I have planted "quick plots" before where I went in with a trimmer and cut down the grass and weeds, then spray weed killer, then spread 10-10-10 fertilizer, then disc everything in to have very fluffy dirt, then spread my brassica seed. I would do this 60 days before season starts and the weed killer got rid of the weeds but didn't kill the brassica seed. I like to over seed plots. The brassica bulbs don't get as big, but the brassica chokes out any weed seed left in the dirt leaving the brassica as the dominant plant. Also for my clover plots twice a summer I cut them to stimulate young growth that the deer really like to eat. I don't cut it low rather just take the old tops off. I hope this helps you.
Good luck!
Whitetail Strategies Guide Service
Fred Scott