TRICKLE-L: 199510XX

is the compilation of discussion during Oct 95

via AB4EL Web Digests @ SunSITE

AGROMOMY Homepage @ SunSITE


>From root@crcnis1.unl.edu Sun Oct  1 07:09 EDT 1995
Date: Sun, 1 Oct 1995 06:01:45 -0500
Message-Id: <199510011101.AA28786@crcnis1.unl.edu>
Subject: TRICKLE-L digest 308

Contents:
Microirrigation in developing countries (MEAD2513@aol.com)



Date: Sat, 30 Sep 1995 19:14:50 -0400 From: MEAD2513@aol.com Subject: Microirrigation in developing countries The following is abstract #7 in a series abstracts selected from the 5th International Microirrigation Congress this past April in Florida. The abstract is presented to stimulate interest and discussion on Trickle-L. Success of Drip in India: An Example to the Third World S. K. Suryawanshi The sixties saw the rapid development of agriculture in India through the intensive use of modern agricultural inputs such as water energy, fertilizer, chemicals, and high-yielding crop varieties. The input-based strategy was successful in that the agricultural production increased three-fold during the past four decades. But predominant use of water and chemicals resulted in a paradoxical situation in which soils in the Northern Plains turned saline, whereas in the South, the water table went down due to excessive pumping. Both shallow and deep water tables affected agricultural productivity to a point of stagnation. In the late eighties, drip irrigation gained popularity with its inherent advantages like saving water and use in problematic soil. Various research institutes conducted experiments on drip irrigation and made people aware of its benefits. Some manufacturers also conducted their own studies first by importing the materials before venturing into commercial production of drip systems. The farming community ususally believes only after personally observing the benefits. Today, more than a 60,700 hectare are is brought under irrigation convering more than 30 crops. Farmers from various places communicated their experiences of drip irrigation on various crops like sugarcane, cotton, grapes, banana, pomegranate, vegetables, tea, ber*, flowers, etc. The increase in yield as compared to conventional irrigation methods is from 20 to 100 %, whereas saving in water ranges from 40% to 70%. The results achieved by drip irrigation in a developing country like India can show many third world countries optimum utilization of resources for increased agricultural production. Keywords: Drip (micro) irrigation, agriculture, farmer, water, yield Abstract taken from paper found on pages 347 to 352 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300, FAX: 616-429-3852 E-mail:HQ@ASAE.ORG * Anyone know what "ber" is?? =========================================================================== Additional information from the paper. India needs to feed more than 1 billion people by the year 2000. An increase of 80 million tons of food grain will be needed in less than a decade (a 50 % increase). There are 140 million arable hectares (346 million acres) in India with 41.2 million hectares (102 million acres) being irrigated. The 60,700 hectares (150,000 acres) under drip quoted in the abstract represents merely 0.15% of the irrigated area. Other interesting factors mentioned were: In India using drip irrigation, labor savings up to 50 - 60 % can be found, poor quality water and soils can be used, fertilizer savings of up to 30 % are being observed. Specific crops with noted yield increases and water savings: Banana (52% yield increase, 45% water savings) Grapes (23% yield increase, 48% water savings) Sweet lime (50% yield increase, 61% water savings) Pomegranate (98% yield increase, 45% water savings) Sugarcane (33% yield increase, 56% water savings) Tomato (50% yield increase, 39% water savings) Watermelon (88% yield increase, 36% water savings) Cotton (27% yield increase, 53% water savings) Papaya (75% yield increase, 68% water savings) Sweet potato (39% yield increase, 60% water savings) If anyone has additional information about developing countries using microirrigation irrigation, please feel free to contribute. Richard Mead Trickle-L owner/manager
End of Digest
>From root@crcnis1.unl.edu Mon Oct  2 07:10 EDT 1995
Date: Mon, 2 Oct 1995 06:02:13 -0500
Message-Id: <199510021102.AA15469@crcnis1.unl.edu>
Subject: TRICKLE-L digest 309

Contents:
WMRL homepage announcements (MEAD2513@aol.com)
Salinity-L announcement (MEAD2513@aol.com)



Date: Sun, 1 Oct 1995 20:52:55 -0400 From: MEAD2513@aol.com Subject: WMRL homepage announcements The Water Management Research Laboratory (Host of Trickle-L) is proud to announce the following update concerning their WWW homepage: http://asset.arsusda.gov/wmrl/WMRL.html 1) The homepage now has the world's largest microirrigation bibliography on the Internet. There are 11 main categories with 2 sub categories totaling more than 1270 titles. Eighty-five abstracts are available by using highlighted links. Please be sure to check this valuable resource if you are looking for research articles concerning microirrigation. 2) Due to the discussion of capacitance probes last month, we have posted pictures of the two capacitance probes. The first is the Troxler 200 AP shown with a multiplexer and portable computer. The second is the Sentek Enviroscan probe, pictured with our Webpage designer/computer guru Richard Soppe. If you are just dying to know what these new tech toys look like, be sure to browse by. They are listed near the Trickle-L information segment. Later this month, we should have pictures of our recent Twin Lysimeter open house which occured on September 14. If you're curious as to what a lysimeter is or if you want to see the most sophisticated lysimeter facility, be sure to check it out later this month. Richard Mead Trickle-L owner/manager
Date: Sun, 1 Oct 1995 20:56:09 -0400 From: MEAD2513@aol.com Subject: Salinity-L announcement The USDA-ARS-Water Management Research Laboratory, Fresno CA, would like to announce the creation of another E-mail discussion list: SALINITY-L Salinity-L focuses on discussions related to salt management in relation to irrigation and drainage. The list has just been created, and will include discussions about irrigation management to maintain salinity problems, drainage management, load-flow relations, soil hydraulic properties as influenced by salts, crop tolerances to salt and more. To subscribe to the list, send an E-mail message to LISTSERV@UNL.EDU Within the body the following lines: SUBSCRIBE SALINITY-L FirstName LastName Where FirstName LastName are your real names. For more information, contact Richard Soppe or Richard Mead at: Water Management Research Laboratory U.S. Department of Agriculture - Agricultural Research Service 2021 South Peach Avenue Fresno, CA 93727-5951 phone: (209) 453-3100 fax: (209) 453-3122 E-mail: RSoppe@ASRR.ARSUSDA.GOV E-mail: RMead@ASRR.ARSUSDA.GOV WWW: http://asset.arsusda.gov/wmrl/WMRL.html
End of Digest
>From root@crcnis1.unl.edu Tue Oct  3 08:43 EDT 1995
Date: Tue, 3 Oct 1995 06:02:20 -0500
Message-Id: <199510031102.AA18217@crcnis1.unl.edu>
Subject: TRICKLE-L digest 310

Contents:
porous pipe study (denis_bacon@csufresno.edu (Denis Bacon))
Re: TRICKLE-L digest 308 (B.Maheshwari@uws.edu.au (Basant Maheshwari))
Controlled irrig for developing countries (evan@griffith.dwr.csiro.au (Evan Christen))



Date: Mon, 2 Oct 95 09:27:53 PDT From: denis_bacon@csufresno.edu (Denis Bacon) Subject: porous pipe study The following is information that was sent to me by Ed Norum at the California State University Fresno, Center for Irrigation Technology. Any comments would be appreciated. PRELIMINARY TEST RESULTS ON POROUS RUBBER PIPE IN A BURIED APPLICATION Recently CIT was asked to test yet another design of a porous pipe product. Porous pipe is an extruded tube manufactured from recycled tires and virgin polyethylene that behaves like a soaker hose. Porous pipe is sold for both landscape and agricultural applications. With a 10-year-plus history of testing these products, we were familiar with most of the arguments on non-uniformity and clogging. Our customer insisted on field tests in a growing situation with 480 ft runs buried about 12 in. and an inlet pressure of 8-10 psi. We attempted design calculations and went on to forecast that the first sections would be over-irrigated with virtually no water at the end. The customer still wanted to go forward and suggested that the product behaves differently in actual buried operations as contrasted with bench testing. Most bench testing, for example, deals with short sections of tubing discharging to the atmosphere. Three beds were installed and planted to melons. Research is conducted on the center row only. This row is fitted with flow and pressure measurements at the inlet and the 1/4 points. The beds were planted in late July. Current measurements then reflect mature field conditions. Recent hydraulic testing produced the following results: STATION PRESSURE (ft) (psi) 0 11.3 120 8.0 240 6.4 360 5.7 480 5.3 This pressure profile along the porous pipe is as could be predicted. The friction loss is, however, 53 percent of the inlet pressure and exceeds any reasonable standard for anticipated uniformity of application. The flow rate results are as follows: SECTION FLOW RATE (ft) (gpm) 0-120 0.294 120-240 0.211 240-360 0.333 360-480 0.297 Total 1.135 gpm This means, for example, that the first section of pipe from 0 to 120 ft was emitting water at a rate of only 0.294 gpm even though it has the highest average pressure. The corresponding UC is 87% and the DU is 74%. Note the higher applications in the second half of the pipe. The failure of the emission rates to correlate directly with pressure was unanticipated. We are still trying to put this result in perspective. Possible explanations include: S Impact of soil-moisture conditions on emission rates S A gradual variation in tubing porosity as a function of length S Emission rates vary in relation to pipeline velocity S Some gross error in the testing method We intend to rerun the tests over a range of inlet pressures. Confirmation of these results could change the way porous pipe systems are viewed as to hydraulic performance capabilities. While this result could impact uniformity questions, still left unresolved is the serious question of dealing with porous pipe potential clogging problems. These results suggest that in situ studies should be run on all buried drip systems to verify estimates of application uniformity. EMN/VJC/9-29-95 Project No. 1036(AQS/95) Denis Bacon CSU Fresno School of Agricultural Sciences and Technology Fresno, Ca 93740-0079
Date: Tue, 3 Oct 1995 11:04:05 +1000 From: B.Maheshwari@uws.edu.au (Basant Maheshwari) Subject: Re: TRICKLE-L digest 308 Dear Richard, You asked - '* Anyone know what "ber" is??'. Ber is a Hindi word for a kind of plum. Regarding your abstact on 'microirrigation in developing countries', I think this method of irrigation has a great potential in saving water and increasing agricultural production in developing countries but the initial investment and maintenance costs for the method are too high at the moment. I know in some parts of India, government gives subsidies up to 50% to farmers for installing the system, but the adoption of the method so far has not been very high. A system based on locally available materials and technology (e.g. pitcher irrigation) will be useful. A lot of adaptive and innovative research is needed in this area. Aid agencies can play an important role here. With kind regards. Basant Maheshwari ________________________________________________________________ Dr. B.L. Maheshwari School of Agri. & Rural Development University of Western Sydney Richmond, NSW 2753, AUSTRALIA Email: b.maheshwari@uws.edu.au Tel.: (61+45) 701 235 or 885 652 Fax: (61+45) 701 750 ________________________________________________________________
Date: Mon, 2 Oct 1995 20:34:01 -0500 From: evan@griffith.dwr.csiro.au (Evan Christen) Subject: Controlled irrig for developing countries "WAGON WHEEL WATERING" In response to the request for irrigation technology for developing countries the following may be of interest. On a visit to a viticultural research station in Stellenbosch, South Africa I was shown a very simple method of irrigating a vegetable garden. I will try to describe it. In the center of the plot was a 44 gallon drum, connected to, and radiating out from the base of the drum were lines of polypipe about 15 m long, like the spokes of a wheel. The pipe had been punctured with holes to act as drip outlets. There were probably 8 lines running from 1 drum. The drum is filled as required, a bag of sheep dung can be hung in the water for fertigation. This system is low cost, low labour for watering a vegetable patch and has much improved water use efficiency than watering cans, flooding etc. I intend to try it on my vegetables this summer! Evan Christen Irrigation and Drainage Management for Horticulture CSIRO Division of Water Resources Griffith Laboratory Griffith NSW 2680 Australia Fax # 61 69 601600 "Errare Humanum Est" J.C. 50 B.C.
End of Digest
>From root@crcnis1.unl.edu Wed Oct  4 07:11 EDT 1995
Date: Wed, 4 Oct 1995 06:02:39 -0500
Message-Id: <199510041102.AA16261@crcnis1.unl.edu>
Subject: TRICKLE-L digest 311

