Hormones are endocrine disrupting compounds, which have been shown to alter the sexual development of aquatic organisms. Animal manure applications to agricultural fields for nutrient management can be a source of environmental hormones. This dissertation investigates the occurrence of hormones in fields applied with various manures and their adjacent streams, as well as the effect of manure application technologies on the fate of hormones in soils, sediments, and runoff. A total of 11 hormone compounds were studied. All studied analytes were quantified using liquid chromatography and triple-quadrupole mass spectrometry following various sample extraction and clean-up strategies.
The spatial and temporal distribution of manure-associated hormones in a manure surface applied agricultural field and adjacent stream was studied at time points up to 7.5 months after a routine manure application. Hormones were detected mainly in the top 0-5cm soils. Significantly higher levels of hormones were found in the drystack applied area of the field when compared to dairy manure slurry applied portion.
New technologies for the subsurface application of poultry litter show promise as a tool to reduce the transportation of environmental hormones in surface runoff. Once adequate sampling protocols were established; it was determined that subsurface injection of both dairy manure and poultry litter reduced the impact of manure surface runoff. Hormones also showed little vertical and lateral movement in the soil.
The transformation rates of 1,4-androstadiene-3,17-dione, 4-androstene-3,17-dione and estrone were studied comparing the effects of temperature, soil type, and application type. The calculated half-life of 1,4-androstadiene-3,17-dione in poultry litter surface-applied soils was 1.9 times higher than that in the poultry litter subsurface-injected soils, indicating a faster dissipation rate in the injection slits. Estrone persisted at detectable levels for the duration of the study in all treatments.
The continued use of best management practices and innovative manure management techniques for the reduction of nutrients, sediment and other contaminants has the potential to also reduce hormone transport to the natural environment. Monitoring many different types of hormones in all areas of an environmental system will continue to provide better information on the occurrence and fate of hormones sourced from manure amended soils. / Ph. D. / Hormones can contaminate streams and cause harm in the environment by interfering with the sexual development of aquatic organisms. Hormones are naturally occurring in animal manure, which is applied to agricultural fields for nutrients. Animal manures are usually spread on the surface of the soil and hormones can travel from the field to the streams when it rains. There are new technologies where the manure is injected into the soil instead of spread on the surface that could reduce the environmental impact of hormones in manure. This dissertation investigated the how hormones behave in fields applied with animal manures using the surface application technique and the subsurface injection technique. We investigated how long hormones persist in the soil, and their levels in manures, runoff from precipitation, and in waterways. Hormones were shown to stay in the top 0-5cm of soil, and to remain in the manure injection slit, showing that they do not easily move in the environment. Hormones were only detected in runoff water from soils that had surface applied manures. The transformation rate of hormones that were found at the highest levels in all the manures analyzed in this research was studied. It was determined that manure subsurface injection caused one of the compounds to transform at a faster rate in the soil. Overall, hormones were detected for up to 9 weeks in soils that were applied with animal manures. Best management practices such as manure subsurface injection and using a buffer zone between an agricultural field and a stream are promising tools for preventing hormones in animal manure from entering the natural environment.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/78342 |
| Date | 14 July 2017 |
| Creators | Sosienski, Theresa Ann |
| Contributors | Crop and Soil Environmental Sciences, Xia, Kang, Shang, Chao, Krometis, Leigh-Anne H., Maguire, Rory O. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Dissertation |
| Format | ETD, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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