TRICKLE-L digests for APRIL 1996

From ab4el@ab4el.com Sat May 18 00:00 EDT 1996
From: Stephen Modena <modena@SunSITE.unc.edu>
Message-Id: <96051801.modena@sunsite.unc.edu>
Subject: TRICKLE-L LOG9604
Date: Sat, 18 May 1996 00:01:00 -0400 (EDT)

This is the compendium of TRICKLE-L digests for April 1996.

It was prepared from the daily digest mailings. Some digests
may be missing, because occasional mailings are lost en route.

From root@crcnis1.unl.edu Mon Apr 1 03:44 EST 1996
Date: Mon, 1 Apr 1996 02:35:40 -0600
Message-Id: <199604010835.AA05705@crcnis1.unl.edu>
Errors-To: rmead@asrr.arsusda.gov
Reply-To: <trickle-l@unl.edu>
To: Multiple recipients of list <trickle-l@unl.edu>
Subject: TRICKLE-L digest 462

Contents:
Sodium silicates (rmead@CyberGate.COM (Richard Mead))
Re: Sodium silicates (Ian Johnson <johncon@ihug.co.nz>)

Date: Sun, 31 Mar 1996 23:23:52 GMT
From: rmead@CyberGate.COM (Richard Mead)
Subject: Sodium silicates

I had the pleasure of meeting the editor of the "Irrigation Journal" (Robert
Reaves) at the Tulare Farm Show several weeks ago.

He had asked me the following question and had this comment:

"Did you ever get a chance to ask anyone (on Trickle-L) about the use of sodium
silicates for iron and manganese sequestration in drip irrigation
water? I sold sodium silicates for seven years to people like
municipal water treatment plants. With silicates there is no algae
or slime growth -- no eutrophication. I really wonder if silicates
could do a better job than some of the phosphate products that are
used."

I have waited for a lull in Trickle-L postings and thought
this would be a good time to post this issue. This kind of goes
with algae/reservoir question posted a couple of weeks ago.

Richard Mead
Trickle-L and MIF owner/manager
http://www.cybergate.com/~rmead

Date: Mon, 1 Apr 1996 17:23:08 +1200 (NZST)
From: Ian Johnson <johncon@ihug.co.nz>
Subject: Re: Sodium silicates

At 17:19 31/3/96 -0600, you wrote:

>"Did you ever get a chance to ask anyone (on Trickle-L) about the use of sodium
>silicates for iron and manganese sequestration in drip irrigation
>water? I sold sodium silicates for seven years to people like
>municipal water treatment plants. With silicates there is no algae
>or slime growth -- no eutrophication. I really wonder if silicates
>could do a better job than some of the phosphate products that are
>used."
Out of interest the use of sodium and more particularly potassium silicates
is proving beneficial for disease suppression in the glasshouse industry. I
have seen evidence of this myself without supporting science. Through the
irrigation system there seems to be added resistance to root disease (eg
Phythium) which may be through healthier plants (although Si is not a
required element) or through actual disease resistance. From Europe I have
seen reports of foliar applications helping with botrytis prevention.
I would therefore be interested in expanding a bit on this thread to see
what people think about potential for this material not just in iron and
manganese sequestration but also as a potential beneficial additive for
plant disease suppression.
Dr Ian Johnson
Johnson Consultancy - Specialising in Environmental and Floricultural
Resaerch and Consultancy
Phone +64 9 2358530
Fax +64 9 2356057
Glenbrook Rd, RD1 Waiuku NEW ZEALAND

End of Digest
************************

From root@crcnis1.unl.edu Tue Apr 2 03:45 EST 1996
Date: Tue, 2 Apr 1996 02:36:19 -0600
Message-Id: <199604020836.AA06835@crcnis1.unl.edu>
Errors-To: rmead@asrr.arsusda.gov
Reply-To: <trickle-l@unl.edu>
To: Multiple recipients of list <trickle-l@unl.edu>
Subject: TRICKLE-L digest 463

Contents:
TRICKLE-L digest 462 - Reply (thomson.tony@wpo.pi.sa.gov.au)
Buried Drip on Grass Runways (Merriott@aol.com)

Date: Tue, 02 Apr 1996 09:53:15 +0930
From: thomson.tony@wpo.pi.sa.gov.au
Subject: TRICKLE-L digest 462 - Reply

Re: sodium silicate for iron control ih drip
Tim Calder has written a fact sheet on sodium silicate.
His address is
Dept Agriculture Western Australia
3 Baron-Hay Court
South Perth
Western Australia 6151
Regards
thomson.tony@pi.sa.gov.au

Date: Mon, 1 Apr 1996 22:49:58 -0500
From: Merriott@aol.com
Subject: Buried Drip on Grass Runways

I recently had a request to look at irrigating a grass runway (bermuda) with
buried tape. Has anyone had any experience with this - depth of placement,
optimum spacing, etc.? Also, what about the potential safety hazard of a
rodent chewing through a line, creating a wet spot causing an accident from a
plane's landing gear hanging up in the mud?

Randall Merriott
AgriDrip Irrigation
Hale Center, TX

End of Digest
************************

From root@crcnis1.unl.edu Wed Apr 3 13:13 EST 1996
Date: Wed, 3 Apr 1996 11:56:02 -0600
Message-Id: <199604031756.AA25379@crcnis1.unl.edu>
Errors-To: rmead@asrr.arsusda.gov
Reply-To: <trickle-l@unl.edu>
To: Multiple recipients of list <trickle-l@unl.edu>
Subject: TRICKLE-L digest 464

Contents:
Sleeping T-Tape (Patrick.Joyce@property.camcnty.gov.uk)

Date: Wed, 3 Apr 1996 18:19:52 +0000
From: Patrick.Joyce@property.camcnty.gov.uk
Subject: Sleeping T-Tape

Dear fellow tricklers,

Do any of you have experience of TTape that has remained buried for
several years without use?

In this part of the UK TTape is commonly used to trickle
irrigate/fertigate strawberries. The crop is grown outside beneath
polythene mulch. Given the cost of establishing a strawberry bed on
this system, and the (relatively) low cost of the tape, we are looking
to install a second tape at planting to use when (if) the initial tape
has become damaged or delivers water innacurately over the lifetime of
the crop.

Grateful for any thoughts or advice.

Patrick Joyce

Patrick.Joyce@property.camcnty.gov.uk

End of Digest
************************

From root@crcnis1.unl.edu Thu Apr 4 13:04 EST 1996
Date: Thu, 4 Apr 1996 11:56:16 -0600
Message-Id: <199604041756.AA24077@crcnis1.unl.edu>
Errors-To: rmead@asrr.arsusda.gov
Reply-To: <trickle-l@unl.edu>
To: Multiple recipients of list <trickle-l@unl.edu>
Subject: TRICKLE-L digest 465

Contents:
EnviroSCAN in United Kingdom (Hortech Services Pty Ltd <hortech@www.ats.com.au>)
Re: Sleeping T-Tape (flowers@Rt66.com (wilderness flowers))

Date: Thu, 4 Apr 1996 19:15:53 +1000
From: Hortech Services Pty Ltd <hortech@www.ats.com.au>
Subject: EnviroSCAN in United Kingdom

For those whom may be interested.

This coming european summer the EnviroSCAN continous soil water monitoring
system will be operating on farms in the United Kingdom. Systems will be
installed into various crops and situations where trickle is used. Later
this year in Portugal.

The local distributor is Peter White.

Mobile : (UK) 0385 393 925
Fax : (UK) (01473) 890001

If you are based in the United Kingdom, and you wish to see the system in
operation, either contact myself by e-mail or fax Peter with your details.

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: Thu, 4 Apr 96 07:36:55 MST
From: flowers@Rt66.com (wilderness flowers)
Subject: Re: Sleeping T-Tape

> you wrote: Dear fellow tricklers,
>
> Do any of you have experience of TTape that has remained buried for
> several years without use?
>
> In this part of the UK TTape is commonly used to trickle
> irrigate/fertigate strawberries. The crop is grown outside beneath
> polythene mulch. Given the cost of establishing a strawberry bed on
> this system, and the (relatively) low cost of the tape, we are looking
> to install a second tape at planting to use when (if) the initial tape
> has become damaged or delivers water innacurately over the lifetime of
> the crop.
>
> Grateful for any thoughts or advice.
>
> Patrick Joyce
>
> Patrick.Joyce@property.camcnty.gov.uk
>
>
>try contacting Dave Enyeart at GroAire@aol.com he has vast experience with
buried tapes ,it seems to me that most t tape (25 mil) lasts 15 years and is
only operating for a few minutes a week and is unused in the off season,
therefore you should be able to put a second tape in without a
problem:question given the long life of the primary tape is the second tape
needed?
>
Martin Connaughton
Wilderness Flowers
Flowers@rt66.com
Rt 19 Box 111-D
Santa Fe, NM 87505
5050 988 3096

End of Digest
************************

From root@crcnis1.unl.edu Fri Apr 5 13:04 EST 1996
Date: Fri, 5 Apr 1996 11:56:22 -0600
Message-Id: <199604051756.AA24239@crcnis1.unl.edu>
Errors-To: rmead@asrr.arsusda.gov
Reply-To: <trickle-l@unl.edu>
To: Multiple recipients of list <trickle-l@unl.edu>
Subject: TRICKLE-L digest 466

Contents:
Re: Sleeping T-Tape ("Dr.David S. Ross" <dr27@umail.umd.edu>)
Re: performance of tape (flowers@Rt66.com (Wilderness Flowers))

Date: Thu, 4 Apr 96 14:42:16 -0500
From: "Dr.David S. Ross" <dr27@umail.umd.edu>
Subject: Re: Sleeping T-Tape

Tapes installed deep in Arizona and used only during the season for many
years were initially used the first year and I would guess they created a
tunnel through the soil. I would guess the only problem after a period of
time might be in getting a compacted soil to move to expand the tube.
Perhaps you will not be very deep and the tube will move the soil away.
This is not an answer based on experience, just some input. I was wondering
also. But, it should work, but do you think you will really need the extra
tubing? It is insurance if you can afford it. David in Maryland, USA

At 11:19 AM 4/3/96 -0600, you wrote:
> Dear fellow tricklers,
>
> Do any of you have experience of TTape that has remained buried for
> several years without use?
>
> In this part of the UK TTape is commonly used to trickle
> irrigate/fertigate strawberries. The crop is grown outside beneath
> polythene mulch. Given the cost of establishing a strawberry bed on
> this system, and the (relatively) low cost of the tape, we are looking
> to install a second tape at planting to use when (if) the initial tape
> has become damaged or delivers water innacurately over the lifetime of
> the crop.
>
> Grateful for any thoughts or advice.
>
> Patrick Joyce
>
> Patrick.Joyce@property.camcnty.gov.uk
>
>
>
>
............................................................................
Dr. David S. Ross 301-405-1188 office
Extension Agricultural Engineer 301-498-2234 home
Dept. of Biological Resources Engineering 301-314-9023 office fax
University of Maryland 301-405-1198 Dept.
College Park, Maryland 20742-5711
NOTE: new department name 3/28/96
>>>>>>>>>>>>>>>>>..........................................<<<<<<<<<<<<<<<<<

Date: Thu, 4 Apr 96 17:16:36 MST
From: flowers@Rt66.com (Wilderness Flowers)
Subject: Re: performance of tape

>>to:Michael Buescher
re: your questipon on drip:

>Some growers in drought sensitive areas in Southern Germany are
>interested in using tape for irrigation during the summer month.
>
>Thus I'd like to pose some questions regarding tape to the group.
>
>1.) How popular is it in the US?
very also gaining wider acceptance in southwest US due to increasing water
costs and lower availablity due to increasing consumption by people in the
cities
>
>2.) Do growers bury tape underground for 2 - 3 seasons?
> It shall be possible - but is it realy done!
can be buried for up to 15 years ! <GroAire@aol.com> has system to
aerate the soil thrugh drip tape increasing productivity reducing fertilizer
and water use.
>
>3.) How much is the performance declining after 2-3 seasons?
not much with proper cleaning and flushing;also use of filters
>
>3.) Is a maschine existing to roll it up after the season?
yes: farm market implement at 814 443 1931 or mail at rd 2c Freidens ,PA USA
15541
>
>4.) Do you have to disposal it due to environmental laws?

buried drip will put off the recycling aspect until the next century or later?
>good luck with drip

Martin Connaughton

>
>Michael Buescher
>
> University of Kassel
> Faculty of Agriculture, International Rural Development
> and Environmental Protection (FB 11)
> Nordbahnhofstr. 1a
> D-37213 Witzenhausen
> (FRG)
>
> email: buescher@wiz.uni-kassel.de
> http://dino.wiz.uni-kassel.de/model_db/Michael_Buescher.html
>
>
Martin Connaughton
Wilderness Flowers
Flowers@rt66.com
Rt 19 Box 111-D
Santa Fe, NM 87505
5050 988 3096

End of Digest
************************

From root@crcnis1.unl.edu Sat Apr 6 13:05 EST 1996
Date: Sat, 6 Apr 1996 11:56:43 -0600
Message-Id: <199604061756.AA10460@crcnis1.unl.edu>
Errors-To: rmead@asrr.arsusda.gov
Reply-To: <trickle-l@unl.edu>
To: Multiple recipients of list <trickle-l@unl.edu>
Subject: TRICKLE-L digest 467

Contents:
Re: Buried Drip on Grass Runways (rmead@CyberGate.COM (Richard Mead))
Re: Buried Drip on Grass Runways (geoflow1@slip.net (Rodney Ruskin))
Re: EnviroSCAN in United Kingdom and continuous soil water monitoring. (Clint Shock <mesosu@primenet.com>)
Re: Phosphite fertilizer ("Peter D. Spyke" <pdspyke@gate.net>)

Date: Sat, 6 Apr 1996 02:05:29 GMT
From: rmead@CyberGate.COM (Richard Mead)
Subject: Re: Buried Drip on Grass Runways

Dear Randall and others interested in SDI and turf:

In May of 1995, I discussed SDI in turf on Trickle-L.

