TRICKLE-L: 199612XX
is the compilation of discussion during Dec 96
via AB4EL Web Digests @ SunSITE
>From root@crcnis1.unl.edu Mon Dec 2 00:00 EST 1996
Date: Sun, 1 Dec 1996 22:47:36 -0600
Message-Id: <199612020447.AA05761@crcnis1.unl.edu>
Subject: TRICKLE-L digest 665
Contents:
Re: Drip Irrigation on Athletic Fields (Rodney Ruskin <geoflow1@slip.net>)
Date: Sun, 01 Dec 1996 08:18:35 -0800
From: Rodney Ruskin <geoflow1@slip.net>
Subject: Re: Drip Irrigation on Athletic Fields
At 11:01 AM 11/30/96 -0600, grapegrower wrote:
>I don't understand all the discussion... contact Purdue university. They
>developed the STANDARD on football feild type installations 15 years ago
>and have been perfecting it since. Everyone else is just guessing or
>firing in the dark.
More information please - department, titles of publications, names, phone
numbers etc.
Thank you,
Rodney Ruskin
geoflow1@slip.net
End of Digest
>From root@crcnis1.unl.edu Tue Dec 3 00:01 EST 1996
Date: Mon, 2 Dec 1996 22:48:16 -0600
Message-Id: <199612030448.AA00638@crcnis1.unl.edu>
Subject: TRICKLE-L digest 666
Contents:
Re: TRICKLE-L digest 662 (TPiatkowsk@aol.com)
RE: Trickle on athletic fields ("Bradley M. M. Smith (512) 245-7846" <BS09@a1.swt.edu>)
Re: Water Conditioners ?? ("J.D. Oster" <oster@mail.ucr.edu>)
Re: On Farm performance (Don Pitts <djp@ICON.IMOK.UFL.EDU>)
Re: TRICKLE-L digest 662 (Don Pitts <djp@ICON.IMOK.UFL.EDU>)
Date: Mon, 2 Dec 1996 02:17:11 -0500
From: TPiatkowsk@aol.com
Subject: Re: TRICKLE-L digest 662
thompson.tony,
Our company has been successful in helping numerous growers in California
"condition" or treat their water used for drip irrigation. The preventative
approach of pre- treating water to address water quality issues such as you
have listed is viable. If you would want more information concerning our
activities, please e-mail me your address and I will be glad to send you a
package.
Tom
AG H2O
Date: Mon, 02 Dec 1996 08:00:51 -0600 (CST)
From: "Bradley M. M. Smith (512) 245-7846" <BS09@a1.swt.edu>
Subject: RE: Trickle on athletic fields
We considered SDI for our athletics fields because we live in an
area of Texas that is experiencing severe drought. The main field
that we were considering for installation was the one that requires
the most water... the sand based field. Unfortunately, that is also
the one that you would expect the least amount of lateral movement
of water from a drip system. We looked at some of the newer
solutions to the lateral movement problem (Vector Flow) but, in the
end, it was simply cost prohibitive (for now).
Nevertheless, I was still concerned about even distribution of the
water in a sand based field.
Brad Smith
bs09@swt.edu
Date: Mon, 2 Dec 1996 10:28:16 -0600
From: "J.D. Oster" <oster@mail.ucr.edu>
Subject: Re: Water Conditioners ??
I have not heard of any research based information generated in California
which supports the statements made by salepersons. My own position on these
products is that unless they add something to the water or remove something
from the water, they do nothing to the water. As for magnetizing water,
water molecules return very quickly -- micoseconds or less --- to their
original random orientations after having been exposed to magnetic fields.
Check with your local operator of a nuclear magnetic resonance (NMR) machine
if your interested in how magnets affect water. As for magnetic effects on
dissolved ions in the water, the effects would be less than for water. These
ions are much larger and are 'coated' with water molecules. In scientific
jargon, they have a hydration shell. Be wary of testimonials. Comparisons of
the effects of 'treated' water to 'untreated' water would require exactly
the same water management for both -- same time, location, water treatments,
water use, crops irriated, etc, etc, and etc. At 10:54 PM 11/27/96 -0600,
you wrote:
>
>Internet Survey: Water Conditioners ?
>
>What are the experiences of Discussion Group Members with using Water
>Conditioners ?
>In South Australia the "Carefree" product (where water passes through tubes
>made from an alloy similar to German Silver and containing Nickel 25%,
>Copper 40%, Zinc 22% Tin 16%) has been marketed for at least 15 years.
>Two additional products have been marketed more recently:
> one passes water between permanent magnets
> the other passes water through electo magnets.
>Marketers of these products do not provide scientific literature which supports
>their claims that the products solve every imaginable water quality problem.
>I have been told that scientific papers written in Polish and Russian have been
>published. Can anyone supply english translations of any reputable papers ?
>I have heard that water research establishments exists in Sussex England
>(Emerson College), Jarna Sweden and Basle Switzerland where work is being
>done on "flow forms" which were first proposed by Rudolf Steiner.
>In 1984 the South Australian State Water Laboratory and The Australian
>Mineral Development Laboratory (AMDEL) carried out chemical analyses of
>water flowing into and and then out from the Carefree conditioner and detected
>no changes in the water.
>Electron microscope studies showed no change in the water.
>The anecdotal evidence reported by many users of water conditioners
>contrasts with the scientific analyses.
>Many (but not all) irrigators who try water conditioners report observing
useful
>results:
> removal of white staining (salt) on nursery potted plants
> on leaf surfaces and on soil surfaces
> avoiding the total loss of a salt affected lettuce crop
> increasing the water infiltration rate into soil
> solution to algae blocking problems
> in tubes hydraulically controlling solenoid valves
> (CSIRO Wagga Wagga)
> solution to iron and iron bacteria problems with drippers.
>If these products do solve water quality problems the water industry should be
>promoting their correct use: if the products are only preying on gullible
>purchasers the water industry should be actively discouraging their sale.
>Regards
>thomson.tony@pi.sa.gov.au
>
>
>
>
>
J.D.(Jim) Oster
Dept. of Soil & Env. Sciences
University of California
Riverside, CA 92521
Phone (909)787-5100
FAX (909)787-5522
Date: Mon, 02 Dec 1996 17:26:43 -0500 (EST)
From: Don Pitts <djp@ICON.IMOK.UFL.EDU>
Subject: Re: On Farm performance
We have measured the performance of many farm irrigation systems. You may
contact me for specific information.
Don Pitts
University of Florida
Ph 941-657-5221
Fax 941-657-5224
At 07:51 PM 11/27/96 -0600, you wrote:
>A colleague of mine, Mark Skewes, at the Loxton Research Centre in
Australia had enquired about any people undertaking the
>measurement of irrigation performance. We are particularly interested in
people and organsiations which are or have undertaken
>on farm performance measurement of irrigation practices. We are therefore
interested in such measures as yield/vol of water
>applied, amount of drainage/unit water applied, the cost of a unit of
water etc.
>
>At Loxton we are undertaking such a project to measure on farm irrigation
performance. In particular we are looking at such
>horticultural crops such as oranges and wine grapes. We have already
gathered data on oranges and have performance values
>ranging from 2 tonnes/hectare to 12.5 t/ha. Our intention is to visit a
number of places if there is some benefit to be gained. This
>would take place in April-June of 1997.
>
>We are also interested in people who are promoting best management
practices for on farm irrigation management. The
>techniques of communicationg this to the irrigator and the rates of
adoption, how you measure this are also of interest to us. We
>have already gathered some information already from South Africa, Israel
and the US, but we are looking for other contacts either
>within the countries mentioned or other countries such as Chile, Italy,
Spain etc. Our particular interest is in semi-arid areas but
>other climatic areas would also be of interest.
>
>If you are involved in any of these activities or know of colleagues who
are, please email me at the address below giving contact
>information (fax, phone, email).
>
>
>Tony Meissner
>Senior Research Scientist (Irrigation)
>Primary Industries, South Australia,
>Loxton Research Centre
>Loxton SA Australia 5333
>Tel: +61 85 959 146
>Fax: +61 85 959 180
>email: meissner.tony@pi.sa.gov.au
>
>
>
Date: Mon, 02 Dec 1996 17:30:12 -0500 (EST)
From: Don Pitts <djp@ICON.IMOK.UFL.EDU>
Subject: Re: TRICKLE-L digest 662
Please send information packet.
Don Pitts
At 01:28 AM 12/2/96 -0600, you wrote:
>thompson.tony,
>
>Our company has been successful in helping numerous growers in California
>"condition" or treat their water used for drip irrigation. The preventative
>approach of pre- treating water to address water quality issues such as you
>have listed is viable. If you would want more information concerning our
>activities, please e-mail me your address and I will be glad to send you a
>package.
>
>Tom
>AG H2O
>
>
End of Digest
>From root@crcnis1.unl.edu Wed Dec 4 00:01 EST 1996
Date: Tue, 3 Dec 1996 22:48:30 -0600
Message-Id: <199612040448.AA29892@crcnis1.unl.edu>
Subject: TRICKLE-L digest 667
Contents:
Re: TRICKLE-L digest 662 ("Ted W. Tyson" <ttyson@acesag.auburn.edu>)
Re: Drip Irrigation on Athletic Fields (MSorren175@aol.com)
DI for wastewater (Paul Reynolds <PREYNOLD@tnrcc.state.tx.us>)
Re: DI for wastewater (Irrometer@aol.com)
Re: DI for wastewater (Rodney Ruskin <geoflow1@slip.net>)
Date: Tue, 3 Dec 1996 08:06:01 -0600 (CST)
From: "Ted W. Tyson" <ttyson@acesag.auburn.edu>
Subject: Re: TRICKLE-L digest 662
Tom, AG H20: what is your e-mail address to send snail mail address to
receive info packet? twt
On Mon, 2 Dec 1996, Don Pitts wrote:
>
> Please send information packet.
>
> Don Pitts
>
> At 01:28 AM 12/2/96 -0600, you wrote:
> >thompson.tony,
> >
> >Our company has been successful in helping numerous growers in California
> >"condition" or treat their water used for drip irrigation. The preventative
> >approach of pre- treating water to address water quality issues such as you
> >have listed is viable. If you would want more information concerning our
> >activities, please e-mail me your address and I will be glad to send you a
> >package.
> >
> >Tom
> >AG H2O
> >
> >
>
>
Date: Tue, 3 Dec 1996 12:03:45 -0500
From: MSorren175@aol.com
Subject: Re: Drip Irrigation on Athletic Fields
Richard,
Thank you and all who responded to my request for information on SDI. I will
pursue the sources given and provide Stockton State College with the info so
they can proceed.
Geoflow, GroAire, and Netafim have contacted through e-mail, as well as
others who have offered discussion and contacts. I'll keep you informed of
results.
Regards,
MaryBeth Sorrentino
Natural Resources Conservation Service
Date: Tue, 03 Dec 1996 13:55:19 -0600
From: Paul Reynolds <PREYNOLD@tnrcc.state.tx.us>
Subject: DI for wastewater
I would like input from readers pertaining to soil requirements for DI
systems for the disposal of municipal wastewaters in flood plain areas.
Basically, I am interested in recommended requirements for monitoring,
application rates for various soil types (by USDA Classification), soil
depths below dripper lines, water tables, and any other information that
may be helpful in evaluating these sites.
Typically, areas of the state that are of major concern have moderate to
very shallow soil depths, such as the hill country in central Texas. I am
not well versed in sub-surface systems, such as drip, and would
appreciate feed back from any and all.
thanks,
preynold
Agronomist
TNRCC
Date: Tue, 3 Dec 1996 19:40:41 -0500
From: Irrometer@aol.com
Subject: Re: DI for wastewater
In a message dated 96-12-03 15:40:13 EST, you write:
>From: PREYNOLD@tnrcc.state.tx.us (Paul Reynolds)
>Sender: trickle-l@unl.edu
>Reply-to: trickle-l@unl.edu
>To: trickle-l@unl.edu (Multiple recipients of list)
>
>I would like input from readers pertaining to soil requirements for DI
>systems for the disposal of municipal wastewaters in flood plain areas.
>Basically, I am interested in recommended requirements for monitoring,
>application rates for various soil types (by USDA Classification), soil
>depths below dripper lines, water tables, and any other information that
>may be helpful in evaluating these sites.
The use of soil moisture measuring devices such as tensiometers,
resistance blocks,neutron probes, etc., have been extensively used
for monitoring the movement of water within the the soil area
occupied by the active root system of a "crop" grown on the land
treatment site, as well as the area below that point for purposes of
keeping track of water thus applied which has been lost to deep
percolation. We manufacturer such devices. If you would like to
have more specific information sent directly contact me at:
irrometer@aol.com
Regards, Bill Pogue, Irrometer Company, Inc.
Date: Tue, 03 Dec 1996 18:41:46 -0800
From: Rodney Ruskin <geoflow1@slip.net>
Subject: Re: DI for wastewater
At 02:13 PM 12/3/96 -0600, Paul Reynolds wrote:
>I would like input from readers pertaining to soil requirements for DI
>systems for the disposal of municipal wastewaters in flood plain areas.
>Basically, I am interested in recommended requirements for monitoring,
>application rates for various soil types (by USDA Classification), soil
>depths below dripper lines, water tables, and any other information that
>may be helpful in evaluating these sites.
>
>Typically, areas of the state that are of major concern have moderate to
>very shallow soil depths, such as the hill country in central Texas. I am
>not well versed in sub-surface systems, such as drip, and would
>appreciate feed back from any and all.
>
>thanks,
>
>preynold
>Agronomist
>TNRCC
>
We have a lot of reports of successful use of SDI for wastewater disposal as
well as our design and installation manual for this application. This manual
is widely used in Texas and other states and accepted by many county and
state regulators as being both conservative and usable. Please send me your
snail mail address and I will send this information to you.
Rodney Ruskin
geoflow1@slip.net
End of Digest
>From root@crcnis1.unl.edu Thu Dec 5 00:36 EST 1996
Date: Wed, 4 Dec 1996 23:22:31 -0600
Message-Id: <199612050522.AA29946@crcnis1.unl.edu>
Subject: TRICKLE-L digest 668
Contents:
Re: Water Conditioners ?? (blsanden@ucdavis.edu (Blake Sanden))
Re[2]: TRICKLE-L digest 662 ("Jerry Neufeld" <jneufeld@fs.scs.unr.edu>)
DI for wastewater -Reply ("Joseph C. Henggeler" <j-henggeler@tamu.edu>)
Date: Wed, 4 Dec 1996 09:12:16 +0000
From: blsanden@ucdavis.edu (Blake Sanden)
Subject: Re: Water Conditioners ??
Water Conditioners
Trickle-L ers,
As usual, Jim Oster has hit the nail on the missing head of this issue.
The "Carefree" conditioner salesmen made their way through the southern end
of the San Joaquin Valley and coastal farming areas of Calilfornia during
the 1989-1993 drought and sold several units. I don't know of any still in
use. One strawberry grower on the coast bought one and thought it was
great. I talked to the farm foreman who said the only difference was that
since the grower spent the $6,000 for this unit on a 20 acre berry field
they should use it more to get the most benefit. The field received an
extra 6 inches of water and berry size was better than last season -- go
figure!!
Blake Sanden
UCCE Kern County
blsanden@ucdavis.edu
>I have not heard of any research based information generated in California
>which supports the statements made by salepersons. My own position on these
>products is that unless they add something to the water or remove something
>from the water, they do nothing to the water. As for magnetizing water,
>water molecules return very quickly -- micoseconds or less --- to their
>original random orientations after having been exposed to magnetic fields.
>Check with your local operator of a nuclear magnetic resonance (NMR) machine
>if your interested in how magnets affect water. As for magnetic effects on
>dissolved ions in the water, the effects would be less than for water. These
>ions are much larger and are 'coated' with water molecules. In scientific
>jargon, they have a hydration shell. Be wary of testimonials. Comparisons of
>the effects of 'treated' water to 'untreated' water would require exactly
>the same water management for both -- same time, location, water treatments,
>water use, crops irriated, etc, etc, and etc. At 10:54 PM 11/27/96 -0600,
>you wrote:
>>
>>Internet Survey: Water Conditioners ?
>>
>>What are the experiences of Discussion Group Members with using Water
>>Conditioners ?
>>In South Australia the "Carefree" product (where water passes through tubes
>>made from an alloy similar to German Silver and containing Nickel 25%,
>>Copper 40%, Zinc 22% Tin 16%) has been marketed for at least 15 years.
>>Two additional products have been marketed more recently:
>> one passes water between permanent magnets
>> the other passes water through electo magnets.
>>If these products do solve water quality problems the water industry should be
>>promoting their correct use: if the products are only preying on gullible
>>purchasers the water industry should be actively discouraging their sale.
>>Regards
>>thomson.tony@pi.sa.gov.au
>>
>>
>>
>>
>>
>J.D.(Jim) Oster
>Dept. of Soil & Env. Sciences
>University of California
>Riverside, CA 92521
>
>Phone (909)787-5100
>FAX (909)787-5522
Date: Wed, 04 Dec 96 08:47:15 PST
From: "Jerry Neufeld" <jneufeld@fs.scs.unr.edu>
Subject: Re[2]: TRICKLE-L digest 662
Tom,
Please send me a package of information for SDI water pre-treatment.
Jerry Neufeld
113 Carson Road, #2
Battle Mountain, NV 89820
______________________________ Reply Separator _________________________________
Subject: Re: TRICKLE-L digest 662
Author: <trickle-l@unl.edu> at smtplink-unscs
Date: 12/1/96 11:37 PM
thompson.tony,
Our company has been successful in helping numerous growers in California
"condition" or treat their water used for drip irrigation. The preventative
approach of pre- treating water to address water quality issues such as you
have listed is viable. If you would want more information concerning our
activities, please e-mail me your address and I will be glad to send you a
package.
Tom
AG H2O
Date: Wed, 04 Dec 1996 18:46:11 -0600
From: "Joseph C. Henggeler" <j-henggeler@tamu.edu>
Subject: DI for wastewater -Reply
Paul,
Check with Bruce Lesikar with Texas A&M University
(b-lesikar@tamu.edu). He has been studying constructive wetlands for
disposal of wastewater using SDI. There are two demonstration sites in
Texas where data is being collected.
Joe Henggeler
>>> Paul Reynolds <PREYNOLD@tnrcc.state.tx.us> 12/03/96 02:23pm
>>>
I would like input from readers pertaining to soil requirements for DI
systems for the disposal of municipal wastewaters in flood plain areas.
Basically, I am interested in recommended requirements for monitoring,
application rates for various soil types (by USDA Classification), soil
depths below dripper lines, water tables, and any other information that
may be helpful in evaluating these sites.
Typically, areas of the state that are of major concern have moderate to
very shallow soil depths, such as the hill country in central Texas. I am
not well versed in sub-surface systems, such as drip, and would
appreciate feed back from any and all.
thanks,
preynold
Agronomist
TNRCC
End of Digest
>From root@crcnis1.unl.edu Fri Dec 6 00:35 EST 1996
Date: Thu, 5 Dec 1996 23:22:58 -0600
Message-Id: <199612060522.AA06280@crcnis1.unl.edu>
Subject: TRICKLE-L digest 669
Contents:
Rodney Ruskin (thomson.tony@wpo.pi.sa.gov.au)
Re: Drip Irrigation on Athletic Fields (grapegrower <grapegrower@earthlink.net>)
Re: Rodney Ruskin (Rodney Ruskin <geoflow1@slip.net>)
Date: Fri, 06 Dec 1996 10:01:58 +0930
From: thomson.tony@wpo.pi.sa.gov.au
Subject: Rodney Ruskin
Rodney
You offered a manual.
I have had no success with EMAIL address rodney.ruskin.geoflow1@slip.net
What is your correct EMAIL ADDRESS ?
Thanks
tony.thomson@pi.sa.gov.au
Date: Thu, 5 Dec 96 19:11:58 -0800
From: grapegrower <grapegrower@earthlink.net>
Subject: Re: Drip Irrigation on Athletic Fields
>At 11:01 AM 11/30/96 -0600, grapegrower wrote:
>>I don't understand all the discussion... contact Purdue university. They
>>developed the STANDARD on football feild type installations 15 years ago
>>and have been perfecting it since. Everyone else is just guessing or
>>firing in the dark.
>
>More information please - department, titles of publications, names, phone
>numbers etc.
>
>Thank you,
>Rodney Ruskin
>geoflow1@slip.net
don't have more. All I know is that they tore out the artificial turf
and installed a state of the art football field that irrigates by way of
SDI and also removes excess water during rain or melting snow periods.
I've played on it. U of M also recentaly decided to install a simular
field and remove the artificial turf. I'm sure the Athletic Dept. can
steer you at Perdue.
An IBM user once told me that he has seen the light, and the IBM is
better. I told him he must be confused...The only light he saw was the
glow of the overheating pentium in the darkness of ignorance.
-SenorJuan (me)
Date: Thu, 05 Dec 1996 21:00:59 -0800
From: Rodney Ruskin <geoflow1@slip.net>
Subject: Re: Rodney Ruskin
At 07:14 PM 12/5/96 -0600, thomson.tony@wpo.pi.sa.gov.au wrote:
>Rodney
>You offered a manual.
>I have had no success with EMAIL address rodney.ruskin.geoflow1@slip.net
>What is your correct EMAIL ADDRESS ?
>Thanks
>tony.thomson@pi.sa.gov.au
>
>
>
My correct e-mail address is geoflow1@slip.net
Rodney Ruskin
End of Digest
>From root@crcnis1.unl.edu Sat Dec 7 01:29 EST 1996
Date: Fri, 6 Dec 1996 23:23:33 -0600
Message-Id: <199612070523.AA02218@crcnis1.unl.edu>
Subject: TRICKLE-L digest 670
Contents:
Drip on athletic fields ("Bradley M. M. Smith (512) 245-7846" <BS09@a1.swt.edu>)
Re: SDI AND CORN, Reply from F. R. Lamm (FLamm@oznet.ksu.edu (Freddie Lamm))
Date: Fri, 06 Dec 1996 08:19:42 -0600 (CST)
From: "Bradley M. M. Smith (512) 245-7846" <BS09@a1.swt.edu>
Subject: Drip on athletic fields
Senor Juan,
I couldn't find the file with the info (I have it around here
somewhere...) so I don't know if it was Purdue that came up with this or
if we're even talking about the same thing or not. However, the
Prescription Athletic Turf system is one that was devised for athletic
fields, sand based fields I imagine, and does add or remove water as
needed and is underground.