Contents:
      Re: porous pipe study ("Gary Clark" <GCLARK@falcon.age.ksu.edu>)
Porous pipe (cburt@oboe.aix.calpoly.edu (Charles M. Burt))
Table Grape yields (meissner.tony@wpo.pi.sa.gov.au)



Date: Tue, 3 Oct 1995 08:05:03 CST From: "Gary Clark" <GCLARK@falcon.age.ksu.edu> Subject: Re: porous pipe study Dear Dennis, The provided results of the porous pipe study are interesting. However, 1 rep is not very worthy for making any conclusions. I am not suprised at the pressure distribution, and the flow rates appear to indicate a very high nonuniformity of discharge. Yet, I still believe that in order to provide a rational interpretation of data, that several reps are needed. I also agree that buried drip systems need to be evaluated in situ. While initial hydraulic uniformity is important and cannot be overlooked, the distribution of water within the soil and the plant response to the irrigation are the final evaluations of a successful system. Gary Clark. ****************************************** 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 ****************************************** ****** GIVE A FLIP AND SAVE A DRIP ******* ******************************************
Date: Tue, 3 Oct 1995 11:05:29 -0700 From: cburt@oboe.aix.calpoly.edu (Charles M. Burt) Subject: Porous pipe The Cal Poly ITRC conducted in situ buried tests on porous pipe 2 years ago, plus tested similar pipe above ground, for cv and emitter exponents. We needed to do the tests because several growers were submitting loan applications for irrigation systems. The ITRC was responsible for reviewing the technical merit of the loan applications. The results were so horrible and variable (note the strong words) that the loans were denied. The ITRC also decided to not conduct further tests on the material on behalf of the company, because we felt that it might lend some credibility to the products (just by virtue of the fact that the product was being tested by us).
Date: Wed, 04 Oct 1995 15:16:04 +0930 From: meissner.tony@wpo.pi.sa.gov.au Subject: Table Grape yields I am interested, for the purposes of a paper I am presenting at the Australian Table Grape Growers Conference (next Tues 10th Oct) of yield of Table Grapes in your respective countries. Also if possible how much water (irrigation + rainfall) is used in growing this yield. Thanking all in anticipation Cheers Tony M :-) ***************************************************** * Tony Meissner * * Senior Research Scientist (Soils) * * Primary Industries, South Australia * * PO Box 411, Loxton SA, Australia 5333 * * Tel. 085 95 9146 * * Fax: 085 95 9199 * * email meissner.tony@pi.sa.gov.au * *********************************************************
End of Digest
>From root@crcnis1.unl.edu Thu Oct  5 07:11 EDT 1995
Date: Thu, 5 Oct 1995 06:02:57 -0500
Message-Id: <199510051102.AA17880@crcnis1.unl.edu>
Subject: TRICKLE-L digest 312

Contents:
Re: Micro Irrig., Pitcher Irrigation (stein@wiz.uni-kassel.de (Thomas Stein))
Re: Micro Irrig., Pitcher Irrigation (citrus@indirect.com (Roger Bourland))



Date: Wed, 4 Oct 1995 20:25:40 +0100 (MEZ) From: stein@wiz.uni-kassel.de (Thomas Stein) Subject: Re: Micro Irrig., Pitcher Irrigation Dr. Basant Maheshwari (B.Maheshwari@uws.edu.au)wrote: >I know in some parts of India, government gives subsidies up to >50% to farmers for installing the system, but the adoption of the >method so far has not been very high. A system based on locally >available materials and technology (e.g. pitcher irrigation) will >be useful. A lot of adaptive and innovative research is needed in >this area. Aid agencies can play an important role here. Talking about 'microirrigation in developing countries' I would like to add some information on 'Pitcher Irrigation'. Traditional techniques cost relatively little and, when combined with appropriate modern technology, can prove extremely effective. The advantage of pitcher irrigation for the developing world technologists is that the system can be used at varying levels of sophistication and that most of the components can be manufactured locally. Water practices which were developed for temperate climates may not work as well in arid regions due to technological, environmental, economic and cultural reasons. Definition: ----------- Pitcher irrigation consists, in its simplest form, of unglazed baked earthen pitchers which are buried to their neck in the soil and filled with water. The water gradually seeps out through the porous walls into the root zone under hydrostatic pressure and/or suction, to maintain plant growth around the pitchers. A Classification may be made by the location of application : ------------------------------------------------------------ As water is applied slowly in low volumes in the plant root zone, and only part of the soil is wetted, it may be classified as a localised irrigation system. It can be further sub classified as a subsurface irrigation system as the "emitter" is located under the soil surface. A Sub classification by means of replenishment : ------------------------------------------------ According to the means of replenishment pitcher irrigation can also be divided into three categories: Manual, semi-automatic and (fully)automatic systems. Manual systems are filled manually with a watering can, bucket or a flexible hose. Semi-automatic systems have a pipe system which connects the pitchers, with outlets into each pitcher. After pitchers have been refilled the water is turned off again. Automatic systems consist of pitchers or capsules as part of a closed system interconnected with pipes. Water is applied constantly under a hydrostatic head. I have tried to gather information on pitcher irrigation for a few years. Most of the information is quite difficult to get hold off. To make some of that information more widely available I have prepared a World Wide Web section including some more detailed information. on pitcher irrigation. Furthermore a pitcher irrigation bibliography and some on-line documents a directly accessible through the World Wide Web. The 'Pitcher Irrigation Pages' are linked to the VL Irrigation http://fserv.wiz.uni-kassel.de/kww/projekte/irrig/irrig_i.htm and are located under the topic "Irrigation Systems". If you would like to directly access the 'Pitcher Irrigation Pages' you may use the following URL: http://fserv.wiz.uni-kassel.de/kww/projekte/gefaess/gefaess_i.html I am still trying to update and supplement the bibliography and information on pitcher irrigation on the Web and would greatly appreciate any comments or contributions. Regards, Thomas ______________________________________________________________________________ Thomas-M. Stein University of Kassel (FB11) Phone : (+49)-5542-98-1632 Dep. of Rural Engineering and Fax : (+49)-5542-98-1588 Natural Resource Protection Email : stein@wiz.uni-kassel.de Nordbahnhofstr. 1a WWW : http://www.wiz.uni-kassel.de/kww/ D-37213 Witzenhausen (FRG) List owner: IRRIGATION-L at LISTSERV@vm.gmd.de ______________________________________________________________________________
Date: Wed, 4 Oct 1995 19:16:19 -0700 From: citrus@indirect.com (Roger Bourland) Subject: Re: Micro Irrig., Pitcher Irrigation At 2:54 PM 10/4/95, Thomas Stein wrote: >Dr. Basant Maheshwari (B.Maheshwari@uws.edu.au)wrote: > >>I know in some parts of India, government gives subsidies up to >>50% to farmers for installing the system, but the adoption of the >>method so far has not been very high. A system based on locally >>available materials and technology (e.g. pitcher irrigation) will >>be useful. A lot of adaptive and innovative research is needed in >>this area. Aid agencies can play an important role here. > >Talking about 'microirrigation in developing countries' I would like >to add some information on 'Pitcher Irrigation'. > >Traditional techniques cost relatively little and, when combined with >appropriate modern technology, can prove extremely effective. >The advantage of pitcher irrigation for the developing world >technologists is that the system can be used at varying levels of >sophistication and that most of the components can be manufactured >locally. Water practices which were developed for temperate climates >may not work as well in arid regions due to technological, >environmental, economic and cultural reasons. > >Definition: >----------- > > Pitcher irrigation consists, in its simplest form, of unglazed > baked earthen pitchers which are buried to their neck in the soil > and filled with water. The water gradually seeps out through the > porous walls into the root zone under hydrostatic pressure and/or > suction, to maintain plant growth around the pitchers. > > >A Classification may be made by the location of application : >------------------------------------------------------------ > As water is applied slowly in low volumes in the plant > root zone, and only part of the soil is wetted, it may be > classified as a localised irrigation system. It can be > further sub classified as a subsurface irrigation system as > the "emitter" is located under the soil surface. > >A Sub classification by means of replenishment : >------------------------------------------------ > According to the means of replenishment pitcher irrigation can > also be divided into three categories: Manual, semi-automatic and > (fully)automatic systems. > > Manual systems > are filled manually with a watering can, bucket or a flexible > hose. > > Semi-automatic systems > have a pipe system which connects the pitchers, with outlets > into each pitcher. After pitchers have been refilled the water > is turned off again. > > Automatic systems > consist of pitchers or capsules as part of a closed system > interconnected with pipes. Water is applied constantly under > a hydrostatic head. > >I have tried to gather information on pitcher irrigation for a few >years. Most of the information is quite difficult to get hold off. >To make some of that information more widely available I have >prepared a World Wide Web section including some more detailed >information. on pitcher irrigation. Furthermore a pitcher irrigation >bibliography and some on-line documents a directly accessible through >the World Wide Web. > >The 'Pitcher Irrigation Pages' are linked to the VL Irrigation > > http://fserv.wiz.uni-kassel.de/kww/projekte/irrig/irrig_i.htm > >and are located under the topic "Irrigation Systems". > >If you would like to directly access the 'Pitcher Irrigation Pages' >you may use the following URL: > > http://fserv.wiz.uni-kassel.de/kww/projekte/gefaess/gefaess_i.html > >I am still trying to update and supplement the bibliography and >information on pitcher irrigation on the Web and would greatly >appreciate any comments or contributions. > >Regards, > >Thomas >______________________________________________________________________________ > > Thomas-M. Stein > University of Kassel (FB11) Phone : (+49)-5542-98-1632 > Dep. of Rural Engineering and Fax : (+49)-5542-98-1588 > Natural Resource Protection Email : stein@wiz.uni-kassel.de > Nordbahnhofstr. 1a WWW : http://www.wiz.uni-kassel.de/kww/ > D-37213 Witzenhausen (FRG) List owner: IRRIGATION-L at LISTSERV@vm.gmd.de >______________________________________________________________________________ Dear Thomas: There is an interesting parallel at Ghost Ranch in Abiqui, N.M.,USA, the experimental farm there. They throw large earthenware pots with lids, bury them and periodically fill them with water. You should see the roots head for these pots. Roger Bourland
End of Digest
>From root@crcnis1.unl.edu Fri Oct  6 07:14 EDT 1995
Date: Fri, 6 Oct 1995 06:03:54 -0500
Message-Id: <199510061103.AA20836@crcnis1.unl.edu>
Subject: TRICKLE-L digest 313

Contents:
Re: Micro Irrig., Pitcher Irrigation (stein@wiz.uni-kassel.de (Thomas Stein))
Re: porous pipe study (parallels) (stein@wiz.uni-kassel.de (Thomas Stein))



