Minnesota Water Science Center
Cedar Creek Biofuels ProjectMinnesota PROJECTSABOUT THE Minnesota
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Project Title: Cedar Creek Biofuels Ground Water Statement of Problem:Nitrate InvestigationThe U.S. EPA reports that nutrients (nitrate, nitrite, and phosphorus) are the leading cause of water-quality impairment in lakes and estuaries and the second leading cause of impairment to rivers in the United States (USEPA, 1998). Nitrate is considered the most prevalent contaminant of ground-water in the US (Spalding and Exner, 1993 as cited by Nolan and Hitt, 2006) and is responsible for methoglobinemia and some types of cancer in humans (Ward et al, 2005). Could diverse prairies be an effective solution for nitrate removal? A study done on sandy soils at Cedar Creek Natural History Area demonstrated that much less dissolved inorganic nitrogen (nitrate and nitrite) leached from diverse prairie systems (16 species) than non-diverse prairie systems (1 species) (Dijkstra et al, 2007). This proposed study will evaluate the ability of diverse prairie, corn, and hay plant communities to reduce nitrate leaching losses to ground water. Emerging Contaminant InvestigationSpreading liquid manure from animal feedlots on agricultural fields is a routine way of disposing of animal manure and providing a nutrient source for crops. Consequently, runoff from these fields, as well as from the animal feedlots, has been a concern for human and environmental health for many years. This concern is justifiable given the recent detection of veterinary pharmaceuticals (i.e. growth hormones and antibiotics) used in animal husbandry in manure (e.g. De Liguoro et al, 2003), soils (Kay et al, 2004), surface-waters (Kolpin et al, 2002) and ground-waters (Hamscher et al, 2005). In addition, the prevalence of these compounds in the environment is likely on the rise due to the increased usage, now on the order of millions of kilograms per year, necessary to maintain an increasing number of large animal feeding operations (Sarmah et al, 2006; USEPA, 2001). There is growing concern that these biologically active contaminants are entering the food chain as they move through the environment thus causing a myriad of effects (e.g. antibiotic resistance, Levy, 1998) and multiple exposure pathways for humans (Boxall, 2004). While there have been a number of studies looking at the movement of pesticides and nutrients through the environment, this information is not directly transferable to veterinary medicines as they are applied differently (within a manure matrix)and are comprised of a wide variety of high molecular weight compounds (Kay et al, 2004). There have been a number of studies examining the fate and transport of these pharmaceuticals through soils (reviewed by Thiele-Bruhn, 2003; Tolls, 2001), but there is “still a considerable lack of knowledge on the input and fate of antibiotics in soils” (Thiele-Bruhn, 2003). Furthermore, very little work has focused on the ability of plants to take up these compounds; the research that has been done thus far has strictly investigated plant uptake from a human health standpoint (e.g. Boxall et al, 2006) and not from a remediation standpoint. Since the majority of a prairie’s biomass is below ground, these systems have the potential for significantly greater contaminant uptake than annually harvested row crops. In addition, prairies influence soil properties, such as soil carbon content (Tilman et al, 2006), that may be important in controlling the sorption and movement of these compounds through the unsaturated zone. Mechanistic studies on the movement and persistence of veterinary pharmaceutical compounds through agricultural fields and buffers are therefore necessary to determine the fate of these compounds in the environment. This part of the study will investigate the fate and transport of a few representative pharmaceutical compounds through both agricultural and prairie plant communities growing on sandy soils to ground water. Biofuel InvestigationAgricultural food and energy production is essential to the United States’, and particularly to Minnesota’s economy. Row crops have traditionally served as a food source, either directly for human consumption or indirectly through the feeding of livestock. More recently, row crops have been used in making renewable biofuels; for example, corn grain is converted to ethanol and soybeans are converted to biodiesel. While the premise of using renewable fuels is positive, using row crops for biofuel production has severe drawbacks. Using a row-crop source for biofuels directly competes with food production, causes surface- and ground-water quality impairments due to erosion and agrichemical use, adds carbon dioxide to the atmosphere, and reduces quality wildlife habitat as lands are converted to agricultural fields. Planting diverse prairie grass buffers along agricultural fields offers a feasible biofuel source in addition to helping alleviate the aforementioned problems. Diverse prairie is an efficient carbon-negative biofuel alternative to row crops with 51% greater net energy production on degraded soil than ethanol made from corn grain grown on fertile soil (Tilman et al, 2006). The biofuel part of the experiment will compare