Drip Irrigation

[Jotham79]

I am trying to switch over from sprinklers to drip irrigation where possible and have a question. I have sourced 5/8 inch (16 mm) drip tape with drip spacing of 20 cm, 30 cm and 60 cm. The 30 and 60 cm tape is rated at 1 bar. The guy at the store with the 20 cm spacing tape said I could go up to 2 bar. No once seems to know how long a tape I can run and I get wildly different stories. The 20 cm spacing tape is 1,600 baht for 1,000 meters so I recon it is not that high of quality. The 30 and 60 cm tape is labeled for cassava and comes in 500 meter spools for about 1400 baht. The longest run I need to make is the full length of my Jujubes which is about 150 meters. I can run from each end which would be about 75-80 meters. Is this doable with any of the tapes while keeping to 1 bar?

Thanks.

[Torrens54]

Don't quite know but have seen a lot of the stuff at GLOBAL in Hang Dong. (CNX)

We brought most of what we wanted with us from Perth but I have seen quite a bit at Global, maybe they can help.

[Jotham79]

Don't quite know but have seen a lot of the stuff at GLOBAL in Hang Dong. (CNX)

We brought most of what we wanted with us from Perth but I have seen quite a bit at Global, maybe they can help.

Finding the materials is not a problem so far, but no one selling seems to know how it works. I just found a couple of references that say I shouldn't have a problem on row length( I will go in from both ends), but now I need to find someone who can show me how to fertilize with the system.

[rice555]

Hello All, there as been several threads here on drip irrigation here,

the best place to get info is from the Co's. own website on flow and

rub length.

I was doing 1+ rai of dent corn and cowpeas off a I" pump, 1" filter,

1" fertilizer injector and a 3/4" pressure control regulator. I could do

2 rai if I had a larger 1" pump. I have 3/4" and 1.5" pressure control

as in the pics, they are 1.1Bar. You maybe could a 1.4Bar if you had

to pump up hill a little.

Netafim sells springs so you can change the pressure setting of the

valve.

Again there is a lot of U-Tube videos on how go's.

rice555

[SUTHAM]

I would assume that cheap dripline is not pressure compensated so you need to install it only on flat area.

if you go up or down hill, the flow would change drastically.

about the lenght you can go, it depends on the flow-rate of emitter you have.

For instance, the 30cm spacing, if you choose the flow rate of 0.66 liter/hr, you can go upto 170m.

of course, the length would get shorter if you choose higher flow.

Good luck krub

[canopy]

Anyone found a link to a nice design guide for drip irrigation? That's probably all I need but rather than start a brand new thread for a similar but different query, I will mention in my case I have a 200M run going down a hill that drops 8-100M from the gravity fed water source at the top. There are 20 banana groves starting out that I wish to drip irrigate the first few years.

[rice555]

Anyone found a link to a nice design guide for drip irrigation? That's probably all I need but rather than start a brand new thread for a similar but different query, I will mention in my case I have a 200M run going down a hill that drops 8-100M from the gravity fed water source at the top. There are 20 banana groves starting out that I wish to drip irrigate the first few years.

Do you have a pic/drawing? How wide of a strip?

rice555

[canopy]

What is meant by a strip?

[rice555]

Draw a picture of your growing area with dimensions and water

supply location, take a picture and post it!

Do you want to add fertilizer with the drip??(Bt.500. extra)

What drip spacing do you plan to use, I've see up to 60cm

at DoHome, will check tomorrow, I need some part my self.

By the way I red you post you had a "strip" of land on the

side of an steep incline, always best to show a drawing/pic

of what is being talked about to help visualize for a solution.

rice555

[canopy]

No need to fertilize at the same time. I have no idea what emitter spacing nor how many emitters nor gpm to use per small banana--that's why I am asking. Technically I have a hill rather than a "strip" of land, not that it matters as we are talking about a line of bananas anyway. I can't think of how a picture would give any useful information up and above what I posted which has all the parameters laid out in 2 short sentences. Besides it would be impossible to get it all in one or even two photos unless I had a helicopter and even then it might not be very clear.

But anyway I have been reading online guides and now realize it is going to be an extremely tough job handling the elevation change. I'm not sure all the specialized gadgets required, of which there are many to handle all the problems, are sold in Thailand but am interested to find out. I had no idea how technical drip irrigating is nor do I know of an easier way save for hand watering by hose which I had hoped to eliminate.

