liquidsquid,

There are some cheaper attachments that will help you "grub" out your trees, rather than cutting them.

One is an inexpensive clamp-on called a ratchet rake. (Typically $300-$400 for smaller tractors.)

https://www.youtube.com/watch?v=6F-RSXtW60s

They work better than just your FEL bucket edge. Beware, if you are grubbing trees that are too big, you can damage your loader arms! (Likewise, for old stumps or rocks in the ground.)

If you can't justify buying the grapple bucket versus your remaining trees to be cleared, there is another option. Go to a big equipment rental place and rent their skidsteer with a grapple bucket.

In my area, it is only $185/day for the 61HP Bobcat, and $235/day for the 66HP Bobcat. They add $90/day for the grapple rake. The rake style grapple will allow you to shake the dirt off of the trees. The dirt stays where you want it, and there is less dirt in your burn pile.

You will also not believe how much more power at the ground edge a 66HP skidsteer delivers compared to your 40HP(?) tractor. You will get the work done much faster, and will probably save more wear & tear value on your tractor than you pay for the rental.