Irrigation Holding Tanks

[Lickey]

Just wondering if you farmers with irrigation holding tanks ever put a souluble/liquid fertiliser in the tank? I would think its ok on a drip feed basis, as this would go straight to the roots of plant ect, but our papaya has such a big root footprint, drip feeding is not really an option, i have recently discovered that papaya dont want overhead water, {only tolerant to rain} so i have modified sprinklers so they dont touch leaves or fruit, hence any additive in irrigation would not go near fruit or leaves,

Is this a feasible possibillity or must i walk round the 9 rai with a bucket and cup? this takes me about 4 days!!

Thanks for any input, Lickey..

[Maizefarmer]

Just wondering if you farmers with irrigation holding tanks ever put a souluble/liquid fertiliser in the tank? I would think its ok on a drip feed basis, as this would go straight to the roots of plant ect, but our papaya has such a big root footprint, drip feeding is not really an option, i have recently discovered that papaya dont want overhead water, {only tolerant to rain} so i have modified sprinklers so they dont touch leaves or fruit, hence any additive in irrigation would not go near fruit or leaves,

Is this a feasible possibillity or must i walk round the 9 rai with a bucket and cup? this takes me about 4 days!!

Thanks for any input, Lickey..

Nope - do not use solid fertiliser granules - you can purchase liquids that are designed to be mixed into irrigation tanks for drip delivery. If you mix in so-called normal fertilser granules they will precipatate out of solution to form a sludge at the bottom of the tank after a few hours.

Also suggest you introduce some kind of aggitator - even if its just a labourer who comes along and sturs the tank a little every hour or so.

The big root footprint is a non-issue - drip irrigation is fine on papaya as the capillary effect of the soil will draw the water and mixed in fertiliser additive to where ever the roots are.

You can of course also deliver with sprinklers - but that is not as efficient as I'm sure you've noticed - you throw water everywhere, watering a lot of areas that have not papapya roots, os it lands up promoting the growth of grass and weeds - but it'll do if its your only option.

MF

[ozzydom]

Just wondering if you farmers with irrigation holding tanks ever put a souluble/liquid fertiliser in the tank? I would think its ok on a drip feed basis, as this would go straight to the roots of plant ect, but our papaya has such a big root footprint, drip feeding is not really an option, i have recently discovered that papaya dont want overhead water, {only tolerant to rain} so i have modified sprinklers so they dont touch leaves or fruit, hence any additive in irrigation would not go near fruit or leaves,

Is this a feasible possibillity or must i walk round the 9 rai with a bucket and cup? this takes me about 4 days!!

Thanks for any input, Lickey..

Lickey, as MF says ,drippers are ideal for papaya,I would put two drippers per tree at 180 degrees,the drippers should be placed at the "drip line"as this is where the feeder roots are located.

Cheers

Dom

[stoneman]

Just wondering if you farmers with irrigation holding tanks ever put a souluble/liquid fertiliser in the tank? I would think its ok on a drip feed basis, as this would go straight to the roots of plant ect, but our papaya has such a big root footprint, drip feeding is not really an option, i have recently discovered that papaya dont want overhead water, {only tolerant to rain} so i have modified sprinklers so they dont touch leaves or fruit, hence any additive in irrigation would not go near fruit or leaves,

Is this a feasible possibillity or must i walk round the 9 rai with a bucket and cup? this takes me about 4 days!!

Thanks for any input, Lickey..

A more effective system used in conjunction with a drip system is a fertilizer injector. This system injects liquid fertilizer directly into the output line at a specified dilution rate. This way you do not get any foreign chemicals into your tanks.. There are a wide variety of systems available and are not that expensive.

