Archive TRICKLE-L: file log9411, part 1/1, size 30811 bytes:

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Once again, I find it my obligation to stimulate conversation. I know we're
all busy this time of year such that contributing to our email list is
difficult. Please respond if you find this topic interesting.
Upon reading the proceedings of the 15th International Irrigation Exposition
and Technical Conference (held in Atlanta), I stumbled upon an article
entitled "Vectored Subsurface Irrigation". In short, vectored subsurface
irrigation is a new technology for manipulating the distribution of
subsurface applied water. It is primarily used in the turf and landscape
industry, specifically on sandy soils. Since we don't have graphic
capabilities (yet), I will try to describe it using text. A "V" shaped
continuous piece of plastic is installed directly below the buried drip line
(i.e. \o/ ). That's the best I can do to describe what this idea looks like
with a keyboard.
The "V" shape nozzle impedes the downward movement of water emitted from the
drip line. After the "V" is filled with water during the first few minutes of
irrigation, moving water is continuously pushed upward and outward using
capillarity into the dry soil at the wetting front. This phenomenon creates a
greater horizontal wetting pattern.
As the soil becomes saturated by horizontally moving water, the effect of
gravity dominates and downward percolation begins. The final wetting pattern
is approximately rectangular vs. elliptical or elongated sphere, specifically
in sandy soils.
My main point of initiating this topic is to bring up certain questions fo
discussion:

1) Have any of you heard of this technology and if so, is it limited to the
turf/landscape industry?
2) Could this technology be used on shallow rooted agricultural crops
(onions, lettuce, cauliflower, radish) specifically on sandy soils?
3) Can you think of any disadvantages of vector-flow technology?
4) If you have heard of this technology, how is installation accomplished? I
am
having trouble envisioning installing the "V" aspect of the system.
5) Do you think this technology would be advantageous in heterogeneous soils?
6) Do you think it would have an economic advantage by saving on the number
of drip laterals placed in a field (further spacing due to more horizontal
distribution)?

We now have 127 subscribers. If any of you have not received a "welcome
document"
from me, please email me at: MEAD2513@AOL.COM

Happy replying!

Richard Mead
List Owner

Date: Mon, 21 Nov 1994 15:39:08 -0500
From: GrapeGrowr@aol.com
Subject: Re: Vectored subsurface irrigation
To: trickle-l@unl.edutrickle-l.unl.edu
Message-id: <941121153321_4250109@aol.com>

I have some limited experience with this practice. I am a grape grower in
the Coachella Valley Calif. Around 10 years ago, I had a problem with water
retention in a very sandy area of a ranch. I deep plowed the vine rows and
laid plastic about 3 feet deep at the greatest depth and about 5 feet wide
in a "V" shape and replanted the vines in the vine row. The vines in this
area grew normally and produced slightly more fruit that before. However,
about 4 years into the project the vines showed signs that they were not as
well rooted as the vines without the plastic. The vines wilted after a
girdle application (knife around the cambiam layer of the trunk for sugar)
followed with high heat (over 115 degrees). I eventually replanted without
the plastic. When I replanted this time I first slip-plowed the vine rows to
a depth of 6 feet and 18 inches wide to mix all layers of soil and to allow
deeper root penetration. This method was far more successful for Table Grape
Vineyards and has now become the standard procedure for new plantings in my
valley.
Rob Carian

From: From: warwick@bettong.EEPO.DIALix.oz.au
One of the major problems we are suffering from in this area of
the world - Australia - is rising salt levels in the topsoil, forcing
farmers to take millions of hectares of land out of production.

The major cause of this is overclearing, bringing water tables
closer to the surface, and then capillarity bringing moisture so high
in the soil profile that high solar radiation, and high velocity low
humidity winds evaporate "surface" water, and so increase salt levels in
the root zones.

But this principle - up to a max of about 100 cms of capillarity above
the water table level - can be used in reverse.

I recently constructed a very small (12m long) variation on the
vectored situation you describe. I selected a site in the local community
garden that received the most sunshine, mainly for the winter months.
I then constructed windbreaks and sun traps to ensure maximum temperatures
above the surface.

