On Apr 10, 12:31*pm, songbird wrote:
Higgs Boson wrote:

...

I regularly renew the ground cover bark compost in my decorative plant
beds -- and even around the base of the new fruit trees -- partly for
water conservation, but mostly for appearance.

I have heard, *as you suggest, that the act of decomposing removes
nutrients, but have not looked deeply into the concept. *Have there
been any reliable studies that quantify this effect? *And as a
corollary, suggest how much more nutrients have to be added?

* there is a large difference between bark on the
surface used as a mulch and bark that is dug in and
is being used as a soil amendment. *the first breaks
down slowly enough and should not have much impact
upon soil fertility in the short term. *longer term
it will gradually add nutrients along with the rain.
the latter will at first deplete nitrogen as it is
decomposing, but then will release the nitrogen back
to the soil. *to help that along the first season i
plant legumes.

* so when using as a mulch adding nitrogen would
defeat the purpose of using it as a decorative cover
and moisture barrier.

* songbird

sigh of relief Now I can sleep o'nights. Tx, 'bird!

HB