I sewed K31 on my 7.5 acres I had mulched years back. The mulch head not only mulched, but kind of tilled that top layer too, so it actually went very well.
I took my Rokon and hooked a 4' chain harrow to it and drug it all and got a lot of excess sticks/limbs picked up and kind of smoothed it all out. I then used a broadcast sack spreader and walked the whole area. IIRC, I put down about 400 or 450 lbs of K31. I then flipped the chain harrows over and drug it all again to kind of embed the seed.
This worked very well. Had beautiful grass come up on whole property.
What didn't work well: eventually everything else came back up too. Weeds, briars, vines, blackberries, saplings out of the remainder of the stumps, poison ivy - everything.
If I had had the equipment at the time, I would have 24D'd it or the like and been able to keep under control through normal bush-hogging or mowing of any sort.
I did not have the equipment, so didn't and frankly mowed the easiest areas to mow with my lawn tractor every so often over the course of about 3-4 years until I bought my first tractor. The other areas got out of hand and went right back to wild in the following years since then. I only kept about half of it in mowable shape and now literally mow those areas with my belly mower on my BX-2370.
I do plan to get it back under control now that I have the equipment and have recovered some sections since I finally bought the first tractor a few years ago. Mainly it will take time and concentrated effort from here on to get back to where I wanted it to be originally. Primarily once I get stuff reclaimed to a decent degree, I will need to spray for weeds and stuff to get back to grass or even pastureland. The biggest thing that I'm struggling with is the privet. That crap is everywhere that I wasn't able to stay on top of and it is out of hand.
My advice, get this work done, sew your grass, then stay on top of it from day one.
The only other thing is that stumps are decaying and now I find the occasional whole and have to fill with dirt. Also, I have found and know exactly where they are, the stumps that didn't get mulched to ground level, but left a couple inches high or unevenly cut.
Good luck.