[JungleBiker]

Just wondering if you farmers with irrigation holding tanks ever put a souluble/liquid fertiliser in the tank? I would think its ok on a drip feed basis, as this would go straight to the roots of plant ect, but our papaya has such a big root footprint, drip feeding is not really an option, i have recently discovered that papaya dont want overhead water, {only tolerant to rain} so i have modified sprinklers so they dont touch leaves or fruit, hence any additive in irrigation would not go near fruit or leaves,

Is this a feasible possibillity or must i walk round the 9 rai with a bucket and cup? this takes me about 4 days!!

Thanks for any input, Lickey..

I agree with what MF has said regarding the use of a drip irrigation system to deliver soluble fertilizers - i.e. it works well. In addition, even with the lateral movement of the fertilizer/water through the soil, I don't think it is necessary for the feed to reach all the roots, those roots which get fertilizer will take it up and then the plant will distribute the nutrients internally to the plant parts that need it (i.e. other roots, stems, leaves, etc).

One suggestion I have... if you put the soluble fertilizer in the irrigation water holding tanks and you do not empty the tanks every time, then you may get variable concentrations of fertilizer being delivered to the plants. For example, suppose you calculated you need to put 5 kg of fertilizer in one full tank of say 1,000 liters, and then you use only 800 litres leaving 200 liters, then next day you fill the tank again and add another 5 kg, you will in fact probably have about 6 kg in the tank, and so on. So, as stoneman has suggested another way to add fertilizer is to inject it into the pipe that is taking water to the field. There are several different types, but one simple/cheap type I have seen sold in Global is a venturi valve type. You insert it into the irrigation pipe and hanging below it is another pipe (flexible) that dips into a bucket of premixed but concentrated fertilizer and water. As the irrigation water flows through the venturi valve it sucks up the fertilizer solution and is automatically mixed/diluted with the main water flow. I am sure if you Google you can find a picture that better explains it. You will need to spend a bit of time calibrating your venturi system to know how much fertilizer is reaching the plants, etc.

By the way, a term that is often used to refer to supplying fertilizer via the irrigation system is "fertigation".

Good luck.

JB.

[Lickey]

Thankyou all for your informative replies, I had thought about fetiliser coagulation in the bottom of tank and could overcome this by the following means, my holding tank is a 2.300ltr clay pot, {cost 700bht} the sub pumps into this via a 2" blue pvc, water just falls into tank, so by fitting a reducer to 1" and extending pipe to near bottom of tank this would keep mixture stirred up. the other problem is if i did use tank for fertiliser, I would have nowhere to cool down when it gets really hot and dusty on farm, so i think an injector system is favourite, installed after the booster pump, {JB, i can picture this system, no prob } MF,Dom and Stoneman, i really want to do drip irrigation on the 6 rai of spare land, {see winged beans post } ive read and studied the cheap irrigation forum and it seems that drip irrigation is done by gravity alone, so Im looking at planting 500 papaya next year, and from comercial growers worldwide on the web say that in the dry season, 1mature fruiting plant needs 10 gallons a day, 50ltrs, I think this is a bit over the top, what im getting at is to drip feed 500 plants, i would need at least 25/30,000 ltrs of water a day in dry times, so would 12 moveable linked clay pots of 27.600 ltrs and a cost of 8,400 be cheaper than 2 concrete ring towers of the same capacity?

Your views and advice is always appreciated, Thanks, Lickey..

[Maizefarmer]

10 gallons a day!!

I'm no papaya expert - I have about 20 of the plants on the farm for domestic use and they get no-where near 10g a day - nothing like that - and they do just fine.

But in any event - lets look at your figures: 500plants - even if they did need around 50 litres aday, what you are saying is you have acess to sufficient water to irrigate them - right? So why do you need to tank it before irrigating? To tank it you have to pump it into the tanks. You would be just as well off (better - as you would not have to invest in any tanks) using a small 1.5hp single phase pump to feed the drip irrigation diretly from your water source.