However, I never thought of this as an SDI system. I'm sure I'll be
corrected if I'm wrong but, from what I have heard/read about the two
systems, I thought that there is a difference in philosophy behind the
two. The PAT system is not necessarily concerned with anything but
growing grass whereas SDI has a concern for using water efficiently.
I, also, thought the two systems were constrructed very differently but
I've never installed either so I have no first hand knowledge.
Perhaps someone can set me straight...
Brad Smith
bs09@swt.edu
Date: 06 Dec 96 14:38:00 CST
From: FLamm@oznet.ksu.edu (Freddie Lamm)
Subject: Re: SDI AND CORN, Reply from F. R. Lamm
Sorry, this message is dated, but I set a filter on my email to
divert trickle-l material and I didn't know it was working so well.
I really don't know the answer why Israel doesn't use SDI for corn.
I would have assumed they didn't grow much field corn or do you mean
sweet corn???? Maybe, their limited water might be better diverted to
higher value crops. If you are wanting info on using SDI for field
corn, we have quite a bit of info at KSU. If so send me a request.
flamm@oznet.ksu.edu
Send m
EARLIER MESSAGE FROM ROD ENNOR
SDI ON CORN IS NOT A NORMAL PRACTICE IN ISRAEL AND I CANT FIND OUT WHY.
PERHAPS SOMEONE OUT THERE CAN PROVIDE SOME POSSIBLE REASONS OR IDEAS FOR
THIS SITUATION. ISRAEL GROWS LARGE QUANTITIES WITH LIMITED WATER SUPPLY SO
I WOULD ASSUME THAT SDI WOULD BE IDEAL FOR A REDUCTION IN EVAPORATION FROM
THE SOIL SURFACE, GIVEN THE HOT DRY CLIMATE. OBVIOUSLY I AM IN ERROR.
ANY IDEAS?????
ROD ENNOR
rodennor@mail.inter.net.il.
-------------------------------------------------------------------
Freddie Lamm *
Research Agricultural Engineer *** o
KSU Northwest Research-Extension Center ***** /|\
105 Experiment Farm Road *******\\
Colby, Kansas 67701-1697 *********
Ph. 913-462-6281 ***********
FAX 913-462-2315 *************
Email:flamm@oznet.ksu.edu It's all downhill from here.
------ THERE'S NO DOMAIN LIKE OZ, THERE'S NO DOMAIN LIKE OZ. ------
End of Digest
>From root@crcnis1.unl.edu Sun Dec 8 00:36 EST 1996
Date: Sat, 7 Dec 1996 23:23:54 -0600
Message-Id: <199612080523.AA15157@crcnis1.unl.edu>
Subject: TRICKLE-L digest 671
Contents:
SDI perf. - after off time (buescher@wiz.uni-kassel.de (Michael Buescher))
Re: SDI perf. - after off time (Jed Waddell <wadde002@maroon.tc.umn.edu>)
CFP: Tunisian Water Forum (TWF) (Jomaa Ben-Hassine <jbh@worldnet.att.net>)
Date: Sat, 7 Dec 1996 12:09:00 +0100 (MEZ)
From: buescher@wiz.uni-kassel.de (Michael Buescher)
Subject: SDI perf. - after off time
Hallo trickle-l
SDI systems in a country with seasons like Germany are used only for 1-3 month.
Will a shut-off time of 9 month influence the performance of a SDI system?
What can be done on the maintainance side to prevent failiures?
Will a winter period with frost, which 'works' soil damage a SDI-tape system (14 mil)?
Thank you very much for your comments
Michael Buescher
Date: Sat, 7 Dec 96 11:51:25 -0600
From: Jed Waddell <wadde002@maroon.tc.umn.edu>
Subject: Re: SDI perf. - after off time
Michael and Trickle-L,
I installed a few rows of 15 mil turbulent flow drip tape 25 cm deep
in the spring of 1994. We inflated the tape with water to insure no leaks
and that the system performed adequately. In the spring of 1995 I planted
sweet corn for the Soil Science Department's picnic. The corn was irrigated
and fertilized solely with the drip tape and got rave reviews by the
faculty, staff and students.
This was in Minnesota when winter air temperatures were below -40 C. The
study was completed in 1995 so I don't have an idea of the longevity of use
of SDI in this manner over many years. Try it.
Jed
At 04:57 AM 12/7/96 -0600, you wrote:
>Hallo trickle-l
>
>SDI systems in a country with seasons like Germany are used only for 1-3
month.
>Will a shut-off time of 9 month influence the performance of a SDI system?
>What can be done on the maintainance side to prevent failiures?
>Will a winter period with frost, which 'works' soil damage a SDI-tape
system (14 mil)?
>
>
>Thank you very much for your comments
>
>
>Michael Buescher
>
>
****************************************************
* Jed T. Waddell *
* Graduate Research Assistant *
* University of Minnesota *
* Department of Soil, Water, and Climate *
* St. Paul, MN 55108 *
* office (612) 625-1968 *
* fax (612) 625-2208 *
****************************************************
Date: Sun, 8 Dec 1996 02:05:31 +0000
From: Jomaa Ben-Hassine <jbh@worldnet.att.net>
Subject: CFP: Tunisian Water Forum (TWF)
Sorry for Cross-posting!
Call For Papers - Tunisian Water Forum (TWF)
Water specialists, researchers and graduate students are invited to submit
papers for publication in the proceedings and/or presentation at the
Tunisian Water Forum, planned for July 16, 17 and 18, 1997 in Tunis.
Abstracts Deadline: January 15, 1997
Paper Deadlie: April 15, 1997
For more information, please visit the TWF Home Page at
http://www.menet.umn.edu/~TSC/TWF or contact:
ITES TSC-Tunisian Water Forum
85 Avenue de la Libert=E9 P. O. Box 13238
Tunis 1002 Minneapolis, MN 55414
Tunisia OR USA
Fax +216 (1) 802 377 Fax +1 (612) 624-5230
(Att. Khaled Sellami) (Att. Salim Khemakhem)
Email: ites@ites.rnrt.tn Email: TWF-CC@me.umn.edu
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Jomaa Ben-Hassine................http://www.engr.utk.edu/~hassine/jomaa.html
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
End of Digest
>From root@crcnis1.unl.edu Mon Dec 9 00:37 EST 1996
Date: Sun, 8 Dec 1996 23:24:05 -0600
Message-Id: <199612090524.AA01287@crcnis1.unl.edu>
Subject: TRICKLE-L digest 672
Contents:
Re: SDI AND CORN, Reply from F. R. Lamm ("M. Meron" <MERON@migal.co.il>)
C.I.I. 1997 Meeting Announcement (rmead@cybergate.com (Richard Mead))
SDI perf. - after off time -Reply ("Joseph C. Henggeler" <j-henggeler@tamu.edu>)
[ADV] Distributors / Installers required for irrigation system ("Colin Austin" <caustin@cohort.com.au>)
Date: Sun, 8 Dec 1996 13:41:35 GMT+0200
From: "M. Meron" <MERON@migal.co.il>
Subject: Re: SDI AND CORN, Reply from F. R. Lamm
Irrigated corn in Israel is grown for forage or sweet-corn. Both need
sprinkler irrigation for "rooting" - allowing adventitious roots to
establish in wet soil, so the irrigation season will be too short to
justify deploying a surface drip system with laterals etc., after a
sprinkling system is already there. There are some water savings and yield
gain in drip irrigated sweet corn, but not enough to worth the extra
investment and effort.
SDI in field crops is not widely used in Israel in general and in sweet
corn. Surface drip systems already cover most of suitable crops and fields
and farmers know how to operate them successfuly, reaping world record
yields in some of their crops. They will need some extremely seducing
evidence (or very strict environmental regulation of reclaimed water use)
to switch to other irrigaiton methods in field crops.
M. Meron
=========================================================================
MIGAL Galilee Technology Center Crop Ecology Laboratory
Kiryat Shmona PO Box 90 000 Rosh Pina 12 100 ISRAEL
Phone +972-6-953559 Fax: +972-6-944980 Email: MERON@migal.co.il
=========================================================================
Date: Sun, 8 Dec 1996 16:04:44 GMT
From: rmead@cybergate.com (Richard Mead)
Subject: C.I.I. 1997 Meeting Announcement
The California Irrigation Institute would like to invite interested
individuals to partake in the upcoming 1997 C.I.I. meeting. If you are
interested in the management, technical or public policy perspective of
irrigation, the California Irrigation Institute's next meeting on January
28th and 29th, should be of interest.
The upcoming meeting will host speakers of regional and international
prominence. Sessions will include: Computers in Water Management,
Irrigation Management:Response to Water Costs and Availability, Irrigation
District Modernization, Making Irrigation Systems Pay, Electric Power
Deregulation, Agricultural Drainage, and an extensive section covering
Crop Response to Water.
California is internationally known for its water delivery systems and
ongoing quest to balance urban, industrial and agricultural water
interests. This meeting is for all individuals willing to obtain insight
into the future of water in California and other similar regions.
The 1997 C.I.I. Meeting will be in Fresno, California at the Holiday
Inn-Centre Plaza. Fresno is within 90 minutes of three national parks. For
registration, hotel and map information, check out the
http://www.cybergate.com/~rmead/cii35fly.html on the web. If you would like
a flyer sent to you via snail mail or fax, contact me at
rmead@cybergate.com. Feel free to also contact me by phone at (209)
453-3109.
Richard Mead
Trickle-L owner
C.I.I. Co-Director
Date: Sun, 08 Dec 1996 06:22:47 -0600
From: "Joseph C. Henggeler" <j-henggeler@tamu.edu>
Subject: SDI perf. - after off time -Reply
Michael,
Growers in West Texas "put their systems to bed" over the winter with
a light chlorination into the system, which they do not flush out. This is
for suppression of any biological growth (e.g., algae) that may form
during the off-season. Secondly, extended periods of down-time in
Texas appears to be associated with increased gopher- and
insect-damage activity.
Joe Henggeler
Ft. Stockton, TX
>>> Michael Buescher <buescher@wiz.uni-kassel.de> 12/07/96 05:13am
>>>
Hallo trickle-l
SDI systems in a country with seasons like Germany are used only for
1-3 month.
Will a shut-off time of 9 month influence the performance of a SDI
system?
What can be done on the maintainance side to prevent failiures?
Will a winter period with frost, which 'works' soil damage a SDI-tape
system (14 mil)?
Thank you very much for your comments
Michael Buescher
Date: Mon, 9 Dec 1996 15:59:31 +1000
From: "Colin Austin" <caustin@cohort.com.au>
Subject: [ADV] Distributors / Installers required for irrigation system
Irrigation consultants / installers wanted.
Aerogation is a pulsed, sub surface irrigation system designed for
both broad acre applications, and row cropping. Aerogation offers
significant productivity increases, with a substantially reduced water
usage. This system has been successfully installed in a number of key
sites in the Kerang and Albury areas, and it provides an economic
alternative to flood irrigation, as well as an environmentally
acceptable method of disposing of effluent water.
Cohort International are seeking to establish a network of licensed
installers. We are seeking energetic persons with a knowledge of the
vineyard or dairy industry, and irrigation techniques. In return,
Cohort offers full technical backup, and a national marketing
campaign.
Further information is available on the Internet at
http://www.cohort.com.au/ or by contacting Cohort International
7 Belfast Road
Montrose, Vic, 3765
Australia
ph: (03) 9761 9922
fax: (03) 9761 9944
email: caustin@cohort.com.au
---------------------------------------------------------
Cohort International
7 Belfast Road, Ph: +61 3 9761 9922
Montrose, Vic, 3765 Fax: +61 3 9761 9944
Australia Email: caustin@cohort.com.au
---------------------------------------------------------
End of Digest
>From root@crcnis1.unl.edu Tue Dec 10 00:37 EST 1996
Date: Mon, 9 Dec 1996 23:24:55 -0600
Message-Id: <199612100524.AA04838@crcnis1.unl.edu>
Subject: TRICKLE-L digest 673
Contents:
Re: TRICKLE-L digest 662 (Don Pitts <djp@ICON.IMOK.UFL.EDU>)
Re: Carefree filtration (HOPSRME@aol.com)
Date: Mon, 09 Dec 1996 08:10:49 -0500 (EST)
From: Don Pitts <djp@ICON.IMOK.UFL.EDU>
Subject: Re: TRICKLE-L digest 662
Don Pitts
University of Florida, SWFREC
PO Box 5127
Immokalee, FL 34143
At 07:57 AM 12/3/96 -0600, you wrote:
>Tom, AG H20: what is your e-mail address to send snail mail address to
>receive info packet? twt
>
>On Mon, 2 Dec 1996, Don Pitts wrote:
>
>>
>> Please send information packet.
>>
>> Don Pitts
>>
>> At 01:28 AM 12/2/96 -0600, you wrote:
>> >thompson.tony,
>> >
>> >Our company has been successful in helping numerous growers in California
>> >"condition" or treat their water used for drip irrigation. The preventative
>> >approach of pre- treating water to address water quality issues such as you
>> >have listed is viable. If you would want more information concerning our
>> >activities, please e-mail me your address and I will be glad to send you a
>> >package.
>> >
>> >Tom
>> >AG H2O
>> >
>> >
>>
>>
>
>
Date: Mon, 9 Dec 1996 22:47:43 -0500
From: HOPSRME@aol.com
Subject: Re: Carefree filtration
I have been reading the discussion on water conditioners and especially the
notes on the use of Carefree systems.
We used a small Carefree system on a small drip field where we could not get
a major filter system in place because of cost. We used a single disk
filter, that in past years had to be cleaned almost daily. After installing
a Carefree system, ahead of the filter we were able to length the time
between cleaning to as long as 5 days. Granted the system was not cheap,
but it cut down our maintaince considerably. We will were not able to
compare it to a check block for other improvements they claim. Next year we
will put a small system in another field, where we will be able to compare it
to a check plot.
As an added note,
I installed a Carefree system in our swimming pool and saw some dramatic
reductions in chlorine use and the quality (appearance) of the water was
greatly enhanced.
Leslie
leslier2@aol.com
----------------------- Headers --------------------------------
>From LESLIE_ROY@ratty.wolfe.net Mon Dec 9 18:38:50 1996
Return-Path: LESLIE_ROY@ratty.wolfe.net
Received: from ratty.wolfe.net (news1.wolfe.net [204.157.98.9]) by
emin20.mail.aol.com (8.6.12/8.6.12) with ESMTP id SAA06594 for
<hopsrme@aol.com>; Mon, 9 Dec 1996 18:38:35 -0500
Received: (from uucorum@localhost) by ratty.wolfe.net (8.7.5/8.6.10) id
PAA07616 for hopsrme@aol.com; Mon, 9 Dec 1996 15:38:22 -0800 (PST)
X-Authentication-Warning: ratty.wolfe.net: uucorum set sender to LESLIE_ROY
using -f
From: V1.efcom!LESLIE_ROY@ratty.wolfe.net (Leslie Roy)
Reply-To: V1.efcom!LESLIE_ROY@ratty.wolfe.net
To: hopsrme@aol.com
Subject: Fwd: re:water conditioners
Date: 09 Dec 1996 15:42:46 GMT
Message-Id: <4064804830.17118410@efcom.uucp>
Organization: efcom
End of Digest
>From root@crcnis1.unl.edu Wed Dec 11 00:38 EST 1996
Date: Tue, 10 Dec 1996 23:25:15 -0600
Message-Id: <199612110525.AA06251@crcnis1.unl.edu>
Subject: TRICKLE-L digest 674
Contents:
Dealing with high Ca-sulfate waters ("Grant Cardon" <gcardon@ceres.agsci.colostate.edu>)
Date: Tue, 10 Dec 1996 11:21:03 +0000
From: "Grant Cardon" <gcardon@ceres.agsci.colostate.edu>
Subject: Dealing with high Ca-sulfate waters
I have a few questions for the group concerning the handling of
gypsum saturated water. An individual with a 5000 TDS water of
mostly calcite and gypsum compositiion, is looking to
sprinkle-irrigate a fescue turf and some trees and shrubs,
particularly Aspen and Lilac.
First of all, does anyone have a good idea of how much the
precipitation of gypsum and calcite is going to affect the soil
solution EC and is there going to be a real salinity effect on the
above mentioned plants? (this question is probably not directly
pertinent to this discussion group, but thanks for your ideas).
Secondly, since most of you are constantly dealing with the plugging
of irrigation systems by salts, what are some of the best ways for
this individual to prevent salt precip in-line on his delivery
system? Is the lowering of pH going to be sufficient/effective in
preventing the plugging of his systems?
Thanks for the help.
Grant E. Cardon
Asst. Professor, Irrigation/Water Quality Management
Colorado State University
Department of Soil and Crop Sciences
Ft. Collins, CO 80523-1170
(970) 491 6235 (voice)
(970) 491 0564 (fax)
gcardon@ceres.agsci.colostate.edu
End of Digest
>From root@crcnis1.unl.edu Thu Dec 12 00:46 EST 1996
Date: Wed, 11 Dec 1996 23:33:24 -0600
Message-Id: <199612120533.AA07683@crcnis1.unl.edu>
Subject: TRICKLE-L digest 675
Contents:
FW: Phone Scam ("Thurston, Anna" <athursto@ci.tacoma.wa.us>)
HIGH CA WATER ("J.D. Oster" <oster@mail.ucr.edu>)
TRICKLE-L assessment (rmead@cybergate.com (Richard Mead))
Re: TRICKLE-L assessment (Jerome Pier <jpier@mindspring.com>)
Date: Wed, 11 Dec 96 11:02:00 PST
From: "Thurston, Anna" <athursto@ci.tacoma.wa.us>
Subject: FW: Phone Scam
F.Y.I.
Please recall a previous warning regarding a phone scam that urges people to
make an "emergency" call to a phone number with an 809 area code. Area code
809 will change to area code 242 in March of 1997. This may help or hinder
the phone scam, if it has not already been disabled.
Best wishes to everyone during the holiday season!
Date: Wed, 11 Dec 1996 14:59:57 -0600
From: "J.D. Oster" <oster@mail.ucr.edu>
Subject: HIGH CA WATER
GRANT: GOOD TO HEAR FROM YOU. I have a few questions for the group
concerning the handling of=20
gypsum saturated water. An individual with a 5000 TDS water of=20
mostly calcite and gypsum compositiion, is looking to=20
sprinkle-irrigate a fescue turf and some trees and shrubs,=20
particularly Aspen and Lilac.(NO SALT TOLERANCE INFORMATION AVAILABLE. SEE
PAGE 284 AND 285 IN ASCE MANUALS AND REPORTS ON ENGINEERING PRACTICE #71 =96
AGRICULTURAL SALINITY ASSESSMENT AND MANAGEMENT.=20
First of all, does anyone have a good idea of how much the=20
precipitation of gypsum and calcite is going to affect the soil=20
solution EC and is there going to be a real salinity effect on the=20
above mentioned plants? WATSUIT ( see chapter 22 in the above manual) IS A
COMPUTER PROGRAM WHICH ACOUNTS FOR SALT PRECIPITATION EFFECTS ON SOIL
SALINITY. IF YOU NEED A COPY, I CAN ARRANGE TO HAVE A COPY SENT TO YOU.
(this question is probably not directly=20
pertinent to this discussion group, but thanks for your ideas).
Secondly, since most of you are constantly dealing with the plugging=20
of irrigation systems by salts, what are some of the best ways for=20
this individual to prevent salt precip in-line on his delivery=20
system? Is the lowering of pH going to be sufficient/effective in=20
preventing the plugging of his systems? ADJUSTING THE PH TO ABOUT 6.5 WITH
AN ACID WOULD PREVENT PRECIPITATION OF CALCITE. BUT IT WOULD NOT HAVE ANY
EFFECT ON GYPSUM PRECIPITATION. PERHAPS GYPSUM PRECIPITATION WILL NOT BE A
PROBLEM. WATSUIT WOULD PROVIDE USEFUL INFORMATION ABOUT THIS POTENTIAL
PROBLEM. =20
J.D.(Jim) Oster
Dept. of Soil & Env. Sciences
University of California
Riverside, CA 92521
Phone (909)787-5100
FAX (909)787-5522
Date: Wed, 11 Dec 1996 23:58:03 GMT
From: rmead@cybergate.com (Richard Mead)
Subject: TRICKLE-L assessment
Dear Trickle-L group:
I am working with a journalist who will soon write a short story about
Trickle-L in the
ARS monthly magazine. She has asked me a specific question which I thought
should be
posed to all of you. Only you as subscribers have a sense of how effective this
discussion group is, so please ponder the following question:
>What are examples of instances in which TRICKLE-L has helped people solve
>problems?<
Maybe there are no instances, but if any of you have some positive comments
of how this
discussion group has benefited you or your organization, please post a reply.
It wouldn't be a bad idea to state negative aspects too, if there are any.
Richard Mead
Trickle-L owner/manager
Date: Thu, 12 Dec 1996 09:35:11 -0800
From: Jerome Pier <jpier@mindspring.com>
Subject: Re: TRICKLE-L assessment
Richard Mead wrote:
> >What are examples of instances in which TRICKLE-L has helped people solve
> >problems?<
I have repeatedly FAXED, emailed, etc. a thread on chlorination which
occurred a while ago to numerous growers who have found it very useful.
I also recommend to any growers I encounter who are connected to the
internet that Trickle-L is *the* most useful Internet source of
information available to me professionally. The fact that Richard has
archived the useful threads on the Micro-Irrigation Forum Web Site
makes the list even more useful. Growers, reknowned, academic,
irrigation experts and industry representatives giving their view points
on one of the most exciting technological advances in agriculture in
some time; that is useful!
