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Professor, Soil Physics
Physical mechanisms that control water motion in soil, porous media, and fractured porous media.
Department of Crop and Soil Science
3173 Ag & Life Sciences BldgCorvallis, OR 97331
BIOWATER RESEARCH: Projections for food demand over the next few decades will require significant increases in agricultural productivity for essentially the same soil footprint but reduced water consumption. Sustaining intensified agricultural productivity over the long term will require clear understanding of fundamental soil processes. We have chosen to contribute to this quest by improving agricultural productivity on sandy-soil in arid and semi-arid agricultural areas. Three questions are being investigated:
- Determine how soil biology can be used to increase water retention quantity and duration in sandy-soils.
- Determine if subtle changes in irrigation practices can be used to eliminate the common problem of subsurface water repellency, which in sandy soils often causes crop stress and hastens deep drainage losses of agricultural nutrients.
- Because seasonal hydrologic cycles in non-irrigated land impacts the establishment and long-term resiliency of plant communities, our goal is to quantify the subsurface vapor-capillary cycle in native grazing lands to improve our understanding of arid land soil hydrology.
EPIKARST EVOLUTION: The epikarst is the transitional region of carbonate parent material between the soil and the underlying karst cavern system. This region slowly evolves into a mature karst via cave enlargement and the erosional opening of micro-fractures. Our investigation focuses on the possible acceleration of micro-fracture erosion by soil water driven by the combined action of chemical and hydrodynamic processes.
WATER REPELLENCY: For many years, even decades, water repellency has been the topic of study in many countries, including Holland, Spain, Australia and the USA. These studies typically focused on the link between water repellency and various soil properties. We are exploring biophysical mechanisms that may lead to remediation and prevention techniques in agricultural settings.
GAS EXCHANGE ACROSS THE EARTH-ATMOSPHERE INTERFACE: When porous media is highly permeable or fractured, gas advection will supersede diffusion as the main mechanism for gas exchange across the soil-atmosphere boundary. In addition to this higher transport rate, diurnal peaks occur at night rather than during the day. In collaboration with colleagues at Ben Gurion University, we are exploring the extent to which this mechanism contributes to vadose zone gas venting and heat exchange with the atmosphere.
SOLARIZATION: Rather than using herbicides and pesticides, soil solarization has been used in many low-latitude agricultural regions to successfully disinfect soil. In collaboration with fellow scientists (Jennifer Parks and Carol Mallory-Smith, Oregon State University), we are exploring the feasibility of using solarization in the Pacific Northwest.
- SOIL 435. Environmental Soil Physics
- SOIL 535. Soil Physics
- SOIL 536. Vadose Zone Hydrology Laboratory
- SOIL 645. Advanced Topics in Soil Physics
I accept graduate students in Soil Science, Water Resources Science, and Water Resources Engineering
|Ph.D.||1999||Hydrogeology||University of Nevada, Reno|
|M.S.||1984||Geophysics and Space Physics||University of California, Los Angeles|
|B.S.||1980||Physics||California Polytechnic Univeristy, Pomona|
|1999-Present||Professor, Soil Physics
Department of Crop and Soil Science
Oregon State University, Corvallis, OR
|1992-1995||Instructor, Physical and Earth Sciences
College of Natural Sciences
Shasta College, Redding, CA
|1989-1991||Instructor, Physics and Geology
Department of Physics, Department of Geoscience (Joint appointment)
California State University, Chico, CA
Director, Natural Science Learning Center
Curriculum Development Team, Member
Deputy Team Chief, Science Requirements and Operations Planning
Deputy Team Chief, Fields and Particles Science Team
Science Planning Lead
|1975-1981||Scientist, Radiation Physics Group
Apollo Project, NASA
Jet Propulsion Laboratory, California Institute of Technology, CA
Dragila, Maria I., Uri Nacshon, and Noam Weisbrod, Fractures as advective conduits at the earth-atmosphere interface, AGU Special Issue 'Dynamics of Fluids and Transport in Fractured-Porous Media' Ed. Boris Faybishenko. Accepted Dec 2013, to be published in 2015.