Then add to this one large (the larger the better) 500 - 1000litre storage tank in which you mix your liquid fertilser for fertigation, and splice it into the main supply on the suction side of the pump (not the output side) - put a cheap ball-valve on and do a couple of dry runs (i.e. with the tank full of water but no fertilser) - use the dry runs to establish a setting for the ball valve that ensures it takes say one whole day for the contents to be sucked out (or however long you wish it to take) - ensuring as good a distribution of the mixed in fertilsier as is possible.

Another advantage of this simple, relaible and almost break-free system is that setting up the tank on the sunction side of the pump, the pre-dilution in the tank coupled with the mixing effect created by the impeller in the pump, will ensure excellent distribution.

And if you want to "inject" the whole tank contents in say a couple of hours - then just open the ball valve more.

It's simple, it's cheap, it's relaible and it's practical.

MF

Edited April 28, 2007 by Maizefarmer

[Lickey]

MF, good info, thanks, yes i can picture exactly what you mean with the ferliliser tank and valve ect, as the 6rai i want to irrigate is 100mtrs from borehole, there is a 1in blue pipe already running close to the field, anyway the mrs and i were looking at the heaps of old drip-feed piping, she then said i want to show you something when we go home lunch, she dragged a pump out from under the stairs, its a MICRO 750watt, max head 32m,100ltr min, it was used for the drip on melons 1 year ago and still works ok, so it seems i have everything to hand to do the drip irrigation.

Burning question,,, the 6 rai is on a hillside, drops about 3in in 1 yard, so do i put feeder pipes across the hill or down the hill, and where would be best to site the pump, top,middle or bottom of field?also i would think that with a 1000 drippers the pump would be hard pushed to feed all, so im thinking on tapping off various sections,

thanks for your advice and time, Lickey..

[Maizefarmer]

Lickey put your pump as close to your water supply as possible, run your dripper lines across the filed if you can, but if not up/down will be fine.

1000 drippers - so long as the drippers are rated for 5 litres per hour or less I can;t see you running into problem's (some smart arse will come along and want to caluculate this all down to fractions - but 5litres p/hour p/dripper and you'll be fine).

Change that 1" line to at least 2" - 3" - otherwise you're going to suffer too much loss with 750watts over 100m (you'll be wasting a fair portion of that 750watts against the friction generated pushing the water through such a long thin feedline - and have less left to push it equally into all the dripper lines. As it is, it's a border line case, but I think it's just in your favour.

MF

Edited April 29, 2007 by Maizefarmer

[Maizefarmer]

Let me run through the above again (a bit clearer if I can):

1) Run a 2” – 3” feed line from the bore hole to the field.

2) Extend it down the side of the field – so that it runs from highest to the lowest point.

3) You want to feed into this line from the highest point of the field – NOT the lowest

4) In any event – to maximise efficiency you want the dripper lines to run across the field as opposed to up/down – so T-Piece the dripper lines off the main-feed.

5) Use 2” to ½” feeds on the lowest half part of the field (because that is where you will have the most hydraulic pressure - immaterial of whether the 2” main feed pipe has the pump located at the lowest end or highest end). i.e. the ½” part is the fitting that fits to the dripper lines.

6) Use 2” to 1” on the upper half of the field, and then step the 1” down to ½” with a reducer.

However you set this up – yes, there is going to be slight imbalance at dripper output, but the above will help balance it all out – I’m trying to keep it simple.

7) Add a ball-valve/tap half – way along the field (on the main feed).

8) Do a couple of runs – adjusting the ball valve in the middle of the field main feed line – to get the dripper at the end of the dripper line at the top of the field to drip as close to the dripper at the end of the dripper line at the end of the field.

Time it using a bucket at each dripper. If you can’t get them to within about 10% or so – simple just calculate how the difference over time at then use that calculation to determine when to close the ball valve for the lower half of the field – thus extending the time for irrigating the upper half of the field, to make up for the difference. You may have to do this in any case if your drippers are not regulated or are dripping more than 5 litres per hours – thus the importance of feeding from the highest point.