three different biomass energy sources: prairie, hay, and corn. The resulting data will be used to answer a couple of key questions. Do prairie and/or hay plant communities provide a source of biofuel that is comparable in production to corn? Do hay and/or prairie plant communities provide ecosystem services, such as carbon sequestration, that make them a competitive biofuel choice in comparison with corn? Objectives:The overall USGS objective is to better understand the fate and transport of veterinary pharmaceuticals and nutrients through the unsaturated zone and to the water table beneath diverse prairie grasses, corn, and hay plant communities. We hypothesize that the selected plant communities will reduce the concentrations of veterinary pharmaceuticals in the unsaturated and saturated zones. Project objectives to be addressed by our cooperators at the University of Minnesota include evaluating the biofuel production and carbon sequestration abilities of diverse prairie grasses, corn, and hay. Relevance and Impact:Study results will provide managers with information needed to assess the effects of land application of veterinary pharmaceuticals on ground-water quality and contaminant transport in sandy soils. Managers will be better able to evaluate the differences between plant uptake of the contaminants by diverse prairie grasses, corn, and hay. By being able to make more educated management decisions, managers can help to ensure greater protection of water supplies and ground-water quality. Improved knowledge on solute transport following application of the contaminants to different crops will result from this study. This study will provide information for land managers and policy makers on the myriad of economically feasible benefits offered by natural prairie communities. This project is relevant to the USGS mission by advancing scientific knowledge on evaluating the effects of farming practices on ground-water quality. This project will help USGS refine the application and accuracy of techniques used to evaluate the fate and transport of agricultural chemicals in the environment. ReferencesBoxall A., P. Johnson, E. Smith., C. Sinclair, E. Stutt, L. Levy 2006. Uptake of veterinary medicines from soils into plants. J. Agric. Food Chem. 54:2288-2297. Boxall A., 2004. The environmental side effects of medication. EMBO reports. 5:(12)1110-1116. Burkart M., D.W. Kolpin, R. Jaquis, K. Cole. 2001. Soil characteristics and agrichemicals in groundwater of the Midwestern United States. Water Science and Technology. 43:251-260. Dijkstra F., J. West, S. Hobbie, P. Reich, and J. Trost. 2007. Plant diversity, CO2, and N influence inorganic and organic N leaching in grasslands (in press). Dosskey, M. 2001. Toward quantifying water pollution abatement in response to installing buffers on crop land. Environmental Management. 28:577-598. Hamscher G., H.T. Pawelzick, H. Hoper, H. Nau. 2005. Different behavior of tetracyclines and sulfonamides in sandy soils after repeated fertilization with liquid manure. Environmental Toxicology and Chemistry. 24:861-868. Kay, P., P.A. Blackwell, A.B.A. Boxall, 2004. Fate of veterinary antibiotics in a macroporous tile drained clay soil. Environmental Toxicology and Chemistry. 23:1136-1144. Levy S., 1998. The challenge of antibiotic resistance. Scientific American. 278:(3)46-53. Kolpin, D., E. Furlong, M. Meyer, E.M. Thurman, S.D. Zaugg, L.B. Barber, H.T. Buxton. 2002. Pharmaceutical compounds, hormones, and other organic wastewater contaminants in U.S. streams 1999-2000: a national reconnaissance. Environmental Science Technology 36:1202-1211. Nolan, B.T., K. Hitt. 2006. Vulnerability of shallow groundwater and drinking-water wells to nitrate in the United States. Environmental Science Technology. 40:7834-7840. Sarmah, A.K., M. Meyer, A.B.A Boxall, 2006. A global perspective on the use, sales, exposure pathways, occurrence, fate and effects of veterinary antibiotics (VA’s) in the environment. Chemosphere. 65:725-759. Spalding, R. F.; Exner, M. E. 1993. Occurrence of nitrate in groundwater-a review. J. Environ. Qual.22:392-402. Thiele-Bruhn, S. 2003. Pharmaceutical antibiotic compounds in soils-a review. Journal of Plant Nutr. Soil Sci. 166:145-167. Tilman, D., J. Hill, C. Lehman. 2006. Carbon-negative biofuels from low-input high-diversity grassland biomass. 314:1598-1600. Tolls, J., 2001. Sorption of veterinary pharmaceutical compounds in soils: a review. Environmental Science and Technology. 35:3397-3406. US Environmental Protection Agency, 1998. National Water Quality Inventory: 1996 Report to Congress. EPA841-R-97-008. Office of Water, Washington, DC, 521 pp. US Environmental Protection Agency), 2001. Development Document for the Proposed Revisions to the National Pollutant Discharge Elimination System Regulation and the Effluent Guidelines for Concentrated Animal Feeding Operations by Engineering and Analysis Division, Office of Science and Technology, EPA-821-R-01-003. Ward, M. H.; deKok, T.; Levallois, P.; Brender, J.; Gulis, G.; Nolan, B. T.; VanDerslice, J. 2005. Drinking water nitrate and health – recent findings and research needs. Environ. Health Perspect. 115:1607-1614. |
U.S. Department of the Interior |
U.S. Geological Survey
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