Category: Statewide

Many questions related to the impact of current phosphorus (P) management practices on P-related water quality problems are being asked by the public, government agencies in charge of nutrient regulations, producers, and researchers. Because of inappropriate P fertilizer or manure management or the need to dispose of manure, excess P often is delivered from agricultural fields to water resources. For example, the Iowa Department of Natural Resources (IDNR) has established that most Iowa lakes are seriously impaired by elevated P concentrations (Olson and Van Gorp, 2003). The Environmental Protection Agency (EPA) is developing new regulations concerning P levels in lakes and streams. The National Resources Conservation Service (NRCS) and state agencies (such as IDNR) have developed or are developing guidelines for fertilizer and manure management based on P, in addition to existing guidelines based on nitrogen (N). These guidelines are based on P risk assessment tools, often referred to as P indexes. The P index considers a variety of factors that influence P loss from agricultural fields. Although a P index has been developed for Iowa and many other states, the gaps and insufficient information of some processes have created a great deal of uncertainty in some P index components. Two co-investigators of this proposal (Mallarino and Baker) were prominent members of the team that developed the Iowa P index (Iowa NRCS, 2001; Mallarino et al., 2002b).

Excessive addition of nutrients to Iowa surface waters from nonpoint and point sources impairs our waters for beneficial uses, and it also affects down-stream users. Gulf Hypoxia, eutrophication, harmful algal blooms, and impairment of aquatic life are just some of the problems related to runoff of nutrients and sediments into Iowa waterways. To date, we do not have cost-effective ways to monitor all of the States waters and to develop Total Maximum Daily Loads (TMDLs). Also, we do not make effective use of modern sensing and computer technologies to improve our environmental cyberinfrastructure. Recent improvements in such technologies, data mining, and genetic algorithms allow radical improvements in our abilities for real-time sensing of the environment, analysis of the problems, and for evaluation of Best Management Practices or other policy decisions involved with water quality management plans under the TMDL process. The objective of this research is to gain experience with environmental cyberinfrastructure for sensing, modeling, and analyzing nutrient and sediment problems. We will purchase an initial backbone of sensors, data nodes, and access nodes for real-time measurement of gage height, velocity, dissolved oxygen, temperature, conductivity, salinity, pH, turbidity, nitrite, and nitrate. Data will be accessed, stored, and used as input for exercising water quality models (QUAL-2EU and HSPF) in a real-time environment.

Non-point source pollution due to agricultural activities is a vital issue for the State of Iowa. This project will provide a first assessment of the overall impact of a large scale conservation policy that includes several practices simultaneously on the in-stream water quality for all major Iowa rivers outlets. This project will consider the sensitivity of the water quality improvements and costs of the policy under several alternative scenarios, thus evaluating cost-efficiency of alternative conservation plans. Sediment, nitrogen and phosphorus reductions will be estimated. The results from the proposed research project will provide critically valuable information to support effective, science-based water quality management in the state of Iowa. Micro-unit-based economic models and data on land use and conservation practices are combined with a watershed-based hydrological model, the Soil and Water Assessment Tool (SWAT), to estimate the costs of obtaining water quality changes from the hypothetical placement of several broad-based sets of conservation practices. The practices analyzed in the assessment include terraces, grassed waterways, contouring, conservation tillage, land set-aside, and nutrient management strategies. The analysis is carried on 35 watersheds corresponding to the United States Geological Survey 8-digit Hydrologic Cataloging Units that are largely contained in the state. The watersheds correspond to 13 outlets, at which the in-stream water quality is measured. For the cost analysis we consider placing the identified set of practices all across the state. The major objective of the research is to estimate the costs of implementing alternative sets of identified conservation practices together with the reductions in sediment loadings, nitrogen, and phosphorus at the 13 outlets.

