THIS THREAD? "Re: Drive-in style bucket forks"
I believe I have more experience with a Bucket Spade than any other current T-B-N contributor.
1) Most Bucket Spades will excavate a hole 3' diameter x 3' deep directly mounted on the FEL bucket.
With Bucket Solutions (brand) Bucket Spade it is not difficult to dig 4' deep but hole diameter may be the width of your bucket.
2) No Bucket Spade on a tractor is going to move tree with an 8" trunk nor grape vines.
(I spent my working years in the California wine business, working for wineries which owned substantial vineyards.)
To move >3" trees an SSQA Tree Spade mounted on a Skid Steer or 6,000 pound bare weight tractor with an FEL is necessary. You cannot transplant established grape vines, they will die.
3) A Bucket Spade mounted on Pallet Forks over 30" has too much leverage, proportional to fork length, working against limited compact tractor hydraulic power, especially relative to spade support strength of a light FEL bucket.
Most, not all, Bucket Spades are designed for direct FEL bucket mounting on tractors and potential Pallet Fork mounting ON SKID STEERS.
PHOTO: BS/BS Pallet Fork sockets.