This is the monthly digest of TRICKLE-L for AUGUST 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.

Hello to all

I am running a lab. experiment to evaluate evaporation from bare soil surface
under point source surface/subsurface drip irrigation. I am heating the
soil surface to 55 (centigrade), no wind.
I am looking for numerical (preferably ,finite element), variably
saturated , two dimensional models , to predict the moisture distribution
as well as calculating evaporation, given potential evaporation. I would
like to try both type of models isothermal and those that handles heat
transfer to predict moisture movement.

Also should any of you out there know of research performed on determination
of evaporation from localized wetting of soil surface under hot climate
condition ,please inform me of the source. To my surprise ,I could only
find one article on this subject.

Thanks in advance for your cooperation and time.

Masoud
--
Masoud Meshkat
128 Agricultural Engineering Building
University of Kentucky
Lexington Ky, 40546-0276
E-mail: mmeshkat@bae.uky.edu
Fax: (606)257-5671
Tel: (606)257-3000 Ext. (280)

>Pete, the FAO is the Food and Agricultural Organization (hope I'm close) of
>the United Nations. Try United Nations in New York first. Sorry, I don't
>have a telephone number or address handy, but someone will. Maybe they are
>on the WWW. Let me know if you get anything good. Also, let me know if you
>are going to the Citrus Expo in Ft. Myers in October. Dale
>

I'm not planning on attending the Expo, but I expect that Mr. Monty Myers,
our pest management specialist, will attend. Will you have a booth, or is
there a way Monty could touch base with you? Let me know.

Thanks for the information on CROPWAT. Actually, Fedro Zazueta had already
E-Mailed a response that the Ag Engineering people at IFAS had just finished
a windows version of their scheduling program that was more appropriate for
FLorida, so I'll probably take a look at that first. See Fedro for more
details.

Thanks again.

Pete Spyke

Pete,

There are other models that are interesting that are not so
well known. One of them is SICODE, which was done in
Mexico by TecTra and the Instituto Mexicano de Tecnologia del
Agua.

SICODE is a full-scale irrigation district management system
that integrates database, data aquisition, modeling, GIS and expert systems.
It manages from --crop, water and planting permits-- to real time water
allocations. The modeling component is based on a Penman water
balance and real time data from automated weather stations.
The mexican government is training specialits to use this system
in the major irrigation districts. So far it has been tested in
15,000 Ha with over 500 users.

The SICODE databases are very comprehensive and contain
user, soils, crop, agronomic reccomendation, and other data.

There is also some work going on with expert systems that you may be
interested in. One is a realtime expert system that controls irrigation,
chemigation and frost protection in spray irrigated citrus. This system
uses a coupled modeling and soil moisture sensor readings approach.
The RTES was developed as the dissertation of Jiannong Xin, who just
graduated last saturday. It was impletemented and tested at the
CONSERV 2 project in Orlando, Florida.
The expert system took 4 years to developed and used as
subject matter experts many of the IFAS specialists you
personally know.

Other recent work is CITPATH, a citrus pathogen related
expert system that Jim Ferguson and myself just completed
and was the basis for a comprehensive citrus production
expert system that Howard Beck did shortly after.

These will be available through the IFAS software support office.
--
Fedro S. Zazueta
Voice: 904 392 7260
FAX: 904 392 4092

> I believe that when one
>purchases FAO 24, CROPWAT comes with it. FAO 24 is sold in major college
>bookstores; I know it's available at UCD.

No, it doesn't.
CROPWAT is sold as FAO 46
there is also a climatic data base available, named
CLIMWAT for CROPWAT, sold as FAO 49

--
Dr. Joachim Mueller
Hohenheim University
Institute of Agricultural Engineering
in the Tropics and Subtropics
Garbenstrasse 9
D-70599 Stuttgart
Germany
Voice: xx49 711 459 3106
Fax: xx49 711 459 3298

Dear Dr. Shackel
I will be delighted if you could do me a small favour.
One of our senior researchers arrived a week ago to the Dept
of Civil Eng in UC Davis, working with Prof. Schroder (?).
Can you please conatct him and ask him to contact me via
my E-Mail or to provide me with Fax/E-Mail address and Tel #.
I guess that we will see you on the AGRITECH exhibition in Israel
on may 1996.
Thank you for your help
Sincerely
Gideon Oron

Does the new IFAS scheduling software take into account upflux from shallow
water tables in Florida flatwoods soils? This is something I've never known
how to calculate. Is there now a model available for this?