Dig a trench – even if it’s only a few inches deep – just to get the main feed-line covered and protected, not only from physical damage of someone breaking it, but nearly all PVC (blue stuff included) is made from re-cycled plastics and become brittle in the Thai sun - will last for years longer covered by soil.

Always end off each additive run (whether it's pesticide or fertilser) with about 20minutes or so of just water - to clean out the lines and drippers, else you will find over time chemical residue will build up and start clogging the drippers.

Have fun

MF

Edited April 30, 2007 by Maizefarmer

[chownah]

Lickey,

What is the layout of the field? Does it mostly run up and down the hill or does it mostly run across the hill?...approximate dimensions? I'm wondering what is the difference in elevation from the top to bottom.....you're report of 3 inches in 1 yard interests me....how did you arrive at this. I'm asking because many people's estimates of this sort of thing can be way off.

Chownah

[Maizefarmer]

Lickey,

What is the layout of the field? Does it mostly run up and down the hill or does it mostly run across the hill?...approximate dimensions? I'm wondering what is the difference in elevation from the top to bottom.....you're report of 3 inches in 1 yard interests me....how did you arrive at this. I'm asking because many people's estimates of this sort of thing can be way off.

Chownah

Right then - lets say he's 50% off in his estimation of elevation - so what, just what is the point you're leading up to??

Im really keen to hear this!

MF

[Lickey]

Let me run through the above again (a bit clearer if I can):

1) Run a 2" – 3" feed line from the bore hole to the field.

2) Extend it down the side of the field – so that it runs from highest to the lowest point.

3) You want to feed into this line from the highest point of the field – NOT the lowest

4) In any event – to maximise efficiency you want the dripper lines to run across the field as opposed to up/down – so T-Piece the dripper lines off the main-feed.

5) Use 2" to ½" feeds on the lowest half part of the field (because that is where you will have the most hydraulic pressure - immaterial of whether the 2" main feed pipe has the pump located at the lowest end or highest end). i.e. the ½" part is the fitting that fits to the dripper lines.

6) Use 2" to 1" on the upper half of the field, and then step the 1" down to ½" with a reducer.

However you set this up – yes, there is going to be slight imbalance at dripper output, but the above will help balance it all out – I'm trying to keep it simple.

7) Add a ball-valve/tap half – way along the field (on the main feed).

8) Do a couple of runs – adjusting the ball valve in the middle of the field main feed line – to get the dripper at the end of the dripper line at the top of the field to drip as close to the dripper at the end of the dripper line at the end of the field.

Time it using a bucket at each dripper. If you can't get them to within about 10% or so – simple just calculate how the difference over time at then use that calculation to determine when to close the ball valve for the lower half of the field – thus extending the time for irrigating the upper half of the field, to make up for the difference. You may have to do this in any case if your drippers are not regulated or are dripping more than 5 litres per hours – thus the importance of feeding from the highest point.

Dig a trench – even if it's only a few inches deep – just to get the main feed-line covered and protected, not only from physical damage of someone breaking it, but nearly all PVC (blue stuff included) is made from re-cycled plastics and become brittle in the Thai sun - will last for years longer covered by soil.

Always end off each additive run (whether it's pesticide or fertilser) with about 20minutes or so of just water - to clean out the lines and drippers, else you will find over time chemical residue will build up and start clogging the drippers.

Have fun

MF

Very good MF, i did wonder about the hydralic potential at the bottom of the hill, which led me to the thought of tapping of sections ect, getting back to the pipework ect, i do have lots of 2" and 1.5 blue laying about the farm, do you think this would be suitable as a main feed to the top of the plantation, Source of water being the borehole, i paced it out today, 135mtrs to top/centre of field, {im 6ft tall and have long legs!! } I also paced out the field to be irrigated, 6rai, big miscalculation on the mrs behalf, down the field was 260mtr, and an average across the field allowing for intrusive tamarind trees ect would be 80mtrs, im pretty adamant on the 80mtrs, but allowing for rough ground and the occasinal stumble ect, lets say 240mtrs, sq mtr 19.200,12 RAI, am i right so far? if so, allowing 2mtrs from edge of field and between plants, this works out at 3786 plants, take a hundred or so off because of the few Lychee trees dotted about in the field, that still leaves over 3500 plants, I really want to fill this field with Papaya because it seems profitable here, intercropping with winged beans because of their ground cover and nitrogen fixing abbilty after the first year/crop.