Thanks again Richard
Jerome Pier
Soil Scientist/Agronomist
Netafim Irrigation, Inc.
jpier@mindspring.com
End of Digest
>From root@crcnis1.unl.edu Fri Dec 13 00:49 EST 1996
Date: Thu, 12 Dec 1996 23:36:38 -0600
Message-Id: <199612130536.AA12364@crcnis1.unl.edu>
Subject: TRICKLE-L digest 676
Contents:
Re: TRICKLE-L assessment (Dripigate@aol.com)
listservice uses ("J.D. Oster" <oster@mail.ucr.edu>)
injection of compressed sulfur dioxide (Don Pitts <djp@ICON.IMOK.UFL.EDU>)
HIGH CA WATERS (oster@mail.ucr.edu)
Re: TRICKLE-L assessment ("Thurston, Anna" <athursto@ci.tacoma.wa.us>)
Date: Thu, 12 Dec 1996 01:42:53 -0500
From: Dripigate@aol.com
Subject: Re: TRICKLE-L assessment
Tricle L is a great forum giving all of us an opportunity to observe the
industry from afar. Personally I have recruited great people and ideas from
the "page" . I believe in the years to come it will become a "source" for our
industry. Great stuff, lets all contribute to it's longevity!
Robin.
Date: Thu, 12 Dec 1996 10:30:29 -0600
From: "J.D. Oster" <oster@mail.ucr.edu>
Subject: listservice uses
Richar:I use trickle-l and other listservers as a Cooperative Extension
Specialist to provide scientific information on various topics related to
irrigation: irrigation water quality, water management for control of soil
salinity, reclamation techniques for saline and sodic soils, chemical
effects on soil physical properties, influences of soil salinity on crop
growth, methods to measure soil physical and chemical properties, and
chemical amendments to modify soil and water quality.
J.D.(Jim) Oster
Dept. of Soil & Env. Sciences
University of California
Riverside, CA 92521
Phone (909)787-5100
FAX (909)787-5522
Date: Thu, 12 Dec 1996 12:19:39 -0500 (EST)
From: Don Pitts <djp@ICON.IMOK.UFL.EDU>
Subject: injection of compressed sulfur dioxide
Trickle-L
Does anyone have information or experience on techniques for the
injection of compressed sulfur dioxide into micro irrigation systems? The
purpose is for pH reduction to dissolve scale and reclaim plugged emitters.
Don Pitts
Date: Thu, 12 Dec 1996 12:14:21 -0600
From: oster@mail.ucr.edu
Subject: HIGH CA WATERS
GRANT: GOOD TO HEAR FROM YOU. I have a few questions for the group
concerning the handling of=20
gypsum saturated water. An individual with a 5000 TDS water of=20
mostly calcite and gypsum compositiion, is looking to=20
sprinkle-irrigate a fescue turf and some trees and shrubs,=20
particularly Aspen and Lilac.(NO SALT TOLERANCE INFORMATION AVAILABLE. SEE
PAGE 284 AND 285 IN ASCE MANUALS AND REPORTS ON ENGINEERING PRACTICE #71 =96
AGRICULTURAL SALINITY ASSESSMENT AND MANAGEMENT.=20
First of all, does anyone have a good idea of how much the=20
precipitation of gypsum and calcite is going to affect the soil=20
solution EC and is there going to be a real salinity effect on the=20
above mentioned plants? WATSUIT ( see chapter 22 in the above manual) IS A
COMPUTER PROGRAM WHICH ACOUNTS FOR SALT PRECIPITATION EFFECTS ON SOIL
SALINITY. IF YOU NEED A COPY, I CAN ARRANGE TO HAVE A COPY SENT TO YOU.
(this question is probably not directly=20
pertinent to this discussion group, but thanks for your ideas).
Secondly, since most of you are constantly dealing with the plugging=20
of irrigation systems by salts, what are some of the best ways for=20
this individual to prevent salt precip in-line on his delivery=20
system? Is the lowering of pH going to be sufficient/effective in=20
preventing the plugging of his systems? ADJUSTING THE PH TO ABOUT 6.5 WITH
AN ACID WOULD PREVENT PRECIPITATION OF CALCITE. BUT IT WOULD NOT HAVE ANY
EFFECT ON GYPSUM PRECIPITATION. PERHAPS GYPSUM PRECIPITATION WILL NOT BE A
PROBLEM. WATSUIT WOULD PROVIDE USEFUL INFORMATION ABOUT THIS POTENTIAL
PROBLEM. =20
Date: Thu, 12 Dec 96 17:03:00 PST
From: "Thurston, Anna" <athursto@ci.tacoma.wa.us>
Subject: Re: TRICKLE-L assessment
As a Water Conservation Specialist for a public utility my interest in the
Trickle-L forum is to maintain an awareness of the irrigation industry and
to learn of new/old water-efficient technologies. I have been able to
establish a number of important contacts with people in the industry who can
assist me with conservation programming - either directly through the list
or indirectly through other people that subscribe. I have also been able to
answer some of those obscure questions that never seem to get asked, just by
reading the subject threads that interest me. This second benefit allows me
to develop a wider perspective on a number of technical horizons, not all of
which are irrigation related, but which benefit me nevertheless. Thanks for
a great forum.
Anna Thurston, Water Conservation Specialist
Tacoma Public Utilities, Water Resource Planning
PO Box 11007 Tacoma, Washington 98411 USA
(206)502-8723 // FAX:(206)502-8694
<athursto@ci.tacoma.wa.us>
----------
From: root
To: Multiple recipients of list
Subject: TRICKLE-L assessment
Date: Wednesday, December 11, 1996 5:41PM
Dear Trickle-L group:
I am working with a journalist who will soon write a short story about
Trickle-L in the
ARS monthly magazine. She has asked me a specific question which I thought
should be
posed to all of you. Only you as subscribers have a sense of how effective
this
discussion group is, so please ponder the following question:
>What are examples of instances in which TRICKLE-L has helped people solve
>problems?<
Maybe there are no instances, but if any of you have some positive comments
of how this
discussion group has benefited you or your organization, please post a
reply.
It wouldn't be a bad idea to state negative aspects too, if there are any.
Richard Mead
Trickle-L owner/manager
End of Digest
>From root@crcnis1.unl.edu Sat Dec 14 00:51 EST 1996
Date: Fri, 13 Dec 1996 23:37:38 -0600
Message-Id: <199612140537.AA13192@crcnis1.unl.edu>
Subject: TRICKLE-L digest 677
Contents:
Re: TRICKLE-L assessment (LRP@ICON.LAL.UFL.EDU)
Re: TRICKLE-L assessment by F.R. Lamm (FLamm@oznet.ksu.edu (Freddie Lamm))
Fe removal from irrigation water (Don Pitts <djp@ICON.IMOK.UFL.EDU>)
Re: Fe removal from irrigation water ("J.D. Oster" <oster@mail.ucr.edu>)
Re: TRICKLE-L assessment (Rodney Ruskin <geoflow1@slip.net>)
Date: Fri, 13 Dec 1996 10:30:22 -0500 (EST)
From: LRP@ICON.LAL.UFL.EDU
Subject: Re: TRICKLE-L assessment
Trickle-L has helped keep me updated on new (and old) developments in the
microirrigation field. It has broadened my horizons and given me ideas
on where to go to get answers to particular problems. It is a useful forum.
Larry Parsons University of Florida
Date: 13 Dec 96 10:14:41 CST
From: FLamm@oznet.ksu.edu (Freddie Lamm)
Subject: Re: TRICKLE-L assessment by F.R. Lamm
Trickle-L has been a very useful tool to me. It's a great place to
learn about the different factors affecting microirrigation in a host
of different regions. I am sure it has helped many people including
myself avoid some pitfalls and knowledge bottlenecks. There are
numerous recurring topics, but I read them all, because quite often
there is new information or a different perspective given.
List-serves can take a lot of time to follow and so this is the only
one I belong to at present, but in this case it is time well spent.
I have followed Trickle-L since about January of 1995. I have kept
nearly all of the raw messages since then, and occasionally I go
back and try to summarize the discussion points on a particular issue
for my own purposes.
Thanks again Richard. Have a happy holiday.
-------------------------------------------------------------------
Freddie Lamm *
Research Agricultural Engineer *** o
KSU Northwest Research-Extension Center ***** /|\
105 Experiment Farm Road *******\\
Colby, Kansas 67701-1697 *********
Ph. 913-462-6281 ***********
FAX 913-462-2315 *************
Email:flamm@oznet.ksu.edu It's all downhill from here.
------ THERE'S NO DOMAIN LIKE OZ, THERE'S NO DOMAIN LIKE OZ. ------
Date: Fri, 13 Dec 1996 16:13:03 -0500 (EST)
From: Don Pitts <djp@ICON.IMOK.UFL.EDU>
Subject: Fe removal from irrigation water
Trickle-L
We are attempting to remove iron from irrigation water by injecting
chlorine and filter with media filtration. The source is groundwater and Fe
levels are about 4 mg/l and pH is 7.3. Does anyone know what factors are
critical? Such as: contact time, importance of mixing, and level of
filtration required.
Don Pitts
Date: Fri, 13 Dec 1996 16:30:12 -0600
From: "J.D. Oster" <oster@mail.ucr.edu>
Subject: Re: Fe removal from irrigation water
Have you checked with an inorganic chemist familar with oxidation/reduction
reactions to determine if the reducing power of chloine is sufficient to
reduce iron from the +3 to the +2 valence state? The other question would
be: can iron (+3) oxidize chlorine? At 03:06 PM 12/13/96 -0600, you wrote:
>Trickle-L
>
> We are attempting to remove iron from irrigation water by injecting
>chlorine and filter with media filtration. The source is groundwater and Fe
>levels are about 4 mg/l and pH is 7.3. Does anyone know what factors are
>critical? Such as: contact time, importance of mixing, and level of
>filtration required.
>
>
>Don Pitts
>
>
J.D.(Jim) Oster
Dept. of Soil & Env. Sciences
University of California
Riverside, CA 92521
Phone (909)787-5100
FAX (909)787-5522
Date: Fri, 13 Dec 1996 18:21:58 -0800
From: Rodney Ruskin <geoflow1@slip.net>
Subject: Re: TRICKLE-L assessment
Trickle -l has been of value to me in the following ways - in approximate
order of value.
1) Spreading the gospel of SDI and increasing the credibility of this new
technology.
2) Technical support. In particular in writing FACTORS IN THE DESIGN,
INSTALLATION AND OPERATION OF A SUBSURFACE DRIP IRRIGATION SYSTEM FOR
PERMANENT CROPS the input from members was invaluable.
3) Making valuable contacts.
We are indeed indebted to Richard Mead for this effort.
Rodney Ruskin
geoflow1@slip.net
End of Digest
>From root@crcnis1.unl.edu Sun Dec 15 00:52 EST 1996
Date: Sat, 14 Dec 1996 23:38:32 -0600
Message-Id: <199612150538.AA26271@crcnis1.unl.edu>
Subject: TRICKLE-L digest 678
Contents:
Re: Fe removal from irrigation water (Leonard Ornstein <lenornst@pipeline.com>)
Minute/ultra-low microirrigation (rmead@cybergate.com (Richard Mead))
Re: TRICKLE-L digest 677 (Merriott@aol.com)
Re: Minute/ultra-low microirrigation (Dripigate@aol.com)
test (John Sorge <jsorg@hal-pc.org>)
Trickle-l assessment (Dennis Roll <rolld@cadvision.com>)
Date: Sat, 14 Dec 1996 09:37:57 -0400
From: Leonard Ornstein <lenornst@pipeline.com>
Subject: Re: Fe removal from irrigation water
I beleive Jim has it backwards.
At pH 7.3, chlorine oxidizes Fe from +2 to +3. Ferrous (+2) is highly
soluible, but ferric (+3) will form extremely insoluble ferric hydroxide at
pH 7.3 (which of course is what you want). However, the initial size of the
ferric hydroxide particles may be so small as to pass through the filter
media. Usually, addition of a very small amount of alum will cause
sufficient aggregation of the ferric hydroxide to have the filter remove it
all. Of course, if the original iron was colloidal feric hydroxide, the
chlorine is not necessary. Addition of alum alone will do the trick.
Len Ornstein
>Have you checked with an inorganic chemist familar with oxidation/reduction
>reactions to determine if the reducing power of chloine is sufficient to
>reduce iron from the +3 to the +2 valence state? The other question would
>be: can iron (+3) oxidize chlorine? At 03:06 PM 12/13/96 -0600, you wrote:
>>Trickle-L
>>
>> We are attempting to remove iron from irrigation water by injecting
>>chlorine and filter with media filtration. The source is groundwater and Fe
>>levels are about 4 mg/l and pH is 7.3. Does anyone know what factors are
>>critical? Such as: contact time, importance of mixing, and level of
>>filtration required.
>>
>>
>>Don Pitts
>>
>>
>J.D.(Jim) Oster
>Dept. of Soil & Env. Sciences
>University of California
>Riverside, CA 92521
>
>Phone (909)787-5100
>FAX (909)787-5522
Date: Sat, 14 Dec 1996 18:07:38 GMT
From: rmead@cybergate.com (Richard Mead)
Subject: Minute/ultra-low microirrigation
I would like to thank all who responded to my request of Trickle-L
assessment. All comments were forwarded to the inquiring journalist. She
was more than impressed with the unexpected deluge of text, and also with
the quality of comments.
Now that I've finished blushing from all your praise, lets move on to
discuss microirrigation.
All of us on this discussion list know the challenging aspects of
sustainable use of water in agriculture (or landscaping for that matter) in
the future. Not only will there be other interests for water but it is
possible if not probable that prime agricultural land could be gobbled by
urban encroachment. We 'might' be farming on foothills instead of valleys,
and in intensive greenhouses instead of open gardens. Thus the potential
for microirrigation technology will undoubtedly help in the efficient use
of water.
Israel has always been on the cutting edge of microirrigation research and
implementation. A new aspect of microirrigation has been researched in
Israel for the past half decade. Known as "minute or ultra-low rate"
irrigation, this new idea involves applying water at a very low rate, even
lower than the natural soil infiltration rate. This process is accomplished
by using spitters or pulsating drippers. I have never seen this technology
with my own eyes, but I envision it as a microspray system which applies
water in to a large area with low flow via thousands of pulses per hour (as
low as 0.5 ml/hr). Drip emitters could be attached to the pulsator to apply
water at a low rate also. As a rule of thumb, flow from minute or ultra-low
irrigation is usually 10 times less than common emitters (i.e. 0.2 l/hr).
The advantages of this system include:
1) No run off on heavy soils.
2) No water loss through the root zone on very sandy soils.
3) Water could be applied efficiently on shallow soils in hilly areas.
4) Volume size of containers in greenhouses could be substantially reduced.
I have posted this not only introduce the topic, but also ask those in the
industry
(especially in Israel) to discuss the pros/cons of this rather new idea or
extension to
microirrigation. Questions I have concerning this topic are:
1) What happens during very high evaporative demand when using this
technology..won't a large percentage of water be loosed through
evaporation in mid day?
2) How could this technology be implemented in subsurface drip irrigation (SDI)?
3) If this technology requires the system to be engaged for long periods of
time, would this save or increase energy costs?
Looking forward to your comments!
Richard Mead
Trickle-L owner
Date: Sat, 14 Dec 1996 16:40:56 -0500
From: Merriott@aol.com
Subject: Re: TRICKLE-L digest 677
Some of the reasons I like Trickle-L
1) It's a great way to keep up with current research, right from the horse's
mouth - especially since I am not a researcher.
2) I have run into old friends from time to time on this list.
3) Whenever I encounter something I've never seen I can throw out my question
and instantly have five salesmen ready to sell me their product and / or
service!
Randall Merriott
Abernathy, Texas
Date: Sat, 14 Dec 1996 20:41:20 -0500
From: Dripigate@aol.com
Subject: Re: Minute/ultra-low microirrigation
A key ingredient is "Just exactly what yield for a given volume of water is
reasonable and practical". The ability to produce low water requiring/high
yielding varieties will play possibly a bigger role than the engineering.
Variety response to applied water has been well demostrated in cotton and
tomatoes.
Tricle -l is a great resource, it is creating a better industry!
Robin.
Date: Sat, 14 Dec 1996 22:40:45 -0600 (CST)
From: John Sorge <jsorg@hal-pc.org>
Subject: test
This is a test 12-14-96
Date: Sat, 14 Dec 1996 21:41:31 -0800
From: Dennis Roll <rolld@cadvision.com>
Subject: Trickle-l assessment
I have subscribed since early 1995 and find the discussions informative
and helpful. Of particular interest are developments and experience in
other areas of the world. When I first subscribed I was searching for
some data on acres of trickle irrigation in different countries and was
able to obtain the information right away! I find the discussions on SDI
and effects of water quality on system performance especially useful.
Keep up the good work.
Dennis Roll
Alberta Agriculture, Food & Rural Development
End of Digest
>From root@crcnis1.unl.edu Mon Dec 16 00:57 EST 1996
Date: Sun, 15 Dec 1996 23:44:33 -0600
Message-Id: <199612160544.AA08254@crcnis1.unl.edu>
Subject: TRICKLE-L digest 679
Contents:
Microirrigation Forum update (rmead@cybergate.com (Richard Mead))
Re: Fe removal from irrigation water (oster@mail.ucr.edu)
Date: Sun, 15 Dec 1996 16:14:07 GMT
From: rmead@cybergate.com (Richard Mead)
Subject: Microirrigation Forum update
The Best of Trickle-L section within the Microirrigation Forum web site*
has been updated. It now includes five archived discussions which occurred
in October. Those discussions include:
-Blackberries on drip
-Iron-phosphate scale
-Do you have rodent damage?
-Suction lysimeter tubes
-Water Use Efficiency
I'm still working on the digital drip directory listings for all companies
associated with the industry. Please drop me a note if your company is not
somewhere within the 12
categories.
Finally, I'm still looking for volunteers to send me digital photos of
anything related to microirrigation. Attached files to your email is the
simplest way to send digital pictures. I am willing to give full credit to
any contributor.
Richard Mead
Trickle-L & MF owner
*http://www.cybergate.com/~rmead
Date: Sun, 15 Dec 1996 23:36:51 -0600
From: oster@mail.ucr.edu
Subject: Re: Fe removal from irrigation water
Oxy/redox: I've always had trouble with this subject. So chlorine is an
oxidizing agent. Len is likely right: But why wouldn't one want to keep the
Fe in the +2 state until the water leaves the emitter. Adding a reducing
agent may be able to do that if it can counteract the effect of exposing the
water to the oxygen in the atmosphere. But being 'backwards' once is an
indicator that the 'less said the better. At 08:48 AM 12/14/96 -0600, you wrote:
>I beleive Jim has it backwards.
>
>At pH 7.3, chlorine oxidizes Fe from +2 to +3. Ferrous (+2) is highly
>soluible, but ferric (+3) will form extremely insoluble ferric hydroxide at
>pH 7.3 (which of course is what you want). However, the initial size of the
>ferric hydroxide particles may be so small as to pass through the filter
>media. Usually, addition of a very small amount of alum will cause
>sufficient aggregation of the ferric hydroxide to have the filter remove it
>all. Of course, if the original iron was colloidal feric hydroxide, the
>chlorine is not necessary. Addition of alum alone will do the trick.
>
>Len Ornstein
>
>>Have you checked with an inorganic chemist familar with oxidation/reduction
>>reactions to determine if the reducing power of chloine is sufficient to
>>reduce iron from the +3 to the +2 valence state? The other question would
>>be: can iron (+3) oxidize chlorine? At 03:06 PM 12/13/96 -0600, you wrote:
>>>Trickle-L
>>>
>>> We are attempting to remove iron from irrigation water by injecting
>>>chlorine and filter with media filtration. The source is groundwater and Fe
>>>levels are about 4 mg/l and pH is 7.3. Does anyone know what factors are
>>>critical? Such as: contact time, importance of mixing, and level of
>>>filtration required.
>>>
>>>
>>>Don Pitts
>>>
>>>
>>J.D.(Jim) Oster
>>Dept. of Soil & Env. Sciences
>>University of California
>>Riverside, CA 92521
>>
>>Phone (909)787-5100
>>FAX (909)787-5522
>
>
>
>
End of Digest
>From root@crcnis1.unl.edu Tue Dec 17 00:58 EST 1996
Date: Mon, 16 Dec 1996 23:45:08 -0600
Message-Id: <199612170545.AA09059@crcnis1.unl.edu>
Subject: TRICKLE-L digest 680
Contents:
Re: TRICKLE-L digest 652 (KEENA@aol.com)
unsubscribe (ferraris@lewy.dmsa.unipd.it (Stefano Ferraris))
Unsubscribing (rmead@cybergate.com (Richard Mead))
Re: Fe removal from irrigation water ("Alan S. Wicks" <awicks@televar.com>)
Re: Fe removal from irrigation water (Richard Mead <rmead@cybergate.com>)
Irrigation Engineer Available ("Craig A. Storlie" <storlie@AESOP.RUTGERS.EDU>)
Re: Unsubscribing (Charles Kome <cek9749@usl.edu>)
Re: Fe removal from irrigation water (Leonard Ornstein <lenornst@pipeline.com>)
Fe treatment in irrigation water (Casper du Plessis <aqua@iafrica.com>)
Date: Mon, 16 Dec 1996 02:58:25 -0500
From: KEENA@aol.com
Subject: Re: TRICKLE-L digest 652
How do I unsubscribe this list?
eric
Date: Mon, 16 Dec 1996 14:53:55 +0100
From: ferraris@lewy.dmsa.unipd.it (Stefano Ferraris)
Subject: unsubscribe
unsubscribe
Date: Mon, 16 Dec 1996 15:16:02 GMT
From: rmead@cybergate.com (Richard Mead)
Subject: Unsubscribing
For all of those just dying to unsubscribe,
either contact me "personally" or send the following command:
unsubscribe trickle-l
to the address of:
listserv@unl.edu
R. Mead
Trickle-L owner
Date: Mon, 16 Dec 1996 09:11:13 -0800
From: "Alan S. Wicks" <awicks@televar.com>
Subject: Re: Fe removal from irrigation water
Greetings,
"J.D. Oster" <oster@mail.ucr.edu>
Wrote:
>if the reducing power of chloine is sufficient to
>reduce iron from the +3 to the +2 valence state?
and
Leonard Ornstein <lenornst@pipeline.com> responded with.