Thanks, Randall
Vero Beach, FL

P.S. I believe the number for FAO pubs is 1-212-963-6036

Please forgive me if this is off-topic but I have to give it a try.

I am wanting to establish a water re-use system at my home.

I had envisaged accumulating waste water from the bath and shower in a
500litre (100gallon) tank under ground and then pumping that out again on
demand to feed an irrigation system in my garden.

My primary concern is that of filtration. What would I need to do to the
ensure that I could use it on my garden on an ongoing basis without dmaging
the garden.

I have been warned that the body oils and soap residue in the bath and
shower water will eventually accumulate in the soil to the extent that it
will bcome infertile.

Any comments would be welcome.

Tim.

>The most impressive PC-based controller system I have seen is made by:
GAL

I just bought two Motorola. The deciding points: service, local
experience, and (perceived) irrigation system compatibility. Let me explain
the last point. The Motorola has programmable delays in starting various
motors and is gentler than the GAL. Maybe the GAL saleman didn't know, but
he admitted the other. I like turning on the well pump, wait for the lines
to fill before turning on the booster.

The Motorola is actually rather dumb. If you have multiple blocks in a
single program, it accumulates all the quantity applied into the first
block. It does not report average flow rate. (big time grumble). The
centralized computer is expensive 20K or so. I think the local guys do not
understand it. They never sold one.

Motorola can only directly control one fertilizer. It can only control one
pump system without a little trickery. It does accumulate fertilizer
applied. It does control backflow. Motorola does not sell the box around
the computer and we have to drill holes in this nice box to plug in the key
board.

Our electrician did it right, but the supplier of the electrical connector
miswired the recepticle (sp?). He burned up both keyboards. We called
Motorola for a fix and they said the technician was on vacation. I said I
need water _now_. Them well the only other technician is on vacation too.
(ridiculous). I complained and they got him to fix a keyboard.

Computerization with daily water and fertilizier application with any size
is a necessity. (sorry for the long post).

Anyone know of a good potash through tape?
Steve Jordan @ Second Foundation

UNSUBSCRIBE, UNSUBSCRIBE

>Does the new IFAS scheduling software take into account upflux from shallow
>water tables in Florida flatwoods soils? This is something I've never known
>how to calculate. Is there now a model available for this?

I don't know -- haven't seen it yet. I suspect that it does not. There are
some models for upflux resident in the Natural Resources and Conservation
Service, but I'm not aware of any public releases.

You raise a good point, I'll have to check into it.

By the way, I didn't make it to Tampa. Things came up.

See ya.

Pete.
>
>Thanks, Randall
>Vero Beach, FL
>
>P.S. I believe the number for FAO pubs is 1-212-963-6036
>
>

Trickle enthusiasts,

I have a client who has come up with some interesting designs of vegetable
beds and is looking for help in placement of a surface drip lines. I don't
have all the particulars on the drip lines, except that they are in line
emitters. The soil type is clay (about 40% clay).

The two bed designs he has come up with are:

1. An 82" bed consisting of three seperate beds, like a pyramid. There are
two outside beds, and one center bed, that sits about 5" above the other two
beds. Kind of like this:

| o |
| o | / *********** \ | o |
*********** ***********

He's now planning on putting two rows of veggies (|) on each bed with one
drip line (o) per bed, placed in the center. Any ideas on depth (he can
bury the drip line a couple of inches) and an alternative placement??

2. The second design is an 82" bed shaped like a quarter moon. I can't
really draw this one, it's like the diagram below but with a smooth curve in
the center. The ends of the bed are 5" high and it is 8" high in the
center. Again, he wants to put 6 rows of veggies with three drip lines (one
between each set of two veggies). At the top of the bed, I would assume we
would put one line in the center. But for the two rows on either side????
If we put the drip line in the center between the two rows on the side,
won't the bottom row get more water? Should we place the drip line closer
to the up row?? How close??

______|____o_____|______ | = plant
|/ \| o = drip line
o/ \o
|/ \|
/ \

The reason for these designs is an attempt to increase yield by minimizing
furrow space. The raising of the bed in the center is to aviod plant
shading, which would occur in the center two rows if we planted six rows on
the same bed, same elevation.