Animal production systems are becoming larger, and the public is concerned about the impacts of large animal facilities on water quality. Of particular concern are losses of nitrogen (N) in the forms of NH4-N, NO3-N, phosphorus (P) as PO4-P, pathogens, and antibiotics with surface runoff and subsurface drainage water. The proposed study deals with assessing the effect of land application of swine manure on NO3-N, PO4-P, bacteria, and antibiotic losses in surface runoff and subsurface drainage water. In 2000, with funding from the Leopold Center, a six-year (20002006) field study was initiated at the Iowa State University Northeast Research Center near Nashua to investigate the impact of land application of swine manure on water quality. The specific objectives of this study are: i) to determine the impact of recommended rates of swine manure, based on N and P uptake requirements of crops, on water quality; ii) to study long-term effects of over-application of swine manure on NO3-N, PO4-P, and bacteria leaching to shallow groundwater; and iii) to study the effects of spring and fall injection methods of swine manure on crop yields and NO3-N, PO4-P, and bacteria concentrations in surface runoff and shallow groundwater. From 2000 to 2003, we did not monitor the concentration of antibiotics in surface runoff and subsurface drain water. In 2004, a renewal grant proposal was submitted to the Leopold Center to continue this study for three more years as we needed to collect six years of water quality data for corn-soybean production system. In this renewal grant we proposed that we should collect data on antibiotics in the surface runoff and subsurface drainage water. The Leopold Center decided not to fund this project as the Leopold Center priorities changed to other areas. This was the first time since 1988 that the water quality research project for the Nashua site was not funded by the Leopold Center. Therefore, we requested the National Manure Management Center (NMMC) at North Carolina State University to fund this proposal and include the monitoring of antibiotics in surface and subsurface drainage water in addition to N, P, and bacteria. The NMMC funded this project for 18 months until December 2005 to analyze drainage water samples for antibiotics in objective (ii) in addition to NO3-N, PO4-P, and bacteria. The NMMC was funded with a USDA grant and this USDA grant will end on Dec. 31, 2005, thus, closing the NMMC permanently. With this proposal, we are requesting the ISWRRI to fund this project for the remaining 18 months (January 2006 to June 2007) so that this ongoing study can be completed and final conclusions of various treatments can be drawn to benefit the producers. This study site has 36 one-acre plots, with complete surface and subsurface drain monitoring system (Kanwar et al, 1999). The state-of-the-art surface runoff water and tile water monitoring facilities were installed at this site in 1988 on each of these 36 plots for sampling tile water for various water quality parameters. In 2000, nutrient management treatments were established on these plots (Table 1). These treatments include the application of swine manure to meet N and P uptake needs of corn and soybeans. Also, a new treatment was introduced in this study to apply swine manure at double the P uptake needs of corn to determine the effect of excessive application of swine manure on water quality. In addition to rate effects, manure was applied in the spring and fall to study the effect of timing of manure application on N and P leaching. Surface and subsurface drain water samples are analyzed on a weekly basis for various water quality parameters when tile drains are flowing. Five years of water quality data have been collected and we need one more years data to make final conclusions of this study. Therefore, funding from the ISWRRI for the next 18 months would be critical to the success of this project. At present, we do not have any other source of funds to complete this study.

