Drip Tape Irrigation

[JackE]

Hi Pete - I'm buying all my stuff from Dripworks, but designed it myself. They seem like good people.

Heritage (how 'bout a name - Harry, Joe, anything but Sue Thanks a million for responding. I really need some help with this - I'm completely baffled by it!

We use Peters 20-10-20 in 25 # bags exclusively - about 50 bags a year before this drought. We also use some soluble calcium nitrate (15-0-0) for toms. Our application method is inefficient. We apply it all from a 100 gal trailer-mounted sprayer, using a garden hose, row by row! With the constant filling stops, fertilizing takes at least 12 man/hours a week. I have to do this myself - the volunteer ladies don't drive the tractor. It also wastes a lot of $4 diesel because the engine must run continually at 1500 rpm to keep the mixture agitated and to operate the roller pump (the pumps cost $350 and don't last all that long!)

So we could definitely use an injector. Before I read the links, what models do you use? It would be good for us to buy exactly the same one you use. That way we would have someone to ask if we can't figure it out.

Jack

[Heritage]

Jack,

I'm using an older model A30 Dosmatic - I've had it for several years and only install a rebuild kit every few years - I don't know if they still make that model, or what is comparable. They seem pretty trouble free as long as you inject clean water through them after every use, don't inject any non-soluble fert through them, and use the recommended upstream filter (cheap). I have a smaller Dosatron that I use as a portable injector. The important thing is to get an injector made for your input pressure, flow rate, and covers the injection ratio(s) that will work best for you. The dealer will be able to give you those recommendations. I have my A30 set at the 1:100 ratio, so, if I want to inject 1 lb of fert into every 100 gals of water, I just mix 1 pound of fert into every gal. of inject-able concentrate. The fert bags have recommended ratios for different conditions so offer good starting points.

Steve

[JackE]

Just installed the filter and pressure regulator. All I have left is to unroll the t-tape and I'll have 5000 sq ft under drip irrigation. Never thought I'd see the day when this was necessary here in the wet, humid, swampy Big Thicket where it's supposed to rain everyday. Gov Perry is still insisting there's no such thing as Global Warming. Perhaps not, but SUMPTHIN is sure as H... goin' on!!

If this works-out, and if our lake ever fills-up, I may switch the whole three acres over to t-tape. Why not - my sons both make more money than I EVER did - they don't need no inheritance. LOL

Jack

[JackE]

so, if I want to inject 1 lb of fert into every 100 gals of water, I just mix 1 pound of fert into every gal. of inject-able concentrate.

Steve, what's "injectable concentrate"? I don't understand what you mean here. Pardon me - I'm an old house painter and pretty dumb about some things.

Jack

[Heritage]

Originally Posted by JackE

Steve, what's "injectable concentrate"? I don't understand what you mean here. Pardon me - I'm an old house painter and pretty dumb about some things.

Jack

Jack, we're all dumb until we learn it - I remember the first time I tried to use an airless sprayer

The fertilizer injector is mounted above a container (bucket, trash can, etc) of highly concentrated liquid fertilizer (what I'm calling the injectable concentrate)
There is a small diameter plastic tube that runs from the injector down into the container of concentrate. The injector sucks up concentrate from the container and injects it into the water line (at the pre-set ratio) when the water is flowing. It is the injector's job to compensate for different flow rates so you will always get the same amount of fertilizer per given volume of water.

[Heritage]

Jack,

Here is a .pdf showing an injector similar to mine... the diagram of the installation might help to clear things up:
http://www.imexcoinc.com/Manual%20A15.pdf

Steve

[JackE]

Thanks, Steve. I've got a handle on that now. It's getting simpler all the time.-:-). It will be a big labor saver for me.

Jack

[JackE]

Just got the tape installed and turned on the system. The preset pressure regulator was blocking the water so I removed it and regulated the pressure by turning-on enough lines. I think that filter may go the same way - I think it's blocking water flow too. I may be operating at a little higher pressure than advised, but it hasn't burst yet.

Working great now - the well holds pressure with 8 100' rows open - I had hoped for 10 or 12 rows, but eight's okay. If it ever rains and fills our 4 acre lake I'll have plenty of water again - but I'm thinking about switching everything over to this drip system - using the lake water (THAT"S when I'll need the filter - leaves, algae, fish scales, insects etc).

