detected concentration of 6.9 μ/gL (for alachlor). Pesticide and high N0₃-N concentrations were detected in wells beneath the restored natural vegetation buffer areas, probably as a result of groundwater transport from application areas upgradient. The data suggest that the buffer strips were not effective at removing N0₃-N or pesticides from the groundwater flowing through these areas. N0₃-N concentrations were high (often over 25 μg/L) during the study, in spite of improved N management on the farm. The high concentrations may be related to mobilization of excess residual N0₃-N that accumulated during the dry years prior to the monitoring.

Publication Date

September-December 1993

Journal Title

Journal of the Iowa Academy of Science

Volume

100

Issue

3-4

First Page

78

Last Page

85

Copyright

© Copyright 1994 by the Iowa Academy of Science, Inc.

Language

EN

File Format

application/pdf

Recommended Citation

Nations, Brenda K. and Hallberg, George R. (1994) "Water Quality Monitoring (1988 to 1991) At The Iowa Academy of Science's Parish Farm, Grundy County, Iowa," Journal of the Iowa Academy of Science: JIAS, 101(3-4), 78-85.
Available at: https://scholarworks.uni.edu/jias/vol101/iss3/5