Manfred, The copper issue seems to me one where analysis of the soil is needed.
Here is a site which has a pretty full set of data: http://www.ene.gov.on.ca/envision/sudbury/ccme_canadian/ Because of the use of copper based fungicides in, especially, orchards, there may be some soils with excessive copper in which the use of copper tools would be ill advised. Swine manures frequently contain copper in amounts and forms that are deleterious to earthworms, and soils which are regularly and heavily treated with such manures would probably not benefit from the use of copper tools. OTOH, copper is often low in soils, and in such soils the use of copper tools may add enough copper to make a positive difference. Looking over the tools in question I noted that they were intended for soils *already* under cultivation, not as primary tillage tools. I wonder if there are sources for the sort of strong alloy tools Steve Storch is talking about. I would still likely want to treat a low copper situation with a naturally rich copper source, matrixed in compost/vermicompost, in relatively precise amounts. Copper tools may have virtues beyond the application of copper to the soil, but I would hesitate to use them unless I knew the soil really needed copper. Frank Teuton lks : I checked with Lee Valley Tools, and apparently they don't carry the copper-button Hoe anymore. I've requested info on their old stock. I remember it more as a large copper rivet.... whose sloughing-off would be much less imposing than sprinkling around filings of copper, methinks. I did not purchase one at the time because i could not reconcile Frank's similar concern with any copper in the ground without a basis in existing presence , ....and the voluminous amount --suggested by Schauberger-via -Steve --thru the use of several plowshares at a time. Frank, Steve, : does it repulse worms/microlife, or over-ridingly benefit in water-retention properties? Should we be that concerned ....as Schauberger seemed to be? The proportion of copper in bronze is obviously less than a "pure" copper contact. Incidentally, Lee Valley also sold longish copper strips -1-inch wide for slugs in the garden for its electro/chemical reaction. .......manfred