To simulate the heavy rainfall in the root zone, I laid out a plastic sheet
in a wide shallow U; \__________________/ about 90 cms wide, and 10 cms
high. This had a slight fall (5 cms) from the ingress point of the water
to the end of the plastic. That the water eventually drained off the end
was checked by using a hose, and "levelling" by trial and error..

This whole channel was then filled with a fine mulch - a mix of compost,
wood chips, grass clippings, and worm castings. The idea was that the high
organic/humus level would hold water, and wick it up off the plastic by
capillary action, and hold it for the plants' use. This mulch was put on 80
- 100 cms deep. It settled by 20-30 cms, and has been topped up twice in
two years to maintain this depth.

It doesn't just hold rainfall or sprinkler water. It is the focal point for
a drainage system, picking up rainfall from 600 sm of carpark and laneway
uphill from the entry point. Some very rough calculations give a yield into
this area of 1 cu m for each 2mm of rainfall (once flow starts). There is an
underground pipe with three front end filters, leading to a sump at the head
of the water storage system.

It is producing sugar cane, sweeet potatoes, cinnamon, ginger, and bananas
are growing but yet to yield.

Another observation that may be of some use:

A trickle pipe going through a sawdust path had a profile going almost
horizontally out from the pipe drippers. It didn't start getting a curved,
and then horizontal boundary, for a surprising distance.

Again graphics are hard - but a simple table tells the story..

Horizontal distance Vertical distance
from pipe (cms) below pipe (cms)

10 0.5
20 1.5
25 2.5
30 7.5
35 15.0

From 10 cms down we were in classic sands of this area - grey, coarse,
non-wetting. But their behaviour was very seriously modified (for the
better) by being under the mulch of sawdust.

Another thought:

Permaculturists around the world have achieved similar "perched water table"
effects in the small scale with newspaper. Twenty or more sheets will sure
slow down the effects of gravity on water..

Wx
--
__________________________________________________________
| warwick.rowell@eepo.com.au |
| |
| Management Consultant Permaculture Designer |
|_"Helping Managers Learn"___"Helping Land Managers Learn"_|

Dear Rob:
I quess the theory of vectored irrigation has its multiple purpose, yet I was
thinking of a "V" directly below the drip line where the drip line actually
touches this small piece of "V"eed plastic. The theory you mentioned is the
same, yet I wonder if what I presented would have made a difference in your
vineyard. I had no idea grape growers did this and I live in grape grower
country!
Let's hope for some more discussion.
Thanks for your contribution.
Richard Mead
List owner

Hello,

I have a couple questions I was hoping you could help me with. We
have a farm in Mexico and mannage/rent many more. Our primary crop is
Brocolli. We are interested in findig our about a state of the art drip
irrigation system involving such things as automated nutrition and
insectisides. We would be very happy if anyone had contacts to which we
could write and get more information. We would like to put together a
couple packages with prices to show our inverstors in Mexico so that they
may make the final desicion on which to buy. We appreciate your time with
this matter.

Thanks
Higinio Maycotte.

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

BBBBBB-------OOOOOO-------SSSS-------SSSS----- ----------------------
BB---BB-----OO----OO-----SS--SS-----SS--SS---- --222--55555--1---000-
BB----B-----OO----OO-----SS---------SS-------- -2---2-5-----11--0---0
BBBBBB------OO----OO-------SS---------SS------ ----2--5555---1--0---0
BB----B-----OO----OO---------SS---------SS---- ---2-------5--1--0---0
BB---BB-----OO----OO-----SS--SS-----SS--SS---- --2--------5--1--0---0
BBBBBB---@---OOOOOO---@---SSSS---@---SSSS---@- -22222-5555--111--000-

I was farming about 200 hectares of flowers in Kenya - we used mostly Israeli
drip. However, I believe that the American product, T-Tape would be well
suited. They are out of San Diego, CA.
We found that most crops needed overhead for the first few weeks. After root
establishment, we would wean the plants over to drip by giving longer and
longer times on drip and shorter on overhead. This allows the roots to
develop and build within the drip lines "onion" wet zone.

