This is the monthly digest of TRICKLE-L for OCTOBER 1995;.

It was prepared from the "daily" digest mailings. It differs in
certain format details from the previous monthly digests obtained
from the trickle-l archive at listserv@unl.edu.

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

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

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

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
________________________________________________________________

"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.

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 *******
******************************************

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).

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 *
*********************************************************

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
______________________________________________________________________________

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

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

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
______________________________________________________________________________

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.

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

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

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

Thanks Richard

Bob Edling

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

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

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

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
******************************************

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

* * * * * * * *

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
______________________________________________________________________________

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

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?

>
> 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?

They come in different colors?

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

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
______________________________________________________________________________

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,

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.

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

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

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

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

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 | |
|____________________________________________|__________________|

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.

>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.
>
>

>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 | |
|____________________________________________|__________________|

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

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

> 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?

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).

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

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
______________________________________________________________________________

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.
>
>

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.

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

resubscribe IN%"roerink@sc.agro.nl" as IN%"roerink@sc.dlo.nl"

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
______________________________________________________________________________

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

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?

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

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

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

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

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)

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