The discussion actually was based on a Sunset magazine article. Enclosed is
the main content. I must add also that this is primarily with the use of
hard hose...I don't have any information on tape, but the basic engineering
should be helpful. The full text of this topic can be found on the
Microirrigation Forum web page
(http://www.cybergate.com/~rmead) under the "best of" trickle-l category.

Excuse the late response to your question :)

Richard Mead
Trickle-L and MIF owner/manager

************************************************************
The guidelines for setting a SDI system in lawns are the following:
For clay soils use: 0.5 gph (2 Lph) emitters, 18 in. (45 cm) apart with
laterals 18 in. (45 cm) apart. For loam soils use 1 gph (4 Lph) emitters with
the same spacing used for clay. And for sandy soil, use 1 gph (4 Lph)
emitters, but space the emitters 12 inches apart with laterals spaced 16 to
18 in. (40-45cm). The depth placement of the drip line should be ~6 in.
(15cm), yet recommendations for sandier soils should be a 4 in. (10 cm)
depth. Lawns that have mature trees with extensive roots and soils that have
extremely sandy or gravely conditions, SDI is not recommended.

Without being too plagiaristic, I have included a formula from the Sunset
article which calculates application rate once the SDI system has been
installed. This formula could also be used in any installation of SDI since
the basic principle still applies. I will give the formula in both the
English system (inches/gallons) and metric.

To calculate mm/hr, use:

9113 x emitter rate(Lph)/emitter spacing(cm) x lateral spacing (cm)

To calculate inches/hr, use:

231.1 x emitter rate(gph)/emitter spacing(in) x lateral spacing (cm)

In general, most landscape companies use the Treflan embedded plastic
emitters to prevent root intrusion. I might mention that CIT (Center for
Irrigation Technology) has done a lot of the research on turf over the years.
For more information contact Dave Zoldoski through ATI-Net at (209)-278-4872
or fax (209) 278-4849.
***************************************************************

>I recently had a request to look at irrigating a grass runway (bermuda) with
>buried tape. Has anyone had any experience with this - depth of placement,
>optimum spacing, etc.? Also, what about the potential safety hazard of a
>rodent chewing through a line, creating a wet spot causing an accident from a
>plane's landing gear hanging up in the mud?
>
>Randall Merriott
>AgriDrip Irrigation
>Hale Center, TX

Date: Fri, 5 Apr 96 18:16 PST
From: geoflow1@slip.net (Rodney Ruskin)
Subject: Re: Buried Drip on Grass Runways

At 9:43 PM 4/1/96 -0600, Merriott@aol.com wrote:
>I recently had a request to look at irrigating a grass runway (bermuda) wit=
h
>buried tape. Has anyone had any experience with this - depth of placement,
>optimum spacing, etc.? Also, what about the potential safety hazard of a
>rodent chewing through a line, creating a wet spot causing an accident from=
a
>plane's landing gear hanging up in the mud?
>
>Randall Merriott
>AgriDrip Irrigation
>Hale Center, TX

In grass the only proven solution is a hard hose protected against root
intrusion with Treflan=AE fused into the emitter (ROOTGUARD=AE). For the
justification of this statement I suggest that you refer to the
publications of C.I.T.
However you raise an interesting point about the risk of a wet spot due to
a break in the hose. While the probability is low the cost of failure is
rather high. If you had quite small areas under control of each valve
(sets) it is possible that you could find a flow meter accurate enough to
detect the increase in flow and switch the system off. With a PLC as a
controller it would be quite easy and practical to program this type of
control. Commercial meters with a claimed accuracy of plus minus 1.5
percent are available. If we define a "break" as a flow of 10 gph then we
can have design flow in the set at 600 gph with a switch off at 610 gph.
This would allow us to have about 1,000' of tube at 1' spacing with 0.5 gph
emitters or 1,500' at 1.5' spacing.
If you are serious about this project and are prepared to spend a
reasonable amount of money for a solution then I suggest that you first
contact CIT for their input. CIT - Tel: 209 278-2066 Fax: 209 278-6033.

Rodney.

Date: Sat, 06 Apr 1996 06:32:44 -0800
From: Clint Shock <mesosu@primenet.com>
Subject: Re: EnviroSCAN in United Kingdom and continuous soil water monitoring.

We use constant soil moisture monitoring to automatically control our drip
irrigation criteria.
--

Dr. Clinton C. Shock
Malheur Experiment Station, Oregon State University
595 Onion Ave.
Ontario, OR 97914
(541) 889-2174
Fax (541) 889-7831
http://www.primenet.com/~mesosu/index.html

Date: Sat, 06 Apr 1996 12:23:27 -0500
From: "Peter D. Spyke" <pdspyke@gate.net>
Subject: Re: Phosphite fertilizer

I recently read an article in "California Citrograph" about
phosphite. It portrayed it as being very beneficial. Any
other experiences out there with Nutriphite or other forms?

Thanks.

Pete Spyke

At 10:57 PM 3/27/96 -0600, you wrote:
>>This may not stay right on target as far as trickle drip goes, but I have
>>a question along the fertilization line. Has anyone out there heard of
>>Phosphites, as a more potent form of phosphates. I hear they're very
>>expensive, very effective and can reduce the overall need of all
>>fertilizers. I hear they are available in California, but in limited
>>amounts. Any knowledge on this out there?
>
>Nutriphite is a brand name of a phosphite. It is sold as a nutrient, but
>certain people are selling as "wink, wink - its the same as Aliette."
>Aliette is an expensive chemical used for control of downey mildew. Bioag
>claims _nothing_ about diseases. Now there is Impact and others which are
>very similar to Nutriphite. Supposedly Nutriphite is patent pending and
>licenced by the UC system. Enough (?) for controversy...
>
>There are growers using phosphite for foliar applications. It is probably
>way too expensive for soil applications.
>
>My application - vegetables- there really is no late season shortage of
>phoshate, no burning need for foliar (unless you have a downey mildew
>problem ;-) )
>Steve Jordan @ Second Foundation
>
>

End of Digest
************************

From root@crcnis1.unl.edu Wed Apr 10 10:42 EDT 1996
Date: Wed, 10 Apr 1996 09:33:43 -0500
Message-Id: <199604101433.AA27380@crcnis1.unl.edu>
Errors-To: rmead@asrr.arsusda.gov
Reply-To: <trickle-l@unl.edu>
To: Multiple recipients of list <trickle-l@unl.edu>
Subject: TRICKLE-L digest 468

Contents:
pressure regulator (Byron Irvine <pf22408@em.agr.ca>)

Date: Wed, 10 Apr 1996 10:14:58 -0400
From: Byron Irvine <pf22408@em.agr.ca>
Subject: pressure regulator

Does anyone know where I can get a 0.5-3 gpm 4psi regulator. I can
find them as low as 6 psi but not lower. Failing that I thought I might use
a length of small diameter tubing and get the pressure drop by friction but
since this is flow dependent this is less desirable. Any thoughts??

Thanks
Byron I

End of Digest
************************

From root@crcnis1.unl.edu Thu Apr 11 10:44 EDT 1996
Date: Thu, 11 Apr 1996 09:34:03 -0500
Message-Id: <199604111434.AA22068@crcnis1.unl.edu>
Errors-To: rmead@asrr.arsusda.gov
Reply-To: <trickle-l@unl.edu>
To: Multiple recipients of list <trickle-l@unl.edu>
Subject: TRICKLE-L digest 469

Contents:
Re: pressure regulator (redling@gumbo.bae.lsu.edu (Robert Edling))
Re: pressure regulator ("W. Bryan Smith" <WSMTH@prism.clemson.edu>)
Re: pressure regulator (Stephen Rawlins <srawlins@ncw.net>)
Re: pressure regulator (FLamm@oznet.ksu.edu (Freddie Lamm))

Date: Wed, 10 Apr 1996 10:53:10 -0500
From: redling@gumbo.bae.lsu.edu (Robert Edling)
Subject: Re: pressure regulator

Byron:
You might also use a constant head device. You are only talking 12-14 ft or so.

Bob Edling

Date: Wed, 10 Apr 1996 12:37:03 -0400 (EDT)
From: "W. Bryan Smith" <WSMTH@prism.clemson.edu>
Subject: Re: pressure regulator

Byron,
Watts Mfg. and others make pressure regulators that are adjustable for
commercial use (read home water service, etc.). They are more expensive
than the typical regulators, but they are made of brass and will regulate
the pressure even at zero flow. I have not worked with a 4 psi head,
but one of these may fit your bill. Be sure and ask them how low you can
set the pressure - most plumbing supplies or hardware stores should have
them.

Bryan

W. Bryan Smith
Area Water Quality Agent
P.O. Box 160
Newberry, SC 29108
(803) 276-1091
---------------------------
All opinions are my own and do not reflect the policies of Clemson University
or the Cooperative Extension Service.

Date: Wed, 10 Apr 1996 10:30:03 -0700
From: Stephen Rawlins <srawlins@ncw.net>
Subject: Re: pressure regulator

At 09:25 AM 4/10/96 -0500, Byron I. wrote: >Does anyone know where I can get
a 0.5-3 gpm 4psi regulator.

Many years ago I had the same problem, and solved with with a manometer
equiped with a capacitance switch that operated a solenoid valve. The
concept is publishe in

"Rawlins, Stephen L. A commercially available, highly sensitive control for
porous-plate apparatus. Soil Sci. Soc. Amer. Proc. 26:207. 1962."

It may not be the simplest way, but it works, and it is precise.

Steve Rawlins
USDA/ARS -- Retired Richland, WA 9352
APPROPRIATE SYSTEMS Phone 509-627-4943
(Precision Farming Consultants) FAX 509-627-1841
2638 Eastwood Avenue Email srawlins@ncw.net

Date: 10 Apr 96 10:54:56 CDT
From: FLamm@oznet.ksu.edu (Freddie Lamm)
Subject: Re: pressure regulator

BYRON I WROTE:
> Does anyone know where I can get a 0.5-3 gpm 4psi regulator. I can
> find them as low as 6 psi but not lower. Failing that I thought I might use
> a length of small diameter tubing and get the pressure drop by friction but
> since this is flow dependent this is less desirable. Any thoughts??

FREDDIE LAMM WROTE ON APRIL 10, 11:30 AM.

I am not sure about where to get a regulator as described but I have
a suggestion about your second sentence.
You can use a pressure regulator (say 6 or 10 psi) to "standardize"
the pressure and thus flow, ahead of your friction drop device (small
tubing, valve, etc). I have used this technique for 7 years to
"standardize" our control head pressure to 20 psi, before throttling the
submain pressure to 10 psi with a valve. In our research setting,
we have plots starting and stopping at various times and mainline
pressures may vary from 30 to 60 psi. The key is you must use
good quality pressure regulators that have an accurate set pressure
with little hysteresis and good repeatability. There are a number
of good brands of regulators on the market. We have used Senninger 20 psi low
flow (1/8 to 8 gpm) with good results.

