Topic: Digging in leaves

[ptennisnet]

Packaging waste directive from a few years back stipulated that all packaging (and this generally applied to the inks) was to contain less than 5 parts per million mercury, lead, hexavalent chromium and something else that has slipped my mind - cadmium I think.  Anyhow, they used to use heavy metals (particularly chromium in yellows) but now they don't.  I assume (dangerous I know!) that something similar has happened with newspaper inks...

[Sarah-b]

OK - so probably don't have to worry about the odd bit of colour on the newspaper.
Windy - Had a look at that guys steaming heaps - nice!!

Hugh - this "upward migration" of stones is something I've been wondering about. Why does it happen. Is it like when you rub butter into flour to make pastry and then shake the bowl to see if you've got any big lumps? - except on a whole-world scale?

[Hugh_Jones]

Basically the effect is the same, although the actual principle is somewhat different.  The way it works is this - where you have undisturbed or packed soil and stone mixture nothing happens (or more correctly it happens so slowly as to be imperceptible).  However, if the soil surface is loosened to allow greater water penetration this allows the `fines` (smaller particles) to work down between the larger ones. In fact the stones don`t rise, but the soil above them sinks down below them.  The same principle also results in the stones at the bottom gradually being loosened from their moorings, so the process becomes continuous.  Growing plants in the soil will simply increase the so called upward migration as the plants roots also contribute to the loosening of the stones at the bottom.   Providing a layer of leaves, newspaper etc simply reduces this action and so impedes the upward migration.

The same principle applies whenever you get a soil containing particles of such disparate sizes that they cannot easily conjoin into a crumb structure.  In any ordinary loam soil the particles are all able to stick together (with some encouragement) to form crumbs, but if you add clay to a coarse sand/gravel soil the clay will slowly but surely sink down into the subsoil, leaving you with the same poor stuff on top.  If you have such poor sandy/stoney soil, simply tipping good soil on top is only a short term solution - eventually the good soil will disappear out of sight and the poor stuff will be back on top.  The only answer is lots and lots of humus to increase the colloidal properties of the soil and encourage the formation of crumbs.

[windygale]

Hi Sarah, i've just read some of the texts and i dont think you should worry to much. If the paper & cardboards are shredded first and then composted with any organic materials for three years it breaks down, so use in your garden,
Stones-- there are a couple ways to fix the problems
1/ raise your growing beds, bring in new top soil-double dig your ground and add wheel barrows loads of well rotted compost and place some charcoal on the ground before digging each year and in time the poisons of any amount will be take up by the charcoal (like a water filter does).
2/ when double digging your ground sieve each spade full of soil to take out the large stones ( some experts say that small stones are good for the soil to stop water evaperation and the soil from blowing away)
Dont forget a garden is a place to enjoy and relax in and not worry over
later
windy

[aquilegia]

Hugh - so that's why my soil looks so much more stoney after it's rain - all the soil covering them must get washed down/away.

I've found that worms are rather keen on newspaper. When I dig through/turn my compost heap, I always find loads of worms in the newspaper clumps (which seem to take ages to break down). I suppose it's because it's so wet.

[Hugh_Jones]

Yes, Aquilegia, that`s why the stones always appear immediately after rain, and when you consider that the same process is occurring right down to the subsoil, then you will realise that you have a never-ending process of stones coming up to the top unless you provide some sort of barrier.

And yes, worms do love damp newspaper.  When I first started making compost 60 odd years ago I was told to put a layer of torn up newspapers at the bottom to attract worms to the heap (we didn`t have bins in those days) - newspaper is popular with both earthworms and brandlings.

[Andy H]

Mmmmm! When metal detecting in woods, the finds are just below the surface and stopped at the clay,just whizzed through the woodland topsoil of natural leaf mould. In sandy areas the coins etc can whizz down deep very fast. Maybe rain doing it or natural vibrations of the earth? Also flood plains are bad news when it comes to digging the holes! Stuff also makes its way down slopes...