Archive TRICKLE-L: file log9410, part 1/1, size 41080 bytes:

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I would suggest that you inject some kind of acid prior to water coming into
the sand media filters. Green phosphoric acid or N-Phuric (sold by Union-76
chemicals) could be injected to lower the water pH to 6.5 or lower.
Do you know your Calcite (CaCO3) concentration and water pH?
Sounds like you have really hard water.
Give me a call (209-453-3109). It looks like your in my area.
I'll help you the best I can.

Richard Mead
Soil Scientist
USDA-ARS-
Water Management Research Lab

For those of you that have signed up recently, please let me know by emailing
me at: RMEAD@ASRR.ARSUSDA.GOV or
MEAD2513@AOL.COM
I will send basic Trickle-l information to get you up to speed.

Richard Mead
List owner

Tim Parichan writes:
>We have a problem with our Sand Media filters completly clogging with
>calcium deposits. Has anyone had a problem with this or have any ideas on
>how to deal with it.
> Thanks

I have not had that particular problem, but I have dealt with sand, silt, and
biologicals. I cannot see that calcium precip. would not be any different
unless we could identify a cause for it precipitating in-situ, in which case
it could be precipitating throughout the filter media instead of capturing on
top.

Please elaborate on your situation:
How long does it take to 'pack' or 'clog' the filters?
Do your filters only clog shortly after start-up, or continously?
Do they clog so bad that you have to open the filters and stir up the media
to even flush them?
What kind of filters do you have, mild steel or stainless?
Are they vertical or horizontal tanks?
What size are they and how many GPM are you pushing through?
What is your water source, surface or well?
Do you have a water analysis? ... what does it say? e.g. ppm HCO3
(bicarbonates).
What if anything do you injected above your filters?
How many filter cans do you have on line?
What kind of media do you have e.g. #20 crushed silica?
Do you know it is calcium, or simply that it is white and crusty?
What is your flush pattern? Manual, auto timed, auto demand? ... and how
often?
When running clean, what are your pressures above and below the filters?
At what pressures above and below, or what pressure differential do you
flush at, and how many hours or minutes do they go before needing to be
flushed again?
During back flush, what are your pressures above and below the filters?
What size is your backflush drain pipe, and how far does it go?
Do you have any accessories before the filters like a sand spinner?
What have you tried to correct the problem thus far?

You may not have answers to all of these questions, but any details about
your situation would be helpful.

Craig Thompson
Lodi, CA

Richard:

>Give me a call (209-453-3109). It looks like your in my area.
>I'll help you the best I can.

If you guys talk on the phone, I hope you will post the results of your
discussion here on the list. I (and I am sure others) would like to know how
this situation turns out.

Craig Thompson

Regarding: >If you guys talk on the phone, I hope you will post the results
of your
discussion here on the list. I (and I am sure others) would like to know how
this situation turns out.< Craig, don't worry, I'm not that secretive,
besides you probably know more about things of this nature than I do. Your
response to his question was great! You real world guys are for the most part
way ahead of us research
nerds. We learn from your comments all the time!!!
Later.
Richard Mead

You replied to a posting of mine some time back, but my response to you
seems to have gotten lost, so I'll try again.

I wanted to say that your comments were right on the money, and quite helpful.

Who is your (local, I presume) supplier for drip equipment.

Regards,

To: Richard and all

You mentioned: > Craig, don't worry, I'm not that secretive,
>besides you probably know more about things of this nature than I >do. Your
>response to his question was great! You real world guys are for the >most
part
>way ahead of us research
>nerds. We learn from your comments all the time!!!

Us 'real world guys' just talk to as many of 'you research nerds' as we can,
then accumulate and share what we learn. No issues I bring up are original
thoughts, they are an accumulation of technology developed in Isreal, the US,
Australia, and many other parts of the world.

Neither are we 'real world' folks bound by the rules of statistacal
reliability. I wish more research folks were forthcoming about potential
relationships and hypothesis they are seeking to test instead of waiting
until they have statistically reliable results, at least on this forum
anyway. This is the place to do it, and if so prefaced as 'speculation', a
great place to test ideas that have foundation only in 'a feel' for the data.
It's a relatively friendly crowd here, with a good feel for the topic.