So, if anyone has any ideas or knows of a good reference for placement of
surface drip lines on a slope, please let me know.
--
Ed Martin
University of Arizona/ Coop Extension
edmartin@ag.arizona.edu

Tim,
Foward Thinking! If you incorporate at least three aquatic ecologies
between your waste water and garden you will have a highly refined nutrient
solution. For example, if you have a small settling tank, a constructed
wetland system complete with plants, and a lagoon with fish, preceeding the
garden you will have an advanced ecologicallly designed wastewater system
known as a "Living Machine". For more information, write to me personally at
ecodesign2@aol.com.
Thank you for future thinking,

JIM KEANE

Announcement:
I R R I S O F T

the Department of Rural Engineering and Natural Resource Protection
at the University of Kassel is glad to announce the following service:
At the moment we are establishing

I R R I S O F T .

IRRISOFT is a WWW-Database which provides LINKS and INFORMATION to SERVERS
and SITES holding information about computer software relevant to
IRRIGATION and HYDROLOGY.

The URL of IRRISOFT is

http://fserv.wiz.uni-kassel.de/kww/irrisoft/irrisoft_i.html

The objectives of IRRISOFT are to

o give an overview on existing irrigation and hydrological programs,

o provide more detailed and structured information on the different
irrigation and hydrological software packages,

o facilitate the software and information retrieval by

o adding links to the servers containing more detailed
information,
o opening up email order or contact forms,
o providing download facilities which have been made available
through the provider.

In order to build up IRRISOFT we are preparing "Software Decription
Pages" on different IRRIGATION and HYDROLOGICAL packages which then
will be linked to IRRISOFT. We would greatly appreciate any information,
discussion or suggestions about the information provided.

If you have no access to the WWW we will be pleased to mail you the
"Standard Software Description Page " on request. In addition we
may also provide you with the information by regular mail or by fax.
To contribute information please contact:
--
Thomas-M. Stein
Department of Rural Engineering and
Natural Resource Protection
University of Kassel
Nordbahnhofstr. 1a
D-37213 Witzenhausen
Germany

Tel. : GERMANY 05542 98-1632
-1613 (Secretary)
Fax : GERMANY 05542 98-1520
Email: stein@wiz.uni-kassel.de

______________________________________________________________________________

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
______________________________________________________________________________

Here is one for the producers and equipment dealers.

I am looking for a quality line of fertilizer/chemical injectors to supply to
my customers. I am a fan of the Mazzei venturi injectors due to their
simplicity. However there are many times when I just can't afford to lose 25%
of my system pressure. Here on the South Plains of Texas the majority of
irrigation on cotton has been flood irrigation. Therefore most of the pumps
in our wells are designed to supply volume rather than pressure. Due to the
limited acreage that is being drip irrigated(usually 10 - 50 ac. plots as an
experimental trial) it is sometimes hard to justify the added expense of
installing new pumps.

So tell me guys, which product gives you the most bang for the buck!
I am currently looking at LMI, Pulsafeeder, Agri-inject, just to name a few.
I would be very interested in getting some feedback from producers and
suppliers on the equipment that they have been most impressed with. All
opinions, good, bad, and ugly will be greatly appreciated.

Thanks for your help,
--
D.B. McNutt
Lefty.B@eWorld.com

I would like to combine a response to Ed Martin's query about bed design with
recent soil salinity findings by University of California researchers Blaine
Hanson and Warren Bendixen*.

Hanson and Bendixen did some extensive soil sampling in a period of a year in
the Santa Maria valley of California. They chose subsurface drip fields with
clay loam and find sand. The clay loam had lettuce and the find sand had
cauliflower. Irrigation water at both sites was above 2 dS/m. Depth of drip
tape was 5 in. (13 cm) with bed and lateral spacing of 38 in (96 cm).
The lettuce crop was planted using two rows per bed while the cauliflower had
one row per bed.

In brief, their findings were:
1) Low salinity portions of the bed occurred near the drip tape.
2) The areas between laterals and in the furrow zone had high salinity
levels.
3) High salinity also occurred above the drip tape.

My own take on #3 is that this provides a challenge to farmers as to where
the drip tape should be placed. Too shallow will bring water (evaporative
loss) and precipitated salts to the surface. Hanson/Bendixen mentioned that
placing the drip lines too deep will eventually require more leaching through
rain/sprinkling to push salts past the drip line for the subsequent crop.

