Location: Soil and Water Management Research2009 Annual Report
1a. Objectives (from AD-416)
1. Integrate knowledge of retention, transformation, and transport of agrochemicals, including newer pesticides and veterinary pharmaceuticals, in soil and water, to facilitate selection and validation of management practices at the field to landscape scale that minimize potential offsite transport to surface and ground waters. 2. Identify practices that protect water quality and conserve soil resources in emerging farming systems of the North Central U.S. 3. Quantify the impact of agricultural drainage management systems on net greenhouse gas emissions and pesticide leaching losses. 4. Quantify the environmental impact of Best Management Practices on water quality in turf systems.
1b. Approach (from AD-416)
Results from research on factors affecting possible offsite transport of agrochemicals (nutrients, pesticides, and veterinary chemicals) to surface and ground waters, conducted on multiple scales (laboratory, field plots, and mini-watersheds) in an interdisciplinary manner, will be used to develop management practices that are relevant to protecting surface and ground waters in the North Central United States. Research will be conducted in interconnected experiments on basic processes affecting agrochemicals, spatial and temporal variation of processes, and impacts of management practices on environmental fate of agrochemicals. For instance, basic research on fate of pesticides and veterinary pharmaceuticals will be conducted in the laboratory on soils from selected field plots and watersheds to obtain basic information on processes. This information will be used in turn to help explain results of management practice effects on fate of agrochemical in fields and small watersheds. Management practices to be studied include: new cropping systems associated with large dairy operations; farming systems providing carbon sources for ethanol production; agricultural drainage management systems; and turf management systems. We will obtain information on the spatial and temporal variability of the processes and an assessment of the impact of altering the agronomic management practices on off-site transport of pesticides and fertilizers from non-agricultural, i.e. turf, and agricultural systems. Information obtained will include: an assessment of the predictive ability of transport models to simulate runoff and estimate chemical loading to surface and ground waters; identification of management practices that protect water quality and conserve soil resources in emerging farming systems in North Central U.S; and redefined agricultural systems models that can predict the impact of management of agricultural drainage systems on net greenhouse gas emissions in tile drained fields under the different climate and soil conditions of the Midwest corn belt.
3. Progress Report
Obj. 1 Progress: An enrichment culture approach was used to isolate a pure culture of the yeast Lipomyces kononenkoae, which had the ability to grow on the herbicide picloram, while completely degrading the picloram by catabolic processes. L. kononenkoae was found to use both N atoms of picloram as a sole nitrogen source for growth, but failed to mineralize it or use it as a sole C source. Product analysis by LC-ESI-MS indicated that biodegradation proceeds via a didechlorinated, dihydroxylated pyridinecarboxylic acid derivative. The effects of olive-mill waste addition to two agricultural soils (clay and sandy loam) on the sorption, persistence, and leaching of the herbicide fluometuron was determined. Organoclay-based formulations the herbicide terbuthylazine were characterized as to their potential to reduce the potential adverse environmental impacts of the herbicide. Over 1000 soil cores from corn and soybean plots managed with conventional, conservation, strip or no tillage were cut at multiple soil depths and stored frozen until extraction for herbicide analysis. Over 1500 soil samples have been extracted and analyzed for herbicides. Laboratory incubations assessing the initial impacts of fast-pyrolysis sawdust biochar additions on herbicide sorption and dissipation indicated that the rate of sorption was increased resulting in decreased dissipation rates for acetochlor and atrazine. These results are important due to the potential decrease in herbicide leaching and runoff losses from biochar amended soils. However, this increased sorption could lead to reduced bioavailability. The second year of measurements examining the impacts of pyrostourublin fungicide applications on the soil system has been conducted. There has been no detectable leaching of this fungicide observed in the field plots. Obj 2 Progress: An experiment was initiated to determine the impact of winter cover crops on erosive losses of sediment and phosphorus in SE Minnesota. Aerial seeding by helicopter will be used to establish the rye cover crop early, prior to corn harvest, and rainfall simulators will be used to compare the erosivity of treatmens versus control plots. In another experiment in western Minnesota, we continued to measure N and P in tile outflow from fields receiving large amounts of dairy manure. The cooperator has agreed to manage the manure differently in the two test fields to allow us to document potential benefits from fertigation versus fall injection. Obj. 3 Progress. Over 375 soil cores were collected from corn plots with various combinations of fertilizer (no fertilizer/manure, banded inorganic fertililzer, or injected manure) and drainage practices (conventional or controlled) for herbicide analyses. Obj. 4 Progress. Implemented new management strategies on fairway turf plots; over 240 application rate disks were extracted and analyzed to confirm and quantify pesticide application throughout several field seasons; more than 1500 rainfall and snow-melt runoff samples were collected from fairway turf plots; around 500 runoff water samples were processed and analyzed for five pesticides.
1. Quantification of fungicide and nutrient transport with runoff from creeping bentgrass turf. The detection of pesticides and excess nutrients in surface waters of urban watersheds has led to increased environmental concern and suspicion of contaminant contributions from residential, urban, and recreational sources. Highly managed biotic systems such as golf courses and commercial landscapes often require multiple applications of pesticides and nutrients that may be transported with runoff to surrounding surface waters. The objective of this study was to evaluate the off-site transport and impact of the fungicide flutolanil, soluble phosphorus, ammonium nitrogen, and nitrate nitrogen with runoff from creeping bentgrass turf managed as a golf course fairway. Edge-of-plot runoff contained phosphorus concentrations that were greater than USEPA water quality criteria to limit eutrophication, nitrate nitrogen levels below the drinking water standard to prevent blue baby syndrome and flutolanil concentrations below the median lethal concentration for 6 of 7 aquatic organisms assessed. Extrapolation of measured runoff loads to estimated environmental concentrations in a receiving surface water resulted in phosphorus concentrations remaining above levels associated with increased algal growth and eutrophication. Quantitative data collected from this study provides information on the transport of chemicals with runoff from turf that can be used in model simulations to predict non-point source pollution potentials and assess ecological and human health risks.
2. The impact of winter cover crops on annual water use in corn/soybean systems. Winter cover crops offer many environmental benefits, but farmers are cautious about using them, largely due to concerns about extra water use. A model was developed to estimate water use by winter rye and to compare it to fallow water loss. The model was run for 8 locations across the corn belt, for 5 years of weather data. The model indicates that water impacts on the subsequent crop depend significantly on the date when the rye is killed. Producers could use the model, in conjunction with weather predictions, to estimate the optimal time to seed and to kill the rye to get maximum environmental benefit with minimal water impacts.Sakaliene, O., Koskinen, W.C., Blazeviciene, G., Petroviene, I. 2009. Level and Fate of Chlorpropham in Potatoes During Storage and Processing. Journal of Environmental Science and Health. 44(1):1-6.