>Usually, addition of a very small amount of alum will cause
>sufficient aggregation of the ferric hydroxide to have the filter remove it
>all.
Interesting difference in viewpoints. The first, from Jim, is to keep
the iron soluble so that the material will simply pass through the
system. The second idea, from Leonard, is to remove the iron at the
filter station. Both interesting ideas. I suspect that which option to
take may be dependent on other considerations.
I understand that in some areas one can have problems with iron slime
bacteria clogging the emitters. What levels of iron are necessary for
this to occur? What other conditions need to be taken into account to
decide on which methodology is best for the particular situation?
One question of Leonard: Alum is a bit of a generic term. There is
more than one compound that is referred to as 'Alum'. Will you please
give us the actual chemical name of the compound and also, could you be
a bit more specific as to what is a 'very snall amount' of alum? For
instance, grams per cubic meter per ppm of iron?
Alan S. Wicks
Date: Mon, 16 Dec 1996 18:39:25 GMT
From: Richard Mead <rmead@cybergate.com>
Subject: Re: Fe removal from irrigation water
To add to the discussion of iron problems in water, but not chemical
treatment per se,
Nakayama et al.(1991) stated that total iron should not be
higher than <0.2, 0.2-1.5 , and >1.5 mg/l for minor, moderate and severe
problems,
respectively.
All this information (and more on clogging) can be found on the web page
entitled
"Clogging Factors for microirrigation systems" at
http://www.cybergate.com/~rmead/clog.html
Richard Mead
Trickle-L and MF owner
Date: Mon, 16 Dec 1996 16:14:50 -0500
From: "Craig A. Storlie" <storlie@AESOP.RUTGERS.EDU>
Subject: Irrigation Engineer Available
------ =_NextPart_000_01BBEB6C.51621B80
IRRIGATION ENGINEER SEEKS EMPLOYMENT
Available Immediately - U.S. Locations Only
(A warm thank you to all who have helped me in my search for employment. =
Until very recently, I thought the search was over. Fate had other =
ideas. Thus, the search continues. Please continue to send leads, =
contacts, tips, etc. Thanks again, everyone - Craig)
Agricultural Engineer with Ph.D. and six years of university extension =
experience seeks employment with educational institution, government =
agency, or commercial industry in irrigation marketing, education, or =
research. I am an expert in drip irrigation and related plasticulture =
production techniques.=20
Other skills include electronics and instrumentation expertise, =
personal computer hardware and software experience, an understanding of =
vegetable production techniques, and extensive experience in =
field-based, applied irrigation research.
=09
I desire employment by an agency that would benefit from the skills of =
an experienced irrigation educator, writer, and researcher. I possess =
excellent personal and communication skills. =20
Dr. Craig A. Storlie
Extension Specialist in Agricultural Engineering
Rutgers Agricultural Research and Extension Center (RAREC)
121 Northville Road
Bridgeton, NJ 08302
(609)455-3100
------ =_NextPart_000_01BBEB6C.51621B80
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------ =_NextPart_000_01BBEB6C.51621B80--
Date: Mon, 16 Dec 1996 15:18:48 -0800
From: Charles Kome <cek9749@usl.edu>
Subject: Re: Unsubscribing
Date: Mon, 16 Dec 1996 16:33:50 -0400
From: Leonard Ornstein <lenornst@pipeline.com>
Subject: Re: Fe removal from irrigation water
Alan:
Alum usually refers to Aluminum Sulfate or Aluminum Ammonium Sulfate.
Either, added in a few moles excess of the contaminating iron, (in Don
Pitts' case, a few times his 4 mg/l, at the stated pH of 7.3) will form a
mixed Ferric and Aluminum Hydroxide flocculating gel, which is easily
removed by a typical sand filter. If the solution is too acid, the alum
won't work. At such low levels, the residual added sulfate should cause no
trouble.
This is part of standard water-purification technology, dating back to the
end of the last century. It's used in sewage treatment, drinking water
supplies,swimming pools and irrigation supplies..
Len Ornstein
>Greetings,
>
> "J.D. Oster" <oster@mail.ucr.edu>
>Wrote:
>>if the reducing power of chloine is sufficient to
>>reduce iron from the +3 to the +2 valence state?
>
>and
>
>Leonard Ornstein <lenornst@pipeline.com> responded with.
>
>>Usually, addition of a very small amount of alum will cause
>>sufficient aggregation of the ferric hydroxide to have the filter remove it
>>all.
>
>Interesting difference in viewpoints. The first, from Jim, is to keep
>the iron soluble so that the material will simply pass through the
>system. The second idea, from Leonard, is to remove the iron at the
>filter station. Both interesting ideas. I suspect that which option to
>take may be dependent on other considerations.
>
>I understand that in some areas one can have problems with iron slime
>bacteria clogging the emitters. What levels of iron are necessary for
>this to occur? What other conditions need to be taken into account to
>decide on which methodology is best for the particular situation?
>
>One question of Leonard: Alum is a bit of a generic term. There is
>more than one compound that is referred to as 'Alum'. Will you please
>give us the actual chemical name of the compound and also, could you be
>a bit more specific as to what is a 'very snall amount' of alum? For
>instance, grams per cubic meter per ppm of iron?
>
>Alan S. Wicks
Date: Tue, 17 Dec 1996 07:43:49 -0800
From: Casper du Plessis <aqua@iafrica.com>
Subject: Fe treatment in irrigation water
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End of Digest
>From root@crcnis1.unl.edu Wed Dec 18 00:58 EST 1996
Date: Tue, 17 Dec 1996 23:45:44 -0600
Message-Id: <199612180545.AA07324@crcnis1.unl.edu>
Subject: TRICKLE-L digest 681
Contents:
Fe treatment in irrigation water (Casper du Plessis <aqua@iafrica.com>)
Re: Fe treatment in irrigation water (Leonard Ornstein <lenornst@pipeline.com>)
Re: Fe treatment in irrigation water (Casper du Plessis <aqua@iafrica.com>)
Job Opening -- California Pest Control Advisor ("Warren E. Clark" <ag-pr@agpr.com>)
Date: Tue, 17 Dec 1996 18:59:27 -0800
From: Casper du Plessis <aqua@iafrica.com>
Subject: Fe treatment in irrigation water
Len,
The method for removal of iron with oxidation and flocculation is as you
wrote old and accepted. We found it to be impracticable in irrigation
were large volumes have to be treated in short periods of time. the
reasons being:
1. In most cases were iron causes problems the pH of the water will be
acidic and for flocculants to be effective the pH has to be raised.
2. By filtering the iron out we found that the maintenance on these
filters is very high. the back flush cycle must also be very short to
prevent pressure losses.
3. With the addition of chlorine and not getting enough contact time
before the filters the iron will oxidise in the emmiter lines and worsen
the problem.
4. This type of treatment can not be done together with fertigation as
Calcium Sulphate forms and precipitate out in the emmiter lines.
We have experienced very good results with water conditioners made up of
mainly copper and zinc coupled to an electron booster. In certain cases
the water still oxidises but will stay in suspension and leave the
system through the emitter. The further advantages are that large
volumes of water can be treated and it is low in maintenance.
Unfortunately it also has its disadvantages:
1. The water might still discolour which is a problem with micro
orrogation. With trickle irrigation this is acceptable.
2. With water high in sulphate, Hydrogen Sulphide might form if the
booster charge is set to high. This can cause serious burning of the
roots and leaves.
3. With the improved leaching properties of the water, nutrients can be
leached out of the root zone if the scheduling is not correct.
4. Where the water is acidic chemical treatment might still be required
to raise the pH.
We also use the Nakayama table as a guide line, but found that the lower
the alkalinity of the water the more severe the problem will be with
iron clogging emitters.
Casper du Plessis
Date: Tue, 17 Dec 1996 13:33:54 -0400
From: Leonard Ornstein <lenornst@pipeline.com>
Subject: Re: Fe treatment in irrigation water
Casper:
Your clarification will be helpful to those who may have thought I was
making a general recommendation about managing iron in irrigation supplies.
I was responding to Jim Oster's response to Don Pitts' original question,
and then to Alan Wicks further queries. Alum MAY work for Pitts' 4mg/l
iron, pH 7.3 chlorinated water, but, as you explain so well, would hardly
be generally appropriate.
Thanks:
Len Ornstein
>Len,
>
>The method for removal of iron with oxidation and flocculation is as you
>wrote old and accepted. We found it to be impracticable in irrigation
>were large volumes have to be treated in short periods of time. The
>reasons being:
>
>1. In most cases where iron causes problems the pH of the water will be
>acidic and for flocculants to be effective the pH has to be raised.
>
>2. By filtering the iron out we found that the maintenance on these
>filters is very high. the back flush cycle must also be very short to
>prevent pressure losses.
>
>3. With the addition of chlorine, and not getting enough contact time
>before the filters, the iron will oxidise in the emmiter lines and worsen
>the problem.
>
>4. This type of treatment can not be done together with fertigation as
>Calcium Sulphate forms and precipitate out in the emmiter lines.
>
>We have experienced very good results with water conditioners made up of
>mainly copper and zinc coupled to an electron booster. In certain cases
>the water still oxidises but will stay in suspension and leave the
>system through the emitter. The further advantages are that large
>volumes of water can be treated and it is low in maintenance.
>Unfortunately it also has its disadvantages:
>
>1. The water might still discolour which is a problem with micro
>irrigation. With trickle irrigation this is acceptable.
>
>2. With water high in sulphate, Hydrogen Sulphide might form if the
>booster charge is set too high. This can cause serious burning of the
>roots and leaves.
>
>3. With the improved leaching properties of the water, nutrients can be
>leached out of the root zone if the scheduling is not correct.
>
>4. Where the water is acidic, chemical treatment might still be required
>to raise the pH.
>
>We also use the Nakayama table as a guide line, but found that the lower
>the alkalinity of the water the more severe the problem will be with
>iron clogging emitters.
>
>Casper du Plessis
Date: Tue, 17 Dec 1996 21:55:30 -0800
From: Casper du Plessis <aqua@iafrica.com>
Subject: Re: Fe treatment in irrigation water
Len,
Thank you for stressing the point that there is no general rule for
treating water. Each water should be analised for potential problems
were micro irrigation is involved and a recommended treatment
prescribed.
There is no general rule!
Maybe this is a good medium to discuss problems with emitter blockages,
but based on a water analyses containing the elements that might be
responsable for causing problems.
Thanks:
Casper du Plessis
> Casper:
>
> Your clarification will be helpful to those who may have thought I was
> making a general recommendation about managing iron in irrigation supplies.
>
> I was responding to Jim Oster's response to Don Pitts' original question,
> and then to Alan Wicks further queries. Alum MAY work for Pitts' 4mg/l
> iron, pH 7.3 chlorinated water, but, as you explain so well, would hardly
> be generally appropriate.
>
> Thanks:
>
> Len Ornstein
Date: Tue, 17 Dec 1996 19:14:31 -0800
From: "Warren E. Clark" <ag-pr@agpr.com>
Subject: Job Opening -- California Pest Control Advisor
PEST CONTROL ADVISOR-Growing crop protection services company located in
the Salinas Valley of California wants career oriented individual.
Primary responsibilities include monitoring client fields, providing
pest control recommendations and coordinating pesticide applications
with cultural opperations. Minimum requirements are the B.S. Degree in
agricultural or biological science and a California Pest Control
Advisors License or the ability to obtain. Salary commensurate with
experience.
Send resume to:
Tom Shannon
General Manager
Kleen Globe, Inc.
P.O. Box 1125
Castroville, CA 95012
Tel: (408)633-2043
Fax:(408)633-2185
E-mail: shannon@dedot.com
End of Digest
>From root@crcnis1.unl.edu Thu Dec 19 01:00 EST 1996
Date: Wed, 18 Dec 1996 23:46:37 -0600
Message-Id: <199612190546.AA07725@crcnis1.unl.edu>
Subject: TRICKLE-L digest 682
Contents:
FE and Drip ("Craig A. Storlie" <storlie@AESOP.RUTGERS.EDU>)
Trickle-L Archive Web Site Address? ("Warren E. Clark" <ag-pr@agpr.com>)
Re: Trickle-L Archive Web Site Address? (rmead@cybergate.com (Richard Mead))
Date: Wed, 18 Dec 1996 12:28:31 -0500
From: "Craig A. Storlie" <storlie@AESOP.RUTGERS.EDU>
Subject: FE and Drip
------ =_NextPart_000_01BBECF3.A9F78680
High iron content is one of the only problems encountered by New Jersey =
drip irrigators. In most cases, growers are NOT treating waters which =
contain as much as 2 ppm of Fe. Fortunately, our groundwater pH ranges =
from 4-5 and the Fe remains in solution (interesting pollution note: I =
have measured NJ rain pH each year and it has ranged from 2-4 - ouch!). =
I have never seen evidence of iron bacteria in this state.
However, I have seen drip lines clogged with precipitated (ferric) =
iron. This information might be important for those of you hoping to =
avoid iron problems by injecting acid to keep Fe in solution. Iron in =
solution which sits in lines may precipitate due to changes in water =
temperature, pH, pressure, and oxygen content. If this happens, it is =
possible that emitters will clog. I have seen this happen.
------ =_NextPart_000_01BBECF3.A9F78680
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------ =_NextPart_000_01BBECF3.A9F78680--
Date: Wed, 18 Dec 1996 19:35:08 -0800
From: "Warren E. Clark" <ag-pr@agpr.com>
Subject: Trickle-L Archive Web Site Address?
Is there a trickle-l archive at a web site location someone might point
me toward?
Regards,
Warren E. Clark
Clark Consulting International, Inc.
http://www.agpr.com/consulting/maillist.html
Cattle Offerings Worlwide, Inc.
http://www.cattleofferings.com
Association of Agricultural Computing Companies
http://www.agriculture.com/aacc.html
Date: Thu, 19 Dec 1996 05:57:10 GMT
From: rmead@cybergate.com (Richard Mead)
Subject: Re: Trickle-L Archive Web Site Address?
>Is there a trickle-l archive at a web site location someone might point
>me toward?
>Regards,
>Warren E. Clark
Warren,
The main reason the Microirrigation Forum at
http://www.cybergate.com/~rmead/ was
created was to have a database for Trickle-L archives. A "Best of" section is at
http://www.cybergate.com/~rmead/best.html
Raw archives were at one time at
gopher://sunsite.unc.edu/70/11/.academic/agriculture/agronomy/agronomy-topic
s/trickle-l, yet I tried that link and it was down at the time.
Hope this helps!
R. Mead
Trickle-L owner/manager
>Clark Consulting International, Inc.
>http://www.agpr.com/consulting/maillist.html
>Cattle Offerings Worlwide, Inc.
>http://www.cattleofferings.com
>Association of Agricultural Computing Companies
>http://www.agriculture.com/aacc.html
End of Digest
>From root@crcnis1.unl.edu Fri Dec 20 01:00 EST 1996
Date: Thu, 19 Dec 1996 23:47:32 -0600
Message-Id: <199612200547.AA18707@crcnis1.unl.edu>
Subject: TRICKLE-L digest 683
Contents:
Re: Fe treatment in irrigation water (Don Pitts <djp@ICON.IMOK.UFL.EDU>)
Date: Thu, 19 Dec 1996 09:13:42 -0500 (EST)
From: Don Pitts <djp@ICON.IMOK.UFL.EDU>
Subject: Re: Fe treatment in irrigation water
Please re-enter your statement on the subject of Fe removal from irrigation
water.
Thank You,
Don Pitts
At 11:38 PM 12/16/96 -0600, you wrote:
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End of Digest
>From root@crcnis1.unl.edu Sat Dec 21 01:00 EST 1996
Date: Fri, 20 Dec 1996 23:47:45 -0600
Message-Id: <199612210547.AA16267@crcnis1.unl.edu>
Subject: TRICKLE-L digest 684
Contents:
Positioning of tensiometers (Jochen.Eberhard@t-online.de (Jochen Eberhard))
Viticulturist Position Open (BRASERJ@aol.com)
Re: Positioning of tensiometers ("OSU Malheur Exp. Station" <mesosu@primenet.com>)
Re: Positioning of tensiometers (Don Pitts <djp@ICON.IMOK.UFL.EDU>)
Re: TRICKLE-L digest 673 (TPiatkowsk@aol.com)
Re: Positioning of tensiometers ("Alan S. Wicks" <awicks@televar.com>)
new member intro ("Buchanan, Joe" <jobu461@ecy.wa.gov>)
Re: Positioning of tensiometers ("J.D. Oster" <oster@mail.ucr.edu>)
New member intro (Ravi Narayanan <rnarayan@plains.nodak.edu>)
Re: Typical numbers from Joe Buchanan (FLamm@oznet.ksu.edu (Freddie Lamm))
Re: Positioning of tensiometers (Jed Waddell <wadde002@maroon.tc.umn.edu>)
Re: Minute/ultra-low microirrigation (Figali@aol.com)
Date: Fri, 20 Dec 1996 10:46:04 -0800
From: Jochen.Eberhard@t-online.de (Jochen Eberhard)
Subject: Positioning of tensiometers
Hallo everybody, :-))
the following question gives me the opportunity to wish everybody Merry
Christmas and a Happy New Year. :-)) (I know, if everybody on the list
would do this, everyone of us would recieve some hundred mails).
Now my question: Recently I red something about the Richard equation for
estimating water distribution in the wetted volume of a drip-irrigated
soil. The result of this calculation is, that the worst place to put a
tensiometer is right under the emitter. I grew up (the last two years)
with the idea, that means, everybody is saying so, that the best place to
monitor soil moisture with a tensiometer to schedule irrigation is right
under the emitter. Now I am a little confused.
My own experiance is that with placing the tensiometer under the emitter,
it is more difficult to avoid overirrigation when the evaporative demand
is low. It is sufficient to place the tensiometers between the emitters
(lateral) when the crop is established, and it is easier to keep soil
moisture at the desired level.
Any comment will help me to celebrate a unconfused Christmastime :-)
Thanks and best wishes
Jochen Eberhard, Germany
email: Jochen.Eberhard@t-online.de
Date: Fri, 20 Dec 1996 09:14:17 -0500
From: BRASERJ@aol.com
Subject: Viticulturist Position Open
Viticulturist postion open for Fresno, California based agricultual
consulting firm. Work includes advising growers in water and nutrition
management and pest control for wine, rasin, and table grape vineyards.
About one-half of work will be with premium wine grapes along the Central
Coast and half in the San Joaquin Valley. Person must have strong background
in Integrated Pest Managment, valid PCA licence, and minimum of BS degree.
Prefer minimum of five years of field experience in on-farm operations or
pest control advising.
Send resume to:
Crop Care Services, Inc.
4323 N Golden State
Fresno, CA 93722
Or e-mail to:
CropCare@aol.com
Contact: Ron Brase or Dan Rodrigues 209/275-8095
Date: Fri, 20 Dec 1996 07:24:39 -0700
From: "OSU Malheur Exp. Station" <mesosu@primenet.com>
Subject: Re: Positioning of tensiometers
To Jochen Eberhart and interested parties,
Positioning of tensiometers or other soil water monitoring devices
depends on several factors that include:
1. Drip line and emmitter spacing,
2. Root distribution of the crop,
3. Problems with salinity if any,
4. Soil properties and the wetting pattern of the soil.
Since these factors vary from crop to crop and site to site, so
tensiometer placement should vary. My preference is to place soil water
monitoring devices at locations that are representative of the wetted
soil volume in the crop root zone because our primary concerns is to
irrigate to attend plant needs --- and thereby assure crop yield and
quality.
Clint
--
Dr. Clinton C. Shock
Malheur Experiment Station
Oregon State University
595 Onion Ave.
Ontario, Oregon 97914
telephone (541) 889-2174
Fax (541) 889-7831
http://www.primenet.com/~mesosu/index.html
Date: Fri, 20 Dec 1996 09:48:27 -0500 (EST)
From: Don Pitts <djp@ICON.IMOK.UFL.EDU>
Subject: Re: Positioning of tensiometers
Dear Jochen,
Placement of tensiometers is very important both in respect to the
depth of the root zone and in respect to the emitter and plant. For
vegetable crops (line source emitter) we generally place the tensiometer in
the plant row. For tree crops we place the tensiometer within the tree
drip-line and within the emitter wetted area. Placement of tensiometers with
respect to crop root depth is also critical. For very shallow rooted (less
than 1 ft) vegetable crops, only one tensiometer may be required. It should
be placed centrally in the crop root zone, but at least 4 to 6 inches below
the surface. For moderately rooted crops, such as drip-irrigated tomatoes,
two tensiometers (6 and 12 inch) should be used at each measurement site.
For citrus and tree crops we often recommend three tensiometers (6,12, and
18 inch) at each site. The tensiometer should not be placed directly under
the emitter (dripper), but it should be totally in the area wetted by the
emitter. The distance from the emitter will vary with soil texture and
hydraulic properties.
Regards,
Don Pitts
E-mail djp@icon.imok.edu
At 04:29 AM 12/20/96 -0600, you wrote:
>Hallo everybody, :-))
>
>
>the following question gives me the opportunity to wish everybody Merry
>Christmas and a Happy New Year. :-)) (I know, if everybody on the list
>would do this, everyone of us would recieve some hundred mails).
>
>Now my question: Recently I red something about the Richard equation for
>estimating water distribution in the wetted volume of a drip-irrigated
>soil. The result of this calculation is, that the worst place to put a
>tensiometer is right under the emitter. I grew up (the last two years)
>with the idea, that means, everybody is saying so, that the best place to
>monitor soil moisture with a tensiometer to schedule irrigation is right
>under the emitter. Now I am a little confused.
