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Impermeable layer: wicking gutter = free mulch and feed for the garden

I should say up front that I spent years messing about with what's called paper clay . That's an eclectic mix of paper pulp and clay 45:55 percent. You can fire it. Make china and sculptural pieces with it. And it will fire stronger than normal clay.
I used it always. I  built puppet heads, masks and  busts out of the stuff.
In my paper gardening habits we're  not talking paper clay-ing but paper gardening.
But for me it's the same sort of material mix. A blend of elements...that respects paper's attributes.
When wet, paper pulps.When dry it hardens. When it rots it becomes 'soil'.

So as I've grown in confidence laying down more stretches of paper trench sponges in my garden I've been thinking that I could adopt some of the methodology of wicking beds.

I'm a bit ambivalent about wicking but the idea that you can lay down  an artificial  permanent reservoir under the soil layer makes a lot of ecological sense.
It's like a seam of buried rock is it not -- upon which the soil perches?
So  in layering another pathway with thick paper today  I added  a water feature: an underground aquifer held in place by a strip of plastic sheeting. 
I laid the plastic out in a 'U' shape: subterranean hardware -- and filled the U with newspaper.
Of course everything over time will pulp up and serve as compost except for the plastic which will continue to function as an impermeable layer which may prevent some of any recently precipitated water from draining away quickly into the sand below.
So my 'wicking gutter' is designed to function as a moisture collector and reservoir for the surrounding mulch and soil. It is supposed to hang onto  water longer than  mulching -- or paper sponging -- alone would.
I dug it one hand spade deep.
Will it be enough environmental manipulation to effect plant health? I don't really know as capillary action does as capillary activity only can do... I can only fiddle with the  context. 
As my plants are not on the path but in the beds -- a distance of some  50-75 cm is involved between any plant and this gutter. Is that distance too far for water to travel by dint of capillary action despite the intervening mulch layer?
Note to self: a drip irrigation system can irrigate up to 1.8 metres each side of hose.I'm not using gravity but water can move through a porous media although wicking action is limited to about 300mm UPWARDS. What about along?
I'm thinking that if the plastic formed gutter stays wet, then the overlaying mulch may at least remain moist so that I'm not losing so much water though the sand. And if the mulch stays moist (if only for longer than otherwise would be the case)...then the plants may get more of the H2O good stuff.
I'm being conservative and have constructed a gutter only 15-20 cm wide and 20-30 cm deep with the plastic in sections so water can still finally drain away after much effort on its part. The price it pays is that it has to soak a lot of that paper as it pulps.
I guess it would be preferable to bury terracotta watering containers but  feed bag plastic and gar bags are items I can recycle and get for free. 
Will it work? Will it work to warrant the extra papering, digging and effort?
I'm interested in deploying this technique for those challenging irrigation areas of my garden where sponge mulching may not be enough. My strips of news paper tubes framing garden beds are the most moist -- moistest -- places I've created. This fact is proven by the penchant for  plants to self seed along these strips because the water access is there. The addition of guttering is a way to keep more water where it can be accessed.

However, trench mulching like this needs depth rather than sheeting out left and right. Every time I inspect the tubes I mulched with months ago the soil is cooler, moister with more biological activity than the surrounding soil.

Without doubt trench mulching is way-to-go gardening on sandy soils and I suspect that real consequence presumes a permanent mulch  depth of at least 5-10 cm. Sheet mulching is a very different process that aspires to alternative but supplementary aims. Whereas plant matter -- leaves, hay, clippings and such -- are the primary source material  for sheet mulching, in my approach trench mulching is overwhelmingly paper dependent.

This  seems to have a lot in common with the  tradition of hugelkultur (in German hugelkultur translates roughly as “mound culture”) which is a gardening and farming technique whereby woody debris (fallen branches and/or logs) are used as a resource and piled into mounds which are then planted out.. Similar results can be achieved, though much more slowly, by simply burying logs and other wood waste in trenches around your yard in areas where you want to improve fertility and moisture control.


