2007 Annual Report
Other CEAP activities involved cross-location and collaborative projects related to rapid geomorphic assessments for three CEAP watersheds, initial soil and sediment collection in Goodwater Creek to determine sources of sediment (overland versus streambank), and a third study is being initiated to measure streambank erosion as a function of stream order and adjacent land use in two watersheds. The streambank erosion project has also facilitated positive relationships with about 20 landowners within the study area.
The PAS work has been continued under this CRIS, with three years of field data collected. The APEX simulations should provide the necessary comparisons of productivity and environmental quality between the conventional and the precision agriculture systems.
The Bonne Femme watershed U.S. EPA 319 Nonpoint Source Pollution Control grant disbursed cost-share funds for several projects related to streambank stabilization, on-site sewer upgrades, use of pervious pavement for a parking lot, and wetland restoration. The Stakeholder Committee completed the watershed plan in February 2007. To date, the plan has received strong support among the local governmental entities within the watershed (i.e., Boone County and the Cities of Ashland and Columbia). It has been approved by the Boone County Planning and Zoning Committee (which sends the plan to the County Commission for approval), the City of Ashland, and it has received verbal, but not formal, approval from the Columbia City Council. Additional education and outreach included a low impact development workshop for local developers, a debate on the economics of development, an on-site sewer BMP tour, the annual open house, and two newsletters sent to all landowners in the watershed.
Vegetative Buffers Reduce Nutrients in Soil and Groundwater Effective vegetative buffers require grass species that can capture nutrients before they run off the surface or leach to groundwater. Scientists with the Cropping Systems and Water Quality Research Unit and the University of Missouri conducted a field study at the University of Missouri’s Horticulture and Agroforestry Center using five grass treatments (orchardgrass, tall fescue, smooth bromegrass, timothy, and switchgrass) plus a bare ground control treatment to evaluate the ability of the grasses to scrub nutrients from soils and prevent their transport to shallow groundwater. All grass species, except timothy, reduced nitrate concentrations in shallow groundwater by ~99% compared to the control, and switchgrass also reduced phosphate leaching by 60 to 74% compared to the control. In addition, grass treatments reduced soil nitrate levels by 41 to 91% below that of the control. Overall, switchgrass, smooth bromegrass, and tall fescue were the most suitable for use in vegetative buffers because of their superior ability to reduce soil nitrate and nutrient leaching. NP201: Problem Area 6, Water Quality Protection Systems; 1. Scientific information regarding nutrient retention, transformation and transport processes, and field management techniques that reduce off-site nutrient movement.
Development of New Analytical Methods for Herbicides and Their Metabolites in Soils and Plants Sensitive analytical methods are needed to accurately assess the environmental fate of herbicides and their metabolites. In collaboration with University of Missouri scientists, two new analytical methods were developed: one for the analysis of atrazine and its chlorinated metabolites in plants; and the other for the analysis of isoxaflutole (IXF) and its two primary metabolites in soils and plants. Both methods employ chromatography, to separate the compounds of interest, with mass spectrometry for detection, resulting in sub-part per billion detection limits and 1 to 2 orders of magnitude better sensitivity than previously published methods. The methods were applied to measurements of plants or soils from a field experiment to demonstrate their utility. In forage grasses, the results revealed that the ratio of metabolites to parent compound were good indicators of the detoxification pathways and overall sensitivity to each herbicide. Scientists, regulators, and industry will benefit from these methods since appropriately sensitive methods are now available for measuring these herbicides and their metabolites in the environment, which will facilitate an improved understanding of their environmental fate and lead to the implementation of vegetative buffers that more effectively prevent contamination of surface and ground waters. NP201: Problem Area 6, Water Quality Protection Systems; 6. New knowledge and prediction capabilities of the physical, chemical, and biological processes affecting the retention, transformation, and transport of pesticides.
Lerch, R.N., Lin, C.H., Leigh, N.D. 2007. Reaction Pathways of the Diketonitrile Degradate of Isoxaflutole with Hypochlorite in Water. Journal of Agricultural and Food Chemistry. 55(5):1893-1899.
Lin, C.H., Lerch, R.N., Garrett, H.E., Yong-Xi, L., George, M.F. 2007. An improved HPLC-MS/MS method for determination of isoxaflutole (Balance) and its metabolites in soils and forage plants. Journal of Agricultural and Food Chemistry. 55:3805-3815.
Lin, C.H., Lerch, R.N., Garrett, H.E., Jordan, J., George, M.F. 2007. Ability of forage grasses exposed to atrazine and isoxaflutole (Balance) to reduce nutrient levels in soils and shallow groundwater. Communications in Soil Science and Plant Analysis. 38:1119-1136.
Means, N.E., Kremer, R.J., Ramsier, C. 2007. Effects of glyphosate and foliar amendments on activity of microorganisms in the soybean rhizosphere. Journal of Environmental Science and Health Part B. 42(2):125.132.