[Jotham79]

Taking what you have written you have a 200 m row of bananas on a slope with a drop of 8 meters in 100 m and you have a gravity fed source at the top. Here is what you could try for the first 50 m run a piece of drip tape, for the second 50 meters run 50 meters of 1" plastic tubing and 50 of drip tape, for the 3rd 50 meters run 100 of plastic tube and 50 meters of tape and 150 m of tubing and 50 m of tape for the last bit. Since your is down hill and I am guessing there is only a total of 16 m you only have a variation of 1.6 atmospheres. Before running the plastic hose I would run 200 m of tape the full length and see what happens. If need be you then could cut into 2 x 100m or 4 x 50 m. sections supported by Most tape is designed to work at 1 atmosphere or less but it shouldn't rupture with only 2 atm of pressure. You could also put "T" connections at the end of each section of plastic tubing and run drip tape down both sides of the bananas. I would use a filter, but everything above would be relatively inexpensive. You don't really need each banana to get exactly the same amount of water. With that slope you have good drainage and if the amount of water at your source is not a factor and you are using gravity feed you can afford to over water some plants. 200m of 1 inch tubing is around 1,000 baht and drip tape with 20 cm spacing is about 1,600 baht for 1,000 meters.

[canopy]

The drop is not 8 in 100, it's 100 in 200! To try to add clarity, I'll say it a different way. The first banana is 8M below the water tank. The last is 100M below the water tank. The distance from tank to last banana is 200M. I concur on the importance of the filter, it's on my list of things to look for.

[Jotham79]

With that kind of drop, I can't see drip tape being practical. Without walking down the line and opening/closing valves in several places I would be at a loss. I have a couple of ideas, but they would be more involved.

[rice555]

Good luck.

rice555

[Jotham79]

The drop is not 8 in 100, it's 100 in 200! To try to add clarity, I'll say it a different way. The first banana is 8M below the water tank. The last is 100M below the water tank. The distance from tank to last banana is 200M. I concur on the importance of the filter, it's on my list of things to look for.

Here is what I have come up with. I'll state my assumptions first:

Most drip tapes are designed for 1 atmosphere (atm) or 1 Bar or 14.7 PSI. They will usually work at less than half that amount. They should still function up to almost 2 atm. 10m of water drop equates to 1 atm of pressure so as you run your tape down hill the pressure in the tape will increase.

So start with a filter and you can run a drip tape directly off of that for a drop of up to 20 meters (I would go for a drop of 15 meters to be safe) then insert a 1 bar pressure regulator and run tape for another drop and insert another pressure regulator and so on until you get to the end. Nowhere should you have more than 2 bar max. If you want you can run a T connection above and below each pressure regulator and run tape down both sides. Tape is cheaper than the firm plastic tubing so it will help offset the 6 (?) pressure regulators. If your source is adequate you should be able to water the whole row at one time.

[Canada]

Ive never bothered to measure pressure in my lines. I run as much drip tape as I can, getting decent, even flow. Every line has a valve. I open them till I open too much, then back up. It's not really rocket science. If trying to irrigate up hill, I pump it up then irrigate down. If you can't irrigate enough or as much as you think you should be able to, get a bigger pump. Drip tape is rated flow per dripper which you can calculate into flow per meter which can be calculated as flow per rai per hour. Your pump is rated as well. So you should be able to calculate how much tape will run off of a particular pump given the flow/pressure rating of the pump.

The only thing that having too much pressure will do or cause is cause you to exceed the limits of your pipe/valve/filter/pvc components. You'll have leaks and things will fall apart. So, run more line, decrease the output of your pump or instal a bleeder valve to decrease pressure in the system.

Simple math and trial and error works for this stuff. Like I said, not too much can go wrong.

[canopy]

Simple math? Not too much can go wrong? Ha ha, I am far enough along in research to see that it is so untrue that it is funny. Speaking of not so simple math, I had to finish a crash course in hydraulics which turns out to be an important prerequisite for my design. This sums it up:

Properly designed piping, with sound hydraulics, can greatly reduce maintenance problems over the life of an irrigation system. Controlling the water flow velocity, holding velocity within proper limits, reduces wear on the system components and lengthens service life. Poor hydraulic design results in poor performance of the irrigation system, leading to stressed landscaping material, or even broken pipes and flood damage. Lack of design

know-how can also cost the system owner more money because the designer may over-design the system to avoid unknown factors. In addition to wasting money, a poor hydraulic design will often waste water. Hydraulic analysis is important to minimize financial risks, produce efficient

designs and eliminate waste.

Now on steep elevations many things go wrong, but let me give a concrete example of just one: low emitter bleed off. It means when you turn off the water at the valve at the top, all the water in the hose then drains out the bottom emitters. In my case that's hundreds of liters of latent water that will flood and be wasted at the bottom. This draining process also causes emitters above to suck in dirt and debris into the system which can clog things up and lead to failures. There are ways around it, but just saying there are many issues lurking here that might not be obvious.

[Jotham79]

Simple math? Not too much can go wrong? Ha ha, I am far enough along in research to see that it is so untrue that it is funny. Speaking of not so simple math, I had to finish a crash course in hydraulics which turns out to be an important prerequisite for my design. This sums it up:

Properly designed piping, with sound hydraulics, can greatly reduce maintenance problems over the life of an irrigation system. Controlling the water flow velocity, holding velocity within proper limits, reduces wear on the system components and lengthens service life. Poor hydraulic design results in poor performance of the irrigation system, leading to stressed landscaping material, or even broken pipes and flood damage. Lack of design

know-how can also cost the system owner more money because the designer may over-design the system to avoid unknown factors. In addition to wasting money, a poor hydraulic design will often waste water. Hydraulic analysis is important to minimize financial risks, produce efficient

designs and eliminate waste.

