Irrigation System Installation

[pnustedt]

A number of members have talked about installing an irrigation system on their farms. I hope this may be useful to those contemplating such a project.

I have a farm of about 15 rai adjacent to a river which doesn't dry up. It is currently used solely for rice production. I have been in Thailand for 4 yrs and have been improving the yield of the farm each year. The objective of the irrigation system is to improve yield, minimise the use of noxious chemicals and possibly achieve a second annual harvest but I am told that birds will eat the crop as it would be the only one in the area at that time - but worth a try. I will also try other crops as a fill in.

The system consists of a Lucky Pro MNF/130A pump on a raised plinth with lockable hut, about 500m of 3in pvc piping and valves etc., flexible inlet with filter from river, about 200m x 2 of power cables with eucalyptus poles. The cost of the system was about Bt35,000 with two Thais working for best part of a week. I also use a portable Honda pump to supplement water on raised ground (about another Bt10,000 with hoses).

A pic is att. showing the plinth/hut with the "lid" open. Behind is the power cable, to the left foreground just planted rice seedlings, behind that is the nursery field where seedlings are growing, to the left of that workers are planting seedlings. The river is just behind the camera.

The system works well, it takes about half a day to flood the field where the workers can be seen planting. One drawback we have found is that it is necessary to open two valves when the pump is running or the pressure is too great and can burst the pipes (we used the cheapest pipe, a tougher pipe may overcome this).

Anyone in the Sisaket area interested is most welcome to come and look.

[WatersEdge]

Something is terribly wrong.

Sorry to be so blunt, but there's no other way to read what you describe.

How exactly does one break pipe while flooding rice?

It's the ultimate low head high volume application.

The low grade pipe is rated 5 bar => 73.5 psi => 51.75 meters vertical lift

Having said that, I can only assume from afar,

that you are pushing entirely too much water through too small a pipe.

There could be some other reason,

I'm just stabbing at the most obvious.

Your flow velocity should never exceed 1.5 m/sec

because above that friction threshold,

you pay for energy that only heats the water

3" Pipe is meant to carry around 400 liters / minute

If you are going 500 meters distance with it,

then you need to drop even more.

If you'd like a bit of help,

Tell me what you are trying to do,

and I'll straighten it up for you.

[glomp]

The locals would love you for louring all the birds in to one place for easy hunting?

I thought there wasnt any flying birds left

[pnustedt]

How exactly does one break pipe while flooding rice?

By pumping in more water into the pipe than one lets out. The solution was to let more water out.

[pnustedt]

The locals would love you for louring all the birds in to one place for easy hunting?

I thought there wasnt any flying birds left

Yes, no doubt there will be bird hunters trying their luck. We are already plagued with dozens of frog hunters early mornings - since we've stopped poisoning the land the frogs have returned, the only land around with frogs.