The first challenge is of course: get the wood. Burying is easy. You'll note that my habit is becoming more and more to treat rolled up newspaper and junk mail as so many logs I can bury.After all, paper is wood pulp.
  • Read more about my experiments with MULCHING

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Comment by Elaine de Saxe on October 22, 2011 at 14:42
That books looks interesting! Just the comparison graphics of the urban runoff vs urban treed block are worth thinking about.
Comment by Dave Riley on October 22, 2011 at 8:35
Check out the great work by Brad Lancaster: Rainwater Harvesting for Dylands and Beyond. Brilliant.
Comment by Dave Riley on October 22, 2011 at 8:31

No the aquifers aren't the lakes. They feed the lakes but the water sits in sand under the surface of the ...um...sand. They function like a sponge. Of course on Fraser especially -- and the other sand islands too -- creeks simply begin out of the sand like a sponge leaking. I think the complication of using water from below is that it is easily contaminated and you wouldn't want to proceed this way on an industrial scale. Permaculturalists, for example,  oppose pumping up of water as it depletes the water table. But on sand no water stays on the surface after precipitation so there is no practical difference between making  dam and using a spear pump except you don't expose the water ti evaporation. The sand becomes your store house. 

The problem with tanks -- and I have 3,000 litre one -- is that you need to do a water budget and I've found that over a year, even with careful rationing, the dry winter (and August is the driest month in SEQ) you need more than that volume. Of course unless you can keep the precious water near where it is used and drunk you are simply flushing water through the sand.So around here people will hose and hose using their Spear pump water which means that you are recycling more or less the same water over and over again as it soaks through the sand and is repumped to the surface.

I also suspect that in capital outlay installing a Spear pump is cheaper than adding large tanks. So it's going to be the same water that fell from above. It is primarily a question of where do you capture and store it.

The ecology is such that the aquifer layer water is concentrated with local minerals and the chemistry of local sand and soils is complex and in places even toxic.You can see this interplay at our local swamp which is variously a garden of Eden and a fetid chemistry disaster. Of course on the islands more so than here on the mainland the water turns Burgundy red from this mix meshed with the Malaleuca oils. 

I find all this fascinating and it seems to be a neglected ecology in terms of inspiring sustainable gardening and agriculture ways and means. There's more to the imagination that forests. 

Comment by Elaine de Saxe on October 21, 2011 at 22:41
If I understand correctly, the lakes on sand islands only exist because of an impermeable layer of organic matter built up over eons. Pumping it up with a spear is OK but wouldn't the water leach out nutrients and add them to the water table? It looks like a sound solution to keep the water in one place and do what you are doing to keep the water close by the plants and not move the water up and down. Tanks are another option - grab the rain before it leaches out the nutrients in your gardens.
Comment by Dave Riley on October 21, 2011 at 21:24

Look at the Moreton Bay islands -- and other great sand islands -- and the sand dune places like my own: there's plenty of accessible water in underground aquifers.Next year I may go harvest with a spear pump like so many here -- but the logic of having water 'in the bank' buried below ground as soon as it precipitates makes so much good sense. Its stains, of course due to Malaleuca oils and iron oxides but just don't spray the whites. Although accessing the water  means you that still have to keep irrigating... What I was after was laziness -- a means to keep water at close quarters to plants.

 

Comment by Elaine de Saxe on October 21, 2011 at 19:57
Yes, burying water is the best way to keep it where you want it and swales are one such solution. The Hugelkultur thing ties in with some Permaculture idea about having rough mulch under trees. Scarlett explained it somewhere here, it's associated with attracting a wide variety of micro and macro organisms which would not otherwise be a part of the garden. Someone with a Permaculture background can explain it better than I can.
Comment by Dave Riley on October 21, 2011 at 19:31
Well with any material the challenge is getting a regular, dependable supply. Whether it's logs or paper the buried item  is still cellulose. What I've read about hugelkultur is a bit confusing as I'm not certain how burying wood supposedly has different consequences from mounding up the stuff and covering it with soil.If you are going to have snow on the ground and maybe freezing soil,(such as in Northern Europe)  then it makes sense to mound. But here....? What we lack is moisture and the best way to protect wetness is, among other options, to bury it. I suspect this may be very true of water per se as it seems better in Australia to 'bury water' in aquifers and artesian basins than expose it to evaporation in dams or along open ditches.
Comment by Elaine de Saxe on October 21, 2011 at 16:11
More fascinating ideas Dave! There's a post or two about Hugelkultur on this forum. A couple of us have experimental mounds, no results as yet though. I've been collecting newspapers too with a view to adapting your method to my raised beds - not on sand but on a slope so drainage is quite fast.

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