Concern about the impact of ethanol production on Iowas water resources has increased due to the large increase in statewide ethanol production. Water use at ethanol plants could soon reach 22 billion gallons per year (Ggal/yr). Groundwater is preferred for these operations because of its high quality and stable quantity; however, placement of ethanol plants is determined by access to corn, not necessarily to groundwater supply. Permits for ethanol-related groundwater withdrawals are being granted in rural areas where determination of local pumping impact is often performed by a well driller or consultant. Tools for assessing the larger-scale impacts of ethanol production in aquifers (including water quality and ecological impacts) and for evaluating the sustainability of aquifers in the State need to be developed in order to provide a scientific basis to strengthen administrative oversight of groundwater use. The proposed research will compare the ability of three different types of groundwater models to assess the potential impact of ethanol production and determine aquifer sustainability using a test case of the Ames aquifer a regional, alluvial/buried valley aquifer in central Iowa. The grant will help fund Phase III of the project Water Supply for Ames in the 21st Century: A Comprehensive Reassessment of the Ames Aquifer and will address the following objectives: 1. Simulate steady-state and transient groundwater flow in the Ames aquifer under non-pumping and pumping conditions using a 3-D, finite-difference, groundwater flow model; 2. Compare output of 2-D and 3-D groundwater models to determine which would best identify impacts of ethanol production in aquifers and the appropriate scale of investigation; 3. Apply simulation-optimization modeling to the calibrated 3-D model to investigate the impact of large-scale ethanol development on drawdown, optimize well pumping schedules, manage future well field expansion, and assess the long-term sustainability of the aquifer. Modeling will take advantage of three USGS stream gages in Squaw Creek and the Skunk River, 65 hydraulic head targets, and nearly 100 boring logs in the Ames aquifer that have been used to construct a 3-D framework for the aquifer. In order to further understand the geology, the 3-D distribution of hydraulic head, and estimate recharge rates for the model, funds are requested for the installation of two new piezometer nests. Nest 1 in the Downtown Well Field would be designed specifically to estimate vertical K (Kv) and recharge (R) in the aquitard. Nest 2 in the Skunk River alluvium will specifically test the hypothesis that the Skunk River is a losing stream and can develop an unsaturated zone beneath the river. Both piezometer nests will be installed in fall 2007 and instrumented with combination pressure transducers/ dataloggers (corrected for barometric pressure) in order to gather real-time data that can be related to pumping schedules and USGS stream gaging data. Modeling with MODFLOW will begin in July 2007 and the simulation will be calibrated to hydraulic head measurements in the model domain and streamflow under pre-development conditions. Transient simulations will commence once the model is calibrated. Results of a regional 2-D, steady-state, analytic element, groundwater/surface water model (GFLOW) and a local-scale, 3-D, transient, groundwater flow model (MODFLOW), will be compared to determine which approach is best suited to evaluating the impacts of ethanol production at different scales. A simulation-optimization model (the Groundwater Management process for MODFLOW 2005) will be applied in spring 2008 to evaluate the sustainability of the Ames aquifer, taking into account limits on groundwater withdrawals, streamflow depletion under multiple uses (pumping) of the aquifer, and alternative climatic scenarios. By using models to assess the impact of ethanol production and to address sustainability for the Ames aquifer, the results of this study will provide a template to guide management and regulation of similar aquifers under pumping stresses from ethanol production in Iowa and the Midwest.