Except for some sand, the well water is clean. I designed a trap to catch the sand before it gets to to the pressure pump. The well I'm using was drilled 20 years ago to serve the house. But it was too sandy so we drilled another, deeper one and simply capped off the sandy one. It came in handy now.

I want to thank all you fellas for your help and advise. I appreciate it very much.

Jack

[Heritage]

Jack,

That's great you got it up and running.

I regulate my pressure by opening the valve on each individual station, similar to what you're doing.

Are you running all the lines off of the same header line? If so, is it the 5/8" black poly you are using as a header line (off of your 2" main)? That header line is always the limiting factor for me and determines the size of my stations. I don't think you can get your full 12GPM through that small of a header (if that is what you're doing)

Also, if you are planning on using an injector I would try and keep a filter in the system - you don't want to run any sand through the injector.

Keep us updated on your progress!

Steve

[JackE]

Steve, my header line is 2" - because I have tons of two inch pvc pipe and many fitttings from the old gravity system we broke down a couple years ago. It's 1" coming out of the pump and into the filter and pressure regulator. Then, 2'' for the supply line and both headers, reduced to 1/2" at each row and plastic 1/2" ball valves installed.

I don't think I'm actually getting a steady flow of 12GPM like I thought. It won't run all 12 rows at once - only about 8. It seems to work best just running one zone of 6 rows at a time - the tape feels pretty "hard" with only six open, though - probably a little too high on the pressure. I'm gonna install an adjustable pressure regulator with a gauge like the one on the sprayer.

I now understand the injectors, thanks to you. But I think I'll hold-off until I decide how much land to irrigate this way. If I do all three acres, I'll need larger unit(s). That all depends on the drought ending and the irrigation pond filling back up. I'll play with this little system all winter and then I should have a better concept of what's involved. All three acres are presently covered by permanently installed 3/4" sprinklers on 2" lines and that works great when the lake pump is operational - 60GPM flow rate on that one with very moderate electricity costs - only pulls 10 amps on 240V.

Right now I'm all psyched-out over this %^$%# drought - if it's a temporary thing I'm better-off money-wise to stay with the sprinklers. From what I read you can inject fertilizer through sprinklers too - but that would be really wasteful to fertilize pathways and all! I just hope we're not turning into a desert like So Calif.

Jack

[JackE]

The dogs got into the newly installed drip tape last night - they always go for something new! Tore it all up, drug it all over, chewed it to pieces etc. No problem, I've got more - and I'll run a hot wire around it about 6" high. The "ring leader" is the neighbor's dog. He leads our dogs astray. On thing's for sure - they all knew I was plenty mad this morning when I let off a couple of shotgun blasts! They didn't know I pointing in the air and they all ran off in the woods and will likely stay there awhile!

Jack -

[Heritage]

Jack, I think you're officially a drip irrigation expert! Hopefully, your pond will fill up and you will be able to put that drip tape into long-term storage. Best of luck!

Steve

[JackE]

Steve, I've noticed one little thing with the drip tape and I wonder if it's normal.

When I turn off the water, the tape humps-up, twists itself into curves,etc. I have to go to the far end and pull it straight - and that pulls it loose from the fitting etc. It improves a little when I turn on the water. Obviously it's expanding and contracting as the ambient temperture changes. Should I bury it?

I planted the whole patch in turnip greens and I'm using sprinklers to get the seed germinated. The drip tape makes a nice 8-10 inch wide band of wet soil - wider than I expected in this sand. It's gonna work-out real well.

Thanks again,

Jack

[Heritage]

Jack, yes, that's a problem if the tape is left on the surface - unless it is under plastic mulch (which will hold it in place). I usually just throw a handful of dirt on it every 10-20 feet to hold it in place until I do the first weeding. At that time, I bury the entire tape about 1" deep. You'll need to adapt it to your method of growing, but yes, you can bury it with no problem.

Steve

[Heritage]

Jack, another method used by some local flower farmers is to run a small 2" deep trench at the plant dripline for the entire length of the row after the first weeding. Then a granular fertilizer is applied in the trench, the drip tape is placed on top, and then it is buried. This method works well for short season crops and when labor is cheap.

Also, I sometimes just apply a layer of mulch to hold the tape in place.