Good luck and best regards

Warren Becker

Dear Higinio Maycotte:
Give me some time to put some basic information together.
We are growing broccolli in two research plots this fall. I'll try to get
something together in a few days.

Richard Mead
List owner/Soil scientist

Dear Higinio:
First of all thanks for your interest in Trickle-l.
Secondly, our lab (as stated before) is doing research on broccolli via
subsurface drip. Both our projects involve growing the crop on 1.5 m beds
having a loam or clay loam soil. There are 3 rows of seedlings per bed. The
depth of subsurface lateral is approximately 40 cm. In one project the drip
system is tape (Typhoon-RAM) and the other is a hard hose
(Rootguard-Geoflow). Germination and stand establishment is accomplished
using sprinkling (several sets of 50 mm). Once roots are several cm deep, the
subsurface system is turned on (I have specific information on scheduling
irrigation if any one is interested, but I won't dwell on this now).
That's about all I can convey right now, until our results are in, but I can
assure you that growing broccolli via subsurface drip is possible. In theory,
one could save approxiamately 50 % of your fertilizer cost and possibly one
third the water (compared to traditional furrow irrigated/tractor applied
fertilizer systems).
To get you started with more information of the drip industry,
I would suggest you contact the following organizations/companies.

The Irrigation Association
1911 North Fort Myer Drive
Suite 1009
Arlington, VA. 22209-1630
(703) 524-1200
This organization should know everybody in the irrigation industry.

In terms of drip companies, the following are the big boys in
drip irrigation, at least in the U.S.

Hardie Irrigation
1588 North Marshall
El Cajon, CA.
92020
(209)562-2950

Geoflow Inc.
236 West Portal Ave. 237
San Francisco, CA. 94127
(415) 553-8048.................I believe they moved to Sausalito last year,
sorry I don't have their current address...call
(415)555-1111 for information on new number.

Netafim Irrigation, Inc.
3025 East Hamilton
Fresno, CA. 93721
(209) 498-6880

T-Systems International
31131 Wild Berry Court
Coarsegold, CA. 93612
(209) 658-7518

Roberts Irrigation Products, Inc.
700 Rancheros Drive
San Marcos,CA. 92069
(619) 744-4511

For fertilizer injection systems you could try:

Mazzei Injector Corportation
11101 Mountain View Road
Bakersfield, CA.
93307
(808) 845-2253

For software to help schedule irrigations...

Orange Enterprises
2377 West Shaw, Suite 205
Fresno, CA. 93711
(209) 229-2195

For design and installation....

Landmark Irrigation Inc.
23400 Road 24
Chowchilla, CA. 93610
(209) 665-3700

If you want a "Consumers Report" type analysis of different types of drip
hose and tapes write to:

Center for Irrigation Technology
5370 North Chestnut
Fresno, CA. 93740-0018
(209)278-2066

Companies pay them to test their products. Ask for Dave Zoldoske, tell him
Richard sent you.

The information above is not intended to sell or endorse any particular
product or company. It is information I had at hand and I'm sure there are
other companies out there. Please email me for specific information or call
me at (209) 453-3109. My FAX number is (209) 453-3122.

Sincerely,

Richard Mead
List owner/Soil Scientist

Sorry...
the new address for Geoflow is:
GEOFLOW
200 Gate 5 Road, #103
Sausalito, CA. 94966

Richard Mead

Dear Richard Mead,

Just a quick comment/question. We always used above ground drip but I always
wanted to do trials with sub-surface. I was reluctant because of comments I
received about roots growing into the drippers. I know that others use an
occational flush with a light herbicide but I don't know the method/material.
Are there any other methods you may know of?