I do have another irrigation option, or water supply to new field, via the holding tank and booster pump you gentlemen farmers helped me set up with your vauluable advice, it will run 3 10mtr dia sprinklers and a good jet out of a 1" pipe, this 2" goes all the way round the Papaya and near the top of new field, { im gonna try and upload some pics after posting this} I also have another 2" centrifugal pump 2.5 hp, continuos duty, doing nothing, perhaps this will come into play when the paid for lagoon across the road comes into play after the wet season, Good mind to make my own lagoon and pump all the water into this, as it dried up after 3 weeks of paying for a year!!will try and do pics now, MF, do you have any new thoughts based on this new info? Thanks Lickey..

[Maizefarmer]

hel_l - a bit bigger than I thought - you bet that was a mis calc!!

12 rai - this changes things alot!!

Let me chew on this over night - a review is called for, and I'm starting to think that 2.5hp pump you have may not be enough.

How does the number of drippers change?

MF

[Lickey]

Lickey,

What is the layout of the field? Does it mostly run up and down the hill or does it mostly run across the hill?...approximate dimensions? I'm wondering what is the difference in elevation from the top to bottom.....you're report of 3 inches in 1 yard interests me....how did you arrive at this. I'm asking because many people's estimates of this sort of thing can be way off.

Chownah

Hi, did you see my last post, the mrs got her sizeing of field quite wrong, its nearer 10/12 rai, rather than the 6 rai she told me, {bless her,}that aside, im very sure of my 3in in a yard elevation, when i worked for a heavy haulage company in the UK, 80tonne plus loads, going on 250 sometimes, this was in the 70s, we had to apply for a police escort across all counties, and they wanted to know the time and speed we could cross the county, so we had to go out and recon the route, low bridges, weight limits, steep hills ect, trying to give cops a time ect, anyway, getting to elevation, simple way was a yard long spirit level and a tape measure, i wont insult your intelligence by explaining how this works, back at the office, they would somehow calculate how fast and at what weight the truck could negotiate the hill, I used a spirit level and a tape measure on the farm, and i can state that 3" is favourite.

This reading was taken from the roadway up the middle of farm, the new field is very similar, although it undulates a bit, the lower width is 80mtr, the uphill lenght is about 240/250mtr, i did try to put some pics on here but cant get my diesel engineer head round that yet, will try again soon,

Rgds Lickey.

[Lickey]

hel_l - a bit bigger than I thought - you bet that was a mis calc!!

12 rai - this changes things alot!!

Let me chew on this over night - a review is called for, and I'm starting to think that 2.5hp pump you have may not be enough.

How does the number of drippers change?

MF

If i still want to fill the field, we are talking 7000 drippers, as ozzy said, 2 per plant is a must, This coming week, will sort out pipework drippers ect, just to see what stock there is, sorry no pics, cant get my diesel engineer head round to PC talk yet,,

[Maizefarmer]

I personally do noty feel 2 drippers is required - lets say 2 are required - 2 what? - 2 x 3 litre p/hour or is that 2 times 4 or 5 litres per hour - and if so, why not use 1 x 6, 8 or 10liter per hour dripper. If it's an issue of spreading the water to cover all the roots, it wont matter if its 6 liter per hour, or 10 or even hour - if you are going to irrigate every day then the capillary effect of the soil is going to spread it all out in any event.

And you run into a 2nd problem here: the greater the dripper output per hour the larger your pump is going to have to be to ensure anywhere near an equal distrabution - even at 3 liters per hour you are looking at 20tons of water per hour - from a 2.5hp pump pver 12 rai. Not possible.

