Hi Heather, I build machines, and I also grow veggies.
If you visit my link for equipment I have built, you’ll see my methods of cover cropping up till now.
Equipment built by Eric
I realize what you are aiming for, and I have not seen anything on the market that would do what you want. I am aiming to build that this winter.
I use the Yang seeders on a drawbar pulled by a tractor, but the ground has been previously loosened by at least strip tilling with a 10 inch wide roto tiller. What I have in mind is to build a three row pto roto-tiller, where the tiller is an inch or two wide to chew up the ground just ahead of the Yang seeder. And that should work. Stay tuned, I’ll be posting pics as I get along, or let me know any ideas you might have.