>My own experiance is that with placing the tensiometer under the emitter,
> it is more difficult to avoid overirrigation when the evaporative demand
>is low. It is sufficient to place the tensiometers between the emitters
>(lateral) when the crop is established, and it is easier to keep soil
>moisture at the desired level.
>
>Any comment will help me to celebrate a unconfused Christmastime :-)
>
>Thanks and best wishes
>Jochen Eberhard, Germany
>email: Jochen.Eberhard@t-online.de
>
Date: Fri, 20 Dec 1996 11:41:01 -0500
From: TPiatkowsk@aol.com
Subject: Re: TRICKLE-L digest 673
Don Pitts,
My e-mail address is TPiatkowsk@aol.com
I apologize to you and others for my slow response for information. I am back
in the office and should have time to catch up on everything over the next
few days.
Tom
Ag H20
Date: Fri, 20 Dec 1996 09:25:50 -0800
From: "Alan S. Wicks" <awicks@televar.com>
Subject: Re: Positioning of tensiometers
Greetings,
My philosophy of placing tensiometers is to put one in the area of the
active root zone and generally to one side of the irrigation line. The
chosen root zone is midway between emitters. This area is used to
indicate when to start irrigating since it has the highest concentratin
of active roots and the water content will decrease the fastest. I also
place a tensiometer below the root zone between the emitters. I watch
this one during irrigation so that I know when the root zone is nearly
full. Additional irrigation simply wastes water and fertilizer. This
second tensiometer does not have to reach zero since there will be some
drainage into that area after the water is turned off. The exact cut
off point is a function of soil but this methodology has worked well for
me in vegetables with SDI as well as for grapes with above surface
emitters.
Best of the holidays to you all,
Alan S. Wicks
Kennewick, WA
Date: Fri, 20 Dec 96 10:58:00 PST
From: "Buchanan, Joe" <jobu461@ecy.wa.gov>
Subject: new member intro
Greetings. Please allow me to introduce myself to fellow Trickle-L
subscribers.
My name is Joe Buchanan. I am a mech engr who developed controls for fossil
power production for the past 15 years. Two years ago, I relocated to
Central Washington (Yakima) to try my hand at developing instrument based
control systems for irrigated agriculture.
Primary crops of interest here include hops, grapes (wine & concord), mint,
and tree fruits. Primary method of application is surface drip, as growers
are as yet uncomfortable with soil moisture monitoring instruments, and
prefer to view the wetted surface pattern to confirm operation.
Water quality here in the PNW is generally good, except for suspended solids
in well and canal-supplied systems. Media filters are common, though some
growers are applying disc-style filters to eliminate the cost of filter
media.
Today I am working on a contract with the Washington State Dept. of Ecology
to develop a spreadsheet-based cost-benefit analysis tool for local growers
to use to asses the financial impact of converting furrow-irrigated crops to
drip. The system design references I'm using include ASAE's Des. & Opr. of
Farm Irrigation Systems, NRCS's Nat'l Engr Handbook Section 15, and the
State of Washington Irrigation Guide. I'm interested in adding to my
library and would appreciate recommendations on other design references.
To conclude the task at hand, I am in need of information on the following
topics:
- I need to assume a typical emitter flow exponent and design pressure
for non-compensating, turbulent flow. Are x = 0.8 and P = 15 psig fairly
typical numbers?
- Can anyone provide quantifiable information on the yield impact of
furrow to drip conversion on grapes, hops, mint? Is it strictly a function
of improved fertilizer management, or does improvement in water management
by reducing over-watering contribute to yield increases?
- Here in the PNW, drip reduces the costs of hop production as weed
growth is decreased, thereby decreasing soil tillage requirments during the
growing season. Do similar cultivation labor decreases occur in grapes
(i.e. is weed growth a significant challenge in vineyards, or are sufficient
herbicides available for control)?
Re current discussions on soil moisture monitoring, I've got some info on a
newly introduced soil moisture probe which measures electro-magnetic wave
propigation rate (rate of propigation is directly proportional to soil
moisture content). Send an e-mail note if you'd like to discuss the
efficacy of such an instrument.
Send e-mail to either jobu461@ecy.wa.gov or to rozaengr@televar.com
Date: Fri, 20 Dec 1996 16:34:05 -0600
From: "J.D. Oster" <oster@mail.ucr.edu>
Subject: Re: Positioning of tensiometers
The highest concentration of roots do not necessarily occur between
emitters. It depends a bit on the amount of water applied relative to ET,
soil hydraulic characteristics, emitter spacing, plant distribution along
the drip line, the rooting characteristics of the crop, and the salinity
level in the soil. For example, for the situation where there is a the same
number of plants and emitters per row, the plant and emitter are at the
same location, and more water infiltrates into the soil than the plant
transpires, the edge of the two rootzones, beneath the drip line, occurs
midway between the emitters. The highest salinities would than also occur
midway between the emitters reflecting water uptake that occurs between the
emitter and the edge of the rootzone located between the emitters. But the
water uptake distribution, i.e. root activity, could decrease expotentially
with distance from the emitter which would result in a salinity distribution
which increases expotentially with distance from the emitter.
Sorry for the 'complicated' sentences: Including a sketch would be helpful
but the time is too limited today to learn how that could be done.
At 11:59 AM 12/20/96 -0600, you wrote:
>Greetings,
>
>My philosophy of placing tensiometers is to put one in the area of the
>active root zone and generally to one side of the irrigation line. The
>chosen root zone is midway between emitters. This area is used to
>indicate when to start irrigating since it has the highest concentratin
>of active roots and the water content will decrease the fastest. I also
>place a tensiometer below the root zone between the emitters. I watch
>this one during irrigation so that I know when the root zone is nearly
>full. Additional irrigation simply wastes water and fertilizer. This
>second tensiometer does not have to reach zero since there will be some
>drainage into that area after the water is turned off. The exact cut
>off point is a function of soil but this methodology has worked well for
>me in vegetables with SDI as well as for grapes with above surface
>emitters.
>
>Best of the holidays to you all,
>
>Alan S. Wicks
>Kennewick, WA
>
J.D.(Jim) Oster
Dept. of Soil & Env. Sciences
University of California
Riverside, CA 92521
Phone (909)787-5100
FAX (909)787-5522
Date: Fri, 20 Dec 1996 17:01:37 -0600 (CST)
From: Ravi Narayanan <rnarayan@plains.nodak.edu>
Subject: New member intro
Dear Trickle-l members,
I am Ravi Narayanan and i am happy to become a member of trickle-l. I am
a graduate student in Ag & Biosystems engg in North Dakota State
University. I am currently working on Economics of using Drip Irrigation for
speciality crops (Carrot, Cabbage, and Onions) in North Dakota. North
Dakota has only about 100 acres irrigated with drip. One of the reason
for the low use of drip irrigation in North Dakota is found to be lack of
information on the cost involved for using drip irrigation. So my study
would involve the use of engineering, agronomy, and economic aspects to
determine the benefit-cost of using Drip irrigation.
I would need help in getting a model which i can use for the optimization
of drip irrigation design. My advisor is helping me in contacting
people and we are yet to receive any positive reply. So it will be
very helpful if any of you could send me any information on this.
To tell more about my background, I did my bachelors in Ag Engg in India
and worked for an Irrigation firm in Tamil Nadu for two years.
In Tamil Nadu we use mostly surface drip and major crops(trees) irrigated are
coconut, mango, pomegranate, guava, citrus, and grapes. One private
timeshare company uses drip irrigation for Teak. Subsurface Drip is
used in some places for sugarcane.
The temperature ranges from 20 deg C to 42 deg C (approx) in this part
of India.
The water source used for drip is usually a open well or a bore
well. Power source for the pump is either a diesel engine or
electricity.
The major constraint for using drip in this place is due to
the high investment cost of the irrigation system although Indian
government offers subsidies up to 50 percent for farmers. NABARD a
nationalized bank for agricultural development offers loans for the
farmers to purchase drip irrigation equipment.
I think there is a lot of potential for the use of subsurface drip irrigation in sugarcane and for the
use of micro sprays in orchards in the future.
I thank everyone for giving me this opportunity and I wish you all a
Happy Christmas and a Happy 1997.
Ravi. N
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
Date: 20 Dec 96 17:01:50 CST
From: FLamm@oznet.ksu.edu (Freddie Lamm)
Subject: Re: Typical numbers from Joe Buchanan
Joe Wrote:
- I need to assume a typical emitter flow exponent and design pressure
for non-compensating, turbulent flow. Are x = 0.8 and P = 15 psig fairly
typical numbers?
Freddie responded:
I would think if "typical" is the word, an emitter exponent of 0.5 is
more typical and then **maybe** P=10 psig. Of course there's a bunch
of products out there and "typical" may be a hard animal to shoot.
Freddie
*
-------------------------------------------------------------------
Freddie Lamm *
Research Agricultural Engineer *** o
KSU Northwest Research-Extension Center ***** /|\
105 Experiment Farm Road *******\\
Colby, Kansas 67701-1697 *********
Ph. 913-462-6281 ***********
FAX 913-462-2315 *************
Email:flamm@oznet.ksu.edu It's all downhill from here.
------ THERE'S NO DOMAIN LIKE OZ, THERE'S NO DOMAIN LIKE OZ. ------
Date: Fri, 20 Dec 96 18:18:23 -0600
From: Jed Waddell <wadde002@maroon.tc.umn.edu>
Subject: Re: Positioning of tensiometers
Jochen and Trickle-L,
The Richards equation is used to calculate transient water flow. It is
simply the conservation equation (In-Out+Storage=0) or a change in water
flux over some distance is equal to a change in water content over some time
(neglecting water uptake for a moment). If the soil is dry, water flow will
be controlled by the matric potential gradient (like a dry sponge soaking
water) in x,y and z directions. When the soil is moist, the water flow will
be dominated by gravity which occurs in the downward (z)direction.
Therefore, if the soil is kept moist with frequent irrigations (and
depending on soil properties) an exceedingly high water content may appear
directly under the emitter.
The solution to this problem can be solved with knowledge of the wetting
pattern under the emitter and the root distribution. The total amount of
water accessible for plant uptake can be estimated from the Richards
equation by knowing the water input and root water uptake. Having one
tensiometer reading placed anywhere within the wetting pattern should be
enough to quantify the amount of available water.
Solving the Richards equation for one dimension is tough because it's a
partial derivative (based both on changes in distance and time). Also, soil
properties may change with depth increasing the complexity of solving the
equation. In my opinion, experience can be as good if not better as a
finite element model that simulates water flow under drip. By placing a
tensiometer directly under the emitter or slightly away should be OK for
predicting when to irrigate as long as you put it in the same place always
and watch the crop response.
Jeeze, I didn't know what I was getting into trying to answer this question.
I have used the Richards equation for 2 dimensional flow under surface and
buried drip lines. My home page should have some data on wetting patterns
under drip soon but as yet doesn't. I'll probably have some results of my
work up tomorrow as I just created the home page today:
http://www.soils.umn.edu/~jwaddell/
Check it out.
Jed
At 04:25 AM 12/20/96 -0600, you wrote:
Recently I red something about the Richard equation for
>estimating water distribution in the wetted volume of a drip-irrigated
>soil. The result of this calculation is, that the worst place to put a
>tensiometer is right under the emitter. I grew up (the last two years)
>with the idea, that means, everybody is saying so, that the best place to
>monitor soil moisture with a tensiometer to schedule irrigation is right
>under the emitter. Now I am a little confused.
****************************************************
* Jed T. Waddell *
* Graduate Research Assistant *
* University of Minnesota *
* Department of Soil, Water, and Climate *
* St. Paul, MN 55108 *
* office (612) 625-1968 *
* fax (612) 625-2208 *
****************************************************
Date: Fri, 20 Dec 1996 23:34:29 -0500
From: Figali@aol.com
Subject: Re: Minute/ultra-low microirrigation
The concept of "Minute" irrigation is not necessarily new but has been
impractical until approximately three years ago. The idea is to apply water
at a very slow rate. To achieve this we would require a drip emitter with
extremely small passages and considerably higher filter requirements. This
emitter would be highly susceptible to clogging. To date there is no emitter
or tape product that is capable of delivering water at a rate which
approaches that considered to be minute irrigation. However, there are a few
individual components that when used together can create this minute
irrigation. I consider minute irrigation to be in the range of 100 - 400 cc
per hour.
The heart of this system is a pulsating device which contains a silicone
sleeve seated upon a specially designed piston. As this sleeve or bladder
swells with water it reaches a critical point where the stored water is
released and then the process repeats itself. This continual action creates
the pulsing effect. The rate of flow through the pulser is determined by
either a compensated or non-conpensated emission device. It is when this
pulser is connected to a secondary emission device that we are able to
achieve minute irrigation. In Israel when using the term minute irrigation
they are referring only to the use of drip emitters. Pulsated
micro-sprinklers or jets is a different concept.
Most applications of this system have been used in green houses. There are
two types of systems of minute irrigation. One system connects about 20
individual pot type drippers (stakes with a labyrinth) to one single pulser.
If the pulser has a discharge rate of 4 LPH or 4,000 cc/hour we divide this
number by the number of outlets and have an individual discharge rate of 200
cc/hour/pot. The second system uses our (Drip In) 1/4" (6mm) soaker dripline
with emitters spaced anywhere from 15cm to 30cm connected to the same pulser.
We can not use a dripline with a larger ID because the line will always be
partially filled with air. The 1/4" because of its small ID is constantly
charged with water. This system is either stretched on top of the pots or
laid directly on the bed. The number of emitters varies but is generally not
more than 60. I recently installed a system where I used an 8 LPH pulser
with 60 emitters or an individual discharge rate per emitter of 133 cc/hour.
These emitters normally are 2 LPH.
The beauty here is that we are able to reduce the flow per emitter to minute
amounts of water and yet maintain large passageways and relative clog
resistance. Like any new technology there are advantages and disadvantages.
In fact this technology is considered by some to be revolutionary. Similar
to what drip was 20 years ago. Most pots are irrigated by spray stakes or
some type of emitter. Water applied at a rate of 2 LPH will form a sausage
near the middle of the pot and drainage will begin within a few minutes.
Irrigation will continue approximately 7-15 minutes. During this time water
will begin to move upwards closer to the sides of the pot pushing the salts
further into the root zone. This mandates frequent flushing and an
additional waste of water and nutrients. With the pulsated drip system the
water will move almost twice as fast laterally until the upper area is
completely wetted. Then the movement will be downward as a front until
drainage occurs. When the first drops drain the pot is at pot capacity and
the irrigation can be shut off. This movement is constantly washing the salts
downward. Additional flushing of the salts is only required when the EC of
the drainage water exceeds the established limits.
Specific advantages of this system include:
1. Water and fertilizer savings up to 40-50%
2. Optimum growing conditions due to the ability to maintain an optimum
balance of air, water and nutrients in the soil.
3. Better utilization of available space; plant density can be increased.
4. Quicker turn around of plant material; reduced growing cycles.
5. Higher yields
6. Better quality
7. Lower system costs; smaller PVC sizes, reduced horsepower
requirements....
This system poses significant challenges and requires us to change our way of
thinking.
For one, the discharge rate of the emitters at the end of the lateral is
higher than the rate at the begining. This is completely opposite from what
we expect with conventional drip technology. Second, we are talking about
using up to 40-50% less water then existing drip systems. If this is true
than we need to reevaluate crop requirements. We applied this technology on
a small scale to 40 almond trees in the Sacramento Valley this summer. From
mid june through October we applied 1 GPH/tree. The dripline was our 1/4"
soaker dripline with emitters spaced at 12". The water was never shut off
except for one day at harvest. The surface wetted area was on average 1 foot
wide and there was no runoff. These trees received no more than 24 gallons
per day. These were mature trees with a full crop. Visual inspection
indicated good growth and yields comparable to the rest of the orchard. We
intend to expand this system and do a small area of grapes in 1997.
We do not have all the answers to these questions yet. Actually we are not
sure what questions we should be asking. While the concept has broad
applications the technology to apply this on a large scale to field crops is
in its infancy. For the present we will be promoting this minute irrigation
technology to the greenhouse industry and evaluating its application in the
broader agricultural market. We would like to invite those interested in
this technology to explore the possibilities and ramifications along with us.
A few papers have been written on the subject in Israel. They have been
translated into english and are available in Israel by contacting Jacob Levin
at Lego Irrigation or contacting me at Drip In Irrigation.
I hope that I have been able to answer a few of the questions.
Philip Lubars
Drip In Irrigation
2836 N. Larkin Ave.
Fresno, CA 93637
Tel: (209) 294-8008
Fax: (209)294-8809
e-mail figali@aol.com
End of Digest
>From root@crcnis1.unl.edu Sun Dec 22 01:01 EST 1996
Date: Sat, 21 Dec 1996 23:48:39 -0600
Message-Id: <199612220548.AA29376@crcnis1.unl.edu>
Subject: TRICKLE-L digest 685
Contents:
Re: Minute/ultra-low microirrigation (Leonard Ornstein <lenornst@pipeline.com>)
Re: Positioning of tensiometers (Trevor Finch <rsne@mpx.com.au>)
Determining DU for existing SDI systems (Merriott@aol.com)
Re: Determining DU for existing SDI systems (Tim1Utah@aol.com)
Date: Sat, 21 Dec 1996 13:23:25 -0400
From: Leonard Ornstein <lenornst@pipeline.com>
Subject: Re: Minute/ultra-low microirrigation
>The concept of "Minute" irrigation is not necessarily new but has been
>impractical until approximately three years ago.>
Well, this gives me an oportunity to introduce Trickle-L list members to a
drip technology, the use of moisture-sensitive, self-regulating irrigation
valves,Irristats, (typically, but not necessarily, one to a plant, bush or
tree) for delivering water at rates which exactly match
evapotranspioration, and therefore is as "Minute" as you would want to get!
Like other forms of "Minute", it typically uses a water-supply continuosly
pressurized at up to 15 lbs/in^2, and requires quality filtration. But it
has a lot more to offer.
As indicated below, I had planned to delay this "announcement" until my Web
site is ready, (in about two weeks), but this discussion cries out for this
respons:
X-Sender: lenornst@pop.pipeline.com
Date: Sat, 30 Nov 1996 13:58:15 -0400
To: SOWACS@aqua.ccwr.ac.za
From: Leonard Ornstein <lenornst@pipeline.com>
Subject: Measuring Evapotranspiration/Lysimeters
Sender: owner-sowacs@aqua.ccwr.ac.za
Precedence: bulk
Greetings to all:
On Nov. 20, Dean Reynolds initiated a thread on methods that might be
useful for updating crop-ET numbers. Because of the expense of lysimeters
and lysimetry, he was interested in the pros and cons of using neutron
probes and TDR as alternatives for such purposes.
Terry Howell quickly responded with a very helpful discussion. He correctly
noted that since evapotranspiration modifies the moisture content of the
air above soil and foliage, strictly speaking, lysimetry, neutron probe
measurements and TDR only provide an indirect measures of ET, whereas eddy
correlation can measure ET directly. However he indicated that it probably
wasn't a practical alternative at this time. He neatly reviewed the hazards
of crop-ET assessment; rain, deep percolation, etc.
On Nov. 22, Dean replied with thanks to all for their contributions to the
discussion, and revealed just why he had raised the subject; namely the
economic factors that governmental bodies, like the State of California
face as farmers choose to sell their State-assigned water rights to one
another (and municipalities).
To oversimplify, it appears the allowed selling price depends upon a
State-approved estimate of crop-ET and acreage. If the estimated crop-ET is
too high, the State essentially is giving away (and wasting) valuable
public resources.
What Dean in fact wants to assess is the crop water consumption, which of
course results mainly from ET, but THAT is directly measurable by lysimetry.
Dean believes, for the reason reviewed above, that updating crop-ET with
lysimetry would have substantial desirable economic consequences, but
apparently judges that the costs of the equipment and labor for the job
will be unacceptable to the officials of the California Department of Water
Resources for whom he works.
The problems he raises are rather universal.
I believe I can offer an inexpensive solution:
I am the inventor and manufacturer of the Irristat, a moisture-sensitive,
self-regulating valve, designed to control the delivery of water to a "drip
emitter". The Irristat is a device with which few if any of the SOWACS
List's members will be familiar. Although the Irristat was developed as an
automated irrigation-scheduling device, it also works fine as an
alternative to a lysimeter to "measure" evapotranspiration:
It was introduced in:
The Irristat: A Moisture-Sensitive, Self-Regulating, Water Valve for
Drip Irrigation Systems: Drip/Trickle Irrigation in Action Vol. 2
ASAE Pub. 10-85, St. Joseph, Mich., pp.623-629; (Proceedings. of the
Third International Drip/Trickle Irrigation Congress, Nov. 18-21, 1985,
Fresno, CA).
The article contains a description of the Irristat and a general
discussion of its applications in agriculture and horticulture,
including a description of an installation for 60 mature cherry trees at
Washington State Uniersity Irrigated Agriculture Research Center,
Prosser, WA (WSU).
Temporarily, an Abode Acrobat version of that publication, irrst2.pdf,
as well as another document, irrist1.pdf, which describes the Irristat
technology in greater detail, can be read and/or downloaded (thanks to
Bruce) from:
<http://www.icfrnet.unp.ac.za/~metele/sowacs/irristat.html>
Adobe Acrobat Readers for PC, Unix or Mac platforms can be downloaded FREE
from:
<http://www.adobe.com/acrobat/>
I am in the midst of preparing a Web Page which will describe the
technology briefly and will contain URL's for downloading these two
papers as well as four others, including an unpublished paper by Robert G.
Evans, documenting the performance of the Irristats that I installed for
him and Ed Proebsting for the 60 mature cherry trees at WSU. I had expected
to introduce the Irristat to SOWACS and Trickle-L when my Web Page is
ready. That should be before the new year. And I will post its address here
as soon as possible.
Briefly, this is how the Irristat works:
The Irristat uses a uniquely formulated, synthetic polyacrylamide gel as
its moisture-sensing element. The valve is buried near a plant's roots, in
intimate contact with the soil,.