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 Fri Apr 12 09:19 EDT 1996
Date: Fri, 12 Apr 1996 08:05:11 -0500
Message-Id: <199604121305.AA04738@crcnis1.unl.edu>
Errors-To: jp@unlinfo.unl.edu
Reply-To: <soils-l@unl.edu>
To: Multiple recipients of list <soils-l@unl.edu>
Subject: SOILS-L digest 510

Contents:
Help with subscribing & unsubscribe (Byron Bodo <bodo@io.org>)
introduction (Wendy.Wang@tas.for.csiro.au (wendy wang))
Re: SOM determination for calcareous soils??? (fwd) (Wendy.Wang@tas.for.csiro.au (wendy wang))
Soil Organic Matter Determination (Graeme D Buchan <BUCHAN@tui.lincoln.ac.nz>)

Date: Thu, 11 Apr 1996 13:33:44 -0400
From: Byron Bodo <bodo@io.org>
Subject: Help with subscribing & unsubscribe

I just got a request from a soil sci type about how to
subscribe, but I've lost the message with the instructions.

Could someone kindly post me the soils-i sign-up /sign-off
instructions.

TIA

-bb
Byron Bodo
240 Markham St., Toronto, ON, Canada M6J 2G6
tel: (416) 967 7286
fax: (416) 967 9004
email: bodo@io.org

Date: Fri, 12 Apr 1996 16:27:41 +1000
From: Wendy.Wang@tas.for.csiro.au (wendy wang)
Subject: introduction

Hi, all

My name is Wendy Wang. I am a postdoc working with CRC for
Temperate Hardwood Forestry, Tasmania, Australia.
My research intersts include soil N and P nutrient and fertilizer
application technique, soil amelioration by chemical and biological
technique, and soil enzyme activity and biochemical reactions.
My current research area, since 1994, is N availability in forest soils.
The project covers N mineralization, nitrification and leaching in
relation to soil type and land use history.

one 'burning' question: is N LOSS through leaching important
in forest soil? What should tree grower do about it?

yours sincerely

Wendy Wang

Date: Fri, 12 Apr 1996 16:43:38 +1000
From: Wendy.Wang@tas.for.csiro.au (wendy wang)
Subject: Re: SOM determination for calcareous soils??? (fwd)

>From: Isabel Sohn Lopez-Forment <isohn@diario1.sureste.com.mx>
>To: Multiple recipients of list <soils-l@unl.edu>
>Subject: SOM determination for calcareous soils???
>
>Hi,
>
>I'm doing my graduate research in Southeast Mexico, and it involves soil
>organic matter and available nitrogen issues.
>
>Can anybody advise me about methods to correct SOM determination through
>soil on ignition (425oC for 4 hrs.) for calcareous soils? We've been
>obtaining values of 25-35% in soils of the Yucatan Peninsula. Are there
>other things to consider using this method?
>
>Thanks a lot for your comments.
>
>Isabel

Hello, Isabel

I am a postdoc working N availability. I have done the comparison of three
measures
of organic matter or carbon: LOI (375 degree C for 17 hrs), Walkley & Black
(Cw&b),
and dry combustion using a LECO CHIN-1000 Analyzer (Ct). Ct and Cw&b were
highly correlated in 119 surface and subsoil samples, and on average, CW&B
provided near complete recovery of CT (97%). Although LOI may have released
some
structural water from the fine textured soils, strong regressions were found
between
LOI and both Cw&b and Ct which were specific for either basalt or non-basalt
soils.
The relationships of Cw&b and Ct to LOI in the basalt soils were
significantly different
with those in the non-basalt soils.

I think you need to develop a regression between LOI and C content measured by
a standard method in your soil, or you may find help from literature if
similar study
was done in similar soils. The following references may be of interest to you:

Ball, D. F. (1964). Loss-on-ignition as an estimate of organic
matter and organic carbon in non-calcareous soils. Journal of Soil Science
15, 84-92.
David, M. B. (1988). Use of loss-on-ignition to assess soil organic
carbon in forest soils. Communication in Soil Science and Plant Analysis 19,
1593-1599.
Davies, B. E. (1974). Loss-on-ignition as an estimate of soil
organic matter. Soil Science Society of America Journal 38, 150-151.
Donkin, M. J. (1991). Loss-on-ignition as an estimator of soil
organic carbon in A-horizon forestry soils. Communication in Soil Science
and Plant Analysis 22, 233-241.
Goldin, A. (1987). Reassessing the use of loss-on-ignition for
estimating organic matter content in noncalcareous soils. Communication in
Soil Science and Plant Analysis 18, 1111-1116.
Honeysett, J. L. and Ratkowsky, D. A. (1989). The use of ignition
loss to estimate bulk density of forest soils. Journal of Soil Science 40,
299-308.
Lowther, J. R., Smethurst P. J., Carlyle J. C. and Nambiar E. K. S.
(1990). Methods for determining organic carbon in podzolic sands.
Communication in Soil Science and Plant Analysis 21, 457-470.
Navarro, A. F., Roig, A., Cegarra, J. and Bernal, M. P. (1993).
Relationship between total organic carbon and oxidizable carbon in
calcareous soils. Communication in Soil Science and Plant Analysis 24,
2203-2212.
Schulte, E. E., Kaufmann, C. and Peter J. B. (1991). The influence
of sample size and heating time on soil weight loss-on-ignition.
Communication in Soil Science and Plant Analysis 22, 159-168.
Soon, Y. K. and Abboud S. (1991). A comparison of some methods for
soil organic carbon determination. Communication in Soil Science and Plant
Analysis 22, 943-954.
Spain, A. V., Probert, M. E., Isbell, R. F. and John R. D. (1982).
Loss-on-ignition and the carbon contents of Australian soils. Australian
Journal of Soil Research 20, 147-152.

I will have a paper published soon on this part, I can send you a reprint if
you are interest.

Good luck for your study.

Wendy Wang

Date: Fri, 12 Apr 1996 20:23:46 +1200
From: Graeme D Buchan <BUCHAN@tui.lincoln.ac.nz>
Subject: Soil Organic Matter Determination

To: Isabel Lopez-Form
Wendy Wang

From: Graeme Buchan, Reader in Environmental Physics,
Soil Science Dept., Lincoln University, NZ

Re: Comparison of methods to determine soil o.m.

I draw your attention to the following paper, which almost exactly
mirrors the work reported by Wendy Wang. (I'm surprised it was not
on her reference list):

`A comparison of three methods of organic carbon determination in
some NZ soils', 1991, K S Grewal, G D Buchan & R R Sherlock,
J.Soil Science 42:251-257.

This paper compares LOI, Walkley-Black, and a dry combustion method;
and reports how regression between LOI-determined organic MATTER, and
d.c.-determined organic CARBON, is improved by inclusion of a clay
term, reflecting removal on ignition of non-organic constituents,
chiefly adsorbed water.

Good wishes,
Graeme Buchan

End of Digest
************************

From root@crcnis1.unl.edu Sat Apr 13 10:43 EDT 1996
Date: Sat, 13 Apr 1996 09:35:29 -0500
Message-Id: <199604131435.AA12901@crcnis1.unl.edu>
Errors-To: rmead@asrr.arsusda.gov
Reply-To: <trickle-l@unl.edu>
To: Multiple recipients of list <trickle-l@unl.edu>
Subject: TRICKLE-L digest 471

Contents:
Longlife Tapes (Patrick.Joyce@property.camcnty.gov.uk)
Re: Longlife Tapes (FLamm@oznet.ksu.edu (Freddie Lamm))
Re: Longlife Tapes (sjordan@seldon.terminus.com (Steve Jordan))

Date: Fri, 12 Apr 1996 16:22:22 +0100
From: Patrick.Joyce@property.camcnty.gov.uk
Subject: Longlife Tapes

Greetings trickle-l!

Thanks to all who responded to my query about the longevity of buried
tape.

It seems that many of you can keep tape going for years seemingly
without problem. How do you do it? Could you give the list a simple 5
point plan for success???

In our systems we have found that after the third season the measured
EU has fallen to c.60%. Sure, the crop receives an irrigation - but
our once precision fertiliser and water applications are now all over
the place. Our soils are chronically short of trace elements and poor
application shows up in tissue analysis.

Does anyone have any references for work on measured EU% over time?
How much work has been done in this field? Is grower perception of
adequate system performance (no offence intended to anyone) based on
hunch or measurement ?

Do those that keep their systems going for years employ any special
hygiene measures, other than use of acids and normal filtration?

Apologies if you've covered all this before.

Patrick.Joyce@property.camcnty.gov.uk

Date: 12 Apr 96 10:37:59 CDT
From: FLamm@oznet.ksu.edu (Freddie Lamm)
Subject: Re: Longlife Tapes

> Patrick.Joyce@property.camcnty.gov.uk wrote:
> It seems that many of you can keep tape going for years seemingly
> without problem. How do you do it? Could you give the list a simple 5
> point plan for success???

RESPONSE FROM FREDDIE LAMM, 4-12-96
I won't be so presumptous to give you a 5 point plan for success, but
it may turn out I can list 5 or more items I have utilized in maintaining
our research SDI systems for 7 years. Success would depend too much
on site, initial conditions and constraints. Perhaps if others take
your challenge, a list of several items can be generated, for all to pick
and choose management tools.

1. Use consistent and timely management and maintenance. Don't let
problems get out of hand, where the problem may be difficult to
diagnose or maybe even just so frustrating that overall management is
eventually neglected.

2. Monitor performance. This is a necessity and a ***natural***
"cost of doing business" to my systems, because a key element of
research is eliminating unnecessary variations and errors in setting
up experiments. I realize most producers can not devote the manpower
and time to do this to the same degree, but it is impossible to
adequately do No. 1 without knowing something about performance.
Analyzing pressure and flow changes over time would appear to be to
be a minimum requirement, followed by interpretation of the problem
and correction.

3. Our deep installation depth (16-18 inches) for field
corn also gives us a longevity advantage through less damage (rodent
and mechanical). I also suspect there could be an advantage in
reduced clogging or plugging since there would be less changes in
tape and water temperature at this depth than if it was near the
surface, and thus less radical shifts in biological and chemical
activity. ***HOWEVER, I HAVE NOT SEEN LAST COMMENT
EVER DOCUMENTED,AND WOULD APPRECIATE ANY
COMMENT POINTING ME TO A REFERENCE.
Obviously, this installation depth cannot be used in all
circumstances.

4. We perform tillage after harvest to reduce residue to manageable
levels, and go to great lengths to ensure residue is handled
relatively evenly. We make sure we don't leave a small area
untilled or with piles of residue that present a "For Rent" sign to
rodents. We manually remove residue from around control heads and
other above-ground system obstructions.

5. Be blessed with good water quality.
If not, know what the water quality and constituents are and how to
handle them.

6. Return to No 1. or in other words, FIX IT NOW, NOT TOMORROW.

Freddie
*

Date: Fri, 12 Apr 1996 11:59:13 +0000
From: sjordan@seldon.terminus.com (Steve Jordan)
Subject: Re: Longlife Tapes

>3. Our deep installation depth (16-18 inches) for field
>corn also gives us a longevity advantage through less damage (rodent
>and mechanical).

It might be hard to _remove_ tape that deep ;-) Depending on soil type
and tape consistency, it might be impossible to remove. I had severe
problems with tape 8 inches deep once.

One of the first things to buy (not the last) is a good flow meter.

Also beware of iron and manganese. They can be almost insolvable. Once
accumulated, cannot be removed. (from one who knows)
Steve Jordan @ Second Foundation

End of Digest
************************

From root@crcnis1.unl.edu Sun Apr 14 10:43 EDT 1996
Date: Sun, 14 Apr 1996 09:35:50 -0500
Message-Id: <199604141435.AA08558@crcnis1.unl.edu>
Errors-To: rmead@asrr.arsusda.gov
Reply-To: <trickle-l@unl.edu>
To: Multiple recipients of list <trickle-l@unl.edu>
Subject: TRICKLE-L digest 472

Contents:
Re: pressure compensating in-line emmitters (GrapeGrowr@aol.com)

Date: Sat, 13 Apr 1996 19:40:02 -0400
From: GrapeGrowr@aol.com
Subject: Re: pressure compensating in-line emmitters

i hear that there is, on the horizon, pressure compensating, in line
emmitters. True or not?

