In article
C153A08F69A5F7A7.BCC8A509612B0CB1.0C641A4AE6055B1 ,
(Babberney) wrote:

I often tell people the best thing they can do for their trees is
improve their soil. My suggestion for the most low-tech, low-cost
approach is to mulch the root zone. I sometimes tell them to add
worms for even more benefit.

My question: would it be a mistake to suggest buying a box of worms
at the bait shop? Recent posts I saw somewhere mentioned that there
are different types of worms that all look about the same, but some
would be suited to a compost pile and some wouldn't. Makes me wonder
if fish-bait worms would be able to plow through our soil and help
carry the mulch downward like I thought.

Thanks,
Keith

I have benefited greatly from some of your posts (uncovered through google
searches on trees in general) so I will try and return the favor. I did a
search through AGRICOLA for earthworms and hit about 751 records. There
is very little published work on earthworm introduction in isolation. In
general the published data sometimes supports benefits of introduction of
earthworms and sometimes does not. The interactions are quite complex
(benefits/negative effects are very species specific both with respect to
the earthworm and the plant under study). UT austin is not an AG school
so much of this literature is not on campus and we do not have online
subscriptions to most of the AG journals.

Web information that makes the same points as the published data is
outlined below.

I do not know what worms they sell as fish bait if it is Lumbricus
terrestris it is probably fine but there are some documented dangers of
introduction of ³foreign earthworms²
http://news.nationalgeographic.com/n...arthworms.html
and here
http://www.stolaf.edu/depts/biology/...le2001202.html

An Extensive study on two forests illustrates how simply difference in the
management history shows significant differences in the changes that
earthworms bring about:
http://www.ecostudies.org/research/r.../grofrep2.html

For more general info:


Nice simple definitions of technical earthworm type (epigeic ,endogeic
etc) , profiles of several californian worms and their effect can be found
he
http://www.sarep.ucdavis.edu/worms/

these two sites answer several general questions, species count, effect of
various crop management techniques (fertilization, tillage etc) on
earthworm count

http://www.crop.cri.nz/curresea/soil/worms.htm
http://res2.agr.gc.ca/london/faq/earth-terre_e.htm


Since you are an arborist your general points for a lay client for the
beneficial effects (if you still beleive they are only beneficial) is
found he

http://danr.ucop.edu/ihrmp/oak99.htm

also the following sites support beneficial effect of earthworms.
http://www.biodiversity.csiro.au/2nd...earthworms.htm
http://www.msue.msu.edu/msue/imp/modtt/modtte.html
http://fadr.msu.ru/rodale/agsieve/txt/vol7/art4.html
http://fadr.msu.ru/rodale/agsieve/txt/vol7/art5.html

So even though it is generally dogma in organic circles that earthworms do
only good it is clear that sometimes they can do harm or may be of no
benefit at all. Taken together it is clear that there is no one answer
wrt to earthworm introduction that is universally true for all plant
species.

Roland