Best,
Warren

Warren:
I submitted this several weeks ago:
First of all, one can obtain emitters which have a herbicide (triflurilin)
imbedded in the plastic of the emitter whereby the herbicide is slowly
released as water passes through it. The company Drip-In makes the tubing
(hard hose) and Geoflow makes the emitter which collectively is called
"Rootguard". There might be other companies trying similar ideas, but I only
know this one. I understand Netafim is pondering something, but this is only
a rumor....
If you choose not to take this route, say for instance you want to use drip
tape (more for row crops), we at the Water Management Research Lab have found
that if you introduce 15 ppm P in the form of phosphoric acid, no root
plugging will occur. We do not know if it is the acidity per se or the actual
P that reduces root intrusion. The draw back on the phos-acid is that green
phos-acid is rather "unpure" and expensive and white phosacid is REALLY
expensive.
Other research has shown chlorine injection via Cl gas is effective. A
chemical called "N-Phuric which is part Urea and part sulfuric acid and is
good for constant injection or shock treatments, although we use this product
to prevent precipitation of certain compounds (CaCO3) due to the lousy water
quality in the area. Some organic buffs on the email list suggest CuSO4 which
we have no experience in, yet we are thinking of involving it in a new
experiment which focuses on root intrusion.
Vapam is another, which we routinely use, although only on a yearly basis.
Email me if you want more info on Vapam.
Subsurface drip irrigation is experiencing a new frontier as to what one
could use for chemigation purposes. If I think of any more products, I'll
send another message. Hope I this will suffice for now.
I have also mentioned in the past that frequent irrigations per day is the
best way to "non-chemically" prevent root intrusion. This keeps the soil
moisture at a steady state and does'nt encourage roots to go hunting for
water if there was a drier regime. Our studies at the West Side Field Station
with the University of California in the last decade has proved this again
and again.
Thanks for your interest and keep pounding questions at me!!

Richard Mead
List owner

Dear Richard,

I can't tell you how amazing this on-line concept is. After 13 years in
Africa on a remote farm (Naivasha, Kenya), we thought the telephone was
wonderful. This "community of growers" is just grand.
Thank's for the thoughts on root intrusion. We used quite a lot of
phosphoric acid in floriculture - sounds like we would not have had a
problem. Your answer now resides in my irrigation binder.
I have wanted to trial a continuous irrigation/feeding program. That
is, constant drip irrigation with low fertilization levels.
Every plant would get a drink and something to eat all day long. This
would help out a lot in third world situations where skilled labour is
difficult to find. The idea is to eliminate segmenting the farm into
irrigation zones with complex irrigation schedules. Of course computer
control can help but these systems are difficult to support in remote
areas. About a year ago, one of the Israeli companies (my files are
somewhere at sea at the moment) introduced an inline pulser which gave
full pressure bursts at regular intervals. Any thoughts?
The other problem we had was with flushing out the lines. With
centralized feeding on a large farm, we ran clear water behind the
fertilizer mix. We certainly pushed the fertilizer below the root zone
- probably more than I knew. In the end, we had to abandon the central
feeding and switch back to taking tanks out to the fields. My hope is
that the constant pulsed feeding would eliminate this.
The other hopeful benefit is to minimize ground water contamination.
The new farm will be in Costa Rica where environmental concerns are
quite high.
May I ask, how long have you been running/supervising this service? Are
there other grower oriented services? Please excuse the novice
questions but I am still a bit baffled by all this (I'm also a rotten
speller).
Thanks again and best regards,
Warren

Dear Warren:
Regarding you question on "inline pulser which gave
full pressure bursts at regular intervals." We at the Water Management Lab
have found that pulsing low amounts of fertilzer via positive pressure
fertilizer injection pumps everytime the irrigation pump comes on (via high
frequency irrigation) is the most efficient way to deliver nutrients. We have
Hutchings pumps, which are quite expensive yet work well most of the time.
They consist of a mixing tank and diaphramed heads of 20 or 40 ml capacity.
Within the system is a paddle wheel which measures the flow of water being
delivered to the field. A "SEAFLOW" water meter hooked to this paddle wheel
is programed to have the injection head inject a certain percentage of
fertilizer (from a nurse tank nearby) into the irrigation system. The
diagramed heads can be adjusted from 1 to 10, meaning 10% to 100% of 20 or 40
mls of actual fertilizer. We have successfully grown numerous crops
(tomatoes, cotton, alfalfa, lettuce, onions, broccoli) with subsurface drip
using these pumps with basically CAN-17 and Phosphoric acid. We do not have
much experience with potassium primarily due to our soils having sufficient K
in them. There are other pumps available which we have used (Dosatron, from
France is one), but we tend to stick to what works the most consistantly.
Regarding >The other problem we had was with flushing out the lines. With
centralized feeding on a large farm, we ran clear water behind the fertilizer
mix.< I do believe pulsed irrigations (fertigation is the key).
Regarding>The other hopeful benefit is to minimize ground water
contamination.< Growers in Salinas valley (California) are installing
subsurface drip as a way to control nitrate contamination. They are probably
the most advanced growers concerning this technique in the U.S. I'm going to
an annual meeting there in February and will disseminate any new info I learn
about this subject. Anything for my loyal subscribers!!!

