Sepp Holzer is one of my favorite permaculturists. In his recent book, Desert or Paradise on two pages Sepp recommends the Fokin hoe (Russian flat-cutter or ploskorez Fokina). Vladimir Fokin is the name of the inventor of this tool. It does not look like much, but the great Sepp Holzer says it saves him loads of time, please watch this video:
For details and to place an order click on the link: https://ecominded.net/heirloom-seeds/garden-tools.html