This got me thinking about Ed Martin's posting. He mentioned:

->The soil type is clay (about 40% clay)<
>The two bed designs he has come up with are:<
>1. An 82" bed consisting of three separate beds, like a pyramid. There are
two outside beds, and one center bed, that sits about 5" above the other two
beds. Kind of like this:<

| o |
| o | / *********** \ | o |
*********** ***********
>He's now planning on putting two rows of veggies (|) on each bed with one
drip line (o) per bed, placed in the center. Any ideas on depth (he can
bury the drip line a couple of inches) and an alternative placement??<

Based on what I've learned from Hanson and Bendixen, salts accumulate at the
end of vectors originating from the emitter source. If we were to bury the
drip line 4 to 6 in. (10-15 cm) as shown below:

I I
I I / *********** \ I I
#[see comment below]
*********** <---o----> ***********
<---- o -----> <--- -o ---->

^ ^
^ ^

the salts would accumulate where I placed the ^ marker. Hopefully these
markings come out (going left to right) in the right furrow of the first bed
and the left furrow of the third bed. The placement of the veggies would be
appropriate since Hanson and Bendixen mentioned that studies of root
distrubution show little root growth goes beyond 6 to 9 in (15-20 cm) from
the drip line.

I'm wondering what will happen when the two vectors from opposing sides
(----> <-----) meet, get saturated enough to possibly create some downward
leaching OR would this create a big salinity zone if saturation does not
occur? This probably would depend on how the system is managed. Ed's second
bed shape idea (quarter moon) would probably have the same salinity
consequence.

Now, my questions back to Ed:
1) How does the farmer shape this pyramid bed? Special implements?
2) Would the rows be North/South or East/West? Seems like in mid-winter in
Arizona, the crops in the middle bed of the East/West orientation would over
shadow the northern most bed area plants.
Then of course, I could be dead wrong...it would'nt be the first time.

I would appreciate it if both Ed Martin and Blaine Hanson (members of
Trickle-L) correct me on any potential errors I might have made above.

Richard Mead
Trickle-L owner/manager

*B.R. Hanson is an Irrigation and Drainage Specialist with U.C. Davis and
W.E. Bendixen is a farm advisor with U.C. Coop. Extension. Their report can
be found in the July-August '95 issue of California Agriculture (p.19-23).

#Doing these drawings by this typewriter method is a bit awkward. This
reminds me that there is a software product called "Lotus Notes" by IBM which
can be used by individuals who use a network. The software permits all
network users to send and receive email mixed with pictures, spreadsheets and
diagrams. I guess we at Trickle-L will have to put this on our wish list for
future uses of the Internet. Would'nt it be GREAT??!!

At last a topic on which I think I can contribute
something! Much of the discussion here is outside my
scale of operations.

Tim asked about:

"water re-use system at my home...waste water from the bath
and shower .. then pumping that out to .. irrigation
system .. concern is filtration."

"What would I need to do to the ensure that I could use it
on my garden on an ongoing basis without damaging the
garden."

"I have been warned that the body oils and soap residue in
the bath and shower water will eventually accumulate in
the soil to the extent that it will become infertile."

One strategy that we have used for two years now, and it
has been used in slight variations for many years, is to
rotate the outlet point, so the plants/microbes/fungi have
a chance to catch up with their processing. The classic use
here is three citrus trees, each getting the washing
machine's output in turn. They thrive on it.

Another is to feed the output to something that is very
hungry, such as comfrey or bananas or kikuyu, and harvest
the output for green manure elsewhere, if you are really
worried about pathogens.

As I hear water engineers, the major hassle they seem to
be concerned about is reticulation clogging; one strategy
is to use large pipes; another (more permaculturish)
is not to reticulate at all! So the system I would prefer
would have the outlets feeding into the plant system with
comfrey, and then harvest the comfrey for mulch. compost,
feed, or green manure.

Now convincing the bureaucrats that this won't kill me and
then the rest of the neighbourhood is another matter!

Hope this helps
--
Warwick
______________________________________________________________
| warwick.rowell@eepo.com.au |
| 20 Onslow Rd Shenton Pk 6008 Western Australia |
| Partner, Permaculture Applications Consultancy & Education |
| |
| Management Consultant Permaculture Designer |
|___"Helping Managers Learn"___"Helping Land Managers Learn"___|

At 5:15 AM 8/17/95 -0500, Tim Jackson wrote:
.>
>I am wanting to establish a water re-use system at my home.
>I had envisaged accumulating waste water from the bath and shower in a
>500litre (100gallon) tank under ground and then pumping that out again on
>demand to feed an irrigation system in my garden.
>etc.

