Byron Forest Preserve does a lot of work on controlling yellow and white sweet clover on their remnants and in hundreds of acres of prairie restorations. Russell Brunner and Austin Webb of BFP liked their Italian made Enorossi sickle bar mower such that they bought a second one this year so both can mow sweet clover patches.
For successful mowing of sweet clover you wait until the clover is well into its bloom, but before it has made any seed. You want to mow the clover very close to the ground, below any leaves that are green on the stem. This is impossible in areas with stumps and rocks, but works fine in our silt loam prairies.
Your typical rotary mower that is pulled behind a tractor often means the tractor tires run over a lot of the clover, and the mower can’t cut this laid down clover as the blades won’t go that low. This leaves the operator reversing over clover patches and/or repeated mowing a patch to try to cut the clover.
These sickle bar mowers cut to the side of the tractor and mowing a patch of clover is quite easy. The sickle bar can be raised from the tractor, where you drive to a patch, lower the sickle, cut, and raise the bar and drive to the next patch. This means you are disturbing the least amount of prairie to get the patch of weeds cut. If the sickle bar hits a stump or an ant mound the bar pivots out of the way, and you can reverse a bit and the bar snaps back into place.
Sickle bar mowers are old technology. They are made for hay cutting. Sweet clover is a hay. If you use the mower for its intended use it will be a reliable tool.
You have to see this in action. Here is a 30 second video showing Austin running the mower: https://youtu.be/kA2A1XSxrA8