Date: Thu, 5 Oct 1995 18:17:19 +0100 (MEZ) From: stein@wiz.uni-kassel.de (Thomas Stein) Subject: Re: Micro Irrig., Pitcher Irrigation Dear Roger, thanks for that information. Great to here about that project. I would like to know more about that work on pitcher irrigation in Abiqui. Is it possible to get some further information on it. And do you know their email or mail address so I may contact them as well ? According to Roger Bourland: >From: citrus@indirect.com (Roger Bourland) >Dear Thomas: > >There is an interesting parallel at Ghost Ranch in Abiqui, N.M.,USA, the >experimental farm there. They throw large earthenware pots with lids, bury >them and periodically fill them with water. You should see the roots head >for these pots. > >Roger Bourland > > Thanks Thomas Stein
Date: Fri, 6 Oct 1995 11:34:36 +0100 (MEZ) From: stein@wiz.uni-kassel.de (Thomas Stein) Subject: Re: porous pipe study (parallels) Dear Denis, We have been running pitcher trials and the results indicate a very strong interaction between the soil moisture (matrix potentials around the pitcher), the hydraulic properties of the soil (saturated and unsaturated hydraulic conductivities), the pitcher material (saturated conductivity), the pressure in the system (in our case: the water level in the pitcher) and the crop and climate (ETo). Keeping the pressure in the pitchers constant (constant water level about 20 cm) we could observe varying seepage rates from the pitcher into the soil resulted in: Seepage rates 'Environment' from pitchers conditions -------------------------------------------------------- o increase with increase of ETo o increase " crops around pitchers (cropped or uncropped) o increase " increase of matrix potentials We also could observe that these effects where less pronounced with pitchers having generally higher seepage rates due to higher porosity of the materials. Other authors indicated that the influence of the soil on the seepage rates from the pitchers was less when increasing pressure in the pitchers (a pressurized pitcher system was used 30 to 100 cm of pressure in that case). I think that there may be parallels between the pitcher behavior and variation in seepage or emmission rates of the burried porous rubber pipes. Varying soil moisture (starting moisture conditions) and varying hydraulic soil and material properties (along the line) should carefully be observed. I believe that there will be a stong difference in emission rates from those porous tubes depending on the soil type they have been layed in. I hope this was of some help. According to Denis Bacon: > >We are still trying to put this result in perspective. Possible >explanations include: >S Impact of soil-moisture conditions on emission rates >S A gradual variation in tubing porosity as a function of length >S Emission rates vary in relation to pipeline velocity >S Some gross error in the testing method [text deleted] Best regards Thomas ______________________________________________________________________________ Thomas-M. Stein University of Kassel (FB11) Phone : (+49)-5542-98-1632 Dep. of Rural Engineering and Fax : (+49)-5542-98-1588 Natural Resource Protection Email : stein@wiz.uni-kassel.de Nordbahnhofstr. 1a WWW : http://www.wiz.uni-kassel.de/kww/ D-37213 Witzenhausen (FRG) List owner: IRRIGATION-L at LISTSERV@vm.gmd.de ______________________________________________________________________________
End of Digest
>From root@crcnis1.unl.edu Sat Oct  7 07:12 EDT 1995
Date: Sat, 7 Oct 1995 06:04:43 -0500
Message-Id: <199510071104.AA14947@crcnis1.unl.edu>
Subject: TRICKLE-L digest 314

Contents:
Re: Table Grape yields (GrapeGrowr@aol.com)
Re: Table Grape yields (GrapeGrowr@aol.com)
Re: Micro Irrig., Pitcher Irrigation (citrus@indirect.com (Roger Bourland))



Date: Fri, 6 Oct 1995 12:39:22 -0400 From: GrapeGrowr@aol.com Subject: Re: Table Grape yields when I have time, I will compile my total water use for the last few years and i nclude them with the same seasons total production for Flame Seedless. By the way, do you know Mr. E G Biggs in Mildura? Or a Shachar Karniel (Isreali grape consultant) who informs me he is consulting on a big project in the central part of your country.
Date: Fri, 6 Oct 1995 12:47:23 -0400 From: GrapeGrowr@aol.com Subject: Re: Table Grape yields Sorry. I didn't notice that the return was going back to you Richard instead of Australia. Please disregard the personal remarks at the end of my messege or simply forward them on to the originator with my e-mail address. Thanks
Date: Fri, 6 Oct 1995 14:00:22 -0700 From: citrus@indirect.com (Roger Bourland) Subject: Re: Micro Irrig., Pitcher Irrigation Dear Thomas: Here is the mailing list for Ghost Ranch. I don't think they have EMail. Ghost Ranch Conference Center HC77, Box 11 Abiquiu, New Mexico, 87510-9601 The experimental farms there deal with high-desert dry land farming and are fascinating to see and visit if any of our readers are ever in the vicinity of Santa Fe or Albuquerque. Roger Bourland (Phoenix, Arizona) Citrus@indirect.com
End of Digest
>From root@crcnis1.unl.edu Sun Oct  8 07:14 EDT 1995
Date: Sun, 8 Oct 1995 06:05:08 -0500
Message-Id: <199510081105.AA22814@crcnis1.unl.edu>
Subject: TRICKLE-L digest 315

Contents:
Upcoming International Events (MEAD2513@aol.com)



Date: Sat, 7 Oct 1995 13:44:27 -0400 From: MEAD2513@aol.com Subject: Upcoming International Events As a service of Trickle-L, I thought it would be useful to occasionally announce upcoming national/international meetings and conferences. The following events are the main ones I am aware of that are coming up in the next half year or so. If anyone on the discussion list knows of other events, please post to all. 1) Irrigation Association's International Exposition and Technical Conference, Phoenix, Arizona. November 12-14, 1995 2) Filtration Water and Waste Water Treatment Systems Conference, Beijing, China. November 24-27, 1995 3) Irrigation Australia 1996, Adelaide, South Australia. May 14-16, 1996. 4) Agro-Expo China '96, Beijing, China. April 16-20, 1996. Richard Mead Trickle-L manager
End of Digest
>From root@crcnis1.unl.edu Mon Oct  9 07:13 EDT 1995
Date: Mon, 9 Oct 1995 06:06:01 -0500
Message-Id: <199510091106.AA00909@crcnis1.unl.edu>
Subject: TRICKLE-L digest 316

Contents:
Re:  Upcoming International Events (redling@gumbo.bae.lsu.edu (Robert Edling))
Re: porous pipe study (parallels) (LodiCraig@aol.com)
Re: porous pipe study (LodiCraig@aol.com)



Date: Sun, 8 Oct 95 12:46:42 CDT From: redling@gumbo.bae.lsu.edu (Robert Edling) Subject: Re: Upcoming International Events Thanks Richard Bob Edling
Date: Mon, 9 Oct 1995 06:04:30 -0400 From: LodiCraig@aol.com Subject: Re: porous pipe study (parallels) In a message dated 95-10-06 06:44:59 EDT, you write: >Keeping the pressure in the pitchers constant (constant water level about >20 cm) we could observe varying seepage rates from the pitcher into >the soil resulted in: > > Seepage rates 'Environment' > from pitchers conditions >-------------------------------------------------------- >o increase with increase of ETo >o increase " crops around pitchers > (cropped or uncropped) >o increase " increase of matrix potentials > >We also could observe that these effects where less >pronounced with pitchers having generally higher seepage rates due to >higher porosity of the materials. > Would it be fair to say that for the low porosity pots that the emission rate of water is almost entirely driven by the matrix potential of the surrounding soils, and that higher cropping and higher ETO simply increased the draw? Also ... does this also mean that a sandy soil would favor a more constant emission rate over time, while a heavier soil maintain a more constant moisture level given a constant pressure on the pots? It appears that pot irrigation is incredibly appropriate for low energy, low technology and small plot farming regions. They appear to function essentially the same as an SDI emittered system wired to go on when the potientimeter reaches a given level of potiential ... and one would choose desired moisture level by the choice of clay. >I think that there may be parallels between the pitcher behavior >and variation in seepage or emmission rates of the burried porous rubber >pipes. I suspect that this effect may be overwhelmed by the pressure ... seven (7) p.s.i. would equate to just under 500 cm ... a pressure that probably overcomes most the influence of conduction ... at that pressure excess emissions simply push upward and outward increasing the surface area of the saturated zone until conduction and porosity of soil match hose emission rate. Any thoughts? Craig Thompson
Date: Mon, 9 Oct 1995 06:04:31 -0400 From: LodiCraig@aol.com Subject: Re: porous pipe study In a message dated 95-10-02 12:31:36 EDT, you write: >We are still trying to put this result in perspective. Possible >explanations include: >S Impact of soil-moisture conditions on emission rates >S A gradual variation in tubing porosity as a function of length >S Emission rates vary in relation to pipeline velocity >S Some gross error in the testing method > > Might you also consider the posibility that the inner layers of the porous pipe are more compressable but smaller pored than the less elastic outer layers? ... this could cause the wall of the pipe to behave similiarly to a diphram emitter with higher pressures resulting in smaller pores. Infact, the soil itself could be the surface the pipe is compressing against under higher pressure. If this is indeed the mechinism, than that could explain the non-linearity of the results and the difference between open air and in-situ trials. Charting the results (interpolating flow and pressure to mid-point of section) suggest that the first and last sections of hose behave as simple orfices (straight line relationship), with this hypothetical compresion (diaphram effect) of the hose taking place where pressure in the hose ranges aproximately between 6 and 7 p.s.i. More sample points and greater pressure ranges would make it easily possible to test this hypothesis. What do you think? Craig Thompson
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>From root@crcnis1.unl.edu Tue Oct 10 07:15 EDT 1995
Date: Tue, 10 Oct 1995 06:06:08 -0500
Message-Id: <199510101106.AA19460@crcnis1.unl.edu>
Subject: TRICKLE-L digest 317

Contents:
Erosion control in Hawaii using drip irrigation (MEAD2513@aol.com)



Date: Mon, 9 Oct 1995 15:48:42 -0400 From: MEAD2513@aol.com Subject: Erosion control in Hawaii using drip irrigation On the hillsides of Waikakalaua Stream in Hawaii, erosion was eminent after major realignment of the stream was completed. The developers that constructed the change had permits that required erosion control via vegetative establishment on all exposed sloped areas. The total surface area of three major slopes was 16908 m2 (182,000 sq. ft.) The cut slopes were 133 percent (0.75 to 1) !!! The steepness of the slopes did not permit sprinkler irrigation to irrigate germinating vegetative material that would be hydromulched as grasses and sun hemp seed. Due to the low out put of drip emitters, an above ground drip system was chosen to wet the slopes. Due to flash flooding which is normal in the area, horizontally laid drip tubing would be too susceptible to damage by flood levels and water velocity. Hence, drip tubing was laid vertically, parallel to the down side of the slopes. Drip tubing with 2 lph (0.5 gph) pressure compensating emitters spaced 60 cm (24 in.) apart was used. The laterals were spaced 90 cm (36 in.) apart. An application rate of 12 mm/hr (0.5 in./hr) was designed. PVC submains were laid along the top of the slopes. Keep in mind all this design was "temporary" in order to establish vegetation to control slope erosion. The first phase the project entailed installation crews using 914 m (3000 ft.) of rope and rappelling down the slopes to install 18.3 km (60000 ft.) of drip tubing. The tubing was staked against the slope. The second phase involved hydromulching the grass and sun hemp seed. After hydromulching and a 24 hour drying period, a germination period began by using short cycles of irrigation (once again, high frequency!). The slopes were kept saturated, but no runoff occurred*. A rain sensor shut down irrigations during heavy rains. After several months the coverage of germinating grasses went well and permanent establishment was successful. Root development was better than expected. =========================================================================== The above information was obtained from an article in the April '95 issue of the Irrigation Association magazine. *I still don't understand why over watering on the lower slopes was not discussed in detail in the article. But it is still an interesting engineering feat never the less. If anyone knows of more detail about this particularly interesting drip project, please contribute. =========================================================================== Richard Mead Trickle-L owner/manager
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>From root@crcnis1.unl.edu Wed Oct 11 07:14 EDT 1995
Date: Wed, 11 Oct 1995 06:06:16 -0500
Message-Id: <199510111106.AA06456@crcnis1.unl.edu>
Subject: TRICKLE-L digest 318

