Wayne H. Hudnall, Ph.D.
B.L. Allen Endowed Professor of Pedology, Department of Plant and Soil Science
TTU, Department of Plant and Soil Science, Box 42122, Lubbock, Texas 79409-2122
806.742.4490 | 806.742.0775
Dr. Wayne Hudnall is the B.L. Allen Endowed Professor of Pedology in the Department of Plant and Soil Science at
Texas Tech University. His research focuses on working with all phases of the Cooperative Soil Survey Program
and supporting field and laboratory research in soil genesis, morphology, and classification in cooperation with the
USDA-NRCS and the Louisiana Agricultural Experiment Station. He is a member of the American Society of
Agronomy, the Soil Science of America, the Soil and Water Conservation Society of America, Sigma Xi, Gamma
Sigma Delta, the Clay Minerals Society and the National Association of Colleges and Teachers of Agriculture.
Q. Why do you research water issues?
I research water because I think water is the most important non-renewable natural resource on the Southern High
Plains. There is very little recharge in this area, and yet water is the most important non-renewable natural resource.
Q. Tell me about the theme of your research.
The objective is to evaluate and understand recharge into the aquifer from playa lakes. There are at least 70,000
playas on the High Plains and we want to evaluate the recharge from them. We are also trying to understand the
different types of recharge and whether it is associated with the adjacent soils or from the playa itself. We are
looking at lateral flow into playa lakes in particular. Lateral flow is when the flow of the water within the soil is
related to some layer within the soil that prevents it from going down due to gravity so it moves laterally. It might
also be discharged into the playa as not all the water in the lake comes from overland flow.
Q. How did you choose this research area?
We chose this research area because, traditionally for the past 10-15 years, people have been thinking that there was
not lateral flow. However, I always thought there was and several years ago, we started looking at it. The original
work was done by North Dakota State University and we collaborated on another project and found that lateral flow
was the major recharge process. I set out to prove that there is lateral flow (through flow) and that there is both
discharge into the playa and recharge into the Ogallala Aquifer. Lateral flow doesn’t occur in all parts of the playa,
but we’re not sure why just yet. It needs further research.
Q. Tell me about your current research.
My current research is part of the Ogallala Aquifer initiative, which is funded by congressional appropriations in
collaboration with the USDA- Agricultural Research Service (ARS). It’s mostly in Texas and Kansas – we’re trying
to confirm vertical movement of recharge using temperature probes. Water moves through the soil and as it moves,
the temperature of the soil will decrease due to the lower temperature of the water. We use such variants as
evaporation, sunlight and others and construct a model to see how much water is being discharged from outside the
playa into the playa and from the soil through lateral flow.
Q. Tell me about the tools that you use in your research.
We use electromagnetic inductance (EMI), which is an instrument that measures conductivity of materials that it
passes over. It records the conductance of materials and from this conductance you can identify the kinds of
materials and/or their characteristics. Wet material will have a different conductance than dry materials. We also use
Global Positioning System (GPS) to gives us the latitude and longitude (position) and the elevation within 1
millimeter. Based upon the elevation, we use software to draw a map and it gives us a clear of picture of soils
variability based upon the materials characteristics and elevation to ground truth or to identify the changes in
materials that are contributing to hydrological properties such as recharge. Then we go back and use a soil probe to
obtain soils cores in order to describe those morphological properties related to throughflow and recharge. We have
four playas that we are studying and we have studied 105 cores. We start at the playa bottom, and obtain soils cores
along a transect based upon the soil variability using the EMI data. IN the lab, we measure the differences in
particle size distribution(texture), the pH and the percentage of calcium carbonate. We describe the soil morphology
(arrange and kind of horizons, color and structure).. Using these data we can determine if the soil is or ahs been wet.
If the soil is or has been wet due to hydrological differences, it has a different color than when it is dry. Once we
have checked these variants, we can construct a flow net so we can tell where water enters the soil, how it moves
and whether it discharges into the play or recharges the aquifer.
Q. Do you have anything noteworthy you would like to publicize?
We have confirmed lateral flow and discharge at the playa’s annulus (that part of the playa that is covered with
water only at extreme rainfall events). We have demonstrated that using the EMI can identify changes in moisture,
particle size and changes in the percentage of calcium carbonate.
Q. With whom do you collaborate?
I work with Rick Zartman and Ken Rainwater of Texas Tech University. I work with Dennis Gitz of the ARS and
Loren Smith of Oklahoma State University. Additionally, the Ogallala Initiative group gets together and regularly
Q. What is your favorite water fact?
My favorite water fact is that water really does run downhill. It’s one of those obvious things, but it’s still very
interesting to me. You go downhill to find out where the water is or has been.