Greywater re-use with subsurface drip irrigation has been approved in
California and is quite frequently applied. Geoflow has a literature
package which I will gladly send to you if you let me have your snail-mail
address.
Over the five years that we have been selling dripline for this application
I have had no experience with clogging of soils due to soaps and oils -
over the long term this is possible. It is advisable to use biodegradable
soaps.

Rodney.

I apologise for the problems some people had to reach the
I R R I S O F T pages.
The server had been disconnected a few times from outside due to
line works. The URL of IRRISOFT is correct:

http://fserv.wiz.uni-kassel.de/kww/irrisoft/irrisoft_i.html

Regards,

Thomas-M. Stein

In response to Richard's questions concerning alternative bed shapes:

>Now, my questions back to Ed:
>1) How does the farmer shape this pyramid bed? Special implements?
>2) Would the rows be North/South or East/West? Seems like in mid-winter in
> Arizona, the crops in the middle bed of the East/West orientation would over
>shadow the northern most bed area plants.
>Then of course, I could be dead wrong...it would'nt be the first time.

1. Both the pyramid/wedding cake bed and the quarter-moon bed are shaped
with special bed shaping implements the growers has built. They already
exist and have been field tested - so far, so good.

2. The rows would run North-South to prevent shading.

Thanks for the input. Anyone else??
--
Ed Martin

edmartin@ag.arizona.edu

contact WWI, waste water inc. in Atlanta , Ga. They have systems
available off the shelf.

On Thu, 17 Aug 1995, Tim Jackson wrote:

> Please forgive me if this is off-topic but I have to give it a try.
>
> I am wanting to establish a water re-use system at my home.
>
> I had envisaged accumulating waste water from the bath and shower in a
> 500litre (100gallon) tank under ground and then pumping that out again on
> demand to feed an irrigation system in my garden.
>
> My primary concern is that of filtration. What would I need to do to the
> ensure that I could use it on my garden on an ongoing basis without dmaging
> the garden.
>
> I have been warned that the body oils and soap residue in the bath and
> shower water will eventually accumulate in the soil to the extent that it
> will bcome infertile.
>
> Any comments would be welcome.
>
> Tim.
>
>

We build our own injectors using the Mazzei injector. Simply consists
of a centrifugal pump in combo with the injector. This unit contains
filtration for nutrient solutions, etc., as well as pressure regulators
where needed. We use this unit on any type of system from drip to center
pivots and high pressure travelers. Any further questions please contact
me on e-mail eshields@grfn.org.

On Fri, 18 Aug 1995 Lefty.B@eworld.com wrote:

> Here is one for the producers and equipment dealers.
>
> I am looking for a quality line of fertilizer/chemical injectors to supply to
> my customers. I am a fan of the Mazzei venturi injectors due to their
> simplicity. However there are many times when I just can't afford to lose 25%
> of my system pressure. Here on the South Plains of Texas the majority of
> irrigation on cotton has been flood irrigation. Therefore most of the pumps
> in our wells are designed to supply volume rather than pressure. Due to the
> limited acreage that is being drip irrigated(usually 10 - 50 ac. plots as an
> experimental trial) it is sometimes hard to justify the added expense of
> installing new pumps.
>
> So tell me guys, which product gives you the most bang for the buck!
> I am currently looking at LMI, Pulsafeeder, Agri-inject, just to name a few.
> I would be very interested in getting some feedback from producers and
> suppliers on the equipment that they have been most impressed with. All
> opinions, good, bad, and ugly will be greatly appreciated.
>
> Thanks for your help,
>
> D.B. McNutt
> Lefty.B@eWorld.com
>

The 6TH INTERNATIONAL CONFERENCE ON COMPUTERS IN AGRICULTURE will be held in
Cancun, Mexico from June 11 through
June 14, 1996

With the interest in modeling irrigation requirements and software
for irrigation scheduling, I would like to have a session on these
topics.

For more information on the conference see

www.agen.ufl.edu/~fzazueta/

This conference provides a forum for agriculture related professionals to
exchange information on applications and developments in the use of
computers in agriculture. Individuals involved in production, service,
consulting, research, education and extension are invited to attend.
Those wishing to participate, please see the world wide web page above,
return this e-mail or send a fax to the contact person below. Paper
proposals must be received by September 30, 1995 to be considered for
inclusion on the program.

