Irrigation for 3.5 rai

[djayz]

Coming from Ireland we had to drain water from the land, so I have zero experience with getting water to the land. 

We currently have 3.5 rai in Korat where we are beginning to grow various fruit plants and some vegetables. Up until now, we only had a small patch planted so we were able to water using a garden hose. Now, there are more and more plants so that option isn't working for us any more (too time consuming). There's a good, year-round supply of water (drain/small canal) around the land and in addition to this there is a small pond on the land, so plenty of water available. The land is flat, so no uphill pumping. 

My questions are:

1) What kind of a pump will we need to water 3.5 rai? I can imagine setting up a system whereby we just water the land in sections at various times. How do I calculate what size pump I need to water 1 rai (if I water in sections)? 

2) I think I'd like to run the pump from a portable generator. What size generator would I need? I'd prefer to use a fuel powered generator. Any recommendations? 

3) I'm also thinking of using solar power to provide juice for the pump. Again, any recommendations on solar power? 

4) I'm wondering if there is a need for water storage tanks? Like I wrote before, the water in the drain/canal around the field flows 24/7/365 days a year so no shortage of water there (plus the fish pond). I've seen some people pump water into storage tanks and then water the crops from those tanks. What are the pros and cons of this system? 

I'm really a novice at this, so all information and advice will be much appreciated. 

 

 

[kickstart]

To get the ball rolling , we have  a 2hp electric pump we use for the garden ,pumping from an old fish pond it dose us well with at least 10 sprinklers coming off the main .my neighbor use to grow cucumbers ,he used a 2 hp pump working on a drip irrigation system pumping the water at least 150 meters no problems with water pressure  .using 2 inch  pipes 

A shop near us sells a Chines made 2 ,1/2 hp pump on a diesel engine ,it says the engine uses 1 lt fuel in 3 hours of pumping,cost about 15 000 baht it has a 3 inch inlet and outlet ,but i would say for you 2 inch would do the job ,could be one for you ok, made in China what the quality is I do not know ,but it will not be used 24/7, so it  should do the job.

Use a drip system or sprinklers ,a drip system is popular with the sugar cane growers  and cassava growers ,but some say ants and rats can be a problem attacking the drip tape ,if left down for a while ,a drip system uses less water than a sprinkler system ,but as we have found out ,sprinklers and pipe can soon be moved to a new location, when needed  a drip tape will take some moving .

But, a guy near here grows maize for maize silage ,he uses drip tape ,water is fed by a stone Ong ,a Thai water storage jar used in Thai houses ,he has lifted it jar up, just put a big heap of soil underneath ,pumps water in to the jar from a underground supply,and supply's the crop by gravity,field must be 7 rie ,last year during the dry season ,he had a good crop of maize ,but getting the head right so you have an even supply could be a problem ,this guy is lucky his land is on a small slop,so that helps

A few small veggie growers use a sprinkler system ,half inch plastic pipe coming off a 2 inch main using a 2 hp pump have counted ,about ,20 small sprinklers ,water pressure seems to be no problem ,but not a long run of pipe  .

 

 

[farmerjo]

If you would like to water the whole lot at once(or sections) and your land is square in shape and you can get the water to a central position on the land this will work.

Sprinkler(Sime duplex) - 10-12,000 baht(sprinkler rotation is adjustable 0-360 degrees)

Pump - 10,000 baht

Hoses,fittings - 5,000 baht

Diesel engine - 35,000 baht

These prices are approximate to give you an idea.

You would just need to run this set up for 7 minutes a day.

 

 

 

 

 

 

[djayz]

Many thanks to both kickstart and farmerjo. 

 

Farmerjo, most of the field is square (approx. 3 rai, the remaining 0.5 rai is off to the side) so your suggestion sounds very interesting. 

Question: If I were to use the method you suggested, does this mean I'd place one Sime Duplex sprinkler in the middle of the field, pump water to it and water from one, single sprinkler?? 

 

[MikeN]

You don't say exactly what you are growing, but presumably you know that different plants have different water requirements. Shallow rooted vegies would need more frequent watering than fruit trees for instance. So it's probable that you will need to water in sections, one sprinkler won't cut it. work out how many sprinklers you need for each section, litres/minute for each one, total it up for each section and work out the pump from the section with the highest water flow. 

(3) The best time for watering is early morning or late afternoon/early evening, when the sun is low.....not the best time for a solar powered pump.

(4) If you go for drip irrigation perhaps have a tank filled by the pump, then use gravity feed ...you would n't need to have the tank all that high for drip irrigation.

