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Dept of Agricultural & Biosystems Engineering University of Arizona 1177 E. Fourth Street Shantz Bldg #38, Room 403 Tucson, AZ 85721-0038 Phone: (520) 621-1753 Fax: (520) 621-3963 Email: abe@arizona.edu Maps: Campus | Tucson |
Home Research & Projects Projects Current Research Projects Water Resources Engineering
Current Water Resources Research Projects
Diael-Deen, Elsheikha
Remote Sensing of Broccoli and Cotton
Jia, Xinhua
Electrokinetic Management of Nitrate Movement in Drip Irrigated Soils
Kim, Min Young
Fate and Transport of Microorganisms in Subsurface System
Perea-Estrada, Hugo
Fertigation Model in Surface Irrigation
Tanksley, Koli
Minimizing Groundwater Contamination: Manure and Compost Appolication to Alfalfa in an Arid Environment
Diael-Deen, Elsheikha
Advisor: Dr. Waller
Remote Sensing of Broccoli and Cotton
ABSTRACT:
Sun angle and sensor
calibration are two of the most common problems related to any remote
sensing data. Sun angle and time of day are evaluated in this research
for four different indices: CCCI, CWSI, RVI, and NDVI. Data is
collected with a ground-based remote sensing system. The absolute
values as well as the standard deviation of values are evaluated. The
rationale behind this research is that ground based remote sensing data
are taken slowly over time (throughout the day), and the effect of sun
angle is important.
Jia, Xinhua
Advisor: Dr. Larson
Electrokinetic Management of Nitrate Movement in Drip Irrigated Soils
ABSTRACT:
Nitrate movement can be
controlled in soil by combining an electrokinetic technique with drip
irrigation system in a field environment. Nitrate can be retained near
the anode and root zone for plant uptake with electrical treatment of
soil. Laboratory experiments are conducted to determine the optimal
electro-drip system parameters. Lysimeter and field experiments are run
to determine nitrate migration rate, plant uptake rate, pH gradient and
sodium removal rate.
Lever, Jean, N
Advisor: Dr. Slack
Effects
of the application of an electric field in a soil, after a
drip-irrigation event, to the retention and distribution of nitrate in
that soil.
ABSTRACT:
This study follows
directly from the work of Xinhua Jia. Currently I am learning HYDRUS 1D
and will learn HYDRUS 2D. My intent right now is to use these models to
get a sense of how and how long it takes nitrate to redistribute in a
soil given a particular concentration gradient. This will enable us to
better know for how long an electric field should be applied and how
retention times vary with two different soils (sand vs clay loam). The
future intent is for field studies to resume at the Campbell Avenue
Farm testing where the electrodes should be placed in relation to the
crop being grown and the length of time that the electricity should be
applied.
Kim, Min Young
Advisor: Dr. Choi
Fate and Transport of Microorganisms in Subsurface System
ABSTRACT:
The fate and transport
of microorganisms in the subsurface environment has been the subject of
research for decades. Early efforts were mainly concerned with public
health and the contamination of drinking water supplies by pathogenic
microorganisms and are linked recently to the investigation of
wastewater application to the land. In this study, it will be motivated
in part by interest in the environmental factors which influence the
transport of microorganisms by introducing to laboratory soil column to
assess the transport phenomena. In addition, it will be found
environmental variables which influence microbial survival, for
instances, temperature, soil moisture content, soil organic matter,
degree of microbial adsorption to the soil and soil pH.
Perea-Estrada, Hugo
Advisor: Dr. Waller
Fertigation Model in Surface Irrigation
ABSTRACT:
In the western states,
there are many farmers who use surface irrigation injection nitrogen
fertilizer into irrigation water (fertigation). When the fertigation is
used with surface irrigation can result in nitrate contamination of the
groundwater due to deep percolation and tail water runoff. In general
the fertilizer is applied during all the irrigation time. In fact the
farmers used to apply irrigation in excess to assure high yield and
adequate leaching of salt from the root zone. For this reason, the
fertilizer needs to be carefully managed to minimize nitrite losses.
Using transport of contaminant models can be useful to develop
guidelines for the best use of fertilizer in irrigation systems.
Tanksley, Koli
Advisor: Dr. Martin
Minimizing Groundwater Contamination: Manure and Compost Application to Alfalfa in an Arid Environment
ABSTRACT:
The application of
manure to agricultural fields has long been practiced. In many
instances, this application is seen as a benefit to the soil because is
adds needed nutrients and organic matter and minimizes the use of
inorganic fertilizers. Sometimes it is a method of relocating the
waste, without the intention of benefiting the crop. Often, the owner
or operator of an animal operation also grows alfalfa hay as feed for
their livestock. In Arizona, the dairy and feedlot industries are the
largest animal operations in the state. Given the proximity of the
field to the animal operation, many of these alfalfa fields receive
manure applications. However, application of manure to these fields may
cause the potential for nitrate leaching and contamination of
groundwater. In this research, the effects of the application of
manure, both fresh and composted, on a production alfalfa field will be
studied.
Manure and compost will be applied to a production
alfalfa field to determine the impact this management strategy has on
crop yield and the potential for nitrate leaching. A conventional "no
nitrogen added" plot will also be maintained as a control. Data will be
collected on alfalfa yield and nitrogen content. Using drainage
lysimeters, leachate will be collected at 2.5 m below the soil surface
and analyzed for nitrate content.
Manure and compost were
applied and incorporated into the soil on November 3, 2000. Since the
average cut is 1,600 pounds of dry alfalfa per acre and 2.5% of the
alfalfa is nitrogen, 40 pounds of nitrogen per acre was added to the
soil in anticipation that the nitrogen will be taken up by the crop. To
calculate how much manure and compost must be added to yield 40 pounds
of nitrogen per acre, the manure and compost were analyzed for nitrogen
composition. It was found that the manure is approximately 15,000 ppm
and the compost is approximately 7,000 ppm nitrogen. So, 2,500 pounds
of manure per acre was added and 5,500 pounds of compost per acre was
added to the field to yield the 40 pounds of nitrogen per acre needed
by the crop.
The field was seeded with alfalfa on November 17,
2000, and irrigated that same day. The first cut will be sometime in
late February or March and subsequent cuts will be done approximately
every 5 weeks year-round. A small area, approximately 1-2 m2, will be
harvested and a harvest weight will be estimated. Then, the nitrogen
content of the alfalfa will be determined using the yield sample. Prior
to regrowth, manure and compost will be applied to the field so that
the amount of total nitrogen applied equals the approximate amount of
nitrogen that was removed by the harvested hay. The plots will then be
irrigated.
Soil samples will be taken approximately every 6
months. Three borings will be taken per plot at depths of: 6, 12, 18,
24, 36, 48, and 60 inches (15, 30, 45, 60, 75, 90, and 120 cm). These
samples will be analyzed for nitrate, phosphorous, ammonium, and total
nitrogen content, which will be used to determine organic nitrogen
content.
The goal of this project is to match the nitrogen use
of the alfalfa and soil with nitrogen supplied in manure or compost
without causing a threat to water quality. Since alfalfa has the
ability to fix nitrogen and does not need it supplied, the formation of
nodules will also be noted. This subject is important because of
current developing requirements for Comprehensive Nutrient Management
Plans (CNMPs) required for all Confined Animal Feeding Operations
(CAFOs).
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