Now on steep elevations many things go wrong, but let me give a concrete example of just one: low emitter bleed off. It means when you turn off the water at the valve at the top, all the water in the hose then drains out the bottom emitters. In my case that's hundreds of liters of latent water that will flood and be wasted at the bottom. This draining process also causes emitters above to suck in dirt and debris into the system which can clog things up and lead to failures. There are ways around it, but just saying there are many issues lurking here that might not be obvious.

I understand wanting to do your due diligence and preparation, but.......First of all the math you need is simple. 1 bar equal 10 meters of height and you probably can't go over 2 bar with "DRIPTAPE" (not hose) with out damaging it so there is your range, you are working with short distances. DRIPTAPE is designed to work on the surface or buried so I don't think you will have the problem with dirt being sucked in. Driptape is only designed to last a couple of years and be replaced. Like I said, you can get (here in Petchabun) 1000 meters of driptape with 20cm emitter distance for 1,600 baht so you are only talking about 320 baht for your row. Yes you will waste water, but you will save 300% of any other way you can deliver water to your plants. Yes you will spend more than is needed. If you never want to do anything where you will probably lose some money learning how, then you need to get as far away from farming as possible. You will only discover those lurking problems by actually doing this project. If you hire someone to design and install your system you will pay 5-10 times as much as doing it yourself. You are talking about a single row "gravity fed" and short distances between pressure regulators so you really do not need to worry about "hydro-dynamics" as the actual movement of water is not your problem and a simple understanding of "hydro-statics" would help you feel better, but you already have everything you need (1 bar equals a column of water 10 meters high and don't go over 2 bar).

You are trying to put irrigation in where it normally wouldn't go and it is an interesting exercise and I hope you do well. There is a thread a few months ago where a guy was going to irrigate a steep area for tea so you might want to take a look at that or contact him to see what he did.

Good luck

[kamalabob2]

I noted that Netafim had three Represetnatives in Buriram at Ruangsangthai Builders Merchants on Highway 2078 across from the Buriram provincial Electricity Authority office on Thursday. Mr. Pichai told me they now had a full time irrigation sales person on staff who would help any expat or Thai citizen with agricultural crop watering design or house garden drip irrigation design and installation. Mr. Pichai seemed confident his selling price for Netafim products would be lower than Global House and his selection would be far wider. I was interested due to the Kyrocera solar panels that were providing electricty for a 3hp water pump in the parking lot of Ruangsangthai.

[brandonincambodia]

I noted that Netafim had three Represetnatives in Buriram at Ruangsangthai Builders Merchants on Highway 2078 across from the Buriram provincial Electricity Authority office on Thursday. Mr. Pichai told me they now had a full time irrigation sales person on staff who would help any expat or Thai citizen with agricultural crop watering design or house garden drip irrigation design and installation. Mr. Pichai seemed confident his selling price for Netafim products would be lower than Global House and his selection would be far wider. I was interested due to the Kyrocera solar panels that were providing electricty for a 3hp water pump in the parking lot of Ruangsangthai.

How much was the solar panel and pump? I have been quoted 90,000 for a solar unit and DC pump that was only going to move 3 to 4m3 a day so am staying with a petrol pump for now.

[canopy]

The slope irrigation project is well underway and lots more work than anticipated. One problem is the water needed to just fill the pipe to the top so the top emitters activate takes a tremendous amount of water--more than I need for the whole irrigation process unfortunately. It also takes too much time to fill the pipe such that the bottom waters a long time before the top comes online. Another problem is even at <2 bar, push on drip hoses pop off due to the pressure and I have added more pressure regulators than planned. While it's still a tough project, I am glad I studied and compensated for so many potential issues before I started. It was invaluable made it much cheaper and easier than it would have been with trial and error (shooting in the dark approach).

you probably can't go over 2 bar with "DRIPTAPE"...Like I said, you can get (here in Petchabun)

Drip tape is not appropriate when there are even low <1 bar pressure differentials, but pressure compensating drip tape would be a good choice. Only problem is no one seems to sell it in Thailand.

[NeverSure]

I had a steep situation like that and I wound up using 8 valves made into a manifold. The filter and regulator were inline before the valves. For the lowest area I ran a solid pipe almost to the bottom and then switched to pipe with emitters. Then I worked my way back up the hill with increasingly shorter lengths of solid pipe and then covered that next area with emitter pipe.

And so it went until I was to the top. I was lucky to be able to use electric valves and a 12 station timer taking all of the work out of it, but it could be done with manual valves.

The two lowest stations built up too much pressure from the drop, so I had to put pressure regulators on those right where the solid pipe changed to emitter pipe.

Once I had it all figured out and working it was great.

Manifolds, which you can make.

[BSJ]

Are the filters just sediment filters or something else?