Woolverton, P. and M.I. Dragila. 2014. Characterization of hydrophobic soils: a novel approach using mid-infrared photoacoustic spectroscopy. Applied Spectroscopy, 68, 1407-1410.
Weisbrod, Noam, Uri Nachshon, Maria I. Dragila and Avrami Grader, 2014, Micro-CT analysis to explore salt precipitation impact on porous media permeability, Ch 20 in E. L. Mercury et. al, Eds, Transport and Reactivity of Solutions I Confined Hydrosystems, Nato Science for Peace and Security Series C: Environmental Security, DOI 10.1007/978-94007-7534-3_20, © Springer Science + Business Media Dordretch 2014.
*Gray, M, Johnson, MG, Dragila, MI, Kleber, M, 2014, Water Uptake in biochars: The roles of porosity and hydrophobicity. Biomass and Bioenergy, 61,196-205, doi:10.1016/j.biombio.2013.12.010
*Ganot, Y, Dragila, MI, Weisbrod, N, 2014, Impact of thermal convection on CO2 flux across the earth-atmosphere boundary in high-permeability soils, Agricultural and Forest Metrology,184, 12-24, doi:10.1016/j.agroformet.2013.09.001
Ganot, Y., M. I. Dragila, et al. (2012). "Impact of thermal convection on air circulation in a mammalian burrow under arid conditions." Journal of Arid Environments 84: 51-62.
Kizito, F., M. I. Dragila, et al. (2012). "Hydraulic redistribution by two semi-arid shrub species: Implications for Sahelian agro-ecosystems." Journal of Arid Environments 83: 69-77.
Nachshon, U., M. Dragila, et al. (2012). "From atmospheric winds to fracture ventilation: Cause and effect." Journal of Geophysical Research-Biogeosciences ,117.
Nachshon*, U., S.Ebrahim*, D. Or, M. Dragila and N. Weisbrod. 2011. (accepted). Infrared thermography of evaporative fluxes and dynamics of salt deposition on heterogeneous porous surfaces. Water Resources Research.
Nachshon*, U., N. Weisbrod, M.I. Dragila and A. Grader. 2011. Combined evaporation and salt precipitation in homogeneous and heterogeneous porous media, Water Resources Research, 47, W03513, doi:10.1029/2010WR009677.
Warren*, J., M, R. Brooks, M.I. Dragila and F.C. Meinzer. 2011. In situ separation of root hydraulic redistribution of soil water from liquid and vapor Transport, Oecologia, 166(4):899-911, doi:10.1007/s00442-011-1953-9
Ochiai*, N., J.L. Parke and M.I. Dragila. 2011. Pattern swimming of Phytophthora citricila zoospores: An example of microbial bioconvection, Fungal Biology, 115:228-235.
Ochiai*, N. M. I. Dragila and J.L. Parke. 2010. 3D tracking of colloids at the pore-scale using epifluorescence microscopy, Vadose Zone Journal, 9(3):576-587. Cover page article, doi: 10.2136/vzj2009.0047
Gervais, J.A., S.M. Griffith, J.H. Davis, J.R. Cassidy and M.I. Dragila. 2010. Effects of Gray-tailed Vole Activity on Soil Properties, Northwest Science, 84(1).
Weisbrod, N., M.I. Dragila, U. Nachshon*, and M. Pillersdorf*. 2009. Falling through the cracks: The role of fractures in Earth-atmosphere gas exchange, Geophysical Research Letters, 36, L02401, doi:10.1029/2008GL036096.
Kamai*, T. N. Weisbrod, and M.I. Dragila. 2009. Impact of ambient temperature on evaporation from surface-exposed fractures. Water Resources Research. 45. W02417. soi:10.1029/2008WR007354.
Weisbrod, N., M. Dragila, U. Nachshon* and M. Pillersdorf*. 2009. The role of cavities in earth-atmosphere interactions. In: From Head Water to the Ocean: Hydrological Changes and Watershed Management. Taniguchi, M., Burnett W.C., Fukushima, Y., Haigh, M. and Y. Umezawa, (Eds), Tayler & Francis Group, London, UK, pp. 9-15 (peer reviewed).