If you are going to want to use that pump, then you are going to have to use 1 liter or 2 liter per hour drippers - nothing bigger - and over the runs you are talking about (and this is why I said run the dripper lines across the shortest length of the field) you are going to haveto use self regulating drippers.

... need to chew on this till tomorrow: off to bed now.

MF

[Maizefarmer]

Let me run through the above again (a bit clearer if I can):

1) Run a 2" – 3" feed line from the bore hole to the field.

2) Extend it down the side of the field – so that it runs from highest to the lowest point.

3) You want to feed into this line from the highest point of the field – NOT the lowest

4) In any event – to maximise efficiency you want the dripper lines to run across the field as opposed to up/down – so T-Piece the dripper lines off the main-feed.

5) Use 2" to ½" feeds on the lowest half part of the field (because that is where you will have the most hydraulic pressure - immaterial of whether the 2" main feed pipe has the pump located at the lowest end or highest end). i.e. the ½" part is the fitting that fits to the dripper lines.

6) Use 2" to 1" on the upper half of the field, and then step the 1" down to ½" with a reducer.

However you set this up – yes, there is going to be slight imbalance at dripper output, but the above will help balance it all out – I'm trying to keep it simple.

7) Add a ball-valve/tap half – way along the field (on the main feed).

8) Do a couple of runs – adjusting the ball valve in the middle of the field main feed line – to get the dripper at the end of the dripper line at the top of the field to drip as close to the dripper at the end of the dripper line at the end of the field.

Time it using a bucket at each dripper. If you can't get them to within about 10% or so – simple just calculate how the difference over time at then use that calculation to determine when to close the ball valve for the lower half of the field – thus extending the time for irrigating the upper half of the field, to make up for the difference. You may have to do this in any case if your drippers are not regulated or are dripping more than 5 litres per hours – thus the importance of feeding from the highest point.

Dig a trench – even if it's only a few inches deep – just to get the main feed-line covered and protected, not only from physical damage of someone breaking it, but nearly all PVC (blue stuff included) is made from re-cycled plastics and become brittle in the Thai sun - will last for years longer covered by soil.

Always end off each additive run (whether it's pesticide or fertilser) with about 20minutes or so of just water - to clean out the lines and drippers, else you will find over time chemical residue will build up and start clogging the drippers.

Have fun

MF

Very good MF, i did wonder about the hydralic potential at the bottom of the hill, which led me to the thought of tapping of sections ect, getting back to the pipework ect, i do have lots of 2" and 1.5 blue laying about the farm, do you think this would be suitable as a main feed to the top of the plantation, Source of water being the borehole, i paced it out today, 135mtrs to top/centre of field, {im 6ft tall and have long legs!! } I also paced out the field to be irrigated, 6rai, big miscalculation on the mrs behalf, down the field was 260mtr, and an average across the field allowing for intrusive tamarind trees ect would be 80mtrs, im pretty adamant on the 80mtrs, but allowing for rough ground and the occasinal stumble ect, lets say 240mtrs, sq mtr 19.200,12 RAI, am i right so far? if so, allowing 2mtrs from edge of field and between plants, this works out at 3786 plants, take a hundred or so off because of the few Lychee trees dotted about in the field, that still leaves over 3500 plants, I really want to fill this field with Papaya because it seems profitable here, intercropping with winged beans because of their ground cover and nitrogen fixing abbilty after the first year/crop.

I do have another irrigation option, or water supply to new field, via the holding tank and booster pump you gentlemen farmers helped me set up with your vauluable advice, it will run 3 10mtr dia sprinklers and a good jet out of a 1" pipe, this 2" goes all the way round the Papaya and near the top of new field, { im gonna try and upload some pics after posting this} I also have another 2" centrifugal pump 2.5 hp, continuos duty, doing nothing, perhaps this will come into play when the paid for lagoon across the road comes into play after the wet season, Good mind to make my own lagoon and pump all the water into this, as it dried up after 3 weeks of paying for a year!!will try and do pics now, MF, do you have any new thoughts based on this new info? Thanks Lickey..