Water is conducted by capillary tubing from a water supply, through a
thin-walled rubber tube within the body of the Irristat and then through
another attached length of capillary tubing to, or near to the soil
surface. On its way past the roots, the water spreads by gravity and
capillarity through the soil, passes through the Irristat's porous
polyester fiber membrane, and reaches the moisture-sensing element, the gel.
As the gel becomes more moist, it swells, pushing the Irristat's piston
against the rubber tube. When the moisture in the soil surrounding the
Irristat reaches a predetermined set-point, (typically -0.15 bars) the
swollen gel causes the piston to pinch the rubber tube closed, cutting off
the supply of water.
As the plant draws moisture from the soil, the gel shrinks, reversing
the cycle. As the moisture level falls below the Irristat's set-point,
the piston moves back, relieving the pressure on the rubber tube, and
water begins to flow.
Buried in the soil, Irristats will function reliably for many years,
PROVIDING AUTOMATED DRIP/TRICKLE IRRIGATION. The Irristat itself is
about 2 cubic centimeters in volume. It, and its connections, are
usually encased in a protective polypropylene shell in the form of a
spear-tip, which simplifies insertion into the soil. The body parts and
piston of the Irristat are molded of polypropylene; the internal water
conduit is made of silicone rubber; the semi-permeable membrane, of
Dacron-like polyester fibers; and the moisture-sensitive gel, of
slightly-cross-linked polyacrylamide. All are chemically, biologically
and physically durable. With 0.125-inch inside-diameter capillary
tubing, and a water supply at 15 pounds per square inch, an Irristat can
deliver up to about 1.7 liters of water per minute. Therefore, one Irristat
can service any plant, up to a medium-size tree; a few Irristats, in
parallel, can service a large tree.
The Irristat delivers to its plant, EXACTLY THE AMOUNT OF WATER NEEDED
TO REPLACE LOSSES DUE TO EVAPOTRANSPIRATION, (plus any additional amount
incorporated into new growth).
If it is set up with a gravity-feed water supply from a tank, after it
has been working for a few days, the measured amount of water drawn from
the tank per unit time (e.g., per 24 hours) is an accurate measure of
evapotranspiration plus "growth water".
Alternatively, if the water supply is a typical drip-lateral, a second
Irristat can be installed in parallel with, and directly adjacent to the
first, with an outlet capillary line of the same inside diameter and length
as the first, delivering its output at the same point. After they have been
working together for a few days, the outlet of either one can then be
placed into a container, and the amount of water delivered per unit time
will be an accurate measure of the evapotranspiration associated with that
plant, bush or tree. (The Irristat has a time-constant of about 2 hours, so
an "instantaneous measurement" usually reflects the evapotranspiration that
occurred 2 hours earlier.)
Of course, this description of how to use Irristats to measure
evapotranspiration is a bit oversimplified; (e.g., if the bottom of the
root ball is at the water table, if it has just rained or if the plant is
growing in such coarse sand that, at -0.15 bars matric potential, a
substantial portion of the delivered water percolates down past the roots),
my method works poorly. With two tensiometers; one beside the Irristat in
the root ball, and the other inserted to a depth somewhat below the root
ball, you can easily check whether the water table is too high or the
irrigation water is perciolating too deep.
You will of course wonder why I have kept this a "secret" so long?
In order to compete with pressure-compensating emitters, we had planned to
manufacture the Irristat at a unit cost of under $1.00, with most of the
cost coming from the labor of manual assembly. But that depended upon
essentially 100% manufacturing-yield of correctly functioning Irristats.
And over the years, the best we've been able to do is a bit better than
90%. That means that EACH finished Irristat needs to be checked by cycling
it a few times between wet and dry states, and this turns out to be quite
expensive. We (and others) judged that the resulting $6.00 unit selling
price, for a spear-tip mounted Irristat, would severely restrict the range
of its application. With rather limited resources, we have been (very
inadequately) trying to enter markets, like landscaping, which might
tolerate the higher, cost. I hope the Web will help us change this.
But, clearly, for use as an ET-measuring tool, our current manufacturing
cost should pose no problem!.
I'll be happy to discuss various other details of use and performance, in
this forum, or privately.
Hope you find this useful.
Leonard Ornstein, Ph.D.
Irristat International Inc.
lenornst@pipeline.com
>The concept of "Minute" irrigation is not necessarily new but has been
>impractical until approximately three years ago. The idea is to apply water
>at a very slow rate. To achieve this we would require a drip emitter with
>extremely small passages and considerably higher filter requirements. This
>emitter would be highly susceptible to clogging. To date there is no emitter
>or tape product that is capable of delivering water at a rate which
>approaches that considered to be minute irrigation. However, there are a few
>individual components that when used together can create this minute
>irrigation. I consider minute irrigation to be in the range of 100 - 400 cc
>per hour.
>
>The heart of this system is a pulsating device which contains a silicone
>sleeve seated upon a specially designed piston. As this sleeve or bladder
>swells with water it reaches a critical point where the stored water is
>released and then the process repeats itself. This continual action creates
>the pulsing effect. The rate of flow through the pulser is determined by
>either a compensated or non-conpensated emission device. It is when this
>pulser is connected to a secondary emission device that we are able to
>achieve minute irrigation. In Israel when using the term minute irrigation
>they are referring only to the use of drip emitters. Pulsated
>micro-sprinklers or jets is a different concept.
>
>Most applications of this system have been used in green houses. There are
>two types of systems of minute irrigation. One system connects about 20
>individual pot type drippers (stakes with a labyrinth) to one single pulser.
> If the pulser has a discharge rate of 4 LPH or 4,000 cc/hour we divide this
>number by the number of outlets and have an individual discharge rate of 200
>cc/hour/pot. The second system uses our (Drip In) 1/4" (6mm) soaker dripline
>with emitters spaced anywhere from 15cm to 30cm connected to the same pulser.
> We can not use a dripline with a larger ID because the line will always be
>partially filled with air. The 1/4" because of its small ID is constantly
>charged with water. This system is either stretched on top of the pots or
>laid directly on the bed. The number of emitters varies but is generally not
>more than 60. I recently installed a system where I used an 8 LPH pulser
>with 60 emitters or an individual discharge rate per emitter of 133 cc/hour.
> These emitters normally are 2 LPH.
>
>The beauty here is that we are able to reduce the flow per emitter to minute
>amounts of water and yet maintain large passageways and relative clog
>resistance. Like any new technology there are advantages and disadvantages.
> In fact this technology is considered by some to be revolutionary. Similar
>to what drip was 20 years ago. Most pots are irrigated by spray stakes or
>some type of emitter. Water applied at a rate of 2 LPH will form a sausage
>near the middle of the pot and drainage will begin within a few minutes.
> Irrigation will continue approximately 7-15 minutes. During this time water
>will begin to move upwards closer to the sides of the pot pushing the salts
>further into the root zone. This mandates frequent flushing and an
>additional waste of water and nutrients. With the pulsated drip system the
>water will move almost twice as fast laterally until the upper area is
>completely wetted. Then the movement will be downward as a front until
>drainage occurs. When the first drops drain the pot is at pot capacity and
>the irrigation can be shut off. This movement is constantly washing the salts
>downward. Additional flushing of the salts is only required when the EC of
>the drainage water exceeds the established limits.
>
>Specific advantages of this system include:
>1. Water and fertilizer savings up to 40-50%
>2. Optimum growing conditions due to the ability to maintain an optimum
>balance of air, water and nutrients in the soil.
>3. Better utilization of available space; plant density can be increased.
>4. Quicker turn around of plant material; reduced growing cycles.
>5. Higher yields
>6. Better quality
>7. Lower system costs; smaller PVC sizes, reduced horsepower
>requirements....
>
>This system poses significant challenges and requires us to change our way of
>thinking.
>For one, the discharge rate of the emitters at the end of the lateral is
>higher than the rate at the begining. This is completely opposite from what
>we expect with conventional drip technology. Second, we are talking about
>using up to 40-50% less water then existing drip systems. If this is true
>than we need to reevaluate crop requirements. We applied this technology on
>a small scale to 40 almond trees in the Sacramento Valley this summer. From
>mid june through October we applied 1 GPH/tree. The dripline was our 1/4"
>soaker dripline with emitters spaced at 12". The water was never shut off
>except for one day at harvest. The surface wetted area was on average 1 foot
>wide and there was no runoff. These trees received no more than 24 gallons
>per day. These were mature trees with a full crop. Visual inspection
>indicated good growth and yields comparable to the rest of the orchard. We
>intend to expand this system and do a small area of grapes in 1997.
>
>We do not have all the answers to these questions yet. Actually we are not
>sure what questions we should be asking. While the concept has broad
>applications the technology to apply this on a large scale to field crops is
>in its infancy. For the present we will be promoting this minute irrigation
>technology to the greenhouse industry and evaluating its application in the
>broader agricultural market. We would like to invite those interested in
>this technology to explore the possibilities and ramifications along with us.
> A few papers have been written on the subject in Israel. They have been
>translated into english and are available in Israel by contacting Jacob Levin
>at Lego Irrigation or contacting me at Drip In Irrigation.
>
>I hope that I have been able to answer a few of the questions.
>
>Philip Lubars
>Drip In Irrigation
>2836 N. Larkin Ave.
>Fresno, CA 93637
>Tel: (209) 294-8008
>Fax: (209)294-8809
>e-mail figali@aol.com
Date: Sun, 22 Dec 96 10:51:54 +1100 (EST)
From: Trevor Finch <rsne@mpx.com.au>
Subject: Re: Positioning of tensiometers
We use an excellent programme that runs various models (including
Richardsons) to predict water flow through soil profiles with different
irrigation regimes.
It allows for varying...
soil layers
the model assumptions
the application regime (volume and frequency)
It was designed for graduate students, so has an excellent help
system/tutorial, but we find it very usefull for commercial design. It
certainly beats solving Richardson's equation ever again. Their site is at:
http://www.greenhat.com
----
Trevor Finch
Research Services New England
8/16 Nicholson St, Balmain NSW 2041 Australia
email: rsne@mpx.com.au
tel: +61 (2) 9810 3563
fax: +61 (2) 9810 3323
----
Date: Sat, 21 Dec 1996 20:01:33 -0500
From: Merriott@aol.com
Subject: Determining DU for existing SDI systems
I was recently asked by a prospective client how to determine Distribution
Uniformity for an installed SDI system. I know how to calculate the
theoretical DU. The only way I know how to find out actual DU would be to
dig up the tape in several places and measure the flow rates as the system is
operating. Any other ideas?
Randall Merriott
Abernathy, Texas
Date: Sat, 21 Dec 1996 22:05:43 -0500
From: Tim1Utah@aol.com
Subject: Re: Determining DU for existing SDI systems
One of my favorite methods to estimate EU (or DU) for SDI is called the
"Vandergulik Swag" technique: If half your field is brown and ugly then you
have a 50% DU. You can also reverse it and say if half your field is a
swamp........... you get the idea. Or if half your field is a swamp and the
other half is brown and dry then you have a 0% DU
Hope this helps :)
End of Digest
>From root@crcnis1.unl.edu Mon Dec 23 01:02 EST 1996
Date: Sun, 22 Dec 1996 23:49:28 -0600
Message-Id: <199612230549.AA13207@crcnis1.unl.edu>
Subject: TRICKLE-L digest 686
Contents:
Determining DU for existing SDI systems (Merriott@aol.com)
Re: Determining DU for existing SDI systems (Leonard Ornstein <lenornst@pipeline.com>)
Re: Determining DU for existing SDI systems (Tim1Utah@aol.com)
Re: Minute/ultra-low microirrigation (shieldsa@andrews.edu (Emmett Shields))
Date: Sun, 22 Dec 1996 13:31:46 -0800
From: Merriott@aol.com
Subject: Determining DU for existing SDI systems
Actual system DU can be estimated in the field as you mentioned, by
digging and measuring. (The "Vandergulik Swag" technique mentioned by
someone else is even less than a swag.) It's a lot of work which is
why most people don't bother with it but sometimes you can be amazed by
what you find (great to poor hydraulic design and sometimes plugging
from all sorts of sources).
I recommend the Cal Poly method of evaluation with a few tips:
1. Do not take less measurements than the program calls for (there are
very specific reasons for the number of measurements taken at which
locations)
2. If digging up tape, be careful to not wipe the mud off it (you just
might artifically plug the outlets)
3. I make little washers out of rubber hose to prevent water from
running along the hose (and not into the measuring cups).
4. On drip tape systems I make one recommended change to the Cal Poly
procedure and that is the first location of flow measurements. The Cal
Poly procedure calls for the first flow measurements to be taken in the
middle of a hose hydraulically closest to the pump. The reason for the
middle of the hose is you need to be able to take all 16 flows at the
same pressure (no significant friction loss in the middle of the hose
if emitters are spaced far apart). To get a more accurate ectimate of
the actual application rate with tape systems, I take those
measurements at the beginning of the hose where the pressure is the
highest.
A NEW WINDOWS VERSION OF THE MICRO-IRRIGATION SYSTEM EVALUATION PROGRAM
CAN BE ORDERED FROM THE CAL POLY / ITRC (805)756-2434.
>I was recently asked by a prospective client how to determine
>Distribution
>Uniformity for an installed SDI system. I know how to calculate the
>theoretical DU. The only way I know how to find out actual DU would
>be to
>dig up the tape in several places and measure the flow rates as the
>system is
>operating. Any other ideas?
>Randall Merriott
>Abernathy, Texas
Date: Sun, 22 Dec 1996 17:16:32 -0400
From: Leonard Ornstein <lenornst@pipeline.com>
Subject: Re: Determining DU for existing SDI systems
Randall:
I may be missing something, (or are the Cal Poly "measurements",
tensiometer measurements)?
Granted it's nice to know the degree of distribution uniformity, but what
really counts is uniformity of available water for the crop. And you
monitor that quite directly with tensiometer readings of matric potential.
Now, for those readings to be uniform not only must the water-delivery be
uniform, but so must the soil-profile. But if that's very variable, a
uniform delivery of water will probably be inadequate anyway. So properly
programmed tensiometer readings can really tell you what's important to
your crop; warn you of the consequences of clogged emitters, breaks in
tape, too large pressure-drops in long runs and/or non-uniform soil
profiles.
Len Ornstein
>Actual system DU can be estimated in the field as you mentioned, by
>digging and measuring. (The "Vandergulik Swag" technique mentioned by
>someone else is even less than a swag.) It's a lot of work which is
>why most people don't bother with it but sometimes you can be amazed by
>what you find (great to poor hydraulic design and sometimes plugging
>from all sorts of sources).
>
>I recommend the Cal Poly method of evaluation with a few tips:
>
>1. Do not take less measurements than the program calls for (there are
>very specific reasons for the number of measurements taken at which
>locations)
>
>2. If digging up tape, be careful to not wipe the mud off it (you just
>might artifically plug the outlets)
>
>3. I make little washers out of rubber hose to prevent water from
>running along the hose (and not into the measuring cups).
>
>4. On drip tape systems I make one recommended change to the Cal Poly
>procedure and that is the first location of flow measurements. The Cal
>Poly procedure calls for the first flow measurements to be taken in the
>middle of a hose hydraulically closest to the pump. The reason for the
>middle of the hose is you need to be able to take all 16 flows at the
>same pressure (no significant friction loss in the middle of the hose
>if emitters are spaced far apart). To get a more accurate ectimate of
>the actual application rate with tape systems, I take those
>measurements at the beginning of the hose where the pressure is the
>highest.
>
>A NEW WINDOWS VERSION OF THE MICRO-IRRIGATION SYSTEM EVALUATION PROGRAM
>CAN BE ORDERED FROM THE CAL POLY / ITRC (805)756-2434.
>
>
>>I was recently asked by a prospective client how to determine
>>Distribution
>>Uniformity for an installed SDI system. I know how to calculate the
>>theoretical DU. The only way I know how to find out actual DU would
>>be to
>>dig up the tape in several places and measure the flow rates as the
>>system is
>>operating. Any other ideas?
>>Randall Merriott
>>Abernathy, Texas
Date: Sun, 22 Dec 1996 19:33:07 -0500
From: Tim1Utah@aol.com
Subject: Re: Determining DU for existing SDI systems
Just in case there are a lot of engineers out there without a sense of humor,
the "Vandergulik Swag" technique was a joke, that's J-O-K-E. I hope I won't
be kicked off the List for being so brash.
Date: Sun, 22 Dec 1996 22:17:05 -0500 (EST)
From: shieldsa@andrews.edu (Emmett Shields)
Subject: Re: Minute/ultra-low microirrigation
End of Digest
>From root@crcnis1.unl.edu Tue Dec 24 01:04 EST 1996
Date: Mon, 23 Dec 1996 23:50:57 -0600
Message-Id: <199612240550.AA00581@crcnis1.unl.edu>
Subject: TRICKLE-L digest 687
Contents:
Merry Christmas (Hortech Services Pty Ltd <hortech@www.ats.com.au>)
Re: Determining DU for existing SDI systems (Merriott@aol.com)
Something is screwy with TRICKLE-L digest 686 (Merriott@aol.com)
Re: Tensiometers to estimate DU (Merriott@aol.com)
Re: Comments on uniformity (FLamm@oznet.ksu.edu (Freddie Lamm))
Date: Mon, 23 Dec 1996 16:24:39 +1000
From: Hortech Services Pty Ltd <hortech@www.ats.com.au>
Subject: Merry Christmas
Please circulate this and perhaps by the time Christmas comes, everyone
will have read it. A sobering poem.
DEATH OF AN INNOCENT
I went to a party, Mum, I remembered what you said.
You told me not to drink, Mum, so I drank coke instead.
I really felt proud inside, Mum, the way you said I would.
I didn't drink and drive, Mum, even though the others said I should.
I know I did the right thing, Mum, I know you are always right.
Now the party is finally ending, Mum, as everyone is driving out of
sight.
As I got into my car, Mum, I knew I'd get home in one piece.
Because of the way you raised me, so responsible and sweet.
I started to drive away, Mum, but as I pulled out into the road,
the other car didn't see me, Mum, and hit me like a load.
As I lay there on the pavement, Mum, I hear the policeman say,
the other guy is drunk, Mum, and now I'm the one who will pay.
I'm lying here dying, Mum. I wish you'd get here soon.
How could this happen to me, Mum? My life just burst like a balloon.
There is blood all around me, Mum, and most of it is mine.
I hear the paramedic say, Mum, I'll die in a short time.
I just wanted to tell you, Mum, I swear I didn't drink.
It was the others, Mum. The others didn't think.
He was probably at the same party as I.
The only difference is, he drank and I will die.
Why do people drink, Mum? It can ruin your whole life.
I'm feeling sharp pains now. Pains just like a knife.
The guy who hit me is walking, Mum, and I don't think it's fair.
I'm lying here dying and all he can do is stare.
Tell my brother not to cry, Mum. Tell Daddy to be brave.
And when I go to heaven, Mum, put "Daddy's Girl" on my grave
Someone should have told him, Mum, not to drink and drive.
If only they had told him, Mum, I would still be alive.
My breath is getting shorter, Mum. I'm becoming very scared.
Please don't cry for me, Mum. When I needed you, you were always there.
I have one last question, Mum, before I say good bye.
I didn't drink and drive, so why am I the one to die?
************************
Someone took the effort to write this poem.
So please, forward this to as many people as you can. And see if we can
get
a chain going around the world that will make people understand that
drinking and driving don't mix.
TOGETHER WE CAN MAKE A DIFFERENCE, so please forward this letter to as
many
people as you can.
-Anonymous
Merry Christmas to all on the trickle list.
Regards
Peter Broomhall
Horticulural Consultant
Hortech Services Pty Ltd
a.c.n. 060 406 957
P.O. Box 370
Kallangur QLD 4503
Australia
P: +61 418 708 573
F: +61 7 3886 0389
hortech@ats.com.au
Date: Mon, 23 Dec 1996 07:29:18 -0500
From: Merriott@aol.com
Subject: Re: Determining DU for existing SDI systems
> One of my favorite methods to estimate EU (or DU) for SDI is called the
> "Vandergulik Swag" technique: If half your field is brown and ugly then
you
> have a 50% DU. You can also reverse it and say if half your field is a
> swamp........... you get the idea. Or if half your field is a swamp and
the
> other half is brown and dry then you have a 0% DU
> Hope this helps :)
>
Very funny, Tim, but I was hoping to be able to find out what the DU was
before the output from these "sensors" was able to be observed.
Randall
P.S. who is/was Vandergulik Swag?
Date: Mon, 23 Dec 1996 09:54:17 -0500
From: Merriott@aol.com
Subject: Something is screwy with TRICKLE-L digest 686
In a message dated 96-12-23 01:03:07 EST, you write:
The last TRICKLE-L digest shows me as writing this message. Someone else
wrote it, not me. And how did my name get attached to it?
> ----------------------------------------------------------------------
>
> Date: Sun, 22 Dec 1996 13:31:46 -0800
> From: Merriott@aol.com
> Subject: Determining DU for existing SDI systems
>
> Actual system DU can be estimated in the field as you mentioned, by
> digging and measuring. (The "Vandergulik Swag" technique mentioned by
> someone else is even less than a swag.) It's a lot of work which is
> why most people don't bother with it but sometimes you can be amazed by
> what you find (great to poor hydraulic design and sometimes plugging
> from all sorts of sources).
>
> I recommend the Cal Poly method of evaluation with a few tips:
>
> 1. Do not take less measurements than the program calls for (there are
> very specific reasons for the number of measurements taken at which
> locations)
>
> 2. If digging up tape, be careful to not wipe the mud off it (you just
> might artifically plug the outlets)
>
> 3. I make little washers out of rubber hose to prevent water from
> running along the hose (and not into the measuring cups).
>
> 4. On drip tape systems I make one recommended change to the Cal Poly
> procedure and that is the first location of flow measurements. The Cal
> Poly procedure calls for the first flow measurements to be taken in the
> middle of a hose hydraulically closest to the pump. The reason for the
> middle of the hose is you need to be able to take all 16 flows at the
> same pressure (no significant friction loss in the middle of the hose
> if emitters are spaced far apart). To get a more accurate ectimate of
> the actual application rate with tape systems, I take those
> measurements at the beginning of the hose where the pressure is the
> highest.