Contact Person: Dr. Fedro S. Zazueta

E-MAIL: FSZ@GNV.UFL.EDU
Phone: (904) 392-7260
FAX: (904) 392 4092
Fedro S. Zazueta
Voice: 904 392 7260
FAX: 904 392 4092

Please unsubscribe

Venturi's from Netafim are often used in conjunction with a small electric or
engine driven booster pump to provide the differential pressure required to
provide pressure differential for the injection pump. This practice avoids
having to change the entire pumping system in the well. If you would like
some data with flow curves and HP requirements, please e-mail or call.
--
Jim Brigham
512-261-3007

I would like some info on the venturis for chem injection at my well sites.
Please mail to
Robert Carian Enterpriese
PO Box 1088Coachella, CA 92236

The fact that the food supply for some 60% of the worlds population is
fertilized entirely with human waste is beyond beauracratic comprehension!

------------------------------

On Fri, 25 Aug 1995 Dripigate@aol.com wrote:

> The fact that the food supply for some 60% of the worlds population is
> fertilized entirely with human waste is beyond beauracratic comprehension!

It seems to be beyond the comprehension of a lot of agriculturalists too.
Truly sustainable agriculture requires the complete recirculation of
nutrients -- impossible without the use of human waste. Anyone who
suggests that agriculture can be sustainable given the present waste
"disposal" systems is attempting to delude their audience.

Just my $.02 worth. It is an issue that I get excited about occasionally.

ob trickle: some years ago (more then 10 anyway) "Organic Gardening"
magazine had an article on recycling grey water in for gardening. At the
time they suggested (this is from memory) filtering the water through a
progressive filter constructed in a dry well. The filter began at the
top with wood ash and ended at the bottom with coarse stone. I think
that this is probably excessively involved as I have known of a number
of homes where the waste water from clothes washing just went out a pipe
onto the lawn and I don't recall ever seeing any damage to the
vegetation. It is surprising how robust ecosystems are if the parameters
are changed slowly enough. The resulting system may not that closely
resemble the original but will in time become accepted as the normal or
natural state.

Cheers,
REM

Care needs to be taken in the removal of salts in this format. I would
suggest at least a flushing cycle every third or fourth irrigation to reduce
accumulation.Steep sloping "Yuma " type beds are an alternative particularly
earlier in the season.

Most venturi injectors ( Maezzi, Netafim ) with the addition of a booster
pump are far better than mechanical injectors in terms of cost, simplicity
and maintainance. Used in conjunction with a "batch" tank all the accuracy
required can be attained. Sizing to create a Delta P of 30 to 40% is best.
Usually resulting booster is no larger than 3 HP max.

DB,

Sorry it took so long to throw my 2c worth in, but I haven't checked my mail
lately. The type of feed equipment you decide to use will of course depend
on a wide variety of factors, cost and application being the two main ones.
Where I work, Stranco, we build custom chemical feed equipment from a single
LMI pump on a portable skid to very sophisticated systems. Please call me
and I would be happy to suggest some to you.
--
Jim Beshears
Engineering Director
Stranco Engineering Services
JimB1331@aol.com

>Most venturi injectors ( Maezzi, Netafim ) with the addition of a booster
>pump are far better than mechanical injectors in terms of cost, simplicity
>and maintainance. Used in conjunction with a "batch" tank all the accuracy
>required can be attained. Sizing to create a Delta P of 30 to 40% is best.
>Usually resulting booster is no larger than 3 HP max.
>
Some disadvantages...

The amount injected with a powered Maezzi may be influenced by the
temperature of the fertilizer (viscosity) and the pressure of the receiving
water. Also, it is easier to vary the amount of fertilizer with a piston
pump...
Steve Jordan @ Second Foundation

Due to some discussion in the past (8/25) week concerning the use of
wastewater or grey water in irrigation, I thought it would be appropriate
that I chose the following abstract for our "Abstract of the week" series. We
have had previous discussions relating to the topic of wastewater use
(filtragation) on Trickle-L.

I would appreciate it if those individuals involved in this technology would
delineate between the use of wastewater for nutrient/water recycling and that
of disposing the water and using the soil and soil microbes as a filter.