Richard Mead
List owner
p.s. If any one out there has any different experience with pulsed fertilizer
injectors, PLEASE let us know...participate!

Don't know if this got out to all. If this is a re-run, my apologies!!! (R.
Mead)

Dear Warren:
Regarding you question on "inline pulser which gave
full pressure bursts at regular intervals." We at the Water Management Lab
have found that pulsing low amounts of fertilzer via positive pressure
fertilizer injection pumps everytime the irrigation pump comes on (via high
frequency irrigation) is the most efficient way to deliver nutrients. We have
Hutchings pumps, which are quite expensive yet work well most of the time.
They consist of a mixing tank and diaphramed heads of 20 or 40 ml capacity.
Within the system is a paddle wheel which measures the flow of water being
delivered to the field. A "SEAFLOW" water meter hooked to this paddle wheel
is programed to have the injection head inject a certain percentage of
fertilizer (from a nurse tank nearby) into the irrigation system. The
diagramed heads can be adjusted from 1 to 10, meaning 10% to 100% of 20 or 40
mls of actual fertilizer. We have successfully grown numerous crops
(tomatoes, cotton, alfalfa, lettuce, onions, broccoli) with subsurface drip
using these pumps with basically CAN-17 and Phosphoric acid. We do not have
much experience with potassium primarily due to our soils having sufficient K
in them. There are other pumps available which we have used (Dosatron, from
France is one), but we tend to stick to what works the most consistantly.
Regarding >The other problem we had was with flushing out the lines. With
centralized feeding on a large farm, we ran clear water behind the fertilizer
mix.< I do believe pulsed irrigations (fertigation is the key).
Regarding>The other hopeful benefit is to minimize ground water
contamination.< Growers in Salinas valley (California) are installing
subsurface drip as a way to control nitrate contamination. They are probably
the most advanced growers concerning this technique in the U.S. I'm going to
an annual meeting there in February and will disseminate any new info I learn
about this subject. Anything for my loyal subscribers!!!

Richard Mead
List owner
p.s. If any one out there has any different experience with pulsed fertilizer
injectors, PLEASE let us know...participate!

Dear Richard and all,

I am familiar with the Dosatron units. Nice little machines - we used
them in both Kenya and Uganda - the French T-tape distributer handled
them. I'm afraid that I need a lesson in terminology: by pulsed are we
discussing the pulsing of the fertilizer solution into the irrigation
water stream?
While this may be tedious, let me elaborate on the little Israeli gadget I
was writing about - and with which I have no experience. Our cut
flower farm was about 200 ha. gross. We would make our mix of fertilizers
and magic fairy powders back at the pump house and inject this "master
batch" into the water stream via the Dosatron units. This then went out
the mains, sub-mains, laterals, etc. Of course, we did not size the
system so that all fields could receive irrigation at the same time. We
had a schedule whereby various "blocks" were
irrigated/fertigated/chemigated each according to its need (hopefully).
It was a pretty complex system of human management into which many errors
crept, leaped, and bounded.
This little Israeli gizmo (about the size of a non-intregal dripper) was
supposed to allow all valves to be open all the time. Each drip line had
its own pulser. The gizmo would then cycle on and off and the great laws
of chance would insure that only a certain percentage of them would be
open at any one time - and the system would not be blead dry.
So, I guess I'm asking about two "pulsings": the pulsing of the master
batch into the irrigation stream and the pulsing of the stream in the
field.
While nothing in farming is ever as easy as it appears, the idea of being
able to turn on the whole darn farm at once is quite appealing.
Anyone have any experience/ideas on this method?

Best regards,
Warren
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