[farmerjo]

5 hours ago, djayz said:

Many thanks to both kickstart and farmerjo. 

 

Farmerjo, most of the field is square (approx. 3 rai, the remaining 0.5 rai is off to the side) so your suggestion sounds very interesting. 

Question: If I were to use the method you suggested, does this mean I'd place one Sime Duplex sprinkler in the middle of the field, pump water to it and water from one, single sprinkler?? 

 

That's what i would do(and do).Same as 3-4 mm rain a day to keep soil moist.

As suggested there are more efficient ways to water,comes down to how much time you want to spend. 

  

[djayz]

On 03/04/2018 at 10:13 PM, MikeN said:

You don't say exactly what you are growing, but presumably you know that different plants have different water requirements. Shallow rooted vegies would need more frequent watering than fruit trees for instance. So it's probable that you will need to water in sections, one sprinkler won't cut it. work out how many sprinklers you need for each section, litres/minute for each one, total it up for each section and work out the pump from the section with the highest water flow. 

(3) The best time for watering is early morning or late afternoon/early evening, when the sun is low.....not the best time for a solar powered pump.

(4) If you go for drip irrigation perhaps have a tank filled by the pump, then use gravity feed ...you would n't need to have the tank all that high for drip irrigation.

Hi Mike! Thanks for the info. Much appreciate it. 

 

I've decided to water in sections so the single big sprinkler, while practical, isn't an option for me now. 

 

I plan on growing vegetables e.g. lettuce, beetroot, peas, beans, cucumbers and tomatoes (drip system only, no sprinklers for the tomatoes) and fruit e.g. passion fruit, various berries, avocados, limes, oranges etc. I'll use drip for the fruit and for the tomatoes, sprinkler probably for the rest. 

 

You said work out how many sprinklers I'll need per section, got that, and then you went on to write about the litres/minute. How do I figure out the litres/minute? Is that based on the type of vegetable being watered or the design of the sprinkler?

 

Thanking you in advance. 

[Mickmick]

1 hour ago, djayz said:

You said work out how many sprinklers I'll need per section, got that, and then you went on to write about the litres/minute. How do I figure out the litres/minute? Is that based on the type of vegetable being watered or the design of the sprinkler?

 

Thanking you in advance. 

A decent brand of sprinkler, ie commercial quality, should have the water flow capacity of the sprinkler somewhere on the packaging, or perhaps a makers website.

just for arguments sake, lets say XXXX brand sprinkler can handle a max of 3 litres/minute, and that you need 6 sprinklers for a particular section, you would need a pump capable of delivering 3*6 litres/minute (18). You might choose to use more sprinklers at a lower pressure and closer together, ie 12 sprinklers at 1.5 l/m.

I used to work part-time for a mate in his landscaping business, always used Rainbird brand ....just as an example this unit (http://store.rainbird.com/sprinklers/impact-sprinklers/14vh-1-2-inch-full-circle-brass-wedge-drive-impact-sprinkler.html#product_tabs_additional_tabbed) uses 0.140  - 0.610 cu.m/hour, which equals 2.3 to 10 litres a minute

Then by trial and error you can work out how long you need to irrigate...that will obviously depend on the vegies and your soil.

[jvs]

We have exactly 3.5 rai also and also have a water source year round.

We made one main waterline 1.5 inch down the middle of our field

and several 1inch lines on a right angle.Al buried around 40 cm in the ground(where else?)

From there we have normal 3/8 waterhose around ten meters each,this gives us the oppertunity to move sprinklers where we need them.

We have two 250 watt 30 volt solar panels and one dc waterpump.

This is enough to run four sprinklers at once,we can keep everything going with this set up.

However we decided we will go one better and go for a bigger solar system.Three panels and a 30 to 100 volt dc pump.i saw one like this setup at a solar shop and it is more then we will ever need and only cost 31000 baht.The pump is intake and out take 1.5 inch the one we have now is 1 inch,we will have more then double the output i think.

Solar works great and no fuel to carry or noise and exhaust fumes.

 

[djayz]

Mickmick and jvs, a big thanks to the both of you. Great info. I'm really beginning to get my head around this. 

[CLW]

For your purpose I would not recommend sprinkler. They would only make sense for some agronomy crops let's say corn or cassava.
For most of vegetables a sprinkler system promotes foliar diseases. Better stick to some type of drip irrigation.
Have you seen those relatively new drip tapes? They have small slits along the tape and are easy to install, operate and also moved to new field area or removed for soil preparation. I'll post some pictures however these are sprinkler tapes but similar layout and principle.