>
> A NEW WINDOWS VERSION OF THE MICRO-IRRIGATION SYSTEM EVALUATION PROGRAM
> CAN BE ORDERED FROM THE CAL POLY / ITRC (805)756-2434.
>
>
>
Here is the message that I actually wrote after quoting Tim's joke (I got
it).
> One of my favorite methods to estimate EU (or DU) for SDI is called the
> "Vandergulik Swag" technique: If half your field is brown and ugly then
you
> have a 50% DU. You can also reverse it and say if half your field is a
> swamp........... you get the idea. Or if half your field is a swamp and
the
> other half is brown and dry then you have a 0% DU
> Hope this helps :)
>
Very funny, Tim, but I was hoping to be able to find out what the DU was
before the output from these "sensors" was able to be observed.
Randall
P.S. who is/was Vandergulik Swag?
Date: Mon, 23 Dec 1996 09:54:21 -0500
From: Merriott@aol.com
Subject: Re: Tensiometers to estimate DU
In a message dated 96-12-23 01:03:07 EST, you write:
> Granted it's nice to know the degree of distribution uniformity, but what
> really counts is uniformity of available water for the crop. And you
> monitor that quite directly with tensiometer readings of matric potential.
> Now, for those readings to be uniform not only must the water-delivery be
> uniform, but so must the soil-profile. But if that's very variable, a
> uniform delivery of water will probably be inadequate anyway. So properly
> programmed tensiometer readings can really tell you what's important to
> your crop; warn you of the consequences of clogged emitters, breaks in
> tape, too large pressure-drops in long runs and/or non-uniform soil
> profiles.
>
> Len Ornstein
Len, I think you're right. The uniformity of available water is what really
counts. As long as the readings on the tensiometers are uniform, there's
probably no need to dig up the tape and measure the DU. (I am curious how
accurate tensiometers would be in estimating DU. Have any of the researchers
out there planted a good number of tensiometers, taken readings, then dug up
the tape at the same location, measured flows and then compared the two? It
would be interesting to know what the DU was based on the tensiometers vs.
that based on the flow measurements alone, and I guess the accuracy would
depend a lot on the uniformity of the soil conditions.)
But what if the tensiometer readings aren't uniform? Is it because of
emitter clogging? Is it because of poor design? Is it because of the soil
or other factors? I would assume that there would be a certain amount of
variability between the tensiometers themselves. The tensiometers are going
to tell me I have a problem, but once I know I have a problem, I need to
figure out what it is and how I can solve it.
I have calculated actual EU with microsprinkler systems using the ASAE
method. Because of the nature of these systems you can also easily measure
the pressure at each point, thus allowing you also to calculate the hydraulic
uniformity. This helps make it easier to determine if the problem lies with
the system design or with clogged emitters. I don't know how you can do this
with tape without punching a hole in it.
I just basically want to be able to let the customer "see" that his system is
working properly, and if it's not, be able to quickly figure out why not.
Randall Merriott
Abernathy, Texas
Date: 23 Dec 96 12:10:22 CST
From: FLamm@oznet.ksu.edu (Freddie Lamm)
Subject: Re: Comments on uniformity
Someone wrote:
> Granted it's nice to know the degree of distribution uniformity, but what
> really counts is uniformity of available water for the crop.
Freddie Lamm replied: Yes, that is partially true. But you miss
the point if you ignore the system aspects. After all, you may not
be able to exchange your land and soil, but you may be able to buy a
more uniform system. Conversely, the most uniform system may not be
of much use on some land areas, so why bother with the best system.
System, crop, soil, and climate, plus a host of other things need to
be "matched" to make it all work. DU, EU, US and the other types
of system uniformity terms are just some of the tools in the
toolbox.
Someone wrote: It would be interesting to know what the DU was based on the
tensiometers vs. that based on the flow measurements alone, and I
guess the accuracy would depend a lot on the uniformity of the soil
conditions.
Freddie Lamm replied: That method may give you a more "global"
estimation of irrigation performance by integrating the system aspects
with the soil aspects, but it may tell you less about what's causing
what. If used properly, with other tools it might be a good tool for
the toolchest. Sometimes knowing what performance a component
aspect might be causing might then point you to look to the next
possible problem, while if it is all integrated, you may have to
split it back into components.
Someone wrote: I have calculated actual EU with microsprinkler
systems using the ASAE method. I don't know how you can do this
(pressure measurements) with tape without punching a hole in it.
Freddie Lamm replied: Depending on what information you want to
obtain or what problems you want to isolate, you may be able to
avoid measuring the pressures. ASAE EP-458 can be used to just
measure US (the statisical uniformity of the emitter discharge rate
) without measuring the pressures. Obviously, you can't isolate
some of the problems without measuring the pressures. But if US
turned out to be extremely high, the hydraulic uniformity, USH and
the emitter performance variation may be moot points.
I have also been told, you can repair the holes punched in the tape with
goof plugs. A pressure gauge with a relatively large diameter
hypodermic needle can be used for the pressure determinations,
Someone wrote: I just basically want to be able to let the customer
"see" that his system is working properly, and if it's not, be able
to quickly figure out why not.
Freddie Lamm replied: This may be too simplistic for your needs, But
The pressure and flows along the system can OR should be determined
by the system design. I know some of the manufacturers have design
programs to calculate theoretical EUs or DUs, etc. The cumulative
flows for the system and the pressures at the system inlet and the
distal flushline could be measured on a regular basis (daily, weekly
etc.). These values could be plotted with time and compared to the
design values. If the deviations in flows or pressures change, the
producer could then look for problems. The changes may be normal or
maybe require immediate attention. If the performance
characteristics are significantly different than the design values
immediately after installation, the producer and contracter should
probably work together to find the cause, and that might mean much
more rigorous procedures such as ASAE EP-458 or the Cal-Poly DU
technique. The complexity of the procedure is sometimes altered by
the difficulties of making the system measurements. IE, deep SDI
systems with low flow tape products are more difficult than surface
systems with higher flow emitters.
Freddie
*
-------------------------------------------------------------------
Freddie Lamm *
Research Agricultural Engineer *** o
KSU Northwest Research-Extension Center ***** /|\
105 Experiment Farm Road *******\\
Colby, Kansas 67701-1697 *********
Ph. 913-462-6281 ***********
FAX 913-462-2315 *************
Email:flamm@oznet.ksu.edu It's all downhill from here.
------ THERE'S NO DOMAIN LIKE OZ, THERE'S NO DOMAIN LIKE OZ. ------
End of Digest
>From root@crcnis1.unl.edu Wed Dec 25 01:04 EST 1996
Date: Tue, 24 Dec 1996 23:51:26 -0600
Message-Id: <199612250551.AA12739@crcnis1.unl.edu>
Subject: TRICKLE-L digest 688
Contents:
Re: Minute/ultra-low microirrigation (Leonard Ornstein <lenornst@pipeline.com>)
Fwd: Small Fruits Program Set For Ohio Growers Congress (Merriott@aol.com)
Re: Tensiometers to estimate DU ("OSU Malheur Exp. Station" <mesosu@primenet.com>)
Re: Tensiometers to estimate DU (Leonard Ornstein <lenornst@pipeline.com>)
Re: Tensiometers to estimate DU ("J.D. Oster" <oster@mail.ucr.edu>)
Date: Tue, 24 Dec 1996 02:24:37 -0400
From: Leonard Ornstein <lenornst@pipeline.com>
Subject: Re: Minute/ultra-low microirrigation
>Date: Sat, 21 Dec 1996 13:23:25 -0400
>To: <trickle-l@unl.edu>
>From: Leonard Ornstein <lenornst@pipeline.com>
>Subject: Re:ultra-low microirrigation & Irristats
>Cc:
>Bcc:
>X-Attachments:
>
Tricle-L and SOWACS list members:
The WebSite I promised to launch (below), though still under construction,
is now online as of this evening:
<http://www.pipeline.com/~lenornst/index.html>
It conects to my Irristat page and, at present, 4 down-loadable Acrobat
documents on the Irristat technology.
Len Ornstein
>>The concept of "Minute" irrigation is not necessarily new but has been
>>impractical until approximately three years ago.>
>
>Well, this gives me an oportunity to introduce Trickle-L list members to a
>drip technology, the use of moisture-sensitive, self-regulating irrigation
>valves,Irristats, (typically, but not necessarily, one to a plant, bush or
>tree) for delivering water at rates which exactly match
>evapotranspioration, and therefore is as "Minute" as you would want to
>get! Like other forms of "Minute", it typically uses a water-supply
>continuosly pressurized at up to 15 lbs/in^2, and requires quality
>filtration. But it has a lot more to offer.
>
>As indicated below, I had planned to delay this "announcement" until my
>Web site is ready, (in about two weeks), but this discussion cries out for
>this respons:
>
>X-Sender: lenornst@pop.pipeline.com
>Mime-Version: 1.0
>Date: Sat, 30 Nov 1996 13:58:15 -0400
>To: SOWACS@aqua.ccwr.ac.za
>From: Leonard Ornstein <lenornst@pipeline.com>
>Subject: Measuring Evapotranspiration/Lysimeters
>Sender: owner-sowacs@aqua.ccwr.ac.za
>Precedence: bulk
>
>Greetings to all:
>
>On Nov. 20, Dean Reynolds initiated a thread on methods that might be
>useful for updating crop-ET numbers. Because of the expense of lysimeters
>and lysimetry, he was interested in the pros and cons of using neutron
>probes and TDR as alternatives for such purposes.
>
>Terry Howell quickly responded with a very helpful discussion. He correctly
>noted that since evapotranspiration modifies the moisture content of the
>air above soil and foliage, strictly speaking, lysimetry, neutron probe
>measurements and TDR only provide an indirect measures of ET, whereas eddy
>correlation can measure ET directly. However he indicated that it probably
>wasn't a practical alternative at this time. He neatly reviewed the hazards
>of crop-ET assessment; rain, deep percolation, etc.
>
>On Nov. 22, Dean replied with thanks to all for their contributions to the
>discussion, and revealed just why he had raised the subject; namely the
>economic factors that governmental bodies, like the State of California
>face as farmers choose to sell their State-assigned water rights to one
>another (and municipalities).
>
>To oversimplify, it appears the allowed selling price depends upon a
>State-approved estimate of crop-ET and acreage. If the estimated crop-ET is
>too high, the State essentially is giving away (and wasting) valuable
>public resources.
>
>What Dean in fact wants to assess is the crop water consumption, which of
>course results mainly from ET, but THAT is directly measurable by lysimetry.
>
>Dean believes, for the reason reviewed above, that updating crop-ET with
>lysimetry would have substantial desirable economic consequences, but
>apparently judges that the costs of the equipment and labor for the job
>will be unacceptable to the officials of the California Department of Water
>Resources for whom he works.
>
>The problems he raises are rather universal.
>
>I believe I can offer an inexpensive solution:
>
>I am the inventor and manufacturer of the Irristat, a moisture-sensitive,
>self-regulating valve, designed to control the delivery of water to a "drip
>emitter". The Irristat is a device with which few if any of the SOWACS
>List's members will be familiar. Although the Irristat was developed as an
>automated irrigation-scheduling device, it also works fine as an
>alternative to a lysimeter to "measure" evapotranspiration:
>
>It was introduced in:
>
>The Irristat: A Moisture-Sensitive, Self-Regulating, Water Valve for
>Drip Irrigation Systems: Drip/Trickle Irrigation in Action Vol. 2
>ASAE Pub. 10-85, St. Joseph, Mich., pp.623-629; (Proceedings. of the
>Third International Drip/Trickle Irrigation Congress, Nov. 18-21, 1985,
>Fresno, CA).
>
>The article contains a description of the Irristat and a general
>discussion of its applications in agriculture and horticulture,
>including a description of an installation for 60 mature cherry trees at
>Washington State Uniersity Irrigated Agriculture Research Center,
>Prosser, WA (WSU).
>
>Temporarily, an Abode Acrobat version of that publication, irrst2.pdf,
>as well as another document, irrist1.pdf, which describes the Irristat
>technology in greater detail, can be read and/or downloaded (thanks to
>Bruce) from:
>
> <http://www.icfrnet.unp.ac.za/~metele/sowacs/irristat.html>
>
>Adobe Acrobat Readers for PC, Unix or Mac platforms can be downloaded FREE
>from:
>
> <http://www.adobe.com/acrobat/>
>
>I am in the midst of preparing a Web Page which will describe the
>technology briefly and will contain URL's for downloading these two
>papers as well as four others, including an unpublished paper by Robert G.
>Evans, documenting the performance of the Irristats that I installed for
>him and Ed Proebsting for the 60 mature cherry trees at WSU. I had expected
>to introduce the Irristat to SOWACS and Trickle-L when my Web Page is
>ready. That should be before the new year. And I will post its address here
>as soon as possible.
>
>Briefly, this is how the Irristat works:
>
>The Irristat uses a uniquely formulated, synthetic polyacrylamide gel as
>its moisture-sensing element. The valve is buried near a plant's roots, in
>intimate contact with the soil,.
>
>Water is conducted by capillary tubing from a water supply, through a
>thin-walled rubber tube within the body of the Irristat and then through
>another attached length of capillary tubing to, or near to the soil
>surface. On its way past the roots, the water spreads by gravity and
>capillarity through the soil, passes through the Irristat's porous
>polyester fiber membrane, and reaches the moisture-sensing element, the gel.
>
>As the gel becomes more moist, it swells, pushing the Irristat's piston
>against the rubber tube. When the moisture in the soil surrounding the
>Irristat reaches a predetermined set-point, (typically -0.15 bars) the
>swollen gel causes the piston to pinch the rubber tube closed, cutting off
>the supply of water.
>
>As the plant draws moisture from the soil, the gel shrinks, reversing
>the cycle. As the moisture level falls below the Irristat's set-point,
>the piston moves back, relieving the pressure on the rubber tube, and
>water begins to flow.
>
>Buried in the soil, Irristats will function reliably for many years,
>PROVIDING AUTOMATED DRIP/TRICKLE IRRIGATION. The Irristat itself is
>about 2 cubic centimeters in volume. It, and its connections, are
>usually encased in a protective polypropylene shell in the form of a
>spear-tip, which simplifies insertion into the soil. The body parts and
>piston of the Irristat are molded of polypropylene; the internal water
>conduit is made of silicone rubber; the semi-permeable membrane, of
>Dacron-like polyester fibers; and the moisture-sensitive gel, of
>slightly-cross-linked polyacrylamide. All are chemically, biologically
>and physically durable. With 0.125-inch inside-diameter capillary
>tubing, and a water supply at 15 pounds per square inch, an Irristat can
>deliver up to about 1.7 liters of water per minute. Therefore, one Irristat
>can service any plant, up to a medium-size tree; a few Irristats, in
>parallel, can service a large tree.
>
>The Irristat delivers to its plant, EXACTLY THE AMOUNT OF WATER NEEDED
>TO REPLACE LOSSES DUE TO EVAPOTRANSPIRATION, (plus any additional amount
>incorporated into new growth).
>
>If it is set up with a gravity-feed water supply from a tank, after it
>has been working for a few days, the measured amount of water drawn from
>the tank per unit time (e.g., per 24 hours) is an accurate measure of
>evapotranspiration plus "growth water".
>
>Alternatively, if the water supply is a typical drip-lateral, a second
>Irristat can be installed in parallel with, and directly adjacent to the
>first, with an outlet capillary line of the same inside diameter and length
>as the first, delivering its output at the same point. After they have been
>working together for a few days, the outlet of either one can then be
>placed into a container, and the amount of water delivered per unit time
>will be an accurate measure of the evapotranspiration associated with that
>plant, bush or tree. (The Irristat has a time-constant of about 2 hours, so
>an "instantaneous measurement" usually reflects the evapotranspiration that
>occurred 2 hours earlier.)
>
>Of course, this description of how to use Irristats to measure
>evapotranspiration is a bit oversimplified; (e.g., if the bottom of the
>root ball is at the water table, if it has just rained or if the plant is
>growing in such coarse sand that, at -0.15 bars matric potential, a
>substantial portion of the delivered water percolates down past the roots),
>my method works poorly. With two tensiometers; one beside the Irristat in
>the root ball, and the other inserted to a depth somewhat below the root
>ball, you can easily check whether the water table is too high or the
>irrigation water is perciolating too deep.
>
>You will of course wonder why I have kept this a "secret" so long?
>
>In order to compete with pressure-compensating emitters, we had planned to
>manufacture the Irristat at a unit cost of under $1.00, with most of the
>cost coming from the labor of manual assembly. But that depended upon
>essentially 100% manufacturing-yield of correctly functioning Irristats.
>And over the years, the best we've been able to do is a bit better than
>90%. That means that EACH finished Irristat needs to be checked by cycling
>it a few times between wet and dry states, and this turns out to be quite
>expensive. We (and others) judged that the resulting $6.00 unit selling
>price, for a spear-tip mounted Irristat, would severely restrict the range
>of its application. With rather limited resources, we have been (very
>inadequately) trying to enter markets, like landscaping, which might
>tolerate the higher, cost. I hope the Web will help us change this.
>
>But, clearly, for use as an ET-measuring tool, our current manufacturing
>cost should pose no problem!.
>
>I'll be happy to discuss various other details of use and performance, in
>this forum, or privately.
>
>Hope you find this useful.
>
>Leonard Ornstein, Ph.D.
>Irristat International Inc.
>
>lenornst@pipeline.com
>
>
>
>>The concept of "Minute" irrigation is not necessarily new but has been
>>impractical until approximately three years ago. The idea is to apply water
>>at a very slow rate. To achieve this we would require a drip emitter with
>>extremely small passages and considerably higher filter requirements. This
>>emitter would be highly susceptible to clogging. To date there is no emitter
>>or tape product that is capable of delivering water at a rate which
>>approaches that considered to be minute irrigation. However, there are a few
>>individual components that when used together can create this minute
>>irrigation. I consider minute irrigation to be in the range of 100 - 400 cc
>>per hour.
>>
>>The heart of this system is a pulsating device which contains a silicone
>>sleeve seated upon a specially designed piston. As this sleeve or bladder
>>swells with water it reaches a critical point where the stored water is
>>released and then the process repeats itself. This continual action creates
>>the pulsing effect. The rate of flow through the pulser is determined by
>>either a compensated or non-conpensated emission device. It is when this
>>pulser is connected to a secondary emission device that we are able to
>>achieve minute irrigation. In Israel when using the term minute irrigation
>>they are referring only to the use of drip emitters. Pulsated
>>micro-sprinklers or jets is a different concept.
>>
>>Most applications of this system have been used in green houses. There are
>>two types of systems of minute irrigation. One system connects about 20
>>individual pot type drippers (stakes with a labyrinth) to one single pulser.
>> If the pulser has a discharge rate of 4 LPH or 4,000 cc/hour we divide this
>>number by the number of outlets and have an individual discharge rate of 200
>>cc/hour/pot. The second system uses our (Drip In) 1/4" (6mm) soaker dripline
>>with emitters spaced anywhere from 15cm to 30cm connected to the same pulser.
>> We can not use a dripline with a larger ID because the line will always be
>>partially filled with air. The 1/4" because of its small ID is constantly
>>charged with water. This system is either stretched on top of the pots or
>>laid directly on the bed. The number of emitters varies but is generally not
>>more than 60. I recently installed a system where I used an 8 LPH pulser
>>with 60 emitters or an individual discharge rate per emitter of 133 cc/hour.
>> These emitters normally are 2 LPH.
>>
>>The beauty here is that we are able to reduce the flow per emitter to minute
>>amounts of water and yet maintain large passageways and relative clog
>>resistance. Like any new technology there are advantages and disadvantages.
>> In fact this technology is considered by some to be revolutionary. Similar
>>to what drip was 20 years ago. Most pots are irrigated by spray stakes or
>>some type of emitter. Water applied at a rate of 2 LPH will form a sausage
>>near the middle of the pot and drainage will begin within a few minutes.
>> Irrigation will continue approximately 7-15 minutes. During this time water
>>will begin to move upwards closer to the sides of the pot pushing the salts
>>further into the root zone. This mandates frequent flushing and an
>>additional waste of water and nutrients. With the pulsated drip system the
>>water will move almost twice as fast laterally until the upper area is
>>completely wetted. Then the movement will be downward as a front until
>>drainage occurs. When the first drops drain the pot is at pot capacity and
>>the irrigation can be shut off. This movement is constantly washing the salts
>>downward. Additional flushing of the salts is only required when the EC of
>>the drainage water exceeds the established limits.
>>
>>Specific advantages of this system include:
>>1. Water and fertilizer savings up to 40-50%
>>2. Optimum growing conditions due to the ability to maintain an optimum
>>balance of air, water and nutrients in the soil.
>>3. Better utilization of available space; plant density can be increased.
>>4. Quicker turn around of plant material; reduced growing cycles.
>>5. Higher yields
>>6. Better quality
>>7. Lower system costs; smaller PVC sizes, reduced horsepower
>>requirements....
>>
>>This system poses significant challenges and requires us to change our way of
>>thinking.
>>For one, the discharge rate of the emitters at the end of the lateral is
>>higher than the rate at the begining. This is completely opposite from what
>>we expect with conventional drip technology. Second, we are talking about
>>using up to 40-50% less water then existing drip systems. If this is true
>>than we need to reevaluate crop requirements. We applied this technology on
>>a small scale to 40 almond trees in the Sacramento Valley this summer. From
>>mid june through October we applied 1 GPH/tree. The dripline was our 1/4"
>>soaker dripline with emitters spaced at 12". The water was never shut off
>>except for one day at harvest. The surface wetted area was on average 1 foot
>>wide and there was no runoff. These trees received no more than 24 gallons
>>per day. These were mature trees with a full crop. Visual inspection
>>indicated good growth and yields comparable to the rest of the orchard. We
>>intend to expand this system and do a small area of grapes in 1997.