Carry on,
Craig

To: Geof and all,

>You replied to a posting of mine some time back, but my response >to you
>seems to have gotten lost, so I'll try again.
[omitted, but thank you cvt]
>Who is your (local, I presume) supplier for drip equipment?

We do most of our business with Lodi Irrigation. Steve Borra, and his Cal
Poly Grad son, also Steve, have put together a good team. They're
practically minded and yet willing to be progressive and always open minded.
I suppose that is the Cal Poly, S.L.O. influence.

Following a local farmer's lead (Charles Lewis) and the well published Mr.
Simpson we went ahead with subsuface with some anxiety. Through the decision
process we spoke with several well qualified experts including Dr. Terry
Prichard. Most answers were 'it should work, but it has not been evaluated
in your conditions.' We harrassed the manufacturers (Rodney Ruskin,
especially). Through the process we learned a great deal and, in the end,
have been overwhelmingly happy with the results.

We also have a very good Netafim dealer here in Lodi by the name of Quantum
Irrigation. Their only hangup is a Netafim promoted skeptascism for
subsurface drip. I wish I knew the whole story behind their reluctance.
They seem to do a great job on surface drip.

By the way, why do you ask who our supplier is?

Craig

(please forgive my not so subtle sneers and cheers ... I'm not in a 'fornt
end' business, so I can get away with this kind of stuff).

Craig:
Speaking of statistical data, we are in the process of designing a drip
irrigation project which would purposely plug emitters with intrusive roots
and we're having a statistian coming down next week to help us design the
project so we can implement as many treatments as possible. Treatments we
have thought of are: high frequency vs low frequency irrigations, vapam,
N-Phuric vs no N-Phuric, phos-acid vs non phos acid, several different
lateral placements, Chlorine vs non chlorine etc. Can you ( or any one else
out there in real world land) suggest other things we might try as treatments
to prove or disprove root plugging on SDI? It will be a complicated
experiment, but I would feel much better about setting up the experiment if
we got more imput from growers and other researchers. Any comments??
Thanks!!
Richard Mead

>we are in the process of designing a drip
>and we're having a statistian coming down next week to help us design the
>project so we can implement as many treatments as possible. Treatments we
>have thought of are: high frequency vs low frequency irrigations, vapam,
>N-Phuric vs no N-Phuric, phos-acid vs non phos acid, several different
>lateral placements, Chlorine vs non chlorine etc. Can you ( or any one else
>out there in real world land) suggest other things we might try as
treatments
>to prove or disprove root plugging on SDI? It will be a complicated
>experiment, but I would feel much better about setting up the experiment if
>we got more input from growers and other researchers. Any comments??

As discussed in earlier threads, somebody needs to look into treatments
acceptable by the Certified Organic Farmers. Mined copper sulfate may be one
such treatment. There could even be additional funding for that one.

For crops that like N, maybe short bursts of concentrated Ammonia might be
interesting ... enough to burn roots and nematodes (especially if added right
before shutdown) ... a crazy thought ... mineral problems too I suppose.

Certainly triflurilin is a classic ... the standard to compare others by.
Look for phytotoxicity limits with that one, and the other treatments too.

Do you think you could throw in a little N isotope study ... add a little of
a special isotope of N and see how the various treatments effect nutrient
uptake? Oh well, I guess even USDA's pockets have bottoms :-).

How many treatments and how many replications are you looking at? What crop
are you using as a root source?

Craig

It would be good to have a look at different emitter designs
too.

Andy Kenyon

Richard:

Andy Kenyon brings up the very valid point:

>It would be good to have a look at different emitter designs
>too.

Is that in the budget? What emitter design did you plan on using? Do you
have room for other emitters?

If emitter comparisons have already been done, would you be kind enough to
post the result? (I know some have ... do you dare?)

You have gone and opened the 'can of worms'. You might as well as elaborate
on the goals and constraints of this next round of tests.

I guess I am in a 'daring mood' right now ... let's see if business politics
can withstand the test of science ... please cite other California
institutions' results if you have them handy.

Do posts like mine make you wish you never started this?

Craig .... :-)

Any more info on the filter calcification problem? If there was any
additional information I somehow missed it.