End of Digest
************************

From root@crcnis1.unl.edu Mon Apr 15 10:44 EDT 1996
Date: Mon, 15 Apr 1996 09:36:30 -0500
Message-Id: <199604151436.AA02351@crcnis1.unl.edu>
Errors-To: rmead@asrr.arsusda.gov
Reply-To: <trickle-l@unl.edu>
To: Multiple recipients of list <trickle-l@unl.edu>
Subject: TRICKLE-L digest 473

Contents:
Re: pressure compensating in-line emmitters (Jerome Pier <jpier@interramp.com>)
Re: pressure compensating in-line emmitters (geoflow1@slip.net (Rodney Ruskin))

Date: Sun, 14 Apr 1996 11:17:13 -0700
From: Jerome Pier <jpier@interramp.com>
Subject: Re: pressure compensating in-line emmitters

GrapeGrowr@aol.com wrote:
>
> i hear that there is, on the horizon, pressure compensating, in line
> emmitters. True or not?

Netafim has been manufacturing pressure compensating in-line drip hose for many years
now. The RAM product is our flagship has has a long history of sucess in everything from
row crops to trees and vines; from surface placed to buried. Let me know if you'd like
more information.

Jerome Pier
Soil Scientist/Agronomist
Netafim Irrigation, Inc.
jpier@interramp.com

Date: Sun, 14 Apr 96 19:50 PDT
From: geoflow1@slip.net (Rodney Ruskin)
Subject: Re: pressure compensating in-line emmitters

At 6:33 PM 4/13/96 -0500, GrapeGrowr@aol.com wrote:
>i hear that there is, on the horizon, pressure compensating, in line
>emmitters. True or not?
Why do you want pressure compensating in line emitters? The tendency has
been to develop pressure compensating drip lines which are made by several
companies. The only U.S. manufacturers are Geoflow and Drip In, and foreign
manufacturers include the Israelis Naan, Lego, and Netafim. In addition
there is Eurodrip in Greece, Irritec in Italy and I have no doubt several
others that I do not know about.

Rodney.

End of Digest
************************

From root@crcnis1.unl.edu Tue Apr 16 10:45 EDT 1996
Date: Tue, 16 Apr 1996 09:36:40 -0500
Message-Id: <199604161436.AA07632@crcnis1.unl.edu>
Errors-To: rmead@asrr.arsusda.gov
Reply-To: <trickle-l@unl.edu>
To: Multiple recipients of list <trickle-l@unl.edu>
Subject: TRICKLE-L digest 474

Contents:
Re: pressure compensating in-line emmitters (cburt@oboe.aix.calpoly.edu (Charles M. Burt))
Re: Buried Drip on Grass Runways ("Blake L. Sanden" <blsanden@ucdavis.edu>)
Re: Buried Drip on Grass Runways ("Blake L. Sanden" <blsanden@ucdavis.edu>)

Date: Mon, 15 Apr 1996 08:01:57 -0700
From: cburt@oboe.aix.calpoly.edu (Charles M. Burt)
Subject: Re: pressure compensating in-line emmitters

>i hear that there is, on the horizon, pressure compensating, in line
>emmitters. True or not?

They have already been around for quite awhile. For example, Netafim's RAM
emitter.

Of course, the initial cost is greater than typical tape products.

Charles M. Burt, P.E., Ph.D.
Professor and Director of the Irrigation Training and Research Center (ITRC)
California Polytechnic State University (Cal Poly)
San Luis Obispo, CA 93407

ph: 805-756-2379
FAX: 805-756-2433

e-mail: cburt@oboe.calpoly.edu

Date: Mon, 15 Apr 1996 08:47:34 -0700
From: "Blake L. Sanden" <blsanden@ucdavis.edu>
Subject: Re: Buried Drip on Grass Runways

Rodney,

Here's my phone number. Next time live your E-Mail address and phone so I
don't need to clog up Trickle-L.

Blake
805-837-0193
blsanden@ucdavis.edu

At 08:14 PM 4/11/96 -0500, you wrote:
>At 10:45 AM 4/11/96 -0500, Blake L. Sanden wrote:
>>At 09:43 PM 4/1/96 -0600, you wrote:
>>>I recently had a request to look at irrigating a grass runway (bermuda) with
>>>buried tape. Has anyone had any experience with this - depth of placement,
>>>optimum spacing, etc.? Also, what about the potential safety hazard of a
>>>rodent chewing through a line, creating a wet spot causing an accident from a
>>>plane's landing gear hanging up in the mud?
>>>
>>>Randall Merriott
>>>AgriDrip Irrigation
>>>Hale Center, TX
>>>
>>>
>>DON'T DO IT!! All of the subsurface systems I have seen make quite a few
>>sand chimneys that saturate and bubble water straight to the surface -- a
>>disaster for a plane wheel!
>>
>>Blake Sanden
>>UC Coop Extension
>>Bakersfield, CA
>
>Reply to Blake Sanden
>I plan to be in Bakersfield area in the last week of May. Please let me
>have your 'phone number and I will be pleased to arrange a tour of
>successful SDI systems both in turf and agriculture without sand chimneys.
>Systems with this problem are distinctly a minority and are an
>insignificant problem with turf because the drippers are typically one for
>2.25 square feet so the irrigation time and volume per dripper is very low
>compared to agriculture.
>I am well aware of the problems with heavy soils and SDI in pistachios in
>the Bakersfield area. Your colleague Dave Goldhamer and I have discussed
>this at length, and we are each separately and cooperatively working
>towards a solution. However this has nothing to do with SDI in turf.
>
>Rodney Ruskin.
>
>
>
>
>
>

End of Digest
************************

From root@crcnis1.unl.edu Wed Apr 17 14:22 EDT 1996
Date: Wed, 17 Apr 1996 13:12:33 -0500
Message-Id: <199604171812.AA15735@crcnis1.unl.edu>
Errors-To: rmead@asrr.arsusda.gov
Reply-To: <trickle-l@unl.edu>
To: Multiple recipients of list <trickle-l@unl.edu>
Subject: TRICKLE-L digest 475

Contents:
Salinity probes (FLamm@oznet.ksu.edu (Freddie Lamm))
Advertising Postgraduate position (evan@griffith.dwr.csiro.au (Evan Christen))
Sap flow sensors-Problems with technique ("Bruce Metelerkamp" <BRUCE@mailgate.icfrnet.unp.ac.za>)

Date: 16 Apr 96 16:38:07 CDT
From: FLamm@oznet.ksu.edu (Freddie Lamm)
Subject: Salinity probes

Anyone out there that can give a brief summary of experiences on
using salinity probes for measuring soil salinity profiles under
SDI ???

Particularly about,
Accuracy and scale of measurement (point or sizable volume)
Ease of use
Depth of operation
Calibration requirements (data needs or processes required)
Ballpark instrument costs
Any significant operating costs
Quirks or special cases

Freddie
*

Date: Wed, 17 Apr 1996 01:28:51 -0500
From: evan@griffith.dwr.csiro.au (Evan Christen)
Subject: Advertising Postgraduate position

Postgraduate Research Scholarship In Subsurface Irrigation Systems

Stipend of $18,000 per annum

Applications are invited for a postgraduate scholarship to work on hydraulic
design and testing of a subsurface irrigation system. Applicants must be
Australian citizens or have permanent residence status and must have
completed a relevant honours degree in applied science, engineering or a
related field. The successful applicant will be required to enrol in a
Masters Degree at Charles Sturt University, Wagga. The scholarship will be
associated with an externally funded research project involving CSIRO,
Division of Water Resources and a commercial industry. The successful
student will be required to sign a commercial confidentiality agreement.

All potential applicants should obtain a copy of the Project Details,
Selection Criteria, and Award Conditions by contacting the Postgraduate
Scholarship Officer Mrs Wendy Cooke on (069) 33 2103.

Professor Wayne Meyer will be the Principal Supervisor and Assoc. Supervisor
Mr Myo Win can be contacted on (069) 33 2802 or email mwin@csu.edu.au.

Written applications which must address the selection criteria and include
the names of at least two referees, should be sent to:

Office of Research and Graduate Studies
Charles Sturt University
PO Box 588
Wagga Wagga NSW 2678
Tel (069) 33 2103

CHARLES STURT
UNIVERSITY
Dr Evan Christen
Irrigation and Drainage Management for Horticulture
CSIRO Division of Water Resources
Griffith Laboratory
Griffith
NSW 2680
Australia
Tel # 61 69 601586
Fax # 61 69 601600

Date: Wed, 17 Apr 1996 10:00:15 +200
From: "Bruce Metelerkamp" <BRUCE@mailgate.icfrnet.unp.ac.za>
Subject: Sap flow sensors-Problems with technique

Evan and others

Following on from a posting earlier this year where directly
measured sap flow measuremnts were discussed (see below), I would
like to get some feedback on a few possible problems with the
theory of sap flow measurements.

In order to ascertain how much sap is moving up a stem, the
energy balance of the system is [more or less intensively]
monitored, and in the case of the heat probe method, an applied
pulse of heat is used to measure the speed of flow.

The cross sectional area through which the sap is flowing is
required to convert the amount of energy transported with the sap
into a volume. (And knowing the specific heat capacity of the
sap, this is possible).

However, does the placement of the needle with respect to how
much sap wood, heart wood, or other discontinuous or abnormal
portion of the stem affect the measured result?

And more specifically, does one not need to know the fraction of
cross sectional area of stem vessels large enough to be
transporting the fluid relative to the whole stem area?

In other words, do different "plumbing systems" have different
abilities to transport water and does/can the heat pulse method
to account for this?
(Larger vessels are more likely to embolize (collapse under
pressure), but are also where most of the water flows).
Does their relative frequency and size distribution affect heat
pulse methods?

Another point is that the calibration of these methods is often
done by the so called cut-plant technique. The transpiring plant
is monitored prior to and after being severed and placed in a
weighed volume of water. The loss in water sucked up by the
planted is used to calibrate the actual amounts moving up the
stem.
It has been argued that the completely disturbed tension
relationships within the plant must upset the system so much that
the calibration is invalid. However, looking at the trace of sap
flow over time, there is indeed a large perturbation on severing
the plant, but the levels return to the approximate pre-cut
values for a while at least before tailing off. During this time,
even though the tension dynamics are not what they would be under
a healthy plant, the sap flow is still measured at the similair
amounts, and so must be valid????

The message below and some local values of tree water use
calcualted by sap flow have prompted this inquiry.

Can anyone suggest a more relevant list to pose this question?

Thanks

-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.
Bruce Metelerkamp SOIL WATER RESEARCH OFFICER
Institute for Commercial Forestry Research,
University of Natal, PO Box 100281
Scottsville, ZA3209
Rep. of South Africa Voice:27 331 62314
E-mail: bruce@icfr.unp.ac.za FAX:27 331 68905
URL http://www.icfrnet.unp.ac.za/~metele
/SoWaCS.html
/RR.html

<<<<<>>>>>
From: Evan Christen (trickle-l) Monday, February 12, 1996
<SNIP>
.. Also sap flow gauges can provide a direct measure of
plant volumetric consumption. The correct 'translation' of ET
information from a depth based system (volume/unit area) to a
volumetric system (volume/plant) is clearly not
SIMPLE!"..............

I believe the work with sap flow sensors on grapevines and citrus
here in Australia indicates that the actual plant water use may
be only 30% of the calculated ET. This must mean we are
calculating ET incorrectly or that the direct evaporation
components are the major part of ET or this could be
rationalised by saying that the non-uniformity of irrigation
appication, root distribution, soil texture and structure are
such that ET is an averaging on a paddock scale of all factors
and thus it cannot be compared to actual individual plant water
use? Agree/disageree?

If plant water use is as low as the early results show then water
use efficiency has even futher to go!
<SNIP>

End of Digest
************************

From root@crcnis1.unl.edu Thu Apr 18 14:21 EDT 1996
Date: Thu, 18 Apr 1996 13:12:44 -0500
Message-Id: <199604181812.AA19684@crcnis1.unl.edu>
Errors-To: rmead@asrr.arsusda.gov
Reply-To: <trickle-l@unl.edu>
To: Multiple recipients of list <trickle-l@unl.edu>
Subject: TRICKLE-L digest 476

Contents:
drip hose cleaner (Royce Goertzen <royce@mobynet.com>)
Re Sapflow (meissner.tony@wpo.pi.sa.gov.au)
Re: Salinity probes (Richard Mead <rmead@cybergate.com>)
Re: Salinity probes (Stephen Rawlins <srawlins@ncw.net>)
Re: Salinity probes (js000021@pixie.co.za)
Re: Salinity probes (ldud@rbt.agsci.usu.edu (Lynn Dudley))
Re: Salinity probes (Stephen Rawlins <srawlins@ncw.net>)

Date: Wed, 17 Apr 1996 13:32:25 +0000
From: Royce Goertzen <royce@mobynet.com>
Subject: drip hose cleaner

To all on trickle-l:
I've installed a new drip system in a vineyard in Fresno Co.,
California with .5gph emitter per vine. Pumping requirements are 500 gph. My
water quality at the moment is
pH 7.2 pHc 7.1 Ecw(ds/m) .68 Carbonate/bicarb meq/l 4.3 Nitrate
N 9.8 ppm
SAR 1.1 Adjusted RNa 2.7

From this sample I predicted that I would have some CaCO3
precipitate. My question is what is the experience of the irrigators on this
list with products such as LineMaster or Drip a Tron in keeping a brand new
system functioning optimally? Are they worth the cost of setting up a
continous metering device? Do they work? Are their others products that do
the same? Since my nitrate/nitrogen is high for a vineyard I do not want to
use an acid base fertilizer such as N-furic.