Contents:
      Re: Upcoming International Events ("Gary Clark" <GCLARK@falcon.age.ksu.edu>)



Date: Tue, 10 Oct 1995 10:37:19 CST From: "Gary Clark" <GCLARK@falcon.age.ksu.edu> Subject: Re: Upcoming International Events A Plasticulture Seminar is being offered on Wed. and Thurs. 11/15,16 at the end of the IA show in Phoenix, AZ . The seminar focus will be on the various uses of plastics in vegetable production systems including general components, microirrigation systems (design considerations, components, and management), fertilizer management in plasticulture systems, chemical injection, the use of row covers and high tunnels for plant growth enhancement and protection. This event is designed for growers, industry representatives, extension specialists, and researchers. This is an American Society for Horticultural Sciences (ASHS) sponsored program in cooperation with the Irrigation Association (IA) and the American Society for Plastics (ASP). For detailed information on registration and specific events contact: the American Society for Horticultural Sciences at (703) 836-4606, or Gary Clark at the Department of Biological and Agricultural Engineering at Kansas State University: (913) 532-5580; or at gclark@falcon.age.ksu.edu ****************************************** 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 ******************************************
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>From root@crcnis1.unl.edu Thu Oct 12 11:25 EST 1995
Date: Thu, 12 Oct 1995 06:06:29 -0500
Message-Id: <199510121106.AA02413@crcnis1.unl.edu>
Subject: TRICKLE-L digest 319

Contents:
Re: Micro Irrig., Pitcher Irrigation (Masoud Meshkat <mmeshkat@groucho.bae.uky.edu>)



Date: Wed, 11 Oct 1995 18:24:55 -0400 (EDT) From: Masoud Meshkat <mmeshkat@groucho.bae.uky.edu> Subject: Re: Micro Irrig., Pitcher Irrigation Dr. Thomas Stein Thanks for your article on Pitcher Irrigation. I had visited your www site before. It seems that you have put much effort into it. My question is: When and in what country or countries did pitcher irrigation orriginate. Thanks. Masoud
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>From root@crcnis1.unl.edu Fri Oct 13 11:17 EST 1995
Date: Fri, 13 Oct 1995 06:09:17 -0500
Message-Id: <199510131109.AA25122@crcnis1.unl.edu>
Subject: TRICKLE-L digest 320

Contents:
Re: Micro Irrig., Pitcher Irrigation (stein@wiz.uni-kassel.de (Thomas-M. Stein))



Date: Thu, 12 Oct 1995 12:20:30 +0100 (MEZ) From: stein@wiz.uni-kassel.de (Thomas-M. Stein) Subject: Re: Micro Irrig., Pitcher Irrigation Dear Mr. Masoud Meshkat, Thanks for your respond on pitcher irrigation. >From: Masoud Meshkat <mmeshkat@groucho.bae.uky.edu> > >Thanks for your article on Pitcher Irrigation. I had visited your www >site before. It seems that you have put much effort into it. > >My question is: When and in what country or countries did pitcher >irrigation orriginate. > >Thanks. Masoud > > I have tried to collect information on the origin, history and distribution of pitcher irrigation. Here what I have collected so far. History and Distribution of Pitcher Irrigation Pitcher irrigation is an ancient irrigation system which originated in northern Africa but became forgotten over the years. First trials on this old system were conducted in 1972 in India and were followed by Iran with the "Kuzeh Pot" in 1977 . The system started to spread also into other countries like Bukina Fasso, Senegal, Tunisia, Nigeria , Ghana, Morocco, Tanzania, Kenya, Botswana and Zimbabwe. An especially interesting area of distribution became Latin America where the use of pitcher irrigation was reported from Brazil, Bolivia, Mexico, Chile, Argentina and Ecuador. In most of these countries the system was mainly used in the experimental stage or on micro scale. In Brazil where the system had already been tested on areas of 5000 sqm, a great effort was made to extend it to larger areas. Like Roger Bourland reported there are interesting parallel at Ghost Ranch in Abiqui, N.M.,USA as well. They are using lage earthenware pots for irrigation. I am trying to contact them to get further information. Best regrads, Thomas Stein ______________________________________________________________________________ Thomas-M. Stein University of Kassel (FB11) Phone : (+49)-5542-98-1632 Dep. of Rural Engineering and Fax : (+49)-5542-98-1588 Natural Resource Protection Email : stein@wiz.uni-kassel.de Nordbahnhofstr. 1a WWW : http://www.wiz.uni-kassel.de/kww/ D-37213 Witzenhausen (FRG) List owner: IRRIGATION-L at LISTSERV@vm.gmd.de ______________________________________________________________________________
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>From root@crcnis1.unl.edu Sat Oct 14 11:18 EST 1995
Date: Sat, 14 Oct 1995 06:10:49 -0500
Message-Id: <199510141110.AA12158@crcnis1.unl.edu>
Subject: TRICKLE-L digest 321

Contents:
Free mulch-shredded leaves (MitLewis@aol.com)
Re: Free mulch-shredded leaves (Tim1Utah@aol.com)



Date: Fri, 13 Oct 1995 16:45:05 -0400 From: MitLewis@aol.com Subject: Free mulch-shredded leaves To all homeowners who have a lot of fall leaves, The following is not specifically about trickle/drip irrigation but it is somewhat related. I believe both go hand in hand with water conservation. We mulch our yard with shredded leaves and use drip and soaker irrigation. The leaves hold the moisture in and the irrigation system puts water just where it is needed - at the root zone. Here in northern Illinois, at this the time of year we turn our thoughts to yard clean up and prepare it for winter. Unfortunately, too many homeowners do not take advantage of free nutrients and mulches for their yard. They rake up their leaves and either burn them or put them out for collection. The collected leaves go to the local compost heap but those who live where it is allowed burn their leaves. 8-( Then during the next growing season, they pour fertilizer on their plants and water more often than they need to. When they remove the leaves they are cheating themselves of a valuable resource. We also all know burning leaves pollutes the air and it agravates respiratory problems. Leaves are part of the natural food chain. They provide food for many organizms and micorganizms that reduce the leaves to rich nutrients for future plants. Thus the growing cycle repeats itself each year. Nature has worked on perfecting this cycle for millions of years; so why do humans think it is okay to burn the leaves? 8'-( Instead of burning yard wastes, we should be putting the leaves on flower beds, around shrubs and trees, and the vegetable garden. The best way to do this it to use the lawnmower or shredder to reduce the volume of the leaves. Then rake the mulch onto the beds, being careful to pull it away from the base of plants (otherwise this encourages rodents to chew the plant). In a short time, hungry insects, worms, and organizms start working up through the soil and begin to eat the organic material. Of course, the leaves can be composted for next year's use. My wife and I have been using leaf mulch for years. In fact, since we do not have many trees on our *subdivision* lot, we use my old pickup to collect leaves from our friends. I think we usually get about 100 yard waste bags each year. We also grind up all our dead plants. We pile a lot of leaves on the garden and rototill them in for the winter. Often we add horse manure to the garden mix. After a few years of this, our vegetable garden soil is rich in organic material, the vegetables love it, and the flower and shrub beds require less water and no fertilizer. 8-) If you are one of those who do not take advantage of the free nutrients and a natural mulch, I encourage you to give it a try. But remember, you must give it a year to prove to you that Nature works. If your community allows leaf burning, please write a letter to your government officials requesting a ban on yard waste burning. *This earth is precious to the Creator and to harm the earth is to heap contempt on its Creator.* Chief Seattle Tim Lewis TLewis@aol.com Rockford, IL
Date: Sat, 14 Oct 1995 01:11:36 -0400 From: Tim1Utah@aol.com Subject: Re: Free mulch-shredded leaves I am from Utah. I think I saw a leaf once. Could you describe it to me? Also, how many leaves would I have to find to mulch a garden?
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>From root@crcnis1.unl.edu Sun Oct 15 11:19 EST 1995
Date: Sun, 15 Oct 1995 06:11:12 -0500
Message-Id: <199510151111.AA17889@crcnis1.unl.edu>
Subject: TRICKLE-L digest 322

Contents:
Re: Free mulch-shredded leaves (shieldsa@andrews.edu (Emmett Shields))



Date: Sat, 14 Oct 1995 22:43:47 -0400 (EDT) From: shieldsa@andrews.edu (Emmett Shields) Subject: Re: Free mulch-shredded leaves > > I am from Utah. I think I saw a leaf once. Could you describe it to me? Also, > how many leaves would I have to find to mulch a garden? > What color would you like?
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>From root@crcnis1.unl.edu Mon Oct 16 11:20 EST 1995
Date: Mon, 16 Oct 1995 06:11:30 -0500
Message-Id: <199510161111.AA27384@crcnis1.unl.edu>
Subject: TRICKLE-L digest 323

Contents:
Re: Free mulch-shredded leaves (Tim1Utah@aol.com)
Vector flow - Abstracts 8 & 9 combined (MEAD2513@aol.com)



Date: Sun, 15 Oct 1995 20:23:43 -0400 From: Tim1Utah@aol.com Subject: Re: Free mulch-shredded leaves They come in different colors?
Date: Sun, 15 Oct 1995 20:46:18 -0400 From: MEAD2513@aol.com Subject: Vector flow - Abstracts 8 & 9 combined I have combined two abstracts for this week's posting to discuss a technology that I sporadically hear about which is said to enhance subsurface drip irrigation. Vectored subsurface irrigation is a concept used to control the wetting pattern from buried drip emitters, particularly enhancing the horizontal movement of water. The vectored concept entails a physical barrier in the shape of a "V" whereby the drip lateral is placed in the bottom portion of the "V". Let me graphically display this concept in an albeit primitive fashion: \ / \ / \O/ The system discussed in abstract A, is normally used in turf irrigation systems, although I wonder if it could be used in the agricultural situations for shallow rooted crops such as onions, garlic and lettuce. The technique discussed in abstract B has been used on cabbage, paprika, tomato, potato and grape. I won't go into detail of the two papers in this posting due to the preponderance of text. However, I will follow up if there is generated interest. Please comment on the vector flow concept (pro or con) if you have experience with it or have observed it from afar. ============================================================= (Abstract A) Enhancing Subsurface Drip Irrigation Through Vector FlowTM D.F. Welsh, U.P. Kreuter, and J. D. Byles Water conservation has become a critical issue within the irrigation industry over the past several years. A leading technology in the search for increased irrigation efficiency and water conservation is subsurface drip irrigation. Over the past decade, subsurface drip irrigation has become a viable water saving technology in agriculture. Transfer of this technology into landscape applications has, however, been troubled by questionable results. Non-uniformity of water application has been of particular concern. Poor horizontal movement of water delivered by subsurface drip irrigation frequently produces intermittent yellowing in turf grasses which had led to reduced spacing of drip lines and thus increased installation costs. A new technique of manipulating the wetting pattern of subsurface drip irrigation is now available. It is based on the use of an impermeable membrane* to transform the point sources of water in drip lines to a broad-band source from which capillarity operates to draw water upward and outward. This technology, called Vector FlowTM, thus incorporates the relative uniformity of broadcast irrigation and reduced evaporative losses associated with subsurface drip systems. Theoretical discussions and field observations for the new technology are presented. Keywords: Capillarity, drip irrigation, landscape irrigation, subsurface irrigation, trickle irrigation, turf irrigation, water conservation, wetting pattern * 76 mm (3 in.) width, 38 mm (1.5 in.) height, angle is 90 degrees Abstract taken from paper found on pages 688 to 693 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA E-Mail: HQ@ASAE.ORG ------------------------------------------------------------------------ (Abstract B) Resource Conservation and Preservation through a New Subsurface Irrigation System H. K. Barth A subsurface microirrigation system was modified to include three innovative elements: (1) A new design of the lateral hoses preventing the penetration of roots into the external water outlets and the blockage by soil particles (2) An impermeable polyethylene foil** placed below the lateral pipes which prevents water loss through deep percolation especially in sandy substrates, and (3) Special installation equipment in a v-shaped device which releases the foil and pipe simultaneously into the soil without disturbance of the natural soil profile. The experience from several years of operation have proved those new elements to be highly effective. Compared to other irrigation methods, the irrigation efficiency was outstanding. Minimum maintenance requirement and long life span are additional positive characteristics of the system. The beneficial outcomes give reason for an optimistic appraisal of strategies for sustainable irrigated agriculture. Keywords: Subsurface irrigation, water savings, resource conservation, productivity, socio-economic benefits ** 60 cm (24 in) wide Abstract taken from paper found on pages 168 to 174 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA E-Mail: HQ@ASAE.ORG ========================================================================= Richard Mead Trickle-L owner/manager
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>From root@crcnis1.unl.edu Wed Oct 18 14:07 EST 1995
Date: Wed, 18 Oct 1995 08:58:09 -0500
Message-Id: <199510181358.AA12033@crcnis1.unl.edu>
Subject: TRICKLE-L digest 324