Interest in biorenewable energy is increasing due to concerns associated with continued reliance on fossil fuels. As the primary producer of crops used as feedstocks for ethanol production and other biorenewable energy sources, the Midwest in general, and Iowa in particular, is likely to incur a high percentage of the benefits and costs of the biorenewable energy initiative. Of significant potential concern is the impact of feedstock selection, management, and harvest on nutrient and sediment losses to receiving water bodies and the resulting impact on the integrity of aquatic resources. In the short term, increases in corn acreage, or large-scale conversion of Conservation Reserve Program lands to feedstock production, have the potential for significant negative impacts on water resources. In the longer term, conversion to perennial-plant based feedstocks for cellulosic feedstocks has great potential to positively impact aquatic integrity and water quality. However, in order to make a credible assessment of impacts of such change, significant knowledge gaps regarding the function of such landscape features need to be addressed. Managed riparian buffers, composed of woody and nonwoody vegetation, are being used to reduce inputs of nutrients, sediments, and chemicals to streams that commonly result from intensive agriculture. In central Iowa, previous studies conducted by the Iowa State University Agroecology Issue Team demonstrated that buffer attributes (e.g., physical structure, root uptake) reduce nutrient and sediment loading to streams. However, responses of most ecosystem components, including populations and communities of aquatic organisms, remain poorly studied. The emerging biorenewables initiative is likely to generate even greater agricultural production, particularly on lands susceptible to high runoff and soil erosion. Therefore, it is critical that we identify functional qualities (e.g., spatial distribution, length and width, vegetation composition and age) of effective riparian buffers and apply this knowledge to design and manage systems that protect aquatic ecosystems in an economically-viable manner. Animal and plant populations and communities respond to and reflect all physical, chemical, and biological attributes of their environment, including conditions affecting human health. Additionally, biological communities are sensitive to episodic events (e.g., pulses of contaminant inputs during high surface-water runoff) and rare contaminants that are undetected by periodic measurement of selected physical and chemical ecosystem attributes. Because organisms are now acknowledged to be definitive indicators of water quality, they are increasingly being used for regulatory assessments (e.g., USEPA) and are likewise essential tools for assessing riparian buffer effectiveness. In this study, invertebrate and fish community characteristics (i.e., species composition, abundance, growth) will be evaluated in three central Iowa streams with and without managed riparian buffers of different age, size, and structure (N = 40 total stream reaches). Instream habitat features (e.g., streambed substrate particle sizes, coarse particulate matter abundance, temperature, turbidity) will also be measured in riffles, pools, and runs where fish and invertebrates are sampled. Results of this study will produce quantitative measures of buffer effectiveness that will help guide future riparian management strategies in agroecosystems. In addition, this study will provide a platform for expanding the scope and scale of our investigations. Planned studies to increase mechanistic understanding of riparian buffer effects in agroecosystems include analyses of buffer effects on stream metabolism (e.g., dissolved oxygen, primary production), and nutrient- and energy-flow pathways through aquatic food webs. The proposed research will also provide a platform for investigating emerging issues across Iowa. Issues include conservation of systems influenced by production of biorenewable feedstocks (i.e., cereal grains, cellulosic materials in riparian buffers), lake and reservoir restoration activities, and biological assessment of recently reclassified headwater stream systems.

Improved watershed modeling, uncertainty analysis and statistical techniques for TMDLs have been identified as immediate TMDL science needs by the National Research Council (US EPA 2002). Recently approved sediment TMDLs in Iowa use versions of the Universal Soil Loss Equation (USLE) with conservation input to account for uncertainty. The uncertainty associated with these USLE estimates cannot be explicitly quantified and the margin of safety (MOS) required by the TMDL program is considered to be implicit in the watershed modeling process. This project proposes to test the following hypothesis: The uncertainty associated with sediment TMDLs can be quantified by applying the process-based Water Erosion Prediction Project model (WEPP) and an explicit computation of the margin of safety (MOS).

The quality and quantity of groundwater resources in Iowa are a growing concern because of increased pressures on quantity and concerns about contamination. Interactions between land management, groundwater, and surface water are conceptually well understood but the impact of temporal shifts on groundwater and surface water are largely unknown. Groundwater and streamwater quality are of particular concern in cities such as Ames because of their reliance on groundwater as a water supply. Recent monitoring near College Creek in Ames identified nitrate in groundwater at two of four transects and significant total P and SRP concentrations present in all 12 wells and in streamwater. Recent groundwater modeling of the Ames aquifer suggests direct interaction between surface water transported through tributaries running through the city and the Ames aquifer. Because most streams that enter the alluvium of Squaw Creek and South Skunk River becoming losing streams at that point, contaminants in the streams will impact the city’s water supply. Thus, efforts to prevent contaminants from getting to streams in headwater areas are necessary to protect groundwater quality downstream. Those responsible for the contaminant loading become as important as the presence of the contaminants themselves. This research proposes the addition of a strongly integrative groundwater-streamwater component to an ongoing urban stormwater research/non-point source pollution research and stream stabilization effort on College Creek in Ames. Our proposal occurs at an interesting and exciting time for College Creek and the Ames community. The City of Ames is partnering with ISU researchers whose work with water resources in the community are supported by multiple agencies and institutions. The City also committed $291,540 of its operating budget over the next three years to match an IWIRB grant they were awarded for College Creek stream stabilization and riparian enhancement. As this momentum for addressing non-point source pollution grows, it is also understood that only a very limited amount of research has been dedicated to exploring groundwater from the perspective of the urban residentthe group likely responsible for much of the contaminant loading occurring in headwater areas. This proposal includes an innovative community-based education based on biophysical and social investigations of the urban groundwater-streamwater system at the neighborhood scale. We focus specifically on interactions between land management, groundwater, soil water and streamwater within the urban residential landscape. Monitoring of a nested well site adjacent to College Creek in Ames is accompanied by simultaneous investigation of groundwater perceptions and technical understanding among a statically representative sample of urban, riparian landowners. Research activities are organized to utilize the results from each component to inform the others. Early monitoring results are utilized to develop a social assessment tool to characterize the perceptions & misconceptions residents hold concerning local hydrologic processes and conditions. Social assessment results add landowner behavior data that, when integrated with monitoring and modeling, contribute to a greater understanding of nutrient movement between the landscape and hydrologic system. Finally, educational curriculum is developed to integrate both monitoring results as well as any lack of understanding or misconceptions identified during social assessment.

