Folks:

1.) Be aware that the starting chemistry of the soil i questions and the
starting chemistry of sawdust both play a role in answering the original
post.
2.) C:N ratio is critical but can be misleading. For example, the C:N ratio
may be the same for raw sawdust added to soil and for highly composted
sawdust added to soil. One critical difference is with the latter a lot of
the C (carbon) will be accounted for in humic acids which are chemically
recalcitrant and do not really figure into the resources needed by soil
microbes. In raw sawdust most of the C is accounted for in long-chain
carbohydrates which are convertible.
3.) The use of sawdust to amended pH in blueberries is well established, but
bear in mind that blueberries are commercially grown only in certain soil
types. Thus, examples from that use may not extrapolate well to other (e.g.
more alkaline) soils
4.) Depending on the sawdust, one may actually make the soil more alkaline.

--
Mike LaMana, MS
Heartwood Consulting Services, LLC
Toms River, NJ
www.HeartwoodConsulting.net



"Phisherman" wrote in message
...
On Tue, 27 Apr 2004 20:11:43 -0400, "Fito"
wrote:


"Phisherman" wrote in message
.. .
On Tue, 27 Apr 2004 18:30:07 -0400, "kyrustic"
wrote:

I have access to tons of very old saw dust. Would it be ok to work
this
into
my garden? What uses would it have


Yes. If the sawdust was left outside for a year, then it can be
worked into the soil without concern about robbing nitrogen. It makes
a good mulch for tender shallow rooted plants such as blueberries and
azaleas.

Phish, rather than disagree with you, let me ask a question as I am not
sure
of the answer. Does the sawdust lose it "Nitrogen stealing" ability as
time
goes by (meaning, is the C:N ration no longer 500:1)? Even after a year,
if
it did get weaker, wouldnt it still be high in carbon? Still too high to
be
placed in soil?

My initial response would have been to use it as a water retaining mulch.

Thanks in advance,
Fito


I can't provide a scientific answer to this, but here's what I know
first hand. I applied some sawdust (aged 2 months) to a blueberry
bush as a mulch, and it weakened the plant with loss of green color.
(Later, I revived the plant using MirAcid fertilizer.) The following
year, I reapplied sawdust which was aged for 14 months and this had no
adverse effects when used as a mulch. My assumption is that sawdust
aged enough declines in its nitrogen robbing properties. I am a
woodworker, so I have a lot of available "time-laddered" heaps that
are decomposing for use with blueberry and azalea bushes. The sawdust
is also good to use in muddy areas, horse stables, walking trails and
under decks. If new sawdust is mixed with grass clippings in a 50:50
mix, it makes an ideal start for a compost heap.