Contents:
Re: porous pipe study (parallels) (stein@wiz.uni-kassel.de (Thomas-M. Stein))
      Re: porous pipe study  (<ABUZREIG@net2.eos.uoguelph.ca>)
New member response (MEAD2513@aol.com)
Re: New member response  (Stavros Macrakis <macrakis@osf.org>)
Introductory questions... (9040707l@levels.unisa.edu.au (Linton Johnston))
RE:  Free mulch-shredded leaves ("Laura Dahl" <Tefra@msn.com>)



Date: Mon, 16 Oct 1995 17:04:28 +0100 (MEZ) From: stein@wiz.uni-kassel.de (Thomas-M. Stein) Subject: Re: porous pipe study (parallels) Dear Craig, >Would it be fair to say that for the low porosity pots that the >emission rate of water is almost entirely driven by the matrix >potential of the surrounding soils, and that higher cropping and >higher ETO simply increased the draw? Yes, I agree with you. As long as the applied hydrostatic pressure is not too high (around 30 cm) There have been trials like those reported from SILVA et al. 1988, with encapsulated porous capsules, which allowed the application of a higher hydrostatic pressures. Here is a citation from their paper: "The mean daily release of water per capsule varied significantly with the hydrostatic pressure to which the porous capsules were submitted. A good corn crop would normally need 400 mm of water, comparing this value with the amount of water used in the present experiment, the importance of this method of irrigation in water economy is quite evident. The release of water with this method of irrigation was not found to be uniform throughout the growing season of corn, a little bit smaller at the beginning and at the end of the growing season which is not difficult to explain keeping in view water requirements of plants. It brings out the fact, that the proposed method does not work solely under hydrostatic pressure, but also autoregulated by plant water demand like irrigation by suction (OLGUIN et al.,1976; SANTOS,1977) at least during the maximum vegetative growth and water requirement period (four weeks after germination till grain filling). This was found to be more relevant for the treatment with the smallest hydraulic head, where apparently the water demand by plants plays a more important role than the hydrostatic pressure." Taken from: Silva, D.A., Carvallo, H.O., Silva, A.S. and Gheyi, H.R., 1988: Irrigation by Porous Capsules under Hydrostatic Pressure. - Zeitschrift fuer Kulturtechnik und Flurbereinigung Vol. 29, 27-35. >>I think that there may be parallels between the pitcher behaviour >>and variation in seepage or emission rates of the buried porous >>rubber pipes. >I suspect that this effect may be overwhelmed by the pressure >seven(7) p.s.i. would equate to just under 500 cm a pressure that >probably overcomes most the influence of conduction at that pressure >excess emissions simply push upward and outward increasing the >surface area of the saturated zone until conduction and porosity of >soil match hose emission rate. Any thoughts? Still I would expect to see differences in emission rates (they may be quite small in our case) between a saturated soil (no suction) and an unsaturated soil (soil suction) as the soil and rubber pipe form a interacting unit bound through the water capillaries. The soil reaching saturation may build up a certain resistance to emitted water (saturated hydraulic conductivity) in contrast to a pipe placed on top of the ground or hanging in free air. Therefore I would agree with your saying, >.... this also mean that a sandy soil would favour a more constant >emission rate over time,.... as sandy soils (taking a coarse sand as an example) having high hydraulic conductivities and therefore producing low resistance and transferring a lower capillary suction towards the rubber pipes. Heavier soils would produce a higher capillary suction onto the rubber pipe when unsaturated and may form a stronger resistance once saturated (lower hydraulic conductivities). Surly this subject is more complex then we have discussed it here and the effects may be less pronounced depending on the constellation of the different interacting components of the system. I would appreciate any thoughts or experiences from you or from anybody on the list. Thomas Stein ______________________________________________________________________________ Thomas-M. Stein University of Kassel (FB11) Phone : (+49)-5542-98-1632 Dep. of Rural Engineering and Fax : (+49)-5542-98-1588 Natural Resource Protection Email : stein@wiz.uni-kassel.de Nordbahnhofstr. 1a WWW : http://www.wiz.uni-kassel.de/kww/ D-37213 Witzenhausen, GERMANY List owner: IRRIGATION-L at LISTSERV@vm.gmd.de ______________________________________________________________________________
Date: Mon, 16 Oct 1995 15:25:03 EDT From: <ABUZREIG@net2.eos.uoguelph.ca> Subject: Re: porous pipe study There are three driving forces for unsaturated flow conditions: 1. gravity potential which is a function of saturated hydraulic conductivity, 2. head potential (depend on water head multiplied by Ks and 3.What is called the matrix flux potential (Qm)which is simply the area under the unsaturated K with matrix potential. Plants and evaporation is another source of driving potential In the situation of a burried pipe, water flow reaches a steady state after some time irrespective of the head potential. Water flow will decrease over time since the driving force specially the Qm will decrease as soil becomes more saturated. For the same soil gravity and matrix potential are similar and water flow is a function of head potential. Higher head potential results in higher water flow. Heavy soils have higher matrix potential but have lower gravity potential since Ks is smaller compared to coarse textured soil. The flow in fine texture soils can be higher compared to sandy soil for example, if the head is sufficiently large to compensate the decrease in Ks. Thus water flow from a burried pipe is not a function of pressure head only. The problem is much more complex. Majed,
Date: Mon, 16 Oct 1995 23:45:44 -0400 From: MEAD2513@aol.com Subject: New member response The following is a response from Brian Chandley to the Welcome Survey questions. >1) Briefly, what is your affiliation with trickle/drip irrigation? I live in an area (central Massachusetts) where water is ample but becoming expensive. I believe in recycling at the office and home and conservation is a natural byproduct of that mind-set. I also believe that I will achieve better results in my flower and vegetable garden with DI. It also might make a good sideline. Our water rates are about to explode due to implementation of federally mandated water treatment programs. I currently do not use DI but plan on implementating in the spring of 1996. >2) What crops or plants do you use drip irrigation on? None. See #1.
Date: Tue, 17 Oct 1995 10:40:24 -0400 From: Stavros Macrakis <macrakis@osf.org> Subject: Re: New member response Hi, MEAD2513@aol.com said: > I live in an area (central Massachusetts) where water is ample but > becoming expensive.... Our water rates are about to explode due to > implementation of federally mandated water treatment programs.... _Sewer_ rates will certainly be going up because of the construction of new treatment facilities. In the MWRA region (eastern Massachu- setts), this includes notably the Deer Island plant (Boston Harbor cleanup). Water rates are _not_ going up much as far as I know. I would guess that something similar is happening in Central Massachusetts. If you use a significant amount of water for irrigation, you can get a separate water meter installed for irrigation use only, and not pay the sewer charges on this water which, after all, never gets to the sewer. This should cost about $250-300 including the meter, a testable pressure vacuum breaker (to prevent siphoning), permit, and labor. In fact, in some towns at least, code _requires_ a separate meter for irrigation systems. As for the 'explosion' of sewer rates, I looked into this last year when the newspapers were getting excited about it. As far as I can tell, the large figures that were being quoted had been 'cooked' for political reasons. For instance, rather than quoting future prices in present dollars, they were quoting them in future dollars, using an arbitrary (and large) estimate of inflation. I could equally well predict that meat prices will double over the next ten years if I assume 7% inflation. -s
Date: Wed, 18 Oct 1995 12:04:22 +0930 From: 9040707l@levels.unisa.edu.au (Linton Johnston) Subject: Introductory questions... Having been on the Trickle-L mailing list for over a week now, I should make an attempt to answer the questions you set out as an introduction .... >To get things started, I have initiated a couple of general introductory >questions. Answering the questions is a voluntary process. >1) Briefly, what is your affiliation with trickle/drip irrigation? Well, like Brian Chandley, I am not directly involved with subsurface drip irrigation. I am, instead, interested in some of the associated technology, namely the devices used for measuring soil moisture. I live in Adelaide, South Australia, and I am in the middle of work on a PhD in Engineering, specifically water engineering. Here is a brief summary of the project - __________________________________________________________________ Title : The Development of a Mathematical Model for the Water Balance of a Residential Housing Estate Incorporating Stormwater Management. Introduction to New Brompton New Brompton Estate in Adelaide, South Australia, is a medium-density residential housing development employing innovative techniques in storm water management. Relatively high quality roof runoff from 15 residences is directed first into temporary storage, and further on to longer term aquifer storage. Stormwater runoff from the roofs of the houses drains into a 106 metre long retention trench, filled with 20mm gravel and enclosed in geotextile fabric. From here, water infiltrates slowly into the surrounding soil of the reserve, or overflows at a central monitoring point to a bore connected into a quaternary aquifer (Q2) 30 metres below ground level. During major storms, a second overflow allows excess water to be removed via the existing street network. This approach serves to (1) reduce peaks in the runoff hydrograph, (2) reduce the quantity of storm water entering the conventional drainage network and in turn hold more water at the site on which it falls, (3) increase soil moisture for greening of the urban environment, and (4) recharge the aquifer with water of low salinity in order to improve the local groundwater quality for irrigation and other beneficial uses. Mathematically Modelling the Water Balance The research is being conducted at the University of South Australia under Associate Professor John Argue at the Urban Water Resources Center. The project focuses on the development of a mathematical model for the water balance of New Brompton Estate. There are two main issues to be addressed; 1. A model must be constructed to mathematically replicate or represent all of the components identified within the physical system, and 2. Monitoring of as many components as possible at the actual site must be performed so as to verify and calibrate the model. The water balance can be defined as something which accounts for all moisture movement into, within and out from the site in question. In order to begin the process of mathematically representing the natural situation, the physical water balance system is broken down into smaller elements. At this stage, a model framework is envisaged which comprises four main interacting 'blocks'; a Soil Moisture block, an Evapotranspiration block, a Trench Flow block and a Groundwater block. These sub-models must be designed so as to facilitate clear data communication/interaction throughout, forming a cohesive mathematical model. Instrumentation is currently in place to monitor rainfall in the reserve and trench water levels. Soil moisture monitoring devices are in the process of being installed, along with a weather station to collect relevant meteorological data. Soil movement in the vicinity of the trench is also being recorded on a monthly basis. _____________________________________________________________________ As you can see, my interests appear to be somewhat removed from the majority of others on the trickle-l list. However, I am keen to hear of the latest innovations in the field, and hope I can contribute to some of the discussions. In particular, I am installing a series of Enviroscan capacitance soil moisture monitoring devices, supplied by Sentek. I understand, from conversations with Peter Buss at Sentek, that some research involving the use of these instruments is being conducted in the drip irrigation circle in Fresno. Any exchange of ideas, advice or comments on common experience could only be helpful for all concerned! >11) How did you find out about our mailing list? As mentioned, Peter Buss of Sentek in Adelaide referred me to your group. Well, I look forward to all future correspondence! Regards, Linton. Linton Johnston BEng(hons), Postgraduate Research Student, Urban Water Resources Centre, School of Civil Engineering, University of South Australia Warrendi Road Telephone +61 8 302 3491 The Levels Facsimile +61 8 302 3373 South Australia, 5095. Email 9040707l@levels.unisa.edu.au
Date: Wed, 18 Oct 95 03:17:54 UT From: "Laura Dahl" <Tefra@msn.com> Subject: RE: Free mulch-shredded leaves It is a good idea to mulch in your garden. But if you are an organic gardener like I am, you will have trouble with bad insects living under your leaves. You may also find that beneficial insects have a difficult time finding the bad guys who hide under leaves. This happened to me early on while trying organic gardening. Living in Utah has taught me to be very careful with my water usage, so trickle irrigation is my only method of watering my humble garden. I have also learned to mulch to help keep soil moist, but I have also learned to be very careful how I mulch. I agree that you need to re-use your leaves, but I also re-use my table scraps (excluding fats and meats), grass clippings, etc: compost. It takes 1-2 years to completely break down leaves. I keep them separate from the rest of my compost. I have also learned that if you don't break down leaves before spreading them, nutrients will be drained from your soil during the process of breaking down. In essence, I baby my soil. Laura tefra@msn.com
End of Digest
>From root@crcnis1.unl.edu Thu Oct 19 14:07 EST 1995
Date: Thu, 19 Oct 1995 08:58:40 -0500
Message-Id: <199510191358.AA06638@crcnis1.unl.edu>
Subject: TRICKLE-L digest 325

