Ecnerwal wrote:
....
I have TERRIBLE clay - not really soil, you can literally throw pots
with it.

Years ago, I tried "double-digging" it - the whole dig up a row, fill
with compost, put the soil back on top back-breaking toil. In very
short time, no trace that that had ever been done. So, years ago, I
admitted that "fixing" the "soil" was a hopeless task. I now treat it
more-or-less as an urban garden on concrete or a rooftop would - I pile
horse manure (ideally well-composted, some years are more ideal than
others) wherever I want a garden bed, and plant in it. Blueberries are
the sole exception - them, I pile all the pine needles available around.

I have lots of worms. In theory the worms would be making holes (I
suppose they must) and mixing things into the clay (no sign of that
within an inch or two of the compost/clay interface, which is not hard
to find even years later - the stuff is _hopeless_.)

whenever we compare our yields and results
with the people around us who have sandier
soil we always do better. clay might have
some tough aspects, but i would not want to
replace it with sandy loam for all the
gardens -- a few for root veggies, ok.

there are many species of worms, some don't
go down very far. look into finding species
in your area which work more deeply. night
crawlers can go down very deep, but there are
others that work in the 6inch to 2feet range.

also, planting deep rooted perennials and
treating them as if they are being grazed a
few times a season will improve the biological
activity of the soil. i try to keep a few
of these plants in a garden as they can also
act as a host for beneficial bugs for the
times when surrounding plants are not. when
the garden plants are growing then trimming
the alfalfa provides a nice green manure and
keeps it from outgrowing the garden veggies.
gradually moving these plants around (letting
them reseed nearby and then chopping off the
old plant) makes deep root channels for garden
veggies or worms. the deep roots also help
bring up nutrients from below.

digging in fine grained organic materials
will help some, but digging in coarser materials
like wood chips, charcoal and plant stems seems
to do a very good job here. and the area
that i fired to make charcoal last season was
a great improvement. making me wish i had
a lot more wood to burn to turn into charcoal
and the bits of surrounding clay that changed
texture too. very nice material to work with
even when dripping wet it did not stick to the
shovel like the surrounding regular clayey soil
was doing.

the only thing i would wonder about with your
setup is surface water contamination. by using
compost on the surface and not digging it in
much then a heavy rain could mean nutrient
runoff into a ditch, stream, pond, lake, etc.
burying compost at least keeps the nutrients
more local.


songbird