wiki

For deep digging there's the broad fork, also called a grelinette. I don't use the broadfork often - only when I really need to break up compacted soil. I stand on the base of the broad fork and jump on it until the forks have penetrated a suitable distance into the soil. Then I move the handles forward and back to open up the soil. This also works for breaking up rhizomatous weeds and exposing the rhizomes, followed by careful picking out the rhizomes.

I use my broadfork (grelinette) from Red Pig Garden Tools for loosening compacted soil. The name Red Pig Garden Tools is a registered trademark of R.Z and R.K. Denman, Boring, Oregon 97009.