Craig

I still have my problem, however I have not replied because I am trying
get my almonds to dry after all this rain. I will update you as soon as I
get them out of the field. The pump station that this is presently
occurring at is only one of five on the system and at the moment presents
no real danger to my operation.
If things go well, I should have them all out if the field this week
and I look forward to tackling this problem. Sorry about the delay but
I've never had to deal with this much rain(1.5") before.
===========================================================================
Tim Parichan | Well the cool breeze came on Tuesday
Tim Parichan Farms, inc. | And the corn's a bumper crop.
P. O. Box 9480 | And the fields are full of dancin',
Fresno, Ca. 93711 | Full of singin' and romancin'.
kluko@cerfnet.com | The music never stopped.
| John Barlow
===========================================================================

Craig:
Regarding:>How many treatments and how many replications are you looking at?
What crop are you using as a root source?<
We are looking at crops with normal to heavy root distribution patterns. Most
solenacious crops (not sure of spelling) such as tomatoes are root evasive.
We have thought of 18 treatments so far, but we're trying to maintain some
simplicity. A minimum of 4 reps will be incorporated. Your CuSO4 idea is
included. Chlorine gas seems to be big too, although that probably would be
an organic no-no. I'll let you know what we come up with and we really
appreciate your input on this subject. It makes me feel better knowing we're
having input from concerned knowledgeble people rather than perpetuating our
own research ideas.
Stay tuned!
Richard Mead

Andy:
We have included that thought into our design. Any particular suggestions??

Richard Mead

Craig:
>If emitter comparisons have already been done, would you be kind enough to
post the result? (I know some have ... do you dare?)<
We have not done emitter comparison tests. We do agronomic experiments. This
future experiment will be the first for our lab. If you want emitter research
results/comparisons, contact Dave Zoldoski at Center for Irrigation
Technology in Fresno (I don't have the ph # in front of me....sorry). They do
more engineering/design analysis. Yet, I'll try to obtain info from them
prior to instigating our experiment to make sure we're covering the spectrum>

>Do posts like mine make you wish you never started this?<
On the contrary. I enjoy every minute of these discussions.
Information is vital to everybody, no matter how controversial.
Richard M.

We do not have a huge range of emitters to choose from here in
Alice Springs! However Netafim reckon they have designed an
emitter that reduces root invasion - will you take them on?

Cheers,
Andy

> If things go well, I should have them all out if the field this week
>and I look forward to tackling this problem. Sorry about the delay but
>I've never had to deal with this much rain(1.5") before.

I sure understand that one: My 4 year old and I were out 'supervising' our
grape harvestors when the first squall moved through Lodi. While I radioed
for the crews to take cover in an equipment shed, my son and I got pinned
down by a levee with only trees for cover and an ATC for transportation.
Fifteen minutes of solid downpour, lightning, and thunder and we had a half
inch of rain on the ground. Not a typical storm for our part of California
... more like the kind of storm I expect for Mississippi. The forcasters
didn't expect anything of this magnitude either. A couple of squalls later
and we had over an inch.

Craig Thompson
Lodi, California

Our harvest is resuming (and should wrap up) this week, so all the best to
you.

Andy:
Regarding>However Netafim reckon they have designed an
emitter that reduces root invasion - will you take them on?<
Sure! If it works into the realm of treatment design.
Keep us informed on the particular products and/or treatments for root
plugging. I will announce sometime in the future what the treatments/products
will be.
Richard M.

Please take my address off your subscription list. Thanks :>

Hi, Dear Trickle-l subscribers:

Would somebody know the chemicals needed in subsurface drip irrigation
to prevent root intrusion? Your information will be greatly appreciated.

Regarding:>Would somebody know the chemicals needed in subsurface drip
irrigation to prevent root intrusion?<

Where do I start?
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 root 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.
Richard Mead

> 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".

The Gowan Company procured a California label (don't know about other states)
which permits the use of Triflurilin for weed suppression by injecting
through any drip system. If used according to the label, it also seems to
have the beneficial effect of creating a 'root free' zone in the vicinity of
the emmitter. I expect you will be amazed at how little material is called
for.

One consideration you may wish to consider ... the material MAY (???) inhibit
root expansion of your crop if misused. When I used it to suppress weeds
where I have above ground drip, I observed a ceasation of water consumption
in the first foot of soil below the emitters. This was a one time (several
field) observation, so I can not apply any scientific validity to my
observations. I recognized no detrimental impact to the grapevines.