Potential of Subsurface Drip Irrigation for Management of Nitrate
in Wastewater

C. J. Phene and R. Ruskin

Annual increases of food demand forecasts for various regions of
the world range from 2.3% (East and South Asia) to 3.8% (West
Asia and North Africa). Even when taking into account the
potential production of rain-fed agriculture, the irrigated
agricultural production sector will need to increase its
productivity by 3 to 4% per annum. Secondary and tertiary treated
domestic wastewaters (WW) are being used more and more
for irrigation of field crops, landscape, groundwater recharge
and other applications. However, the use of treated WW for
irrigation is subject to major concerns because of the potential
nitrate contamination of domestic water supplies possibly
resulting in the occurrence of methemoglobinemia. In California,
only 18% of the 5 billion cubic meters of generated WW is treated
and returned to the state's fresh water system for incidental
uses but only about 7% of it is used intentionally. The Water
Management Research Laboratory (USDA-ARS-Fresno) developed a
practical water and fertilizer efficient irrigation and
management method which minimizes and sometimes even eliminates
the downward movement of soluble nitrate-N below the root zone of
field crops. The method known as deep high frequency subsurface
drip irrigation (SDI) achieved minimum leaching when four
conditions were satisfied: (1) irrigation events are short and
frequent and designed to replace crop water uptake as closely as
possible (no leaching fraction); (2) nitrogen is applied with the
water through the SDI system at a rate equivalent to the uptake
rate of the crop less the amount mineralized from the soil; (3)
the crop is deep rooted; and (4) the shallow water table is
at least 2.0 m from the soil surface. Results obtained for a ten
year period with irrigated field crops demonstrate the potential
of the SDI method for minimizing non-point source agricultural
pollution with NO3-N. The SCI method also shows some unique and
economical potential for safely irrigating field crops with
treated WW. In addition to the controlled movement of NO3-N to
the ground water, the mere fact that the treated WW
does not come to the soil surface adds another safety dimension
to the handling of a potentially hazardous material. In locations
where year around cropping is possible, continuous disposal could
be carried out without requiring major storage facilities.
However, during the winter months when evapotranspiration (ET) is
low, some reservoir might be required to store the excess WW not
evapotranspired by the crop. The objectives of this paper are to
present and discuss the design and operation of SDI systems,
their physical characteristics, and research results defining
soil water, nitrate-N and deep rootzone profiles obtained when
deep SDI systems are used. The authors will relate how this
method can be adapted for irrigation with treated WW.

Keywords: Reuse, Water use, Leaching, Treated Water

Abstract taken from paper found on pages 155 to 167 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 EMAIL:
HQ@ASAE.ORG

Irrigation time usually exceeds fertilizer time, Batch tank can be used to
adjust timing and concentrations.P

Bravo Bravo. Simple pond construction with even simpler aeration can do
miricals. Merced County California are about to choke on their own S------.
Not much better elsewhere.

.........Unsubscribe Russell Shlagel

.........Unsubscribe Higinio Maycotte
--
E-mail: maycotte@utxvms.cc.utexas.edu
maycotte@eco.utexas.edu
Home Phone: 512-794-5805
Fax: 512-794-0506

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Please assist, I have made several attempts to UNSUBSCRIBE,
with no success. Could you please delete me from your list of
subscribers.Thank you for your kind attention.

The following are two responses from new subscribers to Trickle-L.

Tim Wilson writes:

Thank you for your wecome letter. I will attempt to answer your first
question. >Briefly, what is your affiliation with trickle irrigation?<

I am the Education Director of the Irrigation Association (I.A.) . My
interest in drip centers around educational programs for both the
agricultural as well as the landscape market. If anyone has any info (class
material, slides, overheads, or manuals) that they would like to recommend or
donate to the cause of industry education, I would be most appreciative.
In exchange I would be happy to keep you updated on what the I.A. is working
on in regards to Drip/micro. We presently have a Drip in the Landscape class,
a Drip\Micro for Ag class and we are working on a chemigation class at this
moment. I look forward to participating in this forum.
Thanks again!

Tim Wilson
TIM1UTAH@AOL.COM

R. Mead's comments:

Tim, I suggest you dive into the archives of Trickle-L for text information.
This material could be educational, albeit subjective in nature.

Also, does the I.A. have a Web home page? If so, our laboratory (Water
Management Research Lab) has one you could link to and vice versa. If the
I.A. does not have a Web page, consider our offer in the future for
information exchange.

*****************************************************************
Nhpjr@aol.com writes:

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

I have a two fold affiliation with drip irrigation. I am a Products
Research and Development Manager for Entek Corporation which manufactures a
new nematicide/soil insecticide/soil fungicide called ENZONE (trademark
protected) used on grapes and citrus. It is applied through irrigation water
and is most effective through drip irrigation systems. My second affiliation
is as a farmer who has both apricots and apples grown on drip irrigation.