Royce
royce@mobynet.com

Date: Thu, 18 Apr 1996 09:14:14 +0930
From: meissner.tony@wpo.pi.sa.gov.au
Subject: Re Sapflow

In answer to Bruces comments, a sapflow calibration was carried out on several potted vines, the water loss being calculated by
lost of weight. Losses of water via soil evaporation were prevented. The calibration showed that the sapflow was overestimating
transpiration by 5%.

Evan indicated that for citrus and vines transpiration was about 30% of ETo and he posed the question of whether we are
calculating ETo in the right way. In a way that does not matter as it is a "standard" against which we calculate our crop factors. The
way I interpreted the 30% figure compared to around 70% - 80% was that we are losing a lot from soil evaporation and some
drainage. This is supported by comapring volumes of water applied to young citrus via drip and the measured sapflow figures
being in close agrreement with the volume of water supplied.

Cheers
Tony M :-)
***************************************************
Tony Meissner
Senior Research Scientist (Soils)
Primary Industries, South Australia
PO Box 411, Loxton SA, Australia 5333
Tel. +61 85 95 9146
Fax: +61 85 95 9199
email meissner.tony@pi.sa.gov.au
***************************************************

Date: Wed, 17 Apr 1996 21:07:38 -0400
From: Richard Mead <rmead@cybergate.com>
Subject: Re: Salinity probes

Freddie,

In my days at the U.S. Salinity Lab, we worked with two
instruments that measured soil salinity:

1) The Martek 4-probe which you actually had to soil sample
a hole and insert the probe and get good contact.

and

2) The Geonics EM-38 meter, which is laid on the soil surface
and interprets what the soil salinity using magnetic
induction about a meter down.

The way we measure soil salinity here is good old soil sampling
using a giddings rig...what fun!... :)
There was a gentlemen on Trickle-L several months ago from
Holland who sold FDR probes which also read in situ salinity.
However, the range only went up to 4.0 dS/m. I'll try to remember
to peek through the Trickle-L archives to see what his name and email address
was.

I plan to call Scott Leach (the instrument guru) at the U.S.S.L next
week anyway for related questions, so I'll pose your question to him also.

Of course...there is always "Salinity-L" which was started
here at the Water Management Reseach Lab by webmaster Richard
Soppe. Are you a subscriber to that list? I guess if you were
you would have posted by now. I can always cut and paste your
comments and post to that group at no charge :)

I'll get back to you on this. Hope what ever I gave you
helped a little.

Richard Mead
Soil Scientist
Trickle-L and M.I.F. owner/manager
http://www.cybergate.com/~rmead

At 05:36 PM 4/16/96 -0500, you wrote:
>Anyone out there that can give a brief summary of experiences on
>using salinity probes for measuring soil salinity profiles under
>SDI ???
>
>Particularly about,
>Accuracy and scale of measurement (point or sizable volume)
>Ease of use
>Depth of operation
>Calibration requirements (data needs or processes required)
>Ballpark instrument costs
>Any significant operating costs
>Quirks or special cases
>
>Freddie Lamm *
>

Date: Wed, 17 Apr 1996 22:07:25 -0700
From: Stephen Rawlins <srawlins@ncw.net>
Subject: Re: Salinity probes

Now in my days at the Salinity Lab., which were a few years ago I must
admit, there were three salinity probe efforts. One, developed by L. A.
Richards, measured the electrical conductivity within a porous sensor block.
I think Soil Moisture Equipment Co. of Santa Barbara commercialized and
sells these.

Another was based on the thermocouple psycrhometer we developed, and which
is now manufactured by Westcor, Logan, UT. This application was very
precise, but is applicable only to the lab. The psychrometer measures total
potential, the sum of the matric and osmotic potentials. We separated the
two component potentials by placing the psychrometer in a pressure chamber
and increasing the air pressure inside in increments. Each increment
balanced an equal increment of matric potential, raising the total potential
measured by the psychrometer. When the matric potential was fully
compensated for, free water filled the pores of the psychrometer chamber
wall, and increasing the air pressure no longer changed the reading of the
psychrometer. At this point the psychrometer measured osmotic potential. I
can provide reprints for this if someone is interested.

A third sensor is described in the SCIENCE Vol 224, ;p. 989, 1984 article
"Time-Domain Reflectometry: Simultaneous Measurement of Soil Water Content
and Electrical Conductivity with a Single Probe", by F. N. DAlton, W. N.
Herkelrath, D. S. Rawlins (not me -- my son), and J. D. Rhodes. I think
this idea has tremdous potential, but to my knowledge it has not been
commercialized.

Enough history, perhaps.

Steve
USDA/ARS -- Retired Richland, WA 99352
APPROPRIATE SYSTEMS Phone 509-627-4943
(Precision Farming Consultants) FAX 509-627-1841
2638 Eastwood Avenue Email srawlins@ncw.net

Date: Thu, 18 Apr 1996 08:44:28 +0000
From: js000021@pixie.co.za
Subject: Re: Salinity probes

> A third sensor is described in the SCIENCE Vol 224, ;p. 989, 1984 article
> "Time-Domain Reflectometry: Simultaneous Measurement of Soil Water Content
> and Electrical Conductivity with a Single Probe", by F. N. DAlton, W. N.
> Herkelrath, D. S. Rawlins (not me -- my son), and J. D. Rhodes.

Is it possible to obtain a copy perhaps?
Regards
Johan Smit

Date: Thu, 18 Apr 1996 06:18:46 +0700
From: ldud@rbt.agsci.usu.edu (Lynn Dudley)
Subject: Re: Salinity probes

Steve wrote:

> A third sensor is described in the SCIENCE Vol 224, ;p. 989, 1984 article
> "Time-Domain Reflectometry: Simultaneous Measurement of Soil Water Content
> and Electrical Conductivity with a Single Probe", by F. N. DAlton, W. N.
> Herkelrath, D. S. Rawlins (not me -- my son), and J. D. Rhodes. I think
> this idea has tremdous potential, but to my knowledge it has not been
> commercialized.
>
A number of people are working to commercialize or otherwise make TDR
technology available. Dani Or (Utah State University) and John Wraith
(Montana State University) have developed software that interpretes the
TDR trace giving both salinity and water content. Dani and I used them
in the field last year to monitor salt and water movement with irrigation.
They worked very well and we were able to collect data in 15 minute
intervals. We're going to use the system to monitor salt and water
movement over a couple of irrigation cycles this year and we'll try
to get the work published this fall. We should have a report that describes
last year's work, published through the Utah Ag. Exp. Station, sometime
this summer. I digress...

Dani Or can be contacted by email at DANI@TAL.AGSCI.USU.EDU or through
his homepage HTTP://TAL.AGSCI.USU.EDU. I believe that he has some
information on his TDR work on his homepage. That might be the best
place to start.

Lynn M. Dudley
Dept. of Plants, Soils, and Biomet.
Utah State University 84322-4820
Phone (801) 797-2184
FAX (801) 797-3376

They run for fun in the hot, hot sun
>From there to here and here to there
Funny things are everywhere - Suess

Date: Thu, 18 Apr 1996 09:17:02 -0700
From: Stephen Rawlins <srawlins@ncw.net>
Subject: Re: Salinity probes

Frank Dalton and Jim Rhoades are still at the Salinity Lab. Jim's phone
number is 909-369-4815. I don't have one listed for Frank, but Jim can give
it to you. The Email for Mike Shannon, the new Salinity Lab Director, is
a03mshannon@attmail.com. He would pass a note along to Frank to send you a
reprint.

If all else fails, I have a reprint that I could copy and send to you.

Steve

At 01:35 AM 4/18/96 -0500, you wrote:
>> A third sensor is described in the SCIENCE Vol 224, ;p. 989, 1984 article
>> "Time-Domain Reflectometry: Simultaneous Measurement of Soil Water Content
>> and Electrical Conductivity with a Single Probe", by F. N. DAlton, W. N.
>> Herkelrath, D. S. Rawlins (not me -- my son), and J. D. Rhodes.
>
>Is it possible to obtain a copy perhaps?
>Regards
>Johan Smit
>
>
USDA/ARS -- Retired Richland, WA 99352
APPROPRIATE SYSTEMS Phone 509-627-4943
(Precision Farming Consultants) FAX 509-627-1841
2638 Eastwood Avenue Email srawlins@ncw.net

End of Digest
************************

From root@crcnis1.unl.edu Fri Apr 19 14:24 EDT 1996
Date: Fri, 19 Apr 1996 13:13:15 -0500
Message-Id: <199604191813.AA04958@crcnis1.unl.edu>
Errors-To: rmead@asrr.arsusda.gov
Reply-To: <trickle-l@unl.edu>
To: Multiple recipients of list <trickle-l@unl.edu>
Subject: TRICKLE-L digest 477

Contents:
Re: drip hose cleaner (sjordan@seldon.terminus.com (Steve Jordan))
Crop water use & irrig research project ("Bruce Metelerkamp" <BRUCE@mailgate.icfrnet.unp.ac.za>)
Re: drip hose cleaner ("M. Meron" <MERON@migal.co.il>)
Re: Crop water use & irrig research project (Stephen Rawlins <srawlins@ncw.net>)
12 ppm Fe!!! (storlie@AESOP.RUTGERS.EDU)
Re: 12 ppm Fe!!! (dagoldhamer@ucdavis.edu)

Date: Thu, 18 Apr 1996 18:34:37 -0700
From: sjordan@seldon.terminus.com (Steve Jordan)
Subject: Re: drip hose cleaner

>
> From this sample I predicted that I would have some CaCO3
>precipitate. My question is what is the experience of the irrigators on this
>list with products such as LineMaster or Drip a Tron in keeping a brand new
>system functioning optimally? Are they worth the cost of setting up a
>continous metering device? Do they work? Are their others products that do
>the same? Since my nitrate/nitrogen is high for a vineyard I do not want to
>use an acid base fertilizer such as N-furic.
>
>

They can work. I use both Linemaster at one site and a product called
SureFlow by CH20. My major problem has been iron precipitate, so my
experience is biased.

Both work, line master is more money. We havent solved all our problems,
though.
Steve Jordan @ Second Foundation

Date: Fri, 19 Apr 1996 9:00:16 +200
From: "Bruce Metelerkamp" <BRUCE@mailgate.icfrnet.unp.ac.za>
Subject: Crop water use & irrig research project

Researchers at Soil Physicas at the Texas Agricultural Experiment
Station Lubbock, Texas are busy with the following project:

(Found on the Web page:
http://achilleus.tamu.edu/projects/projects.html )

Real Time Measurement and Calculation of Crop Water Use and
Application: an Integrated Approach

The objectives of this research are: 1) to provide a computer
system that integrates in real time the
measurement and calculation of plant water requirements and the
control of a water delivery system
(irrigation); and, 2) to compare the efficiency and effectiveness
of real time control, based on direct
measurements, with that of control based on computer simulation
that is periodically verified with
field measurements.

