Under the Choko Tree By Nevin Sweeney

Low Cost, Low Tech Irrigation - Overview

I have been using the ideas in the low cost low tech irrigation series for a while, some for years, and they all have their merits and their down sides. I started out making ollas from scratch and it was my intention to fill our 14 veggie patches with them (4 or 6 per patch depending on size), but it was a slow and expensive process, all I could manage was two every three weeks. Having said that I did manage to make over 30 of them before quitting.

Installing from-scratch ollas

The low cost low tech irrigation types I have been working on include –

• Ollas, both made from scratch and made from commercial terracotta pots,
• Buried pipe,
Buried capsule,
• Deep pipe,
• Leaky pipe
• Bottle and wick

Of these, the ones I have installed in the back yard veggie patches are ollas (of both types), buried capsules and buried pipe. The deep pipe and leaky pipe are more designed for the perennials so they are used in the front yard for fruit trees and shrubs etc, and the bottle and wick I use with pots (obviously).

General Comments

The reason I made and used these different irrigation techniques is because here in western Sydney the summers are getting hotter and drier. I think climate change is catching up with us but that is for smarter minds than mine to debate! Nevertheless I find myself watering more and more in summer (as well as other times) to keep the food coming, so it made sense to do it the most efficient way possible.

The irrigation methods, while having their own peculiarities, do all seem to reduce the amount of time and water spent on irrigation, while putting the water exactly where it needs to go. There is no substitute for rain, but these irrigation methods do allow me to still get a harvest in the hot, dry times. The new methods have also allowed me to go for longer in the dry times, watering from the tanks rather than town water, but we are now having to go months without rain and we just don’t have enough water storage.

Here are some thoughts on what of learned through experience with the low cost/low tech irrigation techniques -

From Scratch vs Terracotta Pot Ollas

Apart from the obvious production difficulties if you are not a potter and/or have no access to kilns and such, from-scratch ollas will take more time to produce. I can make half a dozen ollas from commercial pots in a few hours but from scratch ollas would take me almost 2 hours each, plus drying and kiln time. Mind you, while I did get lots of production experience I would not call myself a skilled potter so someone more skilled in the art (as they say) would be quicker.

Making ollas from terracotta pots

Also, I was using a technique called coiling, which tends to be slower that say, throwing on a wheel or even better, slip casting so again, someone with more skill/experience than myself in these alternative techniques could do a quicker job.

My from-scratch ollas have thicker walls, 10-12mm or so whereas the commercial terracotta pots have walls half that thickness. The result is that water will move through the walls in a terracotta pot olla in a day or two but may take a week or more for a from-scratch olla to completely empty. The amount of veggie patch watered by each is a bit difficult to estimate but you get a quick watering with the terracotta and a longer slower watering with the from-scratch one.

Plug vs No Plug

All of the from scratch ollas have a purpose build lit to keep crap and bugs (including mosquitos) out and water in, because they have a wide opening at the top, sometimes big enough to get my hand in. The opening in the bottom of a terra cotta pot is much smaller and some are of a size which can be fitted with plugs (bought form the ‘irrigation fittings’ section), again to keep the water in and crap out. To simplify watering, I tend to leave the plugs out, which makes it quicker and easier to get the water in, the plug will be refitted before the chooks get access to the area. Due to the quicker emptying of the plant pot ollas, mozzies seem to be less of a problem.

Watering

Putting water into the irrigations systems by hand (any automatic system would need to be completely removed before the chooks got access) can be a bit slow, although it is still a lot quicker than standing there with the trigger nozzle set on “shower” and hoping the water gets where it needs to go! Also, with experience I have come up with a way which makes watering reasonably bearable. Hoselink (look ‘em up) have an item on their inventory called a “Root Waterer and Soil Breaker” which is essentially 840mm of 15mm diameter metal tubing fixed onto a trigger nozzle. The idea is you can push it into the ground and water roots of plants directly into the soil and while I haven’t tried to, you could probably make one yourself (or just buy one of theirs).

Root waterer and soil breaker

What I have found is that it is perfect for going into the filling holes of both types of olla, the hole in the top of the buried capsule reservoir as well as the filler area of the buried pipes and deep pipes. It even fits the filler necks of our self-watering pots. The end of the tube is bevelled so most of the time I can lever it up under the cap of the from-scratch ollas, fill them with water, then pull the tube out allowing the cap to fall back into place.

Me using it to water

In most cases it allows you do this in a standing position (unless you are hugely taller than me), easing the strain on your back while delivering the water directly to where it is needed. We have it set up so that it will work on the hose (through a pump) on the main tank or on the town water if our tanks are empty. The town water is a bit higher in pressure so reservoirs are a bit quicker to fill than when we use the tank. Having said that, even with the tank water it only takes a bit over an hour to fill all irrigation points in the backyard, every few days (unless you are in a real hot spot).

Reservoir vs Direct Water Use

While all of these techniques direct the water to where it is needed most, some provide an amount of water storage, while others just direct the water flow under the ground, thus minimising water wastage. Ollas (of either type) and buried capsules provide some level of water storage while all of the other irrigation methods supply water but do not store it. This just means that reservoir type will provide a longer time between irrigations, although it is better to refill the ollas at least when they are half full to ensure the amount of water available is sufficient.

Installation

All irrigation methods will require to be dug in to be most effective. While this is easiest at the construction stage of the garden when beds, trees, shrubs and herbs are being put in, retrofitting is always an option.

Ollas and buried capsules can be dug in using an auger post hole digger, they usually come in 150mm or 200mm size, which is a good start even if your olla has a greater diameter.

The deep pipe can be installed by making a soil hole borer out of some 50mm galvanised steel pipe (as laid out in the article about deep pipe waterers).

Deep pipe in place

Unfortunately the leaky pipe and buried pipe need to be dug into the bed they are going to irrigate and that is all there is to it. I did it when the beds were vacant after being cleaned off by the chook tractor. That way I was only doing one at a time rather than a whole stack at once.

The bottle and wick, of course, is just made and put into action as required when planting new pot plants or repotting old ones.

Final Comments

Putting all of the different irrigation methods into practice has been a lot of fun and taught me a lot. It has been good to look at my food growing systems with new eyes, to work out which methods will do best where and if you have knowledge of you options before putting a garden together it makes things easier. I didn’t design my garden, it developed over almost 40 years, so being able to retrofit was important to me, but if you are looking at putting a garden together, cover your water issues first!

Buried pipe during installation

If you are in a place where your climate is likely to become warmer and drier and sadly that seems to be a lot of Australia, take a good look at these ideas, try them out and work out which ones are for you. At the very least you will save time and water!

 

Click Here to check out our YouTube Channel