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

apples, apricots, grapes, and citrus.

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

N/A

>What problems have you encountered with subsurface drip?<

Drip irrigation requires a high level of maintainance with poor quality
water. Also, we must treat on a regular basis with N-pHURIC to keep the
irrigation lines from plugging up.

For other interested parties, outside of the US, Canada and Mexico, a similar
product named N-pHLO (trademark protected) is available through my company,
Entek Corporation. Both products are very effective line cleaners, are easy
to handle compared to strong acids, and are economical.

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

I have used both N and K fertilization on a regular basis for years.

> Have you experienced a reduction in fertilizer and water use?<

Yes, I have experienced a reduction in fertilizer use rates.

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

We have serious water quality problems due to high bicarbonate in our well
water.

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

We irrigate our orchards 2-3 times per week for 24-48 hours each time.
During the spring and fall when conditions are optimum for disease problems
like Phytophthora root rot we reduce the irrigation run to 24 hours. Our
emitters are 0.5 gal/hr. emitters though so there is almost never free water
around the emitters.

>Do you have rodent damage? If so, how do you tackle the problem?<

We do not have rodent damage. But we are aggressive about controlling
weeds in the tree row. In one of the apple orchards, we have fought a clover
problem for years but we are able to keep it under control.

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

We are pleased with the uniformity of our systems. The systems were
designed correctly.

>How did you hear about Trickle-L?<

I found out about your mailing list by entering "agriculture" when
searching the Internet mailing lists.

Neil P. User
Nhpjr@aol.com

For those of you who are just so darn anxious to unsubscribe, please refer to
your welcome message that have the instructions for unsubscribing OR let me
know personally at my e-mail address and DO NOT post to Trickle-L !!

Thank you for your cooperation and hang in there remaining loyal Trickle-L
subscribers.
--
Richard Mead
List owner/manager

Dear Trickle-L subscriber,

I would like to personally invite you to the Water Management Research
Laboratory's Open House of our new "Twin Lysimeter facility" in Parlier,
California on September 14. Tours will begin at 1 P.M. and end at 4 P.M.
You will see the latest in high-tech water management research using
cutting edge technology. There is no other lysimeter system of its kind
in the world.

We would enjoy seeing you there. Let me know if you plan to attend by
September 11. For those who can not make this special occasion, we will
have pictures and descriptions of the Open House activities on our Web
homepage after September 14.
--
Richard Mead
Soil Scientist
Phone: (209) 453-3100

p.s. A map to the Open House can be provided if you let me know your fax
number.

Don't worry about unsuscribe messages being posted in Trickle-L. Those
who are interested will remain subscribed and those who aren't won't.
That simple!
Keep it up!
Armando Tasistro

On Wed, 30 Aug 1995 MEAD2513@aol.com wrote:

> For those of you who are just so darn anxious to unsubscribe, please refer to
> your welcome message that have the instructions for unsubscribing OR let me
> know personally at my e-mail address and DO NOT post to Trickle-L !!
>
> Thank you for your cooperation and hang in there remaining loyal Trickle-L
> subscribers.
>
> Richard Mead
> List owner/manager
>

We build custom feed equipment for any application, and introduce industrial
control technology to the agricultural world. PC based control systems are
the norm in our world, and we would love the chance to apply them to the
varied applications in irrigation.

Please call for info.
--
Jim Beshears
Engineering Director
Stranco Engineering Services
800 882-6466
JimB1331@aol.com

>We build custom feed equipment for any application, and introduce industrial
>control technology to the agricultural world. PC based control systems are
>the norm in our world, and we would love the chance to apply them to the
>varied applications in irrigation.
>

Custom feed equipment... As in computers to operate? As in fertigation
systems?

How about measurement systems? For some crazy (actually not crazy) reason I
want to read and log water levels in wells. I know the manual way is best,
but probably not in this instance.
Steve Jordan @ Second Foundation

Anyone know of an opening for an irrigation engineer? B.S. Ag Engineering,
EIT, Irrigation Association Drip/Micro CID. Four years design experience.
Creative, hard-working, dependable, team player. Ten years of computer
experience. Likes working in the field and getting hands dirty. Willing to
relocate. Especially interested in opportunities that would involve overseas
travel.

For full resume send E-mail to Merriott@aol.com or call 407-770-2056.

Thanks, Randall Merriott
Vero Beach, Florida