PROJECT SUMMARY

Urban and agricultural areas increasingly compete for water
resources.
Agriculture claims a large portion of water removed
from rivers, lakes and aquifers thus making efficiency in
irrigation a top priority to move towards a sustainable water
use.
Agencies such as the Texas Water Commission and Texas Water
Development Board must have up-to-date information on
statewide agricultural water use requirements to comply with the
forthcoming Texas Water Plan. Thus, there is need for an
accurate method to calculate and to measure crop water use on a
real time basis. We propose to implement a system that
combines existing knowledge of crop water use and newly developed
technology to control the timely application of water in
the correct amount. The technologies involved are the measurement
of plant water use with electronic stem gauges and
measurement of soil water with time domain reflectometry.
Measurements are coupled with calculated values of crop water
use obtained with the mechanistic simulation model, ENWATBAL,
developed at Texas A&M University. The proposed
system is integrated because all functions, e.g., measurements,
model execution, activation of water delivery system, are
controlled by a single computer. The proposed research relies on
the active participation of both Graduate and
Undergraduate students. The use of the specialty equipment will
be supported by the participation of two Texas companies,
Dynamax Inc. of Houston and Vadose Zone Equipment of Amarillo. We
will test and evaluate the proposed system over a
two year period using cotton under a drip irrigation system in
Lubbock, TX. The resulting system could be used as a
research tool by scientists, to schedule irrigations by farmers,
and to determine the water requirements of different crops,
trees and ornamentals by urban and agricultural planners.

http://achilleus.tamu.edu/projects/f307/f307.html

--
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.
Bruce Metelerkamp SOIL WATER RESEARCH OFFICER
Institute for Commercial Forestry Research,
University of Natal, PO Box 100281
Scottsville, ZA3209
Rep. of South Africa Voice:27 331 62314
E-mail: bruce@icfr.unp.ac.za FAX:27 331 68905
URL http://www.icfrnet.unp.ac.za/~metele
/SoWaCS.html
/RR.html

Date: Fri, 19 Apr 1996 10:25:46 GMT+0200
From: "M. Meron" <MERON@migal.co.il>
Subject: Re: drip hose cleaner

You may use Phosphoric acid as P fetilizer to clean CaCO3 deposits, without
spending money for special cleaning materials.
=========================================================================
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: Fri, 19 Apr 1996 01:08:42 -0700
From: Stephen Rawlins <srawlins@ncw.net>
Subject: Re: Crop water use & irrig research project

At 02:43 AM 4/19/96 -0500, Bruce Metelerkamp wrote:
>Researchers at Soil Physicas at the Texas Agricultural Experiment
>Station Lubbock, Texas are busy with the following project:
>
>(Found on the Web page:
>http://achilleus.tamu.edu/projects/projects.html ) . . .
>
>PROJECT SUMMARY
>
>Urban and agricultural areas increasingly compete for water
>resources.
>Agriculture claims a large portion of water removed
>from rivers, lakes and aquifers thus making efficiency in
>irrigation a top priority to move towards a sustainable water
>use.
>Agencies such as the Texas Water Commission and Texas Water
>Development Board must have up-to-date information on

Very interesting proposal. I'll look forward to seeing some results. The
WEB page referred to was last updated September 1995. It might be
informative to place your note there, as well as progress notes.

Steve Rawlins
USDA/ARS -- Retired Richland, WA 99352
APPROPRIATE SYSTEMS Phone 509-627-4943
(Precision Farming Consultants) FAX 509-627-1841
2638 Eastwood Avenue Email srawlins@ncw.net

Date: Fri, 19 Apr 1996 09:00:03 -0400 (EDT)
From: storlie@AESOP.RUTGERS.EDU
Subject: 12 ppm Fe!!!

Looking for HELP!

I have a grower contemplating a land purchase for bell pepper
production using mulch and drip. Results of a preliminary water
test from a well on the site were (in ppm except for pH): TDS =
490; Hardness (as CaCO3) = 65; Chloride = 50; Iron = 12; pH = 6.8.

I am concerned about the iron level. We have growers using
water with iron at 3 ppm with NO clogging or iron bacteria problems
(guess those bact. don't like our winters). However, our water
normally comes out of the ground at pH = 5.0 (and out of the sky at
pH = 2.0 - 3.0) and iron and everything else stays in solution. At
ph = 6.8, I'm wondering what to recommend.

I will suggest he buy the land, grow the crop, and hope its a
wet year. I will also suggest that he flush the system regularly,
open hose ends and inspect for precipitates, monitor the flow rate,
and if anything appears funny he begin an acid reclamation project
and a chlorine oxidation regime (he doesn't want to start with
either of the latter).

Does anyone have experience with iron levels this high? I'd
like to hear from you.

Craig Storlie
Extension Specialist n Agricultural Engineering
Rutgers University

Date: Fri, 19 Apr 1996 08:07:01 -0700
From: dagoldhamer@ucdavis.edu
Subject: Re: 12 ppm Fe!!!

A couple years ago, I visited Macedonia to try to solve an iron
precipitation problem. High levels of iron in the well water had produced
precipitates that plugged conventional tortuous path emitters resuling in
one of the few drip systems in that country being ripped out after 6 years;
replaced by flood irrigation. Since that country has limited availability
of acids and other possible chemical solutions, we set up a trial using the
Bowsmith, Inc. "Non Stop" emitters. These are designed for "dirty water"
and use layers of rubber disks with small holes that allow particles to
pass through the emitter. As far as I know, these emitters solved the
problem.

Bowsmith is located in Exeter, CA; about 50 SE of Fresno.

Dave Goldhamer

End of Digest
************************

From root@crcnis1.unl.edu Sat Apr 20 14:22 EDT 1996
Date: Sat, 20 Apr 1996 13:14:02 -0500
Message-Id: <199604201814.AA28580@crcnis1.unl.edu>
Errors-To: rmead@asrr.arsusda.gov
Reply-To: <trickle-l@unl.edu>
To: Multiple recipients of list <trickle-l@unl.edu>
Subject: TRICKLE-L digest 478

Contents:
Re: Sap flow sensors-Problems with technique (Jerome Pier <jpier@interramp.com>)
Re: 12 ppm Fe!!! (sjordan@seldon.terminus.com (Steve Jordan))
VEG-PROD> American Society for Plasticulture (fwd) (storlie@AESOP.RUTGERS.EDU)
RE: VEG-PROD> American Society for Plasticulture (fwd) (dreynold@cd-eso.water.ca.gov (Dean Reynolds))
Re: VEG-PROD> American Society for Plasticulture (fwd) (GroAire@aol.com)

Date: Fri, 19 Apr 1996 11:42:06 -0700
From: Jerome Pier <jpier@interramp.com>
Subject: Re: Sap flow sensors-Problems with technique

Bruce Metelerkamp wrote:
> [stuff deleted]

> However, does the placement of the needle with respect to how
> much sap wood, heart wood, or other discontinuous or abnormal
> portion of the stem affect the measured result?

A word of caution when using sap-flow cuffs with perrenials. I have seen two
instances where the sap flow gage has girdled young saplings. A friend of mine was doing
his research on water balance of young mesquite trees using sap flow gages. He almost
never completed his doctorate for he killed every tree he obtained with the gages.
Another fellow at Sap flow symposium at the ASA meetings in Denver in 1991 discussed the
same problem with larger trees. Sap flow gages seem to work quite well with annual
plants which do not have a cambium. My 2 cents!
--
Jerome Pier
Soil Scientist/Agronomist
Netafim Irigation, Inc.
jpier@interramp.com

Date: Fri, 19 Apr 1996 12:14:36 -0700
From: sjordan@seldon.terminus.com (Steve Jordan)
Subject: Re: 12 ppm Fe!!!

>test from a well on the site were (in ppm except for pH): TDS =
>490; Hardness (as CaCO3) = 65; Chloride = 50; Iron = 12; pH = 6.8.
>
>
> I will suggest he buy the land, grow the crop, and hope its a
>wet year. I will also suggest that he flush the system regularly,
>open hose ends and inspect for precipitates, monitor the flow rate,
>and if anything appears funny he begin an acid reclamation project
>and a chlorine oxidation regime (he doesn't want to start with
>either of the latter).

Flush is a good idea. To resolublize the ferric it takes a ph under 4.0.
That can be problematic... Linemaster has "new" acidifiying dry chemical.
Haven't seen it yet.
>
> Does anyone have experience with iron levels this high? I'd
>like to hear from you.
>
>

Supposedly, there are farmers using drip with 29 ppm Fe in Washington. CH20
supplies them with the cleaner. According to the company, the farmer
undertreats the water and gets 1 to 2 years. According to the formulas,
full treatment is prohibitively expensive.

It is not Fe but the Ferric that causes problems. You should measure Fe
soluble at the well and total Fe to get the amount of Ferric. Ferrous
(Fe++) is soluble and can stay in solution. Ferric (Fe +++) precipitates,
often forming larger particles in too late to be caught by filter. Also Fe
precipitate sits in bottom of tape and "catches" slimey bacteria.

Textbook solutions to iron precipitate: Lower pH to 4.0
or oxidize with Cl
or reservoir to settle
or some of these polymoleic acid or poly phosphonate.

be aware not all magic chemical "attack" iron the same way.
Steve Jordan @ Second Foundation

Date: Fri, 19 Apr 1996 15:15:37 -0400 (EDT)
From: storlie@AESOP.RUTGERS.EDU
Subject: VEG-PROD> American Society for Plasticulture (fwd)

Trickle Group:

Attached is a message briefly describing the upcoming American
Society for Plasticulture Congress. This meeting is being held in New
Jersey in mid-June, 1996. Drip irrigation is usually an important part
of this group's emphasis, but many other "plastic" topics are covered. If
you would like to receive a complete description of the meeting, drop me
an email.

Craig Storlie
Extension Specialist in Agricultural Engineering
Rutgers University

---------- Forwarded message ----------
Date: Wed, 06 Mar 1996 16:56:54 -0400 (EDT)
From: vanvranken@AESOP.RUTGERS.EDU
To: veg-prod@maat.reeusda.gov,
The multiple recipients of the list <veg-prod@reeusda.gov>
Subject: VEG-PROD> American Society for Plasticulture

ASP96 Congress
and
American Greenhouse Vegetable Growers Association Confer,
New.Jersey.June.14.-.18@maat.reeusda.gov, 1996@maat.reeusda.gov

The 26th Congress of the American Society for Plasticulture promoting
the theme of Educating the Teachers of Plasticulture for the Future will
convene June 14-18, 1996 in Atlantic City, New Jersey at the boardwalk
Holiday Inn under the direction of A.S.P. President Gene A. Giacomelli of
Rutgers Cook College Bioresource Engineering Department. Conference
Co-Chair's Craig Storlie, Pete Nitzsche, Bill Tietjen and Rick
VanVranken of Rutgers Cooperative Extension invite all persons interested
in plasticulture to attend and present their research and development in
plasticulture, and join in this opportunity for education and information
exchange. For the first time, the American Greenhouse Vegetable Growers
Association will convene during the ASP conference, bringing a
major complimentary aspect of Greenhouse production to ASP.

Several innovative programming ideas will be presented within
the four day congress. Two conference protocols new to ASP are the
educational, hands-on, demonstration workshops, and technical paper
presentations utilizing a shortened, "to the point" 10 minute format.
Traditional on-farm tours and technical sessions will round out the
congress. In addition, the AGVGA, The American Greenhouse Vegetable
Growers Association will provide a full day session, consisting of 10
invited lecture presentations focusing on greenhouse vegetable production.

ASP96 will capitalize not only on Rutgers expertise in intensive
plasticulture of field-grown row crops, long a tradition at Rutgers
and New Jersey, but also the University's nationally-recognized
excellence in controlled environment plant production technology of
greenhouses. Therefore, ASP96 will have the double focus of field grown
vegetable crops and greenhouse crops. CCEA, the Center for Controlled
Environment Agriculture, as a co-sponsor and cooperator for the congress, will
boost the greenhouse systems and technology component, while AGVGA will
complement the greenhouse vegetable crop, plant production aspects.

Education within the industry, from county agents and regional
specialists to our national and international industrial and manufacturing
colleagues, is one major goal for the conference. There are
great opportunities for professional improvement available to the
conference participants in New Jersey, with access to the vast and highly
developed intensive agricultural business community, and the university-
based cooperative extension research and development network. Education
of this segment of people who "reach and teach the people" will become a h
ighly efficient means to inform those in need of plasticulture technology.
Attendees will be encouraged to participate, not only for the
learning experience, but also for the expertise and regional experiences
that they can bring to ASP96.

The organizing committee anticipates an exciting and unique opportunity
for professional interaction at the ASP Congress, not only from the diversity
of the national and international participants expected to attend, but also
because of both their multi-disciplinary and cross-professional interests which
they bring. The 26th Congress will be a technically fulfilling and highly
exciting opportunity for ASP, as it returns to one of the most prominent
areas of intensive production agriculture in the US. Some of the most
innovative and earliest advancements in the plasticulture revolution were
completed by New Jersey researchers and growers.

Registration fees which are all inclusive (technical sessions, tour,
workshops, proceedings, banquet, reception, 2 lunches, 1 breakfast) are $22
5 for members of ASP or AGVGA. A weekend special is offered for Sat/Sun
(tour & workshop & proceedings only) for $175. The Holiday Inn Boardwalk
Hotel is $100 per night, single or double occupancy.