Contents:
A drip that will not plug. (Sal Schettino <sals@rain.org>)
RE:  Free mulch-shredded leaves  (SMTP Id - Reply (<sun1.TCPBRIDGE.VIC1.DGR@sun1.Vic.CoopersLybrand.CA>  (Doug Rhodes ))
Plug-resistant emitters (dagoldhamer@ucdavis.edu)
RE:  Free mulch-shredded leaves  (SMTP Id - Reply (bmchan@cleome.ultranet.com (Brian Chandley))
Re: Plug-resistant emitters (Sal Schettino <sals@rain.org>)



Date: Wed, 18 Oct 1995 07:48:10 -0700 From: Sal Schettino <sals@rain.org> Subject: A drip that will not plug. I have been using drip for a long time ,over 15 years and the main problem I have is that of pluging emiters. Maybe because I'm organic everytime I water I have plugs. I was wondering why in all this time they have not come up with a emiter that will not plug like the one I have been using. Once I had a emiter made by rain bird that was round with a big hole in it. It never seemed to plug. The hole going out was much bigger then the hole that came in. What a great idea simple . For some reason they quit making them. Why when you have a drip that doesnot seem to plug would you quit making them. If there was a drip that did not plug it would make life so easy. I could just let the grass grow over the line and mow over the line. I'm getting old and I would like to see the drip emiter that will save this old back of mine. Is there one? Help? sals@rain.org http://www.rain.org/~sals/my.html
Date: Wed Oct 18 12:22:15 1995 From: <sun1.TCPBRIDGE.VIC1.DGR@sun1.Vic.CoopersLybrand.CA> (Doug Rhodes ) Subject: RE: Free mulch-shredded leaves (SMTP Id - Reply Laura Dahl and others wrote about problems with leaves in composts and mulch... Leaves will compost effectively in a hot compost system. I use animal manure (usually cow or horse) for the nitrogenous layer in an air tube compost box system. Compost is finished and ready to use in about 6 weeks in summer, somewhat longer in winter. Working temperatures exceed 140 degrees F in this system. In our dry summer, rainy winter climate, mulching with leaves does not rob the soil of nutrients. Just the opposite, as by slowing the rain getting through the upper layers of soil, there is noticeably less leaching of nutrients downward. I suppose this mimics what nature does on the forest floor. I appreciate circumstances may be different in Utah, but I grow concerned whenever I hear people talking about leaves not being suitable for compost or mulch. Every year I haul loads and loads of leaves to my "urban farm" from people who are sure: oak leaves will "poison" the compost leaves takes years to break down leaf mulch will "harm" the soil leaf mulch will engender pests etc etc All these circumstances are quite manageable (or even somewhat overblown) especially when the proponents of these views are typically burning those leaves or sending them to landfill. This is not a "flame" (we want to keep flames away from our leaves) but a plea to everyone to use this great resource wisely! Yours for better compost, Doug Rhodes _______________________________________________________________ |internet:vic1.dgr@sun1.vic.cooperslybrand.ca| tel:(604)360-5409| |Compuserve: 70412.364@compuserve.com | fax:(604)388-7331| | | | |mail: 1232 Vista Heights | Pacific Time Zone| | Victoria, B.C. V8T 2H8 | GMT-8 Hours | | Canada | | |____________________________________________|__________________|
Date: Wed, 18 Oct 1995 12:36:58 -0700 From: dagoldhamer@ucdavis.edu Subject: Plug-resistant emitters On Oct. 18, Sal Schettino posted the following: "I have been using drip for a long time ,over 15 years and the main problem I have is that of pluging emiters. Maybe because I'm organic everytime I water I have plugs. I was wondering why in all this time they have not come up with a emiter that will not plug like the one I have been using. Once I had a emiter made by rain bird that was round with a big hole in it. It never seemed to plug. The hole going out was much bigger then the hole that came in. What a great idea simple . For some reason they quit making them. Why when you have a drip that doesnot seem to plug would you quit making them. If there was a drip that did not plug it would make life so easy. I could just let the grass grow over the line and mow over the line. I'm getting old and I would like to see the drip emiter that will save this old back of mine. Is there one? Help?" sals@rain.org http://www.rain.org/~sals/my.html It's my understanding that Bowsmith, Inc. made the emitters described above that were marketed by Rainbird. This emitter may still be available since Bowsmith currently makes and markets a line of emitters they call "Nonstop" which consist of a sandwich arrangements of rubber disks with small holes in them. The holes expand to let potential clogging material pass through. I've used them in my research and found them quite resistant to clogging. The info. for Bowsmith follows: Bowsmith, Inc. P.O. Box 428 131 2nd St. Exeter, CA 93221 800 269-7648 FAX 209 592-2314 Submitted by Dave Goldhamer.
Date: Wed, 18 Oct 1995 20:45:28 -0400 From: bmchan@cleome.ultranet.com (Brian Chandley) Subject: RE: Free mulch-shredded leaves (SMTP Id - Reply >Laura Dahl and others wrote about problems with leaves in composts >and mulch... > >Leaves will compost effectively in a hot compost system. I use animal >manure (usually cow or horse) for the nitrogenous layer in an air tube >compost box system. Compost is finished and ready to use in about 6 >weeks in summer, somewhat longer in winter. Working temperatures exceed >140 degrees F in this system. > > Would you explain what an "air tube compost box system" is. I use a two-bin system that gets air the old fashion way: by hand turning. This happens infrequently because it is WORK.
Date: Wed, 18 Oct 1995 19:14:40 -0700 From: Sal Schettino <sals@rain.org> Subject: Re: Plug-resistant emitters Thanks I will give them a call. I have some that have been working for over 12 years. I hope its the same one. Thanks again. At 02:42 PM 10/18/95 -0500, dagoldhamer@ucdavis.edu wrote: >On Oct. 18, Sal Schettino posted the following: > >"I have been using drip for a long time ,over 15 years and the main problem >I >have is that of pluging emiters. Maybe because I'm organic everytime I >water I have plugs. I was wondering why in all this time they have not >come >up with a emiter that will not plug like the one I have been using. Once >I >had a emiter made by rain bird that was round with a big hole in it. It >never seemed to plug. The hole going out was much bigger then the hole >that >came in. What a great idea simple . For some reason they quit making them. >Why when you have a drip that doesnot seem to plug would you quit making >them. If there was a drip that did not plug it would make life so easy. I >could just let the grass grow over the line and mow over the line. I'm >getting old and I would like to see the drip emiter that will save this old >back of mine. Is there one? Help?" >sals@rain.org >http://www.rain.org/~sals/my.html > >It's my understanding that Bowsmith, Inc. made the emitters described above >that were marketed by Rainbird. This emitter may still be available since >Bowsmith currently makes and markets a line of emitters they call "Nonstop" >which consist of a sandwich arrangements of rubber disks with small holes >in them. The holes expand to let potential clogging material pass through. > I've used them in my research and found them quite resistant to clogging. > >The info. for Bowsmith follows: > >Bowsmith, Inc. >P.O. Box 428 >131 2nd St. >Exeter, CA 93221 > >800 269-7648 >FAX 209 592-2314 > >Submitted by Dave Goldhamer. > >
End of Digest
>From root@crcnis1.unl.edu Fri Oct 20 14:07 EST 1995
Date: Fri, 20 Oct 1995 08:59:16 -0500
Message-Id: <199510201359.AA01499@crcnis1.unl.edu>
Subject: TRICKLE-L digest 326

Contents:
RE:  Free mulch-shredded leaves  (SMTP Id - Reply (<sun1.TCPBRIDGE.VIC1.DGR@sun1.Vic.CoopersLybrand.CA>  (Doug Rhodes ))
RE: Free mulch-shredded leaves  (SMTP Id - Reply ("Laura Dahl" <Tefra@msn.com>)



