Farming in the Midwest, especially Iowa, is in ample supply as crop fields and livestock farms stretch for miles. With such an abundance of agriculture in the region, environmental discord resulting from farming techniques such as fertilization is something Iowa State researchers are working to resolve.
Fertilization, a necessity when growing high-quality corn, can compromise water quality. In Iowa, where fertilization is often in the form of animal manure, bacteria can travel to streams, wells, and lakes in runoff or through the soil into drainage tiles. Some of these bacteria are pathogens that could sicken people who play in or drink untreated water.
Well aware of these environmental issues, Claire Hruby, PhD student in agricultural and biosystems engineering (ABE), is determined to improve Iowa’s water quality. “Using manure as fertilizer makes sense in a state with so much animal agriculture, but there are risks you have to understand in order to manage,” she says.
Through expertise gained from her work with the Department of Natural Resources (DNR) and her education, Hruby is making headway into improving water conditions through a research project called “Potential Role of Poultry Manure Fertilizer in Pathogen and Hormone Contamination of Soil and Water.”
Unanswered Questions
Hruby obtained her master’s in geology from Iowa State in 2002. During that time, she took a number of courses on groundwater, which sparked her interest in water quality. Following her master’s degree, she began working at the Iowa DNR where she served as a hydrogeological consultant and geographic information system specialist for the Animal Feeding Operations (AFO) program.
Within the AFO program, Hruby’s efforts were focused on the DNR’s role in regulating confinement and open feedlot operations. Animals in each of these AFOs are confined for 45 days or more per year in a lot, yard, corral, building, or other area. In contrast to livestock kept in pastures, large quantities of manure are stored at these facilities. To prevent harmful substances in the manure from reaching surface waters and groundwater, the DNR enacts and enforces certain regulations such as separation distances to streams and additional construction requirements in vulnerable areas. Hruby was responsible for ensuring that livestock producers understood the requirements when proposing new facilities.
To make it easier for farmers to understand environmental risks, she was involved with creating an online mapping program that showed farmers the locations of potential flood plains, sinkholes, and wetlands. “The tools we created help farmers make informed decisions about their farming practices based on what the risks are and what they can do to minimize those risks,” explains Hruby.
Hruby also helped write policies related to water quality issues. Those policies led to a variety of intriguing questions that she felt were important for policy makers to answer. “I began to think, what do we even know about bacteria? Does it die? Does it re-grow? How does it move? Those questions really fueled my natural curiosity,” Hruby says.
Pursuing Answers
Compelled to find answers to her water quality questions, Hruby began perusing her options. After hearing there was a new ABE professor at Iowa State focused on water quality research, she was sure of what she needed to do. Upon talking with assistant professor Michelle Soupir, Hruby discovered a research project that suited her goals and began working towards a PhD in environmental science in January 2010. Once at Iowa State, Hruby was sent out on her own to begin her research with the help of a few undergraduates, who she says have helped tremendously.
For Hruby’s project, soil is fertilized with chicken manure, and then corn is planted in the fertilized soil. A variety of fertilizer amounts are applied to different plots in a field, and each plot has tiles that drain water into a storage device that samples hourly during and after each storm.
Hruby monitors each tiling system, and when it rains, she heads out to the field and collects samples. She then transports her samples to the lab so they can be processed.
The assessment process takes about four days due to the amount of time involved with collecting the samples, filtering samples, growing the bacteria, and then counting the number of bacteria grown from each sample. “To analyze the samples, we use simple methods of filtering and counting and more complex genetic testing that allows us to detect the invA gene that occurs in Salmonella,” explains Hruby. Through this process, Hruby and her contributors are learning more about the movements of bacteria in the environment.
Hruby has chosen to narrow her research from a broad range of bacteria sources to focus on Salmonella due to the clear association of the bacteria with poultry manure, which has received a lot of media attention due to recent Salmonella outbreaks. “What’s interesting is that this project is funded by the Iowa Egg Council,” she says. “I think that shows they are trying to be proactive by understanding water quality impacts to minimize negative effects.”
Collecting bacteria isn’t always easy. Samples are dependent on rain accumulation, which has been in short supply this summer. The summer of 2010 saw record amounts of rainfalls, causing Hruby to check her tile systems daily. This year has been almost the opposite, as her sample numbers dropped to almost nothing after the month of June.
Despite the lack of rainfall this summer, Hruby feels it provides a good perspective for her research. “Because each summer was in such contrast, we now know what the worst case scenario is and what the best case scenario is, which makes our research more realistic,” states Hruby.
It’s this perspective and insight that makes Hruby’s advisor, Soupir, so thrilled to have her on the team. With eight years of experience working in the real world on everyday issues relating to farming and water quality, Hruby has a rare but beneficial point of view. “Working for the DNR has given Claire a great perspective of the realistic possibilities, which benefits the rest of us when trying to formulate new applications for our research,” Soupir says.
Contributions to water quality research
Hruby says her work aims to reduce the risk of illness associated with pathogens, but it will also give policy makers scientific evidence for their decisions regarding DNR regulations, giving their policies more credibility. “If policy makers understand how bacteria survive and move in the environment, they can do a better job of communicating with farmers about what the best practices are to reduce water contamination,” she says.
Her research project is one of many projects being conducted at Iowa State under the direction of Soupir in the hopes of improving water quality. “The Iowa Egg Council has been funding our long-term study of hen manure on water quality since 1998. Claire’s project is a smaller pathogen study within the initial study,” explains Soupir.
In addition to the study funded by the Iowa Egg Council, Soupir’s group investigates re-suspension of E. coli from stream bottom sediments, integrating wetlands into watershed planning, and the movement of antibiotic resistant bacteria into tile water.
Although the research Soupir elicits is pivotal to Iowa’s water quality issues, Hruby hopes to expand her experience after she completes her PhD. Ever since a trip to Jordan and the West Bank, where she got the opportunity to see first-hand the role water plays in regional conflicts, Hruby has been hopeful to return. “It’s amazing that wherever you go in the world there are similar issues based on agricultural aspects of water use and water quality,” she says. “It’s a dream of mine to return to the Middle East someday and conduct research that might help improve water quality.”