For more information contact :
Dr. Gene Giacomelli
Bioresource Engineering
Box 231 Cook College
New Brunswick, NJ 08903.
(908) 932-9753 phone; (908) 932-7931 FAX;
E-mail: giacomel@bioresource.rutgers.edu

26th Congress of the American Society for Plasticulture
and
American Greenhouse Vegetable Growers Association Conference

Atlantic City, New Jersey
June 14 - 18, 1996
_______________________________________________________________________________

Academic & Grower Registration Form
Use this form for academics, growers, researchers, government, press,
and guests
_______________________________________________________________________________

4-Day Congress 2-Day Weekend Special
(Circle Appropriate Fee) by May 1 after May 1 by May 1 after May 1 Total

ASP or AGVGA $225 $275 $175 $225 ______
Member

Non-member $275 $325 $225 $275 ______

Spouse Registration Before June 1st
(cannot guarantee after Banquet $50 ______
June 1st) Tour (& clambake) $45 ______
Clambake $30 ______
Workshop $40 ______

Total Enclosed (make check payable to "A.S.P." in U.S. $) ______

4-Day Congress Registration fee includes: ASP technical sessions, AGVGA
conference sessions, tour, workshop, conference proceedings, reception,
5 meals (Saturday Tour box lunch, Saturday night clambake, Sunday Workshop
B-B-Q lunch, Sunday night banquet & Tuesday breakfast). Spouse included
except for food, tour and workshop events.

2-Day Weekend Special Registration fee includes: weekend activities
(tour, workshop, conference proceedings, reception, 3 meals (Saturday Tour box
lunch, Saturday night clambake, Sunday Workshop B-B-Q lunch). DOES NOT
INCLUDE THE SUNDAY BANQUET OR THE AGVGA CONFERENCE SESSIONS, OR MONDAY AND
TUESDAY EVENTS.

The Holiday Inn Boardwalk Hotel (800) 548-3030 is $90.00 per night (4-day
stay), or is $110 per night (weekend only), both are single or double
occupancy, plus 6% state tax and 12% city tax. Reserve room prior to
May 13th. Rooms and prices are not guaranteed after May 13th.

? Tour Preference: Tour 1 ____ Tour 2 ____ Tour 3 ____
I will not attend Tour ____
(select 1st & 2nd choice)

? Workshop Station Preference: ____ ____ ____ ____ ____
I will not attend Workshop ____

Mail by June 1st to:
Gene Giacomelli
Bioresource Engineering
Box 231
Cook College
New Brunswick, NJ 08903
(908) 932-9753 voice; [-7931 FAX];
E-mail: giacomel@bioresource.rutgers.edu

your name / spouse name____________________________________________

address/POB __________________________________________________

address __________________________________________________

city, state & ZIP__________________________________________________

phone/FAX/E-mail __________________________________________________

Date: Fri, 19 Apr 96 11:54:19 PDT
From: dreynold@cd-eso.water.ca.gov (Dean Reynolds)
Subject: RE: VEG-PROD> American Society for Plasticulture (fwd)

Date: Fri, 19 Apr 1996 21:50:34 -0400
From: GroAire@aol.com
Subject: Re: VEG-PROD> American Society for Plasticulture (fwd)

There was no message attached and there are participants interested in your
organization.

Dave Enyeart
GroAire@aol.com

End of Digest
************************

From root@crcnis1.unl.edu Sun Apr 21 14:22 EDT 1996
Date: Sun, 21 Apr 1996 13:14:33 -0500
Message-Id: <199604211814.AA23791@crcnis1.unl.edu>
Errors-To: rmead@asrr.arsusda.gov
Reply-To: <trickle-l@unl.edu>
To: Multiple recipients of list <trickle-l@unl.edu>
Subject: TRICKLE-L digest 479

Contents:
RE: 12 ppm Fe!!! (Manrique Brenes <mjbrenes@ucdavis.edu>)
Drip irrigation census. (Manrique Brenes <mjbrenes@ucdavis.edu>)
RE: 12 ppm Fe!!! (sjordan@seldon.terminus.com (Steve Jordan))
ET Rates for Canczn, Mexico (shrevem@interserv.com)
Microirrigation in Landscaping (rmead@CyberGate.COM (Richard Mead))

Date: Sat, 20 Apr 1996 19:05:01 -0700
From: Manrique Brenes <mjbrenes@ucdavis.edu>
Subject: RE: 12 ppm Fe!!!

Iron Precipitation problems in Guatemala and Colombia have been =
traditionally solve with aeration. It is usually cheaper and safer to =
oxidize the Ferric by any aeration system (it can be done by just =
pumping a few meters above a reservoir and then releasing the water in a =
cascade). The reservoir shoul act as a settling basin before the =
filters.

Manrique Brenes
Bio. & Ag. Eng.
UC Davis

----------
From: Steve Jordan[SMTP:sjordan@seldon.terminus.com]
Sent: Friday, April 19, 1996 12:12 PM
To: Multiple recipients of list
Subject: Re: 12 ppm Fe!!!

>test from a well on the site were (in ppm except for pH): TDS =3D
>490; Hardness (as CaCO3) =3D 65; Chloride =3D 50; Iron =3D 12; pH =3D =
6.8.=20
>=20
>=20
> I will suggest he buy the land, grow the crop, and hope its a
>wet year. I will also suggest that he flush the system regularly,
>open hose ends and inspect for precipitates, monitor the flow rate,
>and if anything appears funny he begin an acid reclamation project
>and a chlorine oxidation regime (he doesn't want to start with
>either of the latter).

Flush is a good idea. To resolublize the ferric it takes a ph under =
4.0. =20
That can be problematic... Linemaster has "new" acidifiying dry =
chemical. =20
Haven't seen it yet.
>=20
> Does anyone have experience with iron levels this high? I'd
>like to hear from you.
>=20
>

Supposedly, there are farmers using drip with 29 ppm Fe in Washington. =
CH20=20
supplies them with the cleaner. According to the company, the farmer=20
undertreats the water and gets 1 to 2 years. According to the formulas, =

full treatment is prohibitively expensive.

It is not Fe but the Ferric that causes problems. You should measure Fe =

soluble at the well and total Fe to get the amount of Ferric. Ferrous=20
(Fe++) is soluble and can stay in solution. Ferric (Fe +++) =
precipitates,=20
often forming larger particles in too late to be caught by filter. Also =
Fe=20
precipitate sits in bottom of tape and "catches" slimey bacteria.

Textbook solutions to iron precipitate: Lower pH to 4.0
or oxidize with Cl
or reservoir to settle
or some of these polymoleic acid or poly phosphonate.

be aware not all magic chemical "attack" iron the same way.
Steve Jordan @ Second Foundation

Date: Sat, 20 Apr 1996 20:19:15 -0700
From: Manrique Brenes <mjbrenes@ucdavis.edu>
Subject: Drip irrigation census.

I need some numbers on total drip irrigated area in the world. Data per country would also be very useful.
If anyone knows where to find this information please let me know.

Manrique Brenes
Bio. & Ag. Eng.
UC Davis

Date: Sat, 20 Apr 1996 21:20:02 -0700
From: sjordan@seldon.terminus.com (Steve Jordan)
Subject: RE: 12 ppm Fe!!!

>Iron Precipitation problems in Guatemala and Colombia have been =
>traditionally solve with aeration. It is usually cheaper and safer to =
>oxidize the Ferric by any aeration system (it can be done by just =
>pumping a few meters above a reservoir and then releasing the water in a =
>cascade). The reservoir shoul act as a settling basin before the =
>filters.
>
>

Supposedly you need 12 to 24 hours storage to get all the iron out.
Steve Jordan @ Second Foundation

Date: Sat, 20 Apr 1996 21:36:01 -0700
From: shrevem@interserv.com
Subject: ET Rates for Canczn, Mexico

Listmembers:

I am in need of historical ET data for the Canczn, Mexico area.
After a couple weeks of searching, (over 140 websites) I have come
up dry. Any help you could offer would be greatly appreciated.

Sincerely,

Michael R. Shreve
Regional Manager, Latin America
Rain Bird International, Inc.

telephone: (941) 682-6252
fax: (914) 686-9634
e-mail: shrevem@interserv.com

Date: Sun, 21 Apr 1996 16:17:53 GMT
From: rmead@CyberGate.COM (Richard Mead)
Subject: Microirrigation in Landscaping

Trickle-L got a little plug recently in "Landscape and Irrigation" magazine
(April '96 issue, page 55). Soon after I read the short article, I noticed
a flurry of new subscribers whom I assume might be "L & I" readers. If so,
I thought I would welcome the landscape people to our coffee shop of drip
irrigation chat.

The agricultural people can always learn from the landscape people since we
all live in some sort of home, condo or apartment that has surrounding
landscape which might use some sort of irrigation system...possibly drip?

>From what I've been reading, drip (let's say microirrigation to include all
forms) is experiencing an accelerated growth in the landscape industry,
especially in the U.S.
The precise nature of microirrigation along with the water conservation
mind-set of any area, arid or humid, will help expand microirrigation's
popularity. Microirrigation is really growing in landscape areas such as
islands, hillsides or median strips in urban areas. Also, shrub beds,
planters near buildings, and high wind areas have a potential niche for the
microirrigation market.

I could list numerous positive aspects of microirrigation, but I think we
should discuss the disadvantages so that we can possibly work out solutions
to the problems.

Most people probably think (and rightfully so) that microirrigation will
take more maintenance. Clogging emitters are probably the number one issue
that would lead to
the landscape designer to think twice about what to put where and how much
time the
groundskeeper has to check things. This fact along with maturing bushes or
plants that would obstruct the view of the plugged emitter increases the
problem.

My backyard is 90% drip, but I must admit, it's a real pain to check all
the emitters
under or near the bushes to make sure they are all working. One particular
company I purchased some emitters from several years ago, produced the
emitters that have a small whistle sound so I can hear where the emitter
is..if it's working. Now that she has grown, my second dog just recently
stopped chewing on exposed emitters....(the wonders of owning a puppy). I
basically solved that problem by putting the emitter right into the
polyethylene tubing and eliminated the spaghetti tubing.

There is some talk about microirrigation not having the water to wash off
leaves of some species of plants such that spider mite populations could
explode. Microirrigation also needs pressure regulation and
filtration...another maintenance up keep.

Another issue I have found frustrating is the non-uniform color coding of
the drip industry...some companies color code their 1/2 gph (2 lph)
emitters red while another will color it green. The same issue applies with
microsprays systems.
Is there a standard within the industry?

In general, microirrigation is an efficient irrigation system with many
benefits for the landscape industry, but has a steeper learning and
maintenance curve than other systems.

If you have comments about some of the problems of landscape
microirrigation which I have not covered, or want to expand on what I
presented, please feel free to comment.

Richard Mead
Soil Scientist
Trickle-L and M.I.F. owner/manager
http://www.cybergate.com/~rmead

End of Digest
************************

From root@crcnis1.unl.edu Mon Apr 22 14:23 EDT 1996
Date: Mon, 22 Apr 1996 13:14:40 -0500
Message-Id: <199604221814.AA01153@crcnis1.unl.edu>
Errors-To: rmead@asrr.arsusda.gov
Reply-To: <trickle-l@unl.edu>
To: Multiple recipients of list <trickle-l@unl.edu>
Subject: TRICKLE-L digest 480

Contents:
Response from new member in Australia (Richard Mead <rmead@cybergate.com>)

Date: Mon, 22 Apr 1996 11:15:20 -0400
From: Richard Mead <rmead@cybergate.com>
Subject: Response from new member in Australia

The following is from a new Trickle-L subscriber, Wally Menke:

1) Briefly, what is your affiliation with trickle/drip irrigation?

My company Triangle Filtration is the Australian distributor for Geoflow
"Rootguard" subsurface drip irrigation products.

>2) What crops or plants do you use drip irrigation on?

We have to date mainly used Geoflow for landscape and turf applications,
with very good results and happy customers. We are currently looking at a
few ag projects which should proceed in the near future.

>3) If using subsurface drip irrigation, what is the average depth of
>placement of the drip lateral?

Depending on conditions, soil etc 10-15 cm (4-6")

>4) What problems have you encountered with drip irrigation?

With subsurface the main problems here have been:
a) Education and getting subsurface seriously accepted in Australia
b) Another supposedly reputable drip irrigation company selling their above
ground drip line for subsurface application, knowing it will fail.
c) Porous pipe products that are designed to fail!

>5) Fertigation is a real advantage of drip irrigation. What form of N, P and
>K have you been trying and to what success?

This is an area I must admit to leaving to the people who know better.

>6) Have you experienced a reduction in fertilizer and/or water use?

