UNIVERSITY OF GUAM
COLLEGE OF AGRICULTURE AND LIFE SCIENCES
AGRICULTURAL EXPERIMENT STATION
Western Regional Research Project
W-128
Progress Report - 2001
Project
Title: Microirrigation Technologies for Protection of Natural Resources
and Optimum Production.
Principal
Investigators: P. Singh
PROGRESS
OF WORK AND PRINCIPAL ACCOMPLISHMENTS:
Objective
1. To evaluate and refine microirrigation management strategies to
promote natural resource protection and optimal crop production.
Objective
2. To improve, modify, and evaluate microirrigation system design and
components for natural resources protection and optimal crop production.
Progress
of Work and Accomplishments:
Work
is in progress to prepare field to conduct experiments to evaluate drip
line spacing and fertigation for watermelons.A
field at the Yigo Agricultural Experiment Station was cleared of rocks.Twelve
stainless steel drainage lysimeters will be installed shortly.Experiments
are planned to start January 2001.
Experiment 1.
Field experiment to evaluate
five popular drip lines for their clogging potential was setup in October
2000 at Yigo Agricultural Experiment Station, Guam.Five
drip lines – H-Tape from Toro, Typhoon 20 from Netafim, Turbulent Twin
9” and 24” from Chapin, and Submatic 24” from Submatic were setup in the
field.The setup consisted of a
set of three 50 feet long and 3 feet apart rows of drip lines for each
drip type connected to a submain.Each
submain was connected to the main via an electronic water meters and solenoid
valve.A filter and pressure regulator
was installed on the mainline.A
datalogger was programmed to water twice everyday for 10 minutes each.The
pressure regulator was set at 10 psi.Ten
emitters were randomly selected from each type of drip line and emitter
flow was measured once every month.Water
samples were also collected for chemical analysis.
The mean flow rate, standard
deviation, and percent decrease in flow rate of each set of ten emitters
for each drip line type are presented in Table 1 for the duration November,
2000 to August, 2001.The Chapin
Turbulent Twin 24” had the lowest clogging at 5% while the Chapin Turbulent
Twin 9” had the highest clogging at 8.25%.However,
the Netafim Typhoon 20 and Toro H-Tape 12” that were considered the best
drip lines on the Island had clogged about 8% during this period.
Usefulness of Findings:
1. Drip lines from the same manufacturer may clog at a different rate.
2.
The information will provide another evaluation parameter for farmers to
consider while choosing a drip line.
Future
Plan of Work:
1. Continue to evaluate drip lines from different manufacturers in terms of clogging potential.
2.
To conduct experiments on irrigation scheduling and fertigation for watermelons.
Publications:None
Table 1: Mean emitter flow rate, standard deviation, and percent decrease in flow.
|
Manufacturer
|
November,
2000
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August,
2001
|
Percent
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||
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|
Mean
|
Stdev
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Mean
|
Stdev
|
Decrease
|
|
TORO
H-Tape (12")
|
|
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Netafim
Typhoon 20 (12")
|
|
|
|
|
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Chapin
Turbulent Twin (9")
|
|
|
|
|
|
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Submatic
(24")
|
|
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|
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Chapin
Turbulent Twin (24")
|
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