TRICKLE-L digests for APRIL 1996

To AGRONOMY homepage @ SunSITE

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.>.
From: 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.>.
From: 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.>.
From: 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.>.
From: 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.>.
From: 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.>.
From: 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.>.
From: 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.>.
From: 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.>.
From: 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.>.
From: 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 * ------------------------------------------------------------------- Freddie Lamm * Research Agricultural Engineer *** o KSU Northwest Research-Extension Center ***** /|\ 105 Experiment Farm Road *******\\ Colby, Kansas 67701-1697 ********* Ph. 913-462-6281 *********** FAX 913-462-2315 ************* Email:flamm@oznet.ksu.edu It's all downhill from here. ------ THERE'S NO DOMAIN LIKE OZ, THERE'S NO DOMAIN LIKE OZ. ------ <------------------------------>
Date: Fri, 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.>.
From: 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.>.
From: 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.>.
From: 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. > > > > > > <------------------------------>
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.>.
From: 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 * ------------------------------------------------------------------- Freddie Lamm * Research Agricultural Engineer *** o KSU Northwest Research-Extension Center ***** /|\ 105 Experiment Farm Road *******\\ Colby, Kansas 67701-1697 ********* Ph. 913-462-6281 *********** FAX 913-462-2315 ************* Email:flamm@oznet.ksu.edu It's all downhill from here. ------ THERE'S NO DOMAIN LIKE OZ, THERE'S NO DOMAIN LIKE OZ. ------ <------------------------------>
Date: 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.>.
From: 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.>.
From: 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.>.
From: 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.>.
From: 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.>.
From: 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.>.
From: 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 > ------------------------------------------------------------------- Freddie Lamm * Research Agricultural Engineer *** o KSU Northwest Research-Extension Center ***** /|\ 105 Experiment Farm Road *******\\ Colby, Kansas 67701-1697 ********* Ph. 913-462-6281 *********** FAX 913-462-2315 ************* Email:flamm@oznet.ksu.edu It's all downhill from here. ------ THERE'S NO DOMAIN LIKE OZ, THERE'S NO DOMAIN LIKE OZ. ------ <------------------------------>
Date: 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.>.
From: 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.>.
From: 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.>.
From: 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.>.
From: 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 ************************
To AGRONOMY homepage @ SunSITE


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