Date: Thu Oct 19 15:09:12 1995 From: <sun1.TCPBRIDGE.VIC1.DGR@sun1.Vic.CoopersLybrand.CA> (Doug Rhodes ) Subject: RE: Free mulch-shredded leaves (SMTP Id - Reply Brian Chandley asked: >Would you explain what an "air tube compost box system" is. I use a >two-bin >system that gets air the old fashion way: by hand turning. This >happens >infrequently because it is WORK. The air tube system I use is known, I believe, as a "modified Indore" system. Compost is made in batches, with two alternating layers. There is a layer of carbon/cellulose materials about 6 inches thick, topped by a layer of nitrogenous material about 3-4 inches thick, alternating until the bin is full. I shred the cellulose materials using a chipper/shredder. A third layer of soil can be used, but this is not necessary, especially once you get a sense of the materials you are using, moisture content etc. The soil makes it easier to be off a bit and still get pretty good results. The air tubes are plastic water supply pipe (black) 1 and 1/4 inch diameter with holes drilled (3/8 inch because that was my largest drill bit at the time). The tubes are placed in the vertical center of each cellulose layer, two per layer, extending through vertical slots in the front and back panels of the compost box. Since the holes are drilled about 6 inches apart, each 90 degrees to the next, and the centers of the cellulose layers are about 10-12 inches apart vertically, and my box is 4 feet square and high, no part of the bin is more than one foot from a supply of fresh air through the tube, and most are less. There are two such bins beside each other, and there is a cover to control the moisture exchange from rain or evaporation. The vertical slots in the box allow the tubes to slide downward as the material shrinks during composting. This works very well. I have heard of people putting air tubes into a heap (without the box) and of course many people do not shred the waste before it goes in. Both would make the system slower, but the big win is that the hard work and the sights and smells of turning are avoided. And, I have negligible problem with animals. Although, if you leave the finished (cool) compost in the bins for a while, wasps, mice and bees all like to use the tubes to access the center of the pile for nesting...but no keen composter would let compost sit unused any longer than necessary! I hope this helps...it's hard to describe without using a diagram. If this falls short, let me know how I can help further! Happy composting! Doug Rhodes _______________________________________________________________ |internet:vic1.dgr@sun1.vic.cooperslybrand.ca| tel:(604)360-5409| |Compuserve: 70412.364@compuserve.com | fax:(604)388-7331| | | | |mail: 1232 Vista Heights | Pacific Time Zone| | Victoria, B.C. V8T 2H8 | GMT-8 Hours | | Canada | | |____________________________________________|__________________|
Date: Fri, 20 Oct 95 04:59:11 UT From: "Laura Dahl" <Tefra@msn.com> Subject: RE: Free mulch-shredded leaves (SMTP Id - Reply Thank you Doug Rhodes for your reply on compost and the ability to easily compost leaves in a moister climate. I often forget that many do not have my same problems. I, too, have beautiful compost three times a year, and I waste none of it. In fact, I depend on it for my organic garden and to keep humus in my dry soil. But I have found that this dry climate causes leaves to break down a little slower. My favorite compost (which I use as mulch because it seeps so nicely) is from leaves, so I have to nurture my second and longer cooking batch of leaves and other added ingredients to get things cooking. I also live in an area where the soil has been abused badly for many years. As a result, I have to be extra careful to not sheet compost. This practice results in problems such as chronic tomato end rot, despite repeated treatments. Thanks again, Laura tefra@msn.com ---------- From: trickle-l@unl.edu on behalf of Doug Rhodes Sent: Wednesday, October 18, 1995 1:38 PM To: Multiple recipients of list Subject: RE: Free mulch-shredded leaves (SMTP Id - Reply Laura Dahl and others wrote about problems with leaves in composts and mulch... Leaves will compost effectively in a hot compost system. I use animal manure (usually cow or horse) for the nitrogenous layer in an air tube compost box system. Compost is finished and ready to use in about 6 weeks in summer, somewhat longer in winter. Working temperatures exceed 140 degrees F in this system. In our dry summer, rainy winter climate, mulching with leaves does not rob the soil of nutrients. Just the opposite, as by slowing the rain getting through the upper layers of soil, there is noticeably less leaching of nutrients downward. I suppose this mimics what nature does on the forest floor. I appreciate circumstances may be different in Utah, but I grow concerned whenever I hear people talking about leaves not being suitable for compost or mulch. Every year I haul loads and loads of leaves to my "urban farm" from people who are sure: oak leaves will "poison" the compost leaves takes years to break down leaf mulch will "harm" the soil leaf mulch will engender pests etc etc All these circumstances are quite manageable (or even somewhat overblown) especially when the proponents of these views are typically burning those leaves or sending them to landfill. This is not a "flame" (we want to keep flames away from our leaves) but a plea to everyone to use this great resource wisely! Yours for better compost, Doug Rhodes _______________________________________________________________ |internet:vic1.dgr@sun1.vic.cooperslybrand.ca| tel:(604)360-5409| |Compuserve: 70412.364@compuserve.com | fax:(604)388-7331| | | | |mail: 1232 Vista Heights | Pacific Time Zone| | Victoria, B.C. V8T 2H8 | GMT-8 Hours | | Canada | | |____________________________________________|__________________|
End of Digest
>From root@crcnis1.unl.edu Tue Oct 24 14:09 EST 1995
Date: Tue, 24 Oct 1995 09:00:58 -0500
Message-Id: <199510241400.AA02012@crcnis1.unl.edu>
Subject: TRICKLE-L digest 327

Contents:
Re: Forwarded mail (Tom Hodges <thodges@beta.tricity.wsu.edu>)
Groundwater monitoring wells (HELEN ENANDER <dairyhelen@beta.delphi.com>)
RE: Free mulch-shredded leaves  (SMTP Id - Reply (bmchan@cleome.ultranet.com (Brian Chandley))
Re: A drip that will not plug. (Tim1Utah@aol.com)
pitcher irrigation (Mike Schulz <SCHULZM@salty.agvic.gov.au>)



Date: Fri, 20 Oct 1995 14:36:23 -0700 (PDT) From: Tom Hodges <thodges@beta.tricity.wsu.edu> Subject: Re: Forwarded mail If you are planning to be at the American Society of Agronomy Annual Meetings in St. Louis, Missouri then consider attenting the Software Scene Committee business meeting on Tuesday evening (Oct. 31, 7:30pm, America's Center, room 121). A major item will be the future role of computers, software, and networks in agriculture and the ASA/CSSA/SSSA. We would appreciate getting ideas from a wide range of people. Tom Hodges, Software Scene Coordinator, 1994-1995 thodges@beta.tricity.wsu.edu
Date: Sat, 21 Oct 1995 09:27:14 -0400 From: HELEN ENANDER <dairyhelen@beta.delphi.com> Subject: Groundwater monitoring wells We are developing a groundwater monitoring program using ten foot wells, two inches in diameter. It has been suggested that the well screens can not be of "poly" material if we are to monitor pesticides. Is this accurate, and is there supporting literature? Thank You Dr. Gail Simonds Wickliffe, KY dairyhelen@beta.delphi.com
Date: Sat, 21 Oct 1995 11:13:27 -0400 From: bmchan@cleome.ultranet.com (Brian Chandley) Subject: RE: Free mulch-shredded leaves (SMTP Id - Reply > As a result, I have to be extra careful to not sheet compost. >This practice results in problems such as chronic tomato end rot, despite >repeated treatments. > >Thanks again, >Laura >tefra@msn.com > > Laura: What is SHEET compost?
Date: Sat, 21 Oct 1995 11:47:44 -0400 From: Tim1Utah@aol.com Subject: Re: A drip that will not plug. In regards to landscape use of drip emitters, cost per emitter isn't always a key factor as in agriculture (there is a big difference between buying 100 emitters and buying 5000!). Your best option will be to get a turbulent flow, pressure compensating emitter. These are more expensive but will not plug as easily. Also If you use a higher flow emitter (2 gph as compared to .5 gph the emitter flow path will be larger. There are also some emitters out there that can be easily taken apart and cleaned. Try consulting a wholesale distributor of drip products. (contractor grade irrigation equipment is typically of higher quality).
Date: Tue, 10 Oct 1995 13:35:14 +0000 From: Mike Schulz <SCHULZM@salty.agvic.gov.au> Subject: pitcher irrigation re. Thomas Stein's pitcher irrigation bibliography An additional non-technical publication by Mondal is; Mondal RC, Gupta SK, Dubey SK (1987) Pitcher Irrigation Better farming in salt affected soils #11 Central Soil Salinity Research Institute, Karnal-132001, India This is a 15 page booklet in English, containing several line drawings and B&W photos. Subjects briefly discussed are; Description, Suitability of the technique, Hydraulics of flow, Moisture distribution around pitchers under various irrigation methods, size and number of pitchers, Installation instructions, Water requirements, Filling schedule, Application of nutrients, Crop performance, Use of saline water, Moisture and salt distribution around pitchers, Cost and benefits, Use in plant breeding, Prospects Copies were available from the ICAR Director at publication and i have one copy. Schulzzzzzzz............ Tatura a campus of the Inst. of Sustainable Irrigated Agriculture an institute of Agriculture Victoria a devision of Agriculture Energy and Minerals a department of the Government of Victoria a state of Australia Postal address
End of Digest
>From root@crcnis1.unl.edu Wed Oct 25 14:12 EST 1995
Date: Wed, 25 Oct 1995 09:02:56 -0500
Message-Id: <199510251402.AA00633@crcnis1.unl.edu>
Subject: TRICKLE-L digest 328

Contents:
Re: pitcher irrigation (stein@wiz.uni-kassel.de (Thomas-M. Stein))
Re: Plug-resistant emitters (Sal Schettino <sals@rain.org>)



Date: Tue, 24 Oct 1995 16:37:11 +0100 (MEZ) From: stein@wiz.uni-kassel.de (Thomas-M. Stein) Subject: Re: pitcher irrigation Thank you very much for your contribution on pitcher irrigation, I have added it to the bibliography on the WWW. I would like to order a copy of that publication. Could you please be so kind and give me the address of the "ICAR Director at publication" ? Regards, Thomas ______________________________________________________________________________ Thomas-M. Stein University of Kassel (FB11) Phone : (+49)-5542-98-1632 Dep. of Rural Engineering and Fax : (+49)-5542-98-1588 Natural Resource Protection Email : stein@wiz.uni-kassel.de Nordbahnhofstr. 1a WWW : http://www.wiz.uni-kassel.de/kww/ D-37213 Witzenhausen, GERMANY List owner: IRRIGATION-L at LISTSERV@vm.gmd.de ______________________________________________________________________________
Date: Tue, 24 Oct 1995 14:34:43 -0700 From: Sal Schettino <sals@rain.org> Subject: Re: Plug-resistant emitters Thankyou I call them and you hit the nail on the head . that was the one and I ordered 200 . will get more later. thanks for your help. At 02:42 PM 10/18/95 -0500, dagoldhamer@ucdavis.edu wrote: >On Oct. 18, Sal Schettino posted the following: > >"I have been using drip for a long time ,over 15 years and the main problem >I >have is that of pluging emiters. Maybe because I'm organic everytime I >water I have plugs. I was wondering why in all this time they have not >come >up with a emiter that will not plug like the one I have been using. Once >I >had a emiter made by rain bird that was round with a big hole in it. It >never seemed to plug. The hole going out was much bigger then the hole >that >came in. What a great idea simple . For some reason they quit making them. >Why when you have a drip that doesnot seem to plug would you quit making >them. If there was a drip that did not plug it would make life so easy. I >could just let the grass grow over the line and mow over the line. I'm >getting old and I would like to see the drip emiter that will save this old >back of mine. Is there one? Help?" >sals@rain.org >http://www.rain.org/~sals/my.html > >It's my understanding that Bowsmith, Inc. made the emitters described above >that were marketed by Rainbird. This emitter may still be available since >Bowsmith currently makes and markets a line of emitters they call "Nonstop" >which consist of a sandwich arrangements of rubber disks with small holes >in them. The holes expand to let potential clogging material pass through. > I've used them in my research and found them quite resistant to clogging. > >The info. for Bowsmith follows: > >Bowsmith, Inc. >P.O. Box 428 >131 2nd St. >Exeter, CA 93221 > >800 269-7648 >FAX 209 592-2314 > >Submitted by Dave Goldhamer. > >
End of Digest
>From root@crcnis1.unl.edu Thu Oct 26 14:12 EST 1995
Date: Thu, 26 Oct 1995 09:03:35 -0500
Message-Id: <199510261403.AA25127@crcnis1.unl.edu>
Subject: TRICKLE-L digest 329

Contents:
Re: Groundwater monitoring wells (GrapeGrowr@aol.com)
Re: pitcher irrigation (stein@wiz.uni-kassel.de (Thomas-M. Stein)) (B.Maheshwari@uws.edu.au (Basant Maheshwari))



