32 Hydrogeology

Added due to amount of discipline abstracts submitted.

Tuesday, 10 March 2026
1:30 PM - 5:30 PM
RCC, 106

Quantifying Nutrient and Sediment Losses in Western Kentucky Row Crop Systems with Edge-of-Field Water Quality Monitoring

Paper number: 32-0
Program: Technical Sessions
Time: 1:30 PM – 1:45 PM

Authors

Abstract

Edge-of-field (EOF) water quality monitoring involves measuring the amount of nutrients and soil lost from a small catchment with the pour point at the edge of an agricultural field.  Often these are developed as a comparison between a control, current management practices, and a treatment under a best management practice (BMP) to evaluate the efficacy of BMPs.  The information gained from these monitored watersheds enables agricultural producers to quantitatively demonstrate the impacts of BMPs on water quality.  In 2017, the University of Kentucky Martin-Gatton College of Agriculture, Food and Environment and Kentucky Geological Survey established a long-term (~10 years) network of 29 EOF water quality monitoring stations on 9 active western Kentucky farms, collectively referred to as Blue Water Farms.  This working partnership between anonymous landowners and the University is supported by the Kentucky Soybean Promotion Board, Kentucky Agricultural Development Board, and the USDA-NRCS. Through this project, BMPs to be evaluated were selected with input from landowners and include poultry litter incorporation, grassed waterways, water and sediment control basins, and cover crops.  These activities are compared to typical production practices within the area.  At each monitored catchment, water samples are collected after each runoff generating precipitation event and analyzed for nutrients (ammonium nitrogen, nitrite plus nitrate nitrogen, total Kjeldahl nitrogen, total dissolved phosphorus, and total phosphorus) and total solids.  Results to date indicate that erosion is a problem in sloping agricultural fields which are common in western Kentucky.  Cover crops have been less effective at reducing erosion relative to grassed waterways.  Approximately one-third to one-half the amount of phosphorus lost relative to phosphorus applied can be attributed to erosion. Nitrogen losses were highest in the first rainfall event after nitrogen application.  The knowledge gained from quantifying nutrient and sediment losses at the edge of production fields enables agricultural producers to quantify the impacts of their management decisions on water quality at the edge-of-farm fields rather than try to estimate conservation effects from in-stream measurements that are subject to influences outside of individual producer’s control.

Geological Society of America Abstracts with Programs. Vol. 58, No. 1

doi: 10.1130/abs/2026SE-411609

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