Okay - here we go:

Use the 2" to run up the length to the half way or 120m point, put in a 2" elbow then a T-piece. Run 2" tubing up the higher 120m length and put the 1.5" tubing on the lower length. Stick in a tap/ball valve on each half length (because you are not going to be able to run the whole field off a 2.5hp pump in one go over those lengths, unless you use small drippers - do it in halves).

Lay out your dripper lines across the widith and stick in your drippers.

Put your pump in as close to the borehole as poss.

Use a hot nail to initiate the hole in the black dripper tubing to hold the drippers - much easier then trying to "push" 3500 or 7000 holes in cold.

Thats my take on it ... have fun

MF

[Lickey]

Makes sense to me MF, sitting here thinking about this and with the materials we already have, it will put them to good use, and burying the pipe will not only prserve it, but perhaps give me the cool ground needed for spuds? worth a try i think!!

I have printed off all your replies and tucked them into my dockey bag ready for the morning, so i can evaluate what weve got and might need,

Thanks for all your help and time, Lickey.

[BAYBOY]

Lickey, just been reading the various posts between you and Maizefarmer on an old thread.

You wanted to install an irrigation system for your papayas. Intrested in knowing the outcome and was it successful?

BAYBOY

[Lickey]

Hi Bayboy, it took me about 6 weeks to set up in the wet season,

The first harvest was inOct 07, collected about 6 tonnes from the 800 plants, unfortunately, the hand carts and 10 odd labour made a right mess of the pipe work, kinking it,splitting and pulling apart, on after thought, i should have pulled the lot out, but to do that would have been labour intensive.

So i scrapped the idea, next was 18mtr blue 1.5 plastic pipe with 3 impact sprinklers on 18in stands, the reason for being so low is that the jets didnt go into the flowering part of the plant, flowers are easily knocked off with water jets, had 2 of these units running of the booster pump,between 20 min cycles, would slide the pipe another 20mtrs along the rows, it was quite succesful,but never tried the fert in the tank angle,

Cheers, Lickey..

[edwinchester]

Thankyou all for your informative replies, I had thought about fetiliser coagulation in the bottom of tank and could overcome this by the following means, my holding tank is a 2.300ltr clay pot, {cost 700bht} the sub pumps into this via a 2" blue pvc, water just falls into tank, so by fitting a reducer to 1" and extending pipe to near bottom of tank this would keep mixture stirred up. the other problem is if i did use tank for fertiliser, I would have nowhere to cool down when it gets really hot and dusty on farm, so i think an injector system is favourite, installed after the booster pump, {JB, i can picture this system, no prob } MF,Dom and Stoneman, i really want to do drip irrigation on the 6 rai of spare land, {see winged beans post } ive read and studied the cheap irrigation forum and it seems that drip irrigation is done by gravity alone, so Im looking at planting 500 papaya next year, and from comercial growers worldwide on the web say that in the dry season, 1mature fruiting plant needs 10 gallons a day, 50ltrs, I think this is a bit over the top, what im getting at is to drip feed 500 plants, i would need at least 25/30,000 ltrs of water a day in dry times, so would 12 moveable linked clay pots of 27.600 ltrs and a cost of 8,400 be cheaper than 2 concrete ring towers of the same capacity?

Your views and advice is always appreciated, Thanks, Lickey..

I know that it's not a crop that I am irrigating but I have a sprinkler system for watering the lawn.

I use a soluble fertiliser dissolved in the tank which seems to work fine.

The pump sucks out the water at such a rate it really stirs up the bottom so coagulation is not an issue.

Here's a link to pics of the setup.

http://coolthaihouse.com/forum/viewtopic.p...0&start=480