Progress 09/15/01 to 08/14/03
Outputs
Preferential flow has been shown in a large body of experimental work to accelerate the movement of nutrients, pathogenic organisms, pesticides, and toxins through soil. The amount of water that moves by preferential flow will vary depending on soil type and moisture con-tent, and is often a relatively small fraction of the total. However, this fraction is disproportionally important because it rapidly moves water - and whatever the water is carrying - down from the surface and out of the root zone where contaminant adsorption or degradation are most likely to occur. For example, a recent experiment with pesticides showed that about 1 percent of several surface-applied herbicides was transported by preferential flow if sufficient rainfall occurred shortly after application. A one percent loss seems negligible but was sufficient to exceed drinking water standards in the subsoil water. Unfortunately, textbooks used for undergraduate instruction in hydrology, soils, and
contaminant transport devote very little attention to preferential transport in soils. (In contrast, geohydrology texts have long cited highly conductive zones that occur in aquifers). With funding from USDA-CSREES, the Soil & Water Engineering group in Cornell's Department of Biological and Environmental Engineering has developed a web site that provides a wide-ranging introduction to preferential flow. The website information is organized in tracks oriented toward educators as well as towards professionals. Assembled by webmaster and doctoral candidate Natalia Peranginangin, the site includes graphics and video clips. Contributions of relevant links and articles to the site are welcomed. The site's address is http://www.bee.cornell.edu/swlab/pfweb/index.htm.
Impacts
We had already several request for using the material for classes and as extension material
Publications
- Richards, B.K., N. Peranginangin, T.S. Steenhuis, and L.D. Geohring. 2003. The Unintentional Secret. J. Soil Water Cons. 59:104A-105A.
- Hatami, T. 2003. Using a Vegetative Filter Strip for Dissolved Phosphorus Removal from Milkhouse Wastewater in Upstate NY. M.Eng. Thesis. Department of Biological and Environmental Engineering. Cornell University
- Kim, Y-J. 2003. Phosphorus Dynamics in the Vegetative Filter Strip Under Various Field Conditions Ph.D dissertation. Department of Biological and Environmental Engineering. Cornell University
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Progress 01/01/02 to 12/31/02
Outputs
Preferential flow is a significant factor in the transport of water and contaminants in soils. Whereas conventional transport approaches assume water and solutes move uniformly through the soil matrix, in reality preferential flow phenomena - including macropore flow in structured soils, unstable wetting front fingering in coarse soils, and funnel flow in layered soils - can rapidly bypass much of the soil matrix and greatly increase the potential for surface and groundwater contamination. Preferential flow has been shown to play a significant role in the transport of pesticides, nutrients, trace metals, and microbial pathogens. Although there has been a significant amount of preferential flow research over the past two decades, the knowledge is still largely confined to the research community. Thus, this project is developing educational outreach materials to facilitate transfer of this information for education and extension professionals. Specific integrated
project objectives are to: (1) prepare an array of educational and extension resources tailored for three groups: educators, policy and regulatory compliance professionals, and the general public, (2) review and test education and extension resources in conjunction with potential stakeholders, and (3) disseminate the completed resources via an active, comprehensive web site. We have developed and collected various modules/contents based on research since the early 1980s. The developed resources include: presentations, graphics addressing different types of preferential flow, video clips, downloadable research papers, images, field/lab-based experiments, modeling, and solute sampling techniques. Partnering and leveraging of resources is occurring through contacts with other researchers and stakeholders to both gather additional materials or web links and to obtain feedback on the content and utility of the web site. Involved stakeholders include academic educators, government agency
researchers, state and local government and county-based extension personnel. The web site design will provide for the addition and expansion of modules so subsequent developments can be incorporated into an on-line distance-learning course segment on preventing agricultural non-point source pollution.
Impacts
Preferential flow is a common occurrence in soils and despite that not widely understood by most people outside the research community. The website http://www.bee.cornell.edu/swlab/pfweb/index.htm will aid in decreasing the knowledge gap.
Publications
- Darnault, C.J.G., Steenhuis, T.S., Parlange, J.-Y., and Baveye, P. 2002. Preferential flow and solute/colloid transport in porous media. OECD Workshop. Proc. Innovative Soil-Plant Systems for Sustainable Agricultural Practices. June 3-10, 2002. Izmir, Turkey.
- Nektarios, P.A., Petrovic, A.M., and Steenhuis, T.S. 2002. Effect of surfactant on fingered flow in laboratory golf greens. Soil Sci. 167:572-579.
- Peranginangin, N. 2002. Preferential flow. http://www.bee.cornell.edu/swlab/pfweb/index.htm
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Progress 01/01/01 to 12/31/01
Outputs
This project started in October 2001. This is at the end of the reporting period.
Impacts
Transport in preferential flow is very important for the many chemicals for which the concentration - calculated as the amount of applied chemical dissolved in 5 cm of water per ha - is higher than the drinking water standard. There is, therefore, a need to include information about preferential flow in undergraduate education curricula and workshops for extension agents and other professionals.
Publications
- No publications reported this period
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