For all you gardeners you should read about Viktor Schauberger he came up with theories on how to grow food without dumping nitrogen fertilizers, also using copper plated implements for digging and plowing created something nicknamed the golden plow which massively increased output of farms and they did a series of scientific studies in 1948 about different farming and his farms using his methods and the copper plow particularly grew much higher quality produce and also were much larger like 450g potatoes. Its hard to explain all in a small post and its been a while since i read it all. Living Energies

Link to the book, in the chapter AGRICULTURE AND SOIL FERTILITY explains things better than i can.

I don't grow much now as my health is bad but used to like to grow a few things which always tasted better than store bought stuff, have a couple of apple trees and grew potatoes and strawberries, brussel sprouts etc. Found Victors work really interesting but never been able to try the things out but would love to see someone else make use of the information.