>>
>>We do not have all the answers to these questions yet. Actually we are not
>>sure what questions we should be asking. While the concept has broad
>>applications the technology to apply this on a large scale to field crops is
>>in its infancy. For the present we will be promoting this minute irrigation
>>technology to the greenhouse industry and evaluating its application in the
>>broader agricultural market. We would like to invite those interested in
>>this technology to explore the possibilities and ramifications along with us.
>> A few papers have been written on the subject in Israel. They have been
>>translated into english and are available in Israel by contacting Jacob Levin
>>at Lego Irrigation or contacting me at Drip In Irrigation.
>>
>>I hope that I have been able to answer a few of the questions.
>>
>>Philip Lubars
>>Drip In Irrigation
>>2836 N. Larkin Ave.
>>Fresno, CA 93637
>>Tel: (209) 294-8008
>>Fax: (209)294-8809
>>e-mail figali@aol.com
>
>
>
Date: Tue, 24 Dec 1996 09:25:49 -0500
From: Merriott@aol.com
Subject: Fwd: Small Fruits Program Set For Ohio Growers Congress
Thought I would pass this along in case some may not be aware of this.
Randall Merriott
Abernathy, Texas
---------------------
Forwarded message:
From: AOLNewsProfiles@aol.net
Date: 96-12-23 12:15:06 EST
COLUMBUS, Ohio, Dec. 20 /PRNewswire/ -- A growers roundtable discussion
on
disease control, in brambles and blueberries, and a business and marketing
update are just some of the items on the agenda for the Small Fruits program
at the 1997 Ohio Fruit and Vegetable Growers Congress and Roadside Marketing
Conference.
The congress, which will be held Feb. 5-8 at the SeaGate Centre in
Toledo,
Ohio, is a joint effort between the Ohio Fruit Growers Society (OFGS), Ohio
Vegetable and Potato Growers Association (OVPGA), the Ohio State University
(OSU), and the Direct Agricultural Marketing Association (DAMA). This is the
first year the Growers Congress and Ohio Roadside Marketing conference are
being held together. By combining the two conferences producers and
marketers
are exposed to the strongest educational event of its kind in the country.
A Strawberry Roundtable will start the program on Wednesday
evening.
Representatives from OSU will be on-hand to provide pesticide updates. Also
featured that evening, the 1996 Strawberry Cultivars- growers discussion on
frost, fruit rot, yield and other topics that impact the industry.
Dr. Joseph Fiola of Rutgers, will be on hand during the Strawberry
Short
Course to discuss information on the high yield plasticulture system and its
feasibility in the east. Dr. Fiola will also discuss information on new
bramble releases. Also, the basics of blueberry production and maintaining
post harvest quality are topics that will be covered.
Dr. Winston Bash, OSU Food Industry Center, will be on hand to
discuss the
progress on ellagic acid research. Rick and Susan Lynn, Lynn's Market, Mt.
Pleasant, Pa., will be discussing marketing issues.
A new item for the Small Fruits program is the five minute blitz,
presented by Dr. Dick Funt, OSU, and Tom Wall, OSU-Piketon. Topics to be
covered include: increasing strawberry yields, trickle irrigation design
facts, and blueberry cultivars. The five minute blitz is a short
presentation
with a handout for the participants to take home.
For more information on the Small Fruit program for the 1997 Ohio
Fruit
and Vegetable Growers Congress and Roadside Marketing Conference, or
registration information contact Mike Pullins, Executive Director, at
614-249-2424.
CO: Ohio Fruit and Vegetable Growers Congress
ST: Ohio
IN: AGR
SU:
To edit your profile, go to keyword NewsProfiles.
For all of today's news, go to keyword News.
Date: Tue, 24 Dec 1996 07:55:04 -0700
From: "OSU Malheur Exp. Station" <mesosu@primenet.com>
Subject: Re: Tensiometers to estimate DU
Friends,
In using tensiometers to estimate the distribution uniformity of a drip
irrigation system, Randall Merriott correctly mentions that there will
be some error among the tensiometers. In studying optimal potato
irrigation (not a series of drip irrigation trials) we dug up many
paired tensiometers and paired Watermark soil moisture sensors and
compared their readings with the soil water contents in the immediate
proximity of the instruments. Much of the variability in instrument
readings was related to spot to spot variability in soil water.
Clint
--
Dr. Clinton C. Shock
Malheur Experiment Station
Oregon State University
595 Onion Ave.
Ontario, Oregon 97914
telephone (541) 889-2174
Fax (541) 889-7831
http://www.primenet.com/~mesosu/index.html
Date: Tue, 24 Dec 1996 12:06:51 -0400
From: Leonard Ornstein <lenornst@pipeline.com>
Subject: Re: Tensiometers to estimate DU
In studying optimal potato
>irrigation (not a series of drip irrigation trials) we dug up many
>paired tensiometers and paired Watermark soil moisture sensors and
>compared their readings with the soil water contents in the immediate
>proximity of the instruments. Much of the variability in instrument
>readings was related to spot to spot variability in soil water.
Which MUST have been due to variability in local soil hydraulic conductivity.
With putatively uniform application of irrigation water, such variabilty
(if it is of large enough magnitude) means that the crop DOES NOT uniform
AVAILABILITY of water. In such soil profiles, what's needed in NON-UNIFORM
application of water to yield uniform availability to the crop!
The only technology that can provide that, automatically, is the Irristat.
See: <http://www.pipeline.com/~lenornst/index.html> and go to the Irristat
page.
Len Ornstein
>
>Clint
>--
>Dr. Clinton C. Shock
>Malheur Experiment Station
>Oregon State University
>595 Onion Ave.
>Ontario, Oregon 97914
>telephone (541) 889-2174
>Fax (541) 889-7831
>http://www.primenet.com/~mesosu/index.html
Date: Tue, 24 Dec 1996 11:14:21 -0600
From: "J.D. Oster" <oster@mail.ucr.edu>
Subject: Re: Tensiometers to estimate DU
At 10:57 AM 12/24/96 -0600, you wrote:
> In studying optimal potato
>>irrigation (not a series of drip irrigation trials) we dug up many
>>paired tensiometers and paired Watermark soil moisture sensors and
>>compared their readings with the soil water contents in the immediate
>>proximity of the instruments. Much of the variability in instrument
>>readings was related to spot to spot variability in soil water.
>
>Which MUST have been due to variability in local soil hydraulic conductivity.
Wouldn't spatial variability in where the roots are located by another factor?>
>With putatively uniform application of irrigation water, such variabilty
>(if it is of large enough magnitude) means that the crop DOES NOT uniform
>AVAILABILITY of water. In such soil profiles, what's needed in NON-UNIFORM
>application of water to yield uniform availability to the crop!
>
>The only technology that can provide that, automatically, is the Irristat.
>
>See: <http://www.pipeline.com/~lenornst/index.html> and go to the Irristat
>page.
>
>Len Ornstein
>
>>
>>Clint
>>--
>>Dr. Clinton C. Shock
>>Malheur Experiment Station
>>Oregon State University
>>595 Onion Ave.
>>Ontario, Oregon 97914
>>telephone (541) 889-2174
>>Fax (541) 889-7831
>>http://www.primenet.com/~mesosu/index.html
>
>
>
>
J.D.(Jim) Oster
Dept. of Soil & Env. Sciences
University of California
Riverside, CA 92521
Phone (909)787-5100
FAX (909)787-5522
End of Digest
>From root@crcnis1.unl.edu Thu Dec 26 01:05 EST 1996
Date: Wed, 25 Dec 1996 23:52:25 -0600
Message-Id: <199612260552.AA20832@crcnis1.unl.edu>
Subject: TRICKLE-L digest 689
Contents:
Root vs Water distribution? (ges@owt.com (Marty Grogan))
Re: Root vs Water distribution? (Leonard Ornstein <lenornst@pipeline.com>)
Date: Wed, 25 Dec 1996 15:00:32 -0800
From: ges@owt.com (Marty Grogan)
Subject: Root vs Water distribution?
I have read with much interest the discussion of a need for water uniformity
in the root zone, but can't the roots do some catching up if the
distribution is lacking?
Has anyone seen research on the optimal point between the dynamics of water
delivery and root growth? It would no doubt vary with different crops and
could greatly impact the level of investment required for an irrigation
system. No point in redoing what Nature already does better.
M. G.
Marty Grogan, BSAE, MSEE
Grogan Engineering Services
1328 Rathwood Ave.
Richland, WA 99352
(509)627-3083 (voice and FAX)
ges@oneworld.owt.com
Specializing in Systems Integration Services for Agriculture: Automation,
Telemetry, Programming, Maintenance, Remote Sensing and Project Delivery.
GES--The technology buckstopper.
Date: Wed, 25 Dec 1996 22:41:45 -0400
From: Leonard Ornstein <lenornst@pipeline.com>
Subject: Re: Root vs Water distribution?
Marty:
I presume your trying to make the following point:
If water is delivered uniformly, but the soil profile variability results
in non-uniform availability (locally variable matric potential), if the
local storage capacity is adequate to hold the locally deliver uniform
aliquot of irrigation water, then most plants will be able to compensate
for the variable availability by expending more or less (photosynthetic)
energy to extract the required amount of water. The impact of this
variability is usually moderated by plants developing somewhat different
root-distributions and densities in the different soil profiles. Thus, well
established perennial crops manage such non-uniformity of available water
quite well, whereas new plantings can be substantially compromised. Since
most plants can SURVIVE at matric potentials from about 0 to -15 bars,
they have a lot of adaptability. But the work to pull water from drier soil
usually comes at the cost of less than optimal growth rates. And the
magnitude of the cost is different from crop to crop and from one stage of
development to another.
This is all anecdotal. Is there crop-specific literature on these subjects
which can be used to manage irrigation?
Len Ornstein
>I have read with much interest the discussion of a need for water uniformity
>in the root zone, but can't the roots do some catching up if the
>distribution is lacking?
>
>Has anyone seen research on the optimal point between the dynamics of water
>delivery and root growth? It would no doubt vary with different crops and
>could greatly impact the level of investment required for an irrigation
>system. No point in redoing what Nature already does better.
>
>M. G.
>Marty Grogan, BSAE, MSEE
>Grogan Engineering Services
>1328 Rathwood Ave.
>Richland, WA 99352
>(509)627-3083 (voice and FAX)
>ges@oneworld.owt.com
>
>Specializing in Systems Integration Services for Agriculture: Automation,
>Telemetry, Programming, Maintenance, Remote Sensing and Project Delivery.
>
> GES--The technology buckstopper.
End of Digest
>From root@crcnis1.unl.edu Fri Dec 27 01:06 EST 1996
Date: Thu, 26 Dec 1996 23:52:58 -0600
Message-Id: <199612270552.AA07696@crcnis1.unl.edu>
Subject: TRICKLE-L digest 690
Contents:
Root vs Water distribution? -Reply ("Joseph C. Henggeler" <j-henggeler@tamu.edu>)
SDI alfalfa and other forage crops ("Joseph C. Henggeler" <j-henggeler@tamu.edu>)
Psychology of buried tape (Merriott@aol.com)
Re: Psychology of buried tape (Leonard Ornstein <lenornst@pipeline.com>)
Date: Thu, 26 Dec 1996 10:03:06 -0600
From: "Joseph C. Henggeler" <j-henggeler@tamu.edu>
Subject: Root vs Water distribution? -Reply
Marty:
In regards to your question:
++++++++++++++
... but can't the roots do some catching up if the distribution is lacking?
+++++++++++++++
Goldhammer, et al. (pg 851 in Proc of 3rd Inter Drip/Trickle Congress)
presented an excellent paper on micro-sprinkler irrigation, in which
uniformity was measured on the soil surface, and then at various depths
below. They also measured uniformity changes over time. In short,
uniformity improved with depth and time. Both soil potential gradients and
enhanced root activity into more "favorable" areas (be it due to water
content, salinity, aeration, etc.) allow the plant to compensate, to a
degree, as you alluded to. This is also the reason that the protocol for
evaluating uniformity in mircro-irrigation evaluations incorporates the
concept of how many emitter points service a plant. Another practical
observation on micro-scale uniformity is that the majority of studies I have
seen on SDI cotton show that when lateral lines are buried between
every-other row pair, as opposed to under every row, yields are as
good, if not better. However, the soil moisture uniformity would have
been better on the closer spaced lateral widths. However, this is on the
micro-scale level.
When uniformity is on the macro-scale, like the bottom of the field getting
significantly less water than the top, it is another story, and the roots are
not able to compensate for these gross uniformity differences.
Joe Henggeler
Ft. Stockton, TX
Date: Thu, 26 Dec 1996 13:43:07 -0600
From: "Joseph C. Henggeler" <j-henggeler@tamu.edu>
Subject: SDI alfalfa and other forage crops
Dear Trickle-L Users,
I am interested in getting information from growers, irrigation dealers,
researchers, etc. on Sub-surface drip irrigated alfalfa (and other
forages) for inclusion in an article on the same.
I am aware of the USDA/ARS work at Brawley, CA, U of NE work in
Reno, and NMSU work at Artesia. Information on yields, historic items,
costs, problems, comparisons, acreages installed, etc. would all be of
interest to me.
Thanks and Happy New Year!
Joe Henggeler
Ft. Stockton, TX
Date: Thu, 26 Dec 1996 18:38:28 -0500
From: Merriott@aol.com
Subject: Psychology of buried tape
I mentioned earlier that I want to let the customer "see" that his system is
working.
I asked about how to determine DU for a buried system, but I really asked the
wrong question. What I am really trying to get at, and probably didn't
communicate well, is that one constraint that keeps some people from adopting
SDI is the fact that it is buried; you can't see it. That is one thing that
may be keeping this technology from being adopted more quickly.
Microsprinklers took off like hotcakes in Florida in the 80's. I think one
reason was that it was easy to see (and hear) them. There are even some
people who won't run their lawn sprinklers before dawn even though it's more
efficient, because they want to see the system run. We need to come up with
some ways to let people "see" their (and their neighbor's) system running,
just to make people psychologically more comfortable with the technology.
One of my favorite books is "Diffusion of Innovations" by Everett Rogers
which was used in a Technology Transfer class I took in school. I know all
the extension types probably have heard all this stuff before, but in the
book there are listed five characteristics of innovations that affect their
rate of adoption:
1) Relative advantage - the degree to which an innovation is "perceived" as
better than the idea it supersedes. I think SDI has many advantages over
other methods of irrigation, but let's not forget these other
characteristics.
2) Compatibility - the degree to which an innovation is "perceived" as being
consistent with the existing values, past experiences, and needs of potential
adopters. Most peoples' past experiences with irrigation includes "seeing"
the water actually being applied.
3) Complexity - the degree to which an innovation is "perceived" as difficult
to understand and use. I think we can all agree that we have some work to do
in this area.
4) Trialability - the degree to which an innovation may be experimented with
on a limited basis. This is one advantage of SDI.
5) Observability - the degree to which the results of an innovation are
visible to others. Long term results are easy to see. Better yields, etc.
Short term - how do you "see" that the system is actually watering the crop?
How do you "see" if the system is stopping up?
Randall Merriott
Abernathy, Texas
Date: Thu, 26 Dec 1996 20:29:43 -0400
From: Leonard Ornstein <lenornst@pipeline.com>
Subject: Re: Psychology of buried tape
Randall:
Now your question is quite clear, and unfortunately, my answer, of
installing an array of tensiometers, which could work, is completely
impractical for the average potential user of SDI; unless someone invents a
very cheap (<$1.00), durable tensiometer, which never needs to be degassed
or refilled! I tried to, with the gel-sensor of the Irristat, but it turned
out to be too expensive,--or in a cheap design, unreliable.
Len Ornstein
Irristat International Inc.
>I mentioned earlier that I want to let the customer "see" that his system is
>working.
>
>I asked about how to determine DU for a buried system, but I really asked the
>wrong question. What I am really trying to get at, and probably didn't
>communicate well, is that one constraint that keeps some people from adopting
>SDI is the fact that it is buried; you can't see it. That is one thing that
>may be keeping this technology from being adopted more quickly.
> Microsprinklers took off like hotcakes in Florida in the 80's. I think one
>reason was that it was easy to see (and hear) them. There are even some
>people who won't run their lawn sprinklers before dawn even though it's more
>efficient, because they want to see the system run. We need to come up with
>some ways to let people "see" their (and their neighbor's) system running,
>just to make people psychologically more comfortable with the technology.
>
>One of my favorite books is "Diffusion of Innovations" by Everett Rogers
>which was used in a Technology Transfer class I took in school. I know all
>the extension types probably have heard all this stuff before, but in the
>book there are listed five characteristics of innovations that affect their
>rate of adoption:
>
>1) Relative advantage - the degree to which an innovation is "perceived" as
>better than the idea it supersedes. I think SDI has many advantages over
>other methods of irrigation, but let's not forget these other
>characteristics.
>
>2) Compatibility - the degree to which an innovation is "perceived" as being
>consistent with the existing values, past experiences, and needs of potential
>adopters. Most peoples' past experiences with irrigation includes "seeing"
>the water actually being applied.
>
>3) Complexity - the degree to which an innovation is "perceived" as difficult
>to understand and use. I think we can all agree that we have some work to do
>in this area.
>
>4) Trialability - the degree to which an innovation may be experimented with
>on a limited basis. This is one advantage of SDI.
>
>5) Observability - the degree to which the results of an innovation are
>visible to others. Long term results are easy to see. Better yields, etc.
> Short term - how do you "see" that the system is actually watering the crop?
> How do you "see" if the system is stopping up?
>
>Randall Merriott
>Abernathy, Texas
End of Digest
>From root@crcnis1.unl.edu Sat Dec 28 01:06 EST 1996
Date: Fri, 27 Dec 1996 23:53:03 -0600
Message-Id: <199612280553.AA24812@crcnis1.unl.edu>
Subject: TRICKLE-L digest 691
Contents:
Re: Psychology of buried tape (Rod Ennor <rodennor@parker.inter.net.il>)
Date: Fri, 27 Dec 1996 20:32:37 +0200
From: Rod Ennor <rodennor@parker.inter.net.il>
Subject: Re: Psychology of buried tape
HELLO RANDALL,
WE ALL KNOW THAT THE SYSTEM WORKS WHEN WE TURN ON THE CORRECT VALVES AND
SWITCHES, BUT, THERE IS NOTHING LIKE A BIT OF VERIFICATION IS THERE.
PERHAPS SOMEONE FROM NETAFIM CAN COMMENT ON THEIR NEW "FLAG" WHICH IS
AVAILABLE (IN ISRAEL ANYWAY), AND SEEMS TO BE THE IDEAL SOLUTION TO THE
PROBLEM. IT IS CHEAPER THAN ANY OF THE HIGH TEC OPTIONS.
REGARDS,
ROD ENNORAt 05:37 PM 12/26/96 -0600, you wrote:
>I mentioned earlier that I want to let the customer "see" that his system is
>working.
>
>I asked about how to determine DU for a buried system, but I really asked the
>wrong question. What I am really trying to get at, and probably didn't
>communicate well, is that one constraint that keeps some people from adopting
>SDI is the fact that it is buried; you can't see it. That is one thing that
>may be keeping this technology from being adopted more quickly.
> Microsprinklers took off like hotcakes in Florida in the 80's. I think one
>reason was that it was easy to see (and hear) them. There are even some
>people who won't run their lawn sprinklers before dawn even though it's more
>efficient, because they want to see the system run. We need to come up with
>some ways to let people "see" their (and their neighbor's) system running,
>just to make people psychologically more comfortable with the technology.
>
>One of my favorite books is "Diffusion of Innovations" by Everett Rogers
>which was used in a Technology Transfer class I took in school. I know all
>the extension types probably have heard all this stuff before, but in the
>book there are listed five characteristics of innovations that affect their
>rate of adoption:
>
>1) Relative advantage - the degree to which an innovation is "perceived" as
>better than the idea it supersedes. I think SDI has many advantages over
>other methods of irrigation, but let's not forget these other
>characteristics.
>
>2) Compatibility - the degree to which an innovation is "perceived" as being
>consistent with the existing values, past experiences, and needs of potential
>adopters. Most peoples' past experiences with irrigation includes "seeing"
>the water actually being applied.
>
>3) Complexity - the degree to which an innovation is "perceived" as difficult
>to understand and use. I think we can all agree that we have some work to do
>in this area.
>
>4) Trialability - the degree to which an innovation may be experimented with
>on a limited basis. This is one advantage of SDI.
>
>5) Observability - the degree to which the results of an innovation are
>visible to others. Long term results are easy to see. Better yields, etc.
> Short term - how do you "see" that the system is actually watering the crop?
> How do you "see" if the system is stopping up?
>
>Randall Merriott
>Abernathy, Texas
>
>
>
End of Digest
>From root@crcnis1.unl.edu Tue Dec 31 13:36 EST 1996
Date: Tue, 31 Dec 1996 12:22:55 -0600
Message-Id: <199612311822.AA28339@crcnis1.unl.edu>
Subject: TRICKLE-L digest 692
Contents:
introduction (jlsylves <jlsylves@indiana.edu>)
Date: Tue, 31 Dec 1996 13:21:15 -0500 (EST)
From: jlsylves <jlsylves@indiana.edu>
Subject: introduction
Having just received the welcome message, which encourages us newbies to
introduce ourselves, I thought I ought to comply. I scanned over the
introductory questions that we are encouraged to answer, and all I can
say is, I am bringing up the rear of this parade. I am a home flower
gardener. I have changed over the years from landscaping to production
gardening. Not for profit, just in order to maximize output, and focus my
efforts more. So I have now long beds of all one type of plant, and when
that plant dies or goes dormant, the whole bed does so also. I have
separate beds of daffodils, irises, peonies, roses, daylilies, lilium,
gladiolus, and a bed of annuals. I started using the black spongy soaker
hoses for irrigation, and discovered that I was not placing them quite
correctly, was not using enough of them, and the plants were not getting enough
water. So that is why I joined this List; to learn more about the whys
and wherefores of watering techniques. Judy Sylvester
End of Digest
Prepared by Steve Modena, AB4EL
Suggestions and comments to: modena@SunSITE.unc.edu