My
focus at the University of Arizona is on development of application and
management systems for water and chemical application to soils and plants.
Monitoring, evaluating, and controlling soil water content and chemical
concentration within agricultural and landscape plant systems is a challenge
that requires creative solutions. The entire system as well as interactions
with other systems must be considered when designing an application or management
system. The engineered solution should include sensors, controls, decision
algorithms, and application systems.
As
a teacher, I attempt to communicate the complex processes within systems, the
interrelationships between systems, and development of the sensors, controls
and decision algorithms needed to control systems. I teach engineers that they
must consider all parts of a system when they evaluate a process, design or
engineered solution. In my engineering classes, students meet with consulting
engineers and design real irrigation systems or constructed wetlands. In my
Natural Science class, Science, Technology, and Environment, students observe
systems such as a constructed wetland, urban irrigation system, garbage dump,
Biosphere 2, or factory. Then they apply basic scientific principles such as
conservation of mass and energy to quantify processes within the system. We
also discuss how each system fits into the global environment.
My
job description includes both teaching (40%) and research (60%), and I have
made significant efforts in both research and teaching. I was the PI on nearly
$1,000,000 in funded grants. Nearly all of the grants have resulted in
significant engineering solutions that save water and chemicals and reduce
off-target contamination. My job description requires that I teach at least 3
classes per year; however, I taught 2 classes per semester - sole or lead teacher in 20 classes, and
participated in 24 formal classes. I redesigned one class completely
(ABE458/558), modified ABE456/556, developed a completely new course for the
Natural Science Core Curriculum, NATS101, and modified ABE404 for distance
education to Yuma. I advised 12 graduate students, co-advised 2 graduate
students, and served on 16 other graduate committees.
Research
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Before I came to the
University of Arizona, my career focused on water and chemical application
systems in agriculture. My primary research focus at the University of Arizona
has continued to be in irrigation and chemigation, but I began an urban
landscape irrigation research program, and an irrigation and chemigation
systems management research program with an emphasis on remote sensing and crop
modeling.
One
of the greatest threats to our environment is nonpoint source contamination by
agricultural and urban irrigation systems. One of the greatest threats to our
quality of life in Arizona is lack of water. My research focuses on increasing
the uniformity and efficiency of water and chemical application in both urban
and agricultural landscapes leads to reduced nonpoint source pollution and
improved water conservation.
My
research group has made 5 important contributions that will help the state of
Arizona and other Western States save water and prevent nonpoint source
pollution. (1), we showed that a
system that was thought to have 90% uniformity and efficiency, landscape drip irrigation, actually
averaged less than 20% uniformity. Degradation of emitters and lack of
adjustment of number of emitters for variable plant sizes resulted in low uniformity.
Site efficiencies ranged from 14 % to 400 % and revealed a lack of ability by
most irrigation managers to calculate watering schedules. We also showed that
2/3 of soil samples below drip emitters had little to no nitrate. Based on our
research, we recommended that an alternative landscape irrigation system,
bubbler irrigation, should be recommended for most landscapes. I also developed
a guidelines manual for bubbler irrigation. (2), we developed a precision
agriculture sensor system. The cornerstone of our remote sensing project is
our mobile sensor system that generates daily reflectance images of an
agricultural field without the use of airplanes or satellites. We will
integrate the mobile remote sensor system with precision application systems,
crop models, and decision models to develop a complete agricultural management
system. Our prototype sensor systems (linear move and tractor) at the Maricopa
Agricultural Center are the only ones of their kind in the world. (3), we developed a chemigation drop generator that enables
chemigators to increase application uniformity of chemigation from nearly zero
to 90% or more. (4), we developed a
method for organic control of insects: carbon
dioxide gas in soap foam. (5),
we developed a model of subsurface drainage. The model will provide a rapid yet accurate solution algorithm for
water and chemical hydrologic models of tile drained watersheds. Other
projects listed in Table 1 below were successful. One project not listed in
Table 1 was electrokinetic technology for nitrate removal from soils and
desalination.
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Teamwork and collaboration are essential for development of
agricultural and landscape management systems because development of the
systems requires expertise in soils, plants, weather, sensor systems,
statistics, decision theory, economics, and crop models.