Excess sediment, phosphorus (P) and nitrogen (N) impair the majority of Iowa lakes and many streams also are impaired during some periods of the year. Most sediment and nutrients originate from agricultural fields or stream banks. A good potential for large-scale bioenergy production in Iowa is challenging researchers and nutrient management planners to develop crop and nutrient management systems to maximize production of feed, fuel, and fiber while utilizing soil and nutrient resources minimizing undesirable environmental impacts. Therefore, there is a need for studies of soil processes and nutrient loss on a field-plot scale that represent actual field conditions as much as possible focusing on bioenergy production and nutrient management systems likely to be adopted soon. The project will evaluate and compare systems that will still predominate for years to come in Iowa (such as corn and soybean for grain production) and new systems with likely adoption for bioenergy production (such as total or partial corn and perennial grass biomass harvest) managed with fertilizer or liquid swine manure. The study results will provide needed information about cropping and management systems for bioenergy production impacts on soil and water quality that can be compared to impacts from currently used systems. The proposed work will integrate efforts by scientists from the Department of Agronomy and the Department of Agricultural and Biosystems Engineering, by the ISU Research and Demonstration Farms System, a group of Northwest Iowa farmers (the Northwest Iowa Experimental Association), and seed funding by the IFLM program of IDALS. These contributions plus requested funding from the Iowa Water Center will be used to develop work during 2008 and 2009 at a runoff study site in Northwest Iowa and a tile-drainage study site in Central Iowa. We propose to study how crops, biomass harvesting systems, fertilizer and manure management practices, and selected soil properties relate to loss of sediment and various forms of N and P with surface runoff and subsurface tile drainage. The main objectives are (1) to determine dissolved reactive P, total dissolved P, algal-available P, total P, and total N concentrations and loads in surface runoff from corn production systems harvested for grain using different tillage and fertilizer or manure P management systems and from continuous corn harvested for grain and cornstalks and (2) to determine loss of nitrate, dissolved reactive P, and total dissolved P through subsurface tile drainage from crops for selected bioenergy production systems managed with fertilizer or manure N-P management systems. We will also analyze soil and harvested biomass for nutrient concentration and relate these results to treatment effects on N and P loss. Overall, the information from the study will be useful to establish new and improved environmentally oriented management guidelines and will provide useful information concerning impacts of anticipated land changes in the near future on export of nutrients to water resources.

Surface water from the Des Moines River is impaired by nitrate-nitrogen for drinking water use. Saylorville Reservoir is a 24.1 km2 impoundment of the Des Moines River located approximately 10 km north of the City of Des Moines. Monthly mean nitrate concentration data collected upstream and downstream of the reservoir for a 30-year period (1977-2006) are analyzed in this study. Our objective is to improve understanding of the reservoir effects on river nitrate concentrations. We hypothesize that monthly water quality downstream of the reservoir depends on the current monthly upstream water quality and its past lags. The dynamic relation is studied via a transfer function model that is shaped by reservoir characteristics such as surface area, volume, and discharge. Research results may used to better manage Saylorville Reservoir to mitigate nitrate concentrations in downstream receiving waters and forecast potential impairment to the Des Moines Water Works.