I'm expanding my front veggie garden at the moment, and decided to add some form of water savings to a section of the expansion in case I have another dry spring and summer like last year.
This is based on (and is) an open wicking bed (within the area of the garden around where its being laid). Rather than the water being in an open trough, its will be in pipe, relying on wicking fabric to transport the water from inside the pipe, to the soil. It will sit on almost flat (maybe/preferably slightly depressed) sheet(s) of plastic wider than the footprint of the pipes. Struck-out April 2016, no plastic sheet used in working trial.
The disadvantage over an open trough is that it will not collect rain water as well. I'm mainly using it because I wish to encroach upon my 300mm of soil with the reservoir (pipes).
This would be nowhere near as efficient as the IBC wicking beds I have, but a good compromise and will save on water. I'm hoping that this is useful for me to just chuck into the bottom of a garden as a quick retrofit to an existing open type of garden bed.
All works based on Colin Austin's wicking beds concepts.
Simple, >11 Litres - 2Metre 90mm, 1 End Cap, 1x PVC 90 Degree Bend, 500mm 90mm PVC.
>22 Litre, 2 Metre Array x 2
>33 Litre, 2 Metre Array x 3
Most microfiber cloths (best to test) make great wicks
How to Add The Cloth Wicks
10 to 20mm size holes are drilled into the top of a horizontally sealed pipe array. Both ends of a micro fibre cloths are then inserted into separate holes with the ends of the cloth always extending to at least the very base of the inside of the pipe. When plugging the hole with the cloth, ensure the insert is a tight fit ... twisting the cloth into the hole helps to achieve this.
Other Possible Configurations
A narrow, lengthways cut/slot along the pipe, and slot 2 x MF cloths in, then another 2 ....
This system can be boosted beyond wicking by filling up the filling pipe to the very top ...
The cloth plugged holes slow down an instant leak, but of course increase the water distribution from the reservoir's wicks' via gravity & displacement coupled with wicking.
This particular skipping rope (broken) is another material I found to wick well.
Pros and Cons
Can be used in many different types of beds. (Raised, level, in-ground ...).
Can be retrofitted.
Parts can be found as recycled parts.
Parts quite cheep if purchased.
Water in reservoir always clean, no anaerobic/nitrogen drawdown issues that some wicking reservoirs may get.
Introduction of plastics to the garden (be as selective as possible over plastic types).
Requires solid base (may not work in sandy soils where the water rapidly continues to travel down).
Small reservoir for a wicking bed.
Pipe array requires to be kept level in order to take advantage of total water holding capability of reservoir.
Update 9th March 2016
Not much has been happening with this. I will make an effort starting tomorrow with the season been a tad dry. I have thought through the 2nd wick option ... to have slightly large holes (than current) drilled into the top of the pipes and geo-fabric lined pockets which are affixed to the outer part of the pipe, have an opening, and extend to the inside base of the pipe (pocket sealed at the base). This could be used instead of the micro-fibre wick. The pockets (which become the wick) would simply be filled with the surrounding soil or sand. Water should then wick up and through the soil from the pocket wick. Update April 2016. I did not go with this option.
Update 14th March 2016
The area for a double 2 metre run of WPR was cleared (I chose not to use a plastic sheet at base)
Then I placed some deco at the base (to help me level the WRP)
Then WRP installed (all connections sealed with pressure pipe pvc glue)
Then WRP Covered with soil. This should hold over 22 Litres of water.
Update 16th March 2016
Soil has now covered the pipe. Due to this being the first run, I have used a long vertical pipe for the water
delivery, as this gives more options for the moment. I have included a second vertical observation pipe in the diagonally opposite corner to the delivery pipe.
On a test run, I filled the pipe to horizontal level (90mm). I noticed that by the end of the fill, I had actually put over 30 litres in. This was due to the water wicking out during filling (the new soil is dry and seems quite willing to take the water away). Within 10 minutes, the reservoir was back to half full.
I toped up the reservoir 2 further times over the next half hour and observed that it now took about 20 minutes for the reservoir to drop down to half on the last top up (the slowing down of wicking is due to the moisture level rising in the soil surrounding the pipe.
I topped up one further time, observed the level to be 3/4 full after half an hour post top up and retired for the evening (it was getting too dark). A level check the next morning shows an empty reservoir.
I dug holes above the pipes, and noted the moisture around 10cm from the surface. (originally dry soil and no rain overnight). This is wicking from pipe to wick and from wick to soil, and soil wicking to sounding soil quite well.
I am quite satisfied with the results so far. So onto planting next.
Update 14th of April 2016
The plants have been fed well with 2 applications to date of charlie carp & seasol, and 1 application of volcanic rock dust & Go Go juice on initial planting.
The plants have also been kept well hydrated thanks to the pipe.
Pipe being filled with garden hose in following shots.
14th April 2016
5th May 2016
I'm planning on putting a similar one in starting around 1 Metre from the existing WRP. I would prefer to use a natural material for the wick, and will start to look around for something that can wick well and last several years with little disintegration as the wick plugged holes need to be kept tight.
Update 27 July 2016
The 2nd WRP has been installed, this time a 2 x array, 3 Metres in length.
Due to the 1st WRP wicking out water too fast for my liking, I only made half the number of holes in this version, this time installing the wick by folding the 4 corners of the cloth, inserting the 4 cloth corners while twisting into the hole. I have left the outer part of the wick short. The wick can be further pulled out in the future to allow for a higher wicking rate if required.
Only the front part of the garden in photo is covered by the array, however excess water from the WRP will flow at the base (on hard ground) to the back part of the garden.
Update December 2016
External Reservoir and Float Valve to be connected to the array...
With this cheep device, the pipe array has a true feedback mechanism with the external reservoir, taking away the blindness of a gravity feed or gravity drip feed.
The external reservoir's feed to the pipe is governed by the pipe's level and therefore (via the cloth wicks), governed by the soil's requirement for water. End to end wicking is back. This is very important for true water saving via wicking, as the external reservoir would just keep on sending water regardless of soil moisture (i.e. - too dry, too wet, or just right) if allowed to just feed the pipe array without any feedback.
Over the next few days/weeks, I will acquire the appropriate float valve, and the external reservoir will be installed, and system trailed.