Table 1. Research projects
at the University of Arizona.
|
Project |
Role |
Results |
|
Agricultural systems |
||
|
Chemigation of nonsoluble
chemicals |
Graduate student and PI |
6 reviewed papers |
|
Remote sensing system for irrigation and chemigation
management. |
PI |
System is operational. Only one in the world. |
|
Organic acid control of drip
emitter clogging |
PI |
1 reviewed paper and
report to HERC Inc. |
|
Evaluation of GLEAMS-IR,
(irrigation and nitrate model) |
PI |
1 ASAE meeting paper |
|
Carbon dioxide foam for
insect control |
Co-PI |
1 reviewed paper |
|
Model of chemical and
water movement to subsurface field drains. |
Post-doc and PI |
1 ASAE meeting paper,
model and dissertation finished |
|
Venturi injection flow
rate dependence on temperature. |
PI |
1 journal paper submitted |
|
Urban landscape systems |
||
|
Bubbler and drip irrigation
of urban landscapes |
PI |
4 ASAE meeting papers 2 ASCE meeting papers website, posters, slide
show |
|
Overwatering controller
for urban landscapes. |
Co-PI |
1 ASAE meeting paper 1 journal paper in
preparation |
|
Subsurface drip irrigation
of turf grass |
Co-PI |
1 journal paper submitted |
In
the near term, I plan to move my projects in the direction of precision
agriculture and site-specific application of water and chemicals (Table
2).
Table 2. Planned Research.
|
Project |
Near term objective |
||
|
urban landscape irrigation |
Develop
site-specific or plant-specific water management systems for urban
landscapes. Develop research and education programs on urban landscapes
irrigation in cooperation with the Desert Museum. |
||
|
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Develop a
site-specific management system for agriculture that is based on data
collected from a ground-based remote sensing system. |
||
|
Chemigation |
Evaluate the drop
generator in the laboratory, and develop precision agriculture applications
for the drop generator |
Teaching/Advising.
I
enjoy teaching. Teaching includes communicating a message to an audience in an
interesting and entertaining style, carefully constructing the message whether
the message is in a speech or a paper, and challenging students to consider all
sides of an issue. My goals are to improve student skills in math and writing,
group participation and communication, and problem solving. In addition to
being a place to communicate knowledge, the classroom should be an environment
where students obtain skills that help them succeed in life.
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Because materials in several
course textbooks were out of date, and because My adventure into developing my
own course materials, web-based teaching, and multi-media teaching was just
that - an adventure. The thing that I did not realize at the beginning of this
adventure was that there is nothing magical about the web - the same amount of
effort that is required to prepare a textbook is required to place materials on
the web.
I
developed a distance education course, ABE 404. Although the distance education
technology has not always worked, I used the technology at a time when it
worked well. The technology never failed, and the students learned the material
well. I found that the keys to success with distance education were frequent
homework and in-class writing assignments - keeping in touch with the students
and encouraging class attendance.
Because NATS101, Science,
Technology, and Environment, was a completely new course, I changed the course
every time that I taught it - 7 times. Teaching
NATS 101 was a challenge - trying to make science interesting to liberal arts
freshman. I was given the freedom to develop my own course within the
guidelines of the Natural Sciences Core Curriculum program. As the course
evolved I developed an interesting field trip and also recruited outstanding
speakers (Dr. Choi, Dr. Rathje, and Dr. Gerba). I also developed a group project
module: I formed groups of 4 to 5 students at the beginning of the semester.
Those students worked together to produce white papers on any one of 8 possible
topics that I picked before class began. Students worked on white papers in
steps: outline, references, rough draft, final draft, group first draft, group
final paper. Thus, I was able to edit many of the papers several times.
Reviewing edits a few times is a valuable experience for students because they
are able to see writing mistakes and correct them. At the end of each semester,
groups presented their white papers to the class in multimedia format (Power
Point on the computer projector). The students and I learned a tremendous
amount from the white paper experience. I developed my own notes for the class
and placed them on the web. Every class period included an in-class writing
assignment, and every field included a write up. Thus, students gained a
tremendous amount of writing experience. Unfortunately for me, a TA was
generally not provided, and I graded most of the writing assignments.
Service/Outreach
I
am speaking and putting up web materials on landscape irrigation. Since Arizona
is the most urbanized state in the nation, and because nearly everyone has a
yard, an outreach program that focuses on improving landscape irrigation is
extremely valuable.
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My near term service goal is
to develop a website that enables homeowners and irrigation managers to adjust
both drip and bubbler irrigation systems for both efficiency and uniformity.