We have many customers who have experienced reductions in water use in both
domestic and commercial (municipal) applications. In some cases 50% reduction.
Fertilizer reductions at this stage we have not documented, but plan to once
we have some comparable ag installations. From my reading in the US it seems
accepted that SDI has this benifit.

>7) Do you have water quality problems? If so, how do you tackle the situation?

We have many water quality problems here, you name it we no doubt have it,
from iron oxide to high suspended solids.

>8) How frequent do you irrigate? Many times a day or just one long session
>per day or several days?

We have been suggesting to our customers to irrigate a number of times per
day for best results and utilisation of available water.

>9) Do you have rodent damage? If so, how do you control the problem?

Not todate, although I have heard in Queensland that the mice cause damage
with light wall tapes when they bury it in suger cane.

>10) Are you pleased with the uniformity of your system or systems? Were they
>designed correctly?

Yes todate uniformity has been very good.

>11) How did you find out about our mailing list?

Through Rodney Ruskin at Geoflow.

I look forward to being part of Trickle-L

Best Regard

Wally Menke
Managing Director
Triangle Filtration - Australia

End of Digest
************************

From root@crcnis1.unl.edu Tue Apr 23 14:24 EDT 1996
Date: Tue, 23 Apr 1996 13:14:58 -0500
Message-Id: <199604231814.AA12284@crcnis1.unl.edu>
Errors-To: rmead@asrr.arsusda.gov
Reply-To: <trickle-l@unl.edu>
To: Multiple recipients of list <trickle-l@unl.edu>
Subject: TRICKLE-L digest 481

Contents:
Re: Drip irrigation census. (Masoud Meshkat <mmeshkat@groucho.bae.uky.edu>)
Re: Drip irrigation census. (FLamm@oznet.ksu.edu (Freddie Lamm))
New member response (rmead@CyberGate.COM (Richard Mead))
Re: 12 ppm Fe!!! ("Gary Clark" <gclark@falcon.age.ksu.edu>)

Date: Mon, 22 Apr 1996 17:57:39 -0400 (EDT)
From: Masoud Meshkat <mmeshkat@groucho.bae.uky.edu>
Subject: Re: Drip irrigation census.

On Sat, 20 Apr 1996, Manrique Brenes wrote:

> I need some numbers on total drip irrigated area in the world. Data per country would also be very useful.
> If anyone knows where to find this information please let me know.
>
> Manrique Brenes
> Bio. & Ag. Eng.
> UC Davis
>
>

I am also interested in such a data, World and U.S. in particular. Please
reply to trickle-l or my e-mail

Thanks

Masoud Meshkat
Bio. and Ag. Eng.
UK

Date: 22 Apr 96 20:37:05 CDT
From: FLamm@oznet.ksu.edu (Freddie Lamm)
Subject: Re: Drip irrigation census.

Dale Bucks highlights this information in his plenary speech to the
5th International Microirrigation Congress, April 2-6, 1995, Orlando
Florida. The Proceedings are available from ASAE, St Joseph,
Michigan USA. Contact ASAE at HQ@asae.org. There is info for
world and most of the larger countries that have microirrigation. In
1991 there was 1.8 million hectares which was less than 1% of world
irrigated acres. The projection for 2000 is 3 million hectares.

Freddie Lamm
*

> Subject: Drip irrigation census.

> I need some numbers on total drip irrigated area in the world. Data per country would also be very useful.
> If anyone knows where to find this information please let me know.
>
> Manrique Brenes
> Bio. & Ag. Eng.
> UC Davis
>

Date: Tue, 23 Apr 1996 04:03:57 GMT
From: rmead@CyberGate.COM (Richard Mead)
Subject: New member response

The following is a welcome survey response from Gerard Pothuis in Ecuador.

I studied soil science in Israel ( the Hebrew University of Jerusalem ),
and specilized in soil physics, mainly on
compaction of agricultural soils. Then I ended up in South America and
started a flower plantacion, and lately a
irrigation company.
Shooting from the hip some answers to your questions:

1) Briefly, what is your affiliation with trickle/drip irrigation?
We have 60 hectares of different flowers under drip irrigation, and
install various combinations of drip and
microsprinklers for other flower companies.

2) What crops or plants do you use drip irrigation on?
Gypsophila, Roses, Carnations, Delfinium, Liatris, Ami magus, Statis,
Sunflowers, Molucella.

3) If using subsurface drip irrigation, what is the average depth of
placement of the drip lateral?
We do not use subsurface drip irr.

4) What problems have you encountered with drip irrigation?
Mainly human errors, a well designed system shouldn't give to many
problems exept for the normal maintainance.

5) Fertigation is a real advantage of drip irrigation. What form of N, P and
K have you been trying and to what success?
For N urea or amonium nitrate.
For P H2SO4.
for K KNO3

6) Have you experienced a reduction in fertilizer and/or water use?
Not realy since we always used drip irrigation.

7) Do you have water quality problems? If so, how do you tackle the situation?
We have gravel and 140 mesh filters, that takes care of most problems.
Our real water problem is a decease and
algea infection, for which we clorinate the irrigation water.

8) How frequent do you irrigate? Many times a day or just one long session
per day or several days?
Because of our sandy soils we irrigate an aprox. 3 times a day.

9) Do you have rodent damage? If so, how do you control the problem?
No problem

10) Are you pleased with the uniformity of your system or systems? Were they
designed correctly?
What can I say, we designed them.

11) How did you find out about our mailing list?
Yahoo internet search.

************************************************************************
Best Regards

Gerard Pothuis

Internet: gpothuis@pi.pro.ec

Date: Tue, 23 Apr 1996 08:15:13 CST
From: "Gary Clark" <gclark@falcon.age.ksu.edu>
Subject: Re: 12 ppm Fe!!!

Craig,

You're right, those are HIGH iron levels. I also experienced 2-4ppm
of iron at pH of 5.5 with no problems, but that same level of iron
with pH of 7 was trouble. I would expect that this person will need
to pretreat the water such as with chlorine to precipitate the iron
and then catch the precips on a filter system. Ilan Bar presented a
paper on that at the 5th Int'l Microirrigation Congress pp 239-243,
also see discussion on pg 180 of Nakayama and Bucks. Another
possibility would be to inject acid to lower the water pH and keep
the iron in solution.

See what else comes in from the Group. Good luck and Best wishes.

Gary.
******************************************
Gary A. Clark, P.E.
Associate Professor
Biological and Agricultural Engineering
147 Seaton Hall
Kansas State University
Manhattan, KS 66506-2906
Tel: 913-532-5580
Fax: 913-532-5825
******************************************

End of Digest
************************

From root@crcnis1.unl.edu Wed Apr 24 14:29 EDT 1996
Date: Wed, 24 Apr 1996 13:16:52 -0500
Message-Id: <199604241816.AA29838@crcnis1.unl.edu>
Errors-To: rmead@asrr.arsusda.gov
Reply-To: <trickle-l@unl.edu>
To: Multiple recipients of list <trickle-l@unl.edu>
Subject: TRICKLE-L digest 482

Contents:
Re: ET Rates for Canczn, Mexico ("Fedro S. Zazueta" <FSZ@gnv.ifas.ufl.edu>)
Re: 12 ppm Fe!!! (IlanBar@aol.com)

Date: Tue, 23 Apr 1996 03:33:49 -0400
From: "Fedro S. Zazueta" <FSZ@gnv.ifas.ufl.edu>
Subject: Re: ET Rates for Canczn, Mexico

At 11:25 PM 4/20/96 -0500, you wrote:
>Listmembers:
>
>I am in need of historical ET data for the Canczn, Mexico area.
>After a couple weeks of searching, (over 140 websites) I have come
>up dry. Any help you could offer would be greatly appreciated.
>
>Sincerely,
>
>Michael R. Shreve
>Regional Manager, Latin America
>Rain Bird International, Inc.
>
>telephone: (941) 682-6252
>fax: (914) 686-9634
>e-mail: shrevem@interserv.com
>

Contact Dr. Ramon Arteaga Ramirez at the
Universidad Autonoma Chapingo in Texcoco Mexico.

Tel 595 43222
fax 595 44587

Date: Tue, 23 Apr 1996 18:39:06 -0400
From: IlanBar@aol.com
Subject: Re: 12 ppm Fe!!!

Hi Craig!
You and Gary are absolutely right.These levels are very high. Consequentely,
I would expect severe problems if the system will not be treated.pH=6.8 is
not low enough to avoid Iron slime formation.On the other hand, I believe
that it can be successfully treated.I have got a success story treating water
for drip irrigation containing up to 7 p.p.m. Iron.There is a paper on this
particular case.
If you, or any body else, interested in this paper I'll be more than happy to
mail it to you.
Wish you good luck!
Ilan Bar

End of Digest
************************

From root@crcnis1.unl.edu Fri Apr 26 01:51 EDT 1996
Date: Fri, 26 Apr 1996 00:43:23 -0500
Message-Id: <199604260543.AA24484@crcnis1.unl.edu>
Errors-To: rmead@asrr.arsusda.gov
Reply-To: <trickle-l@unl.edu>
To: Multiple recipients of list <trickle-l@unl.edu>
Subject: TRICKLE-L digest 483

Contents:
Re: Drip irrigation census. (Tim1Utah@aol.com)

Date: Fri, 26 Apr 1996 01:46:49 -0400
From: Tim1Utah@aol.com
Subject: Re: Drip irrigation census.

Try calling the Irrigation Assoc. office in Virginia 703-573-3551. Tim
Wilson

End of Digest
************************

From root@crcnis1.unl.edu Mon Apr 29 00:44 EDT 1996
Date: Sun, 28 Apr 1996 23:35:57 -0500
Message-Id: <199604290435.AA13413@crcnis1.unl.edu>
Errors-To: rmead@asrr.arsusda.gov
Reply-To: <trickle-l@unl.edu>
To: Multiple recipients of list <trickle-l@unl.edu>
Subject: TRICKLE-L digest 484

Contents:
Response from new member (rmead@CyberGate.COM (Richard Mead))

Date: Mon, 29 Apr 1996 04:25:31 GMT
From: rmead@CyberGate.COM (Richard Mead)
Subject: Response from new member

The following is a response from new subscriber, Abelardo Contreras of Peru.
=============================================================================

> 1) Briefly, what is your affiliation with trickle/drip irrigation?

I am a researcher on trickle/drip irrigation control systems.

> 2) What crops or plants do you use drip irrigation on?

I am interested specially with Asparagus.

> 3) If using subsurface drip irrigation, what is the average depth of
placement of the drip lateral? <

I don't use subsurface drip irrigation.

> 4) What problems have you encountered with drip irrigation?

I don't have much problems on the contrary I find it very advantageous.

> 5) Fertigation is a real advantage of drip irrigation. What form of N, P and
K have you been trying and to what success?<

I don't know much about it I'm more interested on the control system.

> 6) Have you experienced a reduction in fertilizer and/or water use? <

Yes, it is evident.

> 7) Do you have water quality problems? If so, how do you tackle the
>situation?

Not much problems

> 8) How frequent do you irrigate? Many times a day or just one long session
per day or several days? <

Very frequently daily more than 8 times daily.

> 9) Do you have rodent damage? If so, how do you control the problem? <

No.

> 10) Are you pleased with the uniformity of your system or systems? Were they
designed correctly? <

Yes I designed them.

> 11) How did you find out about our mailing list? <

Navigating the web. Don't remember exactly where.

End of Digest
************************

From root@crcnis1.unl.edu Tue Apr 30 00:44 EDT 1996
Date: Mon, 29 Apr 1996 23:36:26 -0500
Message-Id: <199604300436.AA15049@crcnis1.unl.edu>
Errors-To: rmead@asrr.arsusda.gov
Reply-To: <trickle-l@unl.edu>
To: Multiple recipients of list <trickle-l@unl.edu>
Subject: TRICKLE-L digest 485

Contents:
SDI herbicide impregnated emitters (Hector Valenzuela <hector@hawaii.edu>)

Date: Mon, 29 Apr 1996 10:23:10 -1000
From: Hector Valenzuela <hector@hawaii.edu>
Subject: SDI herbicide impregnated emitters

Could someone refer me to suppliers which provide herbicide impregnated
emitter SDI systems? Thank-you. Hector.

Hector Valenzuela
Vegetable Extension Specialist
Horticulture, University of Hawaii at Manoa
hector@hawaii.edu
http://agrss.sherman.hawaii.edu/hort/

End of Digest
************************

Prepared by Steve Modena, AB4EL.
Comments and suggestions to: modena@SunSITE.unc.edu