Now the trick to using Triflurilin for weed suppression (and to maximize the
no intrusion side benefit) is to get it out of the system evenly, but not
allow it to carry through the soil. I believe that the best way to do that
is to apply it at the tail end of a long cycle irrigation. (I believe) The
label calls for an injection time that equals or exceeds the time it take for
the material to reach the emitter furthest from the filter station. ( In my
system that is about an hour . ) Then run clean water behind the material
long enough to purge it from the drip system.

I used a 30 gallon barrel to dilute the material so that I could meter the
small amount of material in about 1 1/2 hours. I then ran the system another
1 1/2 to purge. I then waited several days before irrigating again to allow
the Triflurilin to 'tie up'.

This is how I did it ... but remember to follow the label. I know another
farmer how used this method for several years before Geoflow was 'invented',
with great success.

I hope somebody else has comments on how to best apply materials to maximize
localized concentration.

>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.

I think I was one who suggested it. I don't know if it works, and don't know
anyone with experience. My point is that it has a chance, and may be one of
few products to facilitate subsurface drip for organic farmers.

Craig.

Just wanted to share some updated info with you.

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As the winter approaches (at least in the northern hemisphere)
more of us will have time to sit down and correspond via Trickle-L. Please
don't hesitate to pose any question or deliver comments regarding drip
irrigation.

Thanks again!

Richard Mead
List owner

Your comments on chemicals that may be used to prevent root intrusion have been very helpful. However, I wonder if 15 ppm phospheric acid would be beneficial to crops such as dry beans? Would there be specific time during the crop growing season that root intrusion may becaome severe?
Also, I would like to know about the metering devices that can be used on a chemigation system. These flow meters may have to be chemical resistant, yet sensitive in the gph range, yet economical. Your info on where, how I can find such devices would be greatly appreciated. Thanks in advance.

Has anyone posted a list of sources for micro-sprinkler heads, chemical/
fertilizer injectors, and other related supplies such as mist bed timers,
etc?

Manny Lorenzo
Miami, Florida

Beans specifically, I don't know, however I've been injecting around 15ppm of
a poly-phosphate for five years on perennials, trees, shrubs, and evergreens
both above and below ground. I use Netafim pressure compensated tubing. I
use a strainer after the treatment pump but before the meter. Water does'nt
get much harder than it is here, and I'm still using the same tubing. Annual
checks have not yet shown any clogging. I've grown probably 500 varieties and
have not had any problems with the concentrate. I've been very satisfied
with the system both performance and support wise. You could contact The
Dexter Company, Mogul Division, 29999 Solon Industrial Parkway, Solon Ohio,
44139 for information on their many system combinations. Myself, I go
through Dexter Water Management Systems, 1455 Davis Road, Elgin, Illinois,
60123, at 708-691-2569, so there might be a facility somewhere in your area.

F.Y.I.: Hummert International, St. Louis, Mo., 800-325-3055, has the most
extensive product listing I've seen. It's a real bible, not too much they
don't list. However, very expensive overall, I use it mainly to identify
what I want and only buy from them if I can't find it elsewhere. As for a
posting, I've not looked for one.

Check "Irrigation Journal". They advertise loads of micro irrigation
products.

Richard M.

Richard,

Let me introduce myself. My name is Peter Waller and I work in the
Department of Agricultural and Biosystems Engineering at the University of
Arizona.

I am submitting a proposal the the Phoenix AMA (Active Management Area) in
Arizona for residential and commercial drip irrigation. We are focusing on
three or four subjects for the proposal: site evaluations and interviews
with contractors in Phoenix, emitter placement criteria, emitter clogging
and soil calcificationa and salinization and, finally, root intrusion. We
were not going to focus on root intrusion; however, the chairman of the
committee that selects proposals suggested that we add it so who am I to
argue with the chairman of the selection committee.

Anyhow, I noticed in trickle-l that you are considering an experiment for
agricultural drip system root intrusion. I am guessing that you are
focusing on agriculture because that is the focus of trickle-l. Anyway,
since we are focusing on the same problem in different environments I
thought it might be helpful for us to interact and throw some ideas around
for experimental design etc...

Pete

yes please!
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