Date: Wed, 25 Oct 1995 18:57:13 -0400 From: GrapeGrowr@aol.com Subject: Re: Groundwater monitoring wells Talk to the engineering department at the Coachella Valley Water District (619) 398-1144. They have many wells monitored in our area for various reasons and are always happy to help.
Date: Thu, 26 Oct 1995 09:35:45 +1000 From: B.Maheshwari@uws.edu.au (Basant Maheshwari) Subject: Re: pitcher irrigation (stein@wiz.uni-kassel.de (Thomas-M. Stein)) Thomas Stein wrote: >I would like to order a copy of that publication. Could you please be so >kind and give me the address of the "ICAR Director at publication" ? The address of ICAR is Indian Council of Agricultural Research Krishi Bhawan Dr. Rajendra Prasad Marg New Delhi - 110 001, INDIA ------------------------- Dr. Basant Maheshwari
End of Digest
>From root@crcnis1.unl.edu Fri Oct 27 14:14 EST 1995
Date: Fri, 27 Oct 1995 09:04:07 -0500
Message-Id: <199510271404.AA19680@crcnis1.unl.edu>
Subject: TRICKLE-L digest 330

Contents:
resubscribe (ROERINK@sc.agro.nl)



Date: Fri, 27 Oct 1995 11:30:22 +0100 (MET) From: ROERINK@sc.agro.nl Subject: resubscribe resubscribe IN%"roerink@sc.agro.nl" as IN%"roerink@sc.dlo.nl"
End of Digest
>From root@crcnis1.unl.edu Sat Oct 28 14:12 EST 1995
Date: Sat, 28 Oct 1995 09:04:50 -0500
Message-Id: <199510281404.AA07162@crcnis1.unl.edu>
Subject: TRICKLE-L digest 331

Contents:
IRRISOFT Database (stein@wiz.uni-kassel.de (Thomas-M. Stein))



Date: Fri, 27 Oct 1995 15:31:53 +0100 (MEZ) From: stein@wiz.uni-kassel.de (Thomas-M. Stein) Subject: IRRISOFT Database This message is (mainly) for those who have recently joined the list. Like previously described we have started up IRRISOFT, a World Wide Web Database on IRRIGATION and HYDROLOGY Software which is provided through the Department of Rural Engineering and Natural Resource Protection at the University of Kassel. The URL of IRRISOFT is: http://www.wiz.uni-kassel.de/kww/irrisoft/irrisoft_i.html In order to build up IRRISOFT we have prepared Software Description Pages including information and LINKS to server holding further information. To facilitate the retrieval (downloading) of public domain, shareware or commercial irrigation and hydrology software on the Internet, IRRISOFT also provides an ftp site. There will be direct links to the corresponding files on the ftp server from the Software Description Pages. We are trying to keep up contacts to the authors of the programs to ensure up-to-date information. Any contributions or suggestions would be gratefully received. Regards Thomas Stein ______________________________________________________________________________ Thomas-M. Stein University of Kassel (FB11) Phone : (+49)-5542-98-1632 Dep. of Rural Engineering and Fax : (+49)-5542-98-1588 Natural Resource Protection Email : stein@wiz.uni-kassel.de Nordbahnhofstr. 1a WWW : http://www.wiz.uni-kassel.de/kww/ D-37213 Witzenhausen, GERMANY List owner: IRRIGATION-L at LISTSERV@vm.gmd.de ______________________________________________________________________________
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>From root@crcnis1.unl.edu Mon Oct 30 14:16 EST 1995
Date: Mon, 30 Oct 1995 08:05:28 -0600
Message-Id: <199510301405.AA27303@crcnis1.unl.edu>
Subject: TRICKLE-L digest 333

Contents:
Trickle-L update (MEAD2513@aol.com)



Date: Sun, 29 Oct 1995 20:00:51 -0500 From: MEAD2513@aol.com Subject: Trickle-L update As of October 28, Trickle-L has 332 subscribers from 24 countries. Individuals from U.S. Universities comprise 31% of the subscribers while independent non-University subscribers amount to 42%. The remaining U.S. representation are from government researchers at 3%. International individuals compose 24%. The following countries are represented on our microirrigation discussion list: Australia, Austria, Belgium, Brazil, Canada, Costa Rica, Columbia, Denmark, Israel, Italy, Germany, Japan, Mexico, Netherlands, New Zealand, Norway, Portugal, South Africa, Spain, Thailand, Turkey, United Kingdom, U.S.A. and Uruguay. It is possible that visiting students, researchers and company reps are residing in a countries that are not their own. Please let me know if your own country is not represented from the list above. If you know of someone with e-mail capability in countries that are not listed, please let those individuals know about Trickle-L if you think they might be interested. It is also possible that I did not send my default "Welcome" message to some new subscribers. If you are missing this information, please e-mail me directly. ****************************************************************************** ******* New pictures are now available on the Web page of the Water Management Research Laboratory. The Twin Lysimeter project is now shown in more detail with both pre and post construction photos. As promised, photos are also shown of the Open House that was featured last September at the lysimeter facility. If you've never seen a lysimeter and you have Web access, I suggest you visit this spot. A lot of discussion last month concerned the Sentek Enviroscan capacitance probes and capacitance probes in general. Two pictures are now available in the Web page photo listing which display the Troxler 200 AP probe and the Sentek system. All photos can be viewed at the URL address: http://asset.arsusda.gov/wmrl/photo.html ****************************************************************************** ******* I guess no one wanted to respond to my previous postings concerning steep slope erosion control using drip irrigation and the combined abstracts which focused on Vector flow in subsurface drip irrigation. My plan is to post a few more abstracts from the '95 International Microirrigation Congress and then move on to other topics. Things in store for the future include: - PVC cement and air quality (fact or fiction?) - TDR probe technology (will it compete with capacitance probes?) - Chlorine use in drip irrigation (what's legal, what's not?) - Cryogenic hardening of metal for strength (is there need for this in irrigation engineering........valves, backflow prevention, etc.) - Fertigation (what NOT to mix with what) - ET estimated by atmometers (are these better than an evap pan?) If you would like to see other items discussed on Trickle-L, please post to me at: rmead@asrr.arsusda.gov or mead2513@aol.com Richard Mead Trickle-L manager USDA-ARS-WMRL
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>From root@crcnis1.unl.edu Tue Oct 31 14:18 EST 1995
Date: Tue, 31 Oct 1995 08:07:06 -0600
Message-Id: <199510311407.AA22450@crcnis1.unl.edu>
Subject: TRICKLE-L digest 334

Contents:
Re: Vector flow - Abstracts 8 & 9 combined (Emmett Shields <eshields@freenet.grfn.org>)
Re: IRRISOFT Database ("Jos Balendonck, IMAG-DLO,PO-Box 43,NL6700AA,Wageningen")
Re: IRRISOFT Database ("Jos Balendonck, IMAG-DLO,PO-Box 43,NL6700AA,Wageningen")
Re: Trickle-L update ("Jos Balendonck, IMAG-DLO,PO-Box 43,NL6700AA,Wageningen")
Re: IRRISOFT Database (stein@wiz.uni-kassel.de (Thomas-M. Stein))
Re: IRRISOFT and other (stein@wiz.uni-kassel.de (Thomas-M. Stein))
Re: IRRISOFT Database ("Jos Balendonck, IMAG-DLO,PO-Box 43,NL6700AA,Wageningen")



Date: Mon, 30 Oct 1995 09:49:13 -0500 (EST) From: Emmett Shields <eshields@freenet.grfn.org> Subject: Re: Vector flow - Abstracts 8 & 9 combined It would be nice if some of the manufacturers reps on this list could tell us if their companies have had trials on these concepts. Is this a practical and economical method of irrigation with tape?
Date: Tue, 31 Oct 1995 08:58:09 +0000 (GMT) From: "Jos Balendonck, IMAG-DLO,PO-Box 43,NL6700AA,Wageningen" Subject: Re: IRRISOFT Database Dear Mr. Stein, I work with the IMAG-DLO, the Institute of Agriculture and Environmental Engineering from the Dutch Agrocultural Research Service in Wageningen. There we work on measurement and control technology for water management. Recently we developed a soil moisture and EC sensor based on dielectric measurement principles. This sensor is now commercially available and procducable in large quentities. It is a solid state sensor because it uses a special designed chip. Based on this sensor we are going to set up several projects that will explore it's use in water management strategies. Especially in semi-arid countries. We are looking for partners and industries for such projects. Perhaps you can do something with this message for setting up your WWW-site. Regards Jos Balendonck Head of dept. of Measurement Technology
Date: Tue, 31 Oct 1995 09:03:16 +0000 (GMT) From: "Jos Balendonck, IMAG-DLO,PO-Box 43,NL6700AA,Wageningen" Subject: Re: IRRISOFT Database Dear Tim Wilson, I saw you annoucement on trickle-l for the software database. Please give me your postage address so I can send you information. Regards, Jos Balendonck Head of dept. Measurement Technology IMAG-DLO Institute for Agricultural and Environmental Engineering (IMAG) Dutch Agricultural Research Service (DLO) P.O. Box 43, 6700 AA WAGENINGEN, The Netherlands
Date: Tue, 31 Oct 1995 09:14:21 +0000 (GMT) From: "Jos Balendonck, IMAG-DLO,PO-Box 43,NL6700AA,Wageningen" Subject: Re: Trickle-L update Dear Richard, As you are the manager of trickle-l I want to tell you something about our recent work. I work with the Dutch Agricultural Reaserch Service within the Institute of Agricultural and Environmental Engineering Research service. IMAG-DLO. Our department (measurement technology) is for more than 10 years now involved in the development of soil moisture sensors, especially on the topic of capacitance (dielectric) sensors. Recently we developed an ASIC with which we can produce a good and cheap soil moisture sensor (solid stated), that can measure temperature and EC (Electrical Conductivity) as well. It is now available on the market. We have a lot of information on these sensors, publications on f.i. how this technology compares to TDR-techniques and how to calibrate them. Furthermore we have information on the chip (ASIC) we have designed to construct this sensor. (Publication on IEEE congres and a datasheet). This ASIC is also available on the market for industries to design there own sensor with it. Perhaps it is interesting for trickle-l to have abstracts or publications available. Please give me your postage address so I could sent you the information. If you want to have something in electronical form, please let me know, or tell me how to sent them to you. Kind Regards, Jos Balendonck
Date: Tue, 31 Oct 1995 10:32:24 +0100 (MEZ) From: stein@wiz.uni-kassel.de (Thomas-M. Stein) Subject: Re: IRRISOFT Database Dear Jos Balendonck, thank you for your response and interest on IRRISOFT, the WWW Database on Irrigation and Hydrology Software. You will find my postage address below. > >Dear Tim Wilson, I am sorry, but my name is Thomas Stein :-) > >I saw you annoucement on trickle-l for the software database. >Please give me your postage address so I can send you information. > >Regards, > >Jos Balendonck My address: Thomas-M. Stein University of Kassel (FB11) Dep. of Rural Engineering and Natural Resource Protection -IRRISOFT Project- Nordbahnhofstr. 1a D-37213 Witzenhausen GERMANY You may also send me a fax under the following number: +49 (0)5542 98 1520 Thank you for your co-operation. Regards Thomas Stein
Date: Tue, 31 Oct 1995 12:00:45 +0100 (MEZ) From: stein@wiz.uni-kassel.de (Thomas-M. Stein) Subject: Re: IRRISOFT and other Sorry for using the list for this question. Dear Mr. Jos Balendonck Could you please let me know you email address. I tried to post a mail personally to you to the following address (like in the mail header) but it was rejected. "Jos Balendonck, IMAG-DLO,PO-Box 43,NL6700AA,Wageningen"@crcnis1.unl.edu Thanks Thomas-M. Stein (stein@wiz.uni-kassel.de)
Date: Tue, 31 Oct 1995 12:06:50 +0000 (GMT) From: "Jos Balendonck, IMAG-DLO,PO-Box 43,NL6700AA,Wageningen" Subject: Re: IRRISOFT Database Sorry for misinterpreting your name. But on Trickle-l you see a lot of names on a single e-mail. I will send you some information on our soil moisture sensors. Regards, Jos Balendonck
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