hey there, i've been doing some research and i thought it might be of some interest. it's to do with the kind of metal you use for garden digging implements. iron is highly magnetic with low electrical conductivity. this causes it to cut and disturb magnetic lines of force in the soil which are beneficial to soil organisms and other processes which probably still go unrecognised. whereas copper, brass, bronze (and gold, silver, platinum etc) have low magnetism and high electrical conductivity. these metals will increase the magnetic field through the process of magnetic induction. you can liken it to 1. iron cutting through the soil would be similar to passing a magnet in front of your tv screen. 2. copper cutting through the soil would be similar to the action of the copper coil in an electrical alternator. 1 is detrimental, 2 actually generates electricity. this technique of using copper digging implements has already been researched on a small scale with very good results. and i found a website in the U.K selling some awesome tools. https://www.implementations.co.*uk Victor Schauberger can take credit for these ideas. it's not me. I've just been reading and thinking about alot of his idea's this also relates to ideas in electroculture etc. there's alot more to it, but i'm trying to keep it simple for people who aren't electrical engineers. definately worth looking into. it shouldn't actually cost too much to get existing tools electroplated with copper. I've even found studies stating that soil magnetism can be directly related to levels of pollution.