Kentucky Geological Survey Information Circular

Abstract

Poultry litter (a mixture of feed, manure, and bedding material) is commonly used as a soil amendment to row-crop fields in western Kentucky. Because of feed additives, litter typically has elevated concentrations of contaminants, including metals and anions. These metals and anions can accumulate in the soil and therefore could be transported to surface water through drainage tiles. In order to assess water quality in tile drains, a pilot study was conducted in 2008 in McLean County, Kentucky, in which 10 tile drains and six drainage ditches were sampled for total metals and anions. Seven of the tile-drained fields were amended with poultry litter and three tile-drained fields were not amended. Drainage ditches received discharge from the tile drains. Acidified and unacidified samples were collected for laboratory analysis, and the acidified samples were analyzed for total major and trace metals (aluminum, arsenic, calcium, cadmium, copper, iron, mercury, magnesium, manganese, nickel, lead, and zinc). To determine the association of major and trace metals to suspended material in the water, the unacidified samples were filtered using 0.45- and 0.20-µm filters, and each filtered sample was analyzed for major and trace metals.

Mean concentrations for total calcium and magnesium were similar for the amended and unamended field samples. Total aluminum, iron, and manganese concentrations were higher in the amended-field samples than in the unamended-field samples. Total arsenic, cadmium, and mercury concentrations were below the method detection limits for all samples. Total copper and nickel concentrations were higher in the amended-field samples than in the unamended-field samples.

Calcium, magnesium, and manganese concentrations did not decrease after samples were filtered. Aluminum and iron concentrations decreased, indicating that these metals are associated with suspended sediment in the tile discharge water. Copper and nickel concentrations did not decrease after the samples were filtered.

Chloride, sulfate, and nitrate concentrations were higher in amended-field samples than in unamended-field samples. The mean nitrate concentration for the tile-drain samples from amended fields was above the U.S. Environmental Protection Agency maximum contaminant level of 10 ppm. All phosphate concentrations were below the MDL.

Additional sampling is needed to more thoroughly document concentrations and evaluate the impact of potential contaminants associated with poultry litter on the quality of tile-drain water in Kentucky.

Publication Date

2015

Series

Series XII

Report Number

Information Circular 32

Digital Object Identifier (DOI)

https://doi.org/10.13023/kgs.ic32.12

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