In the past we have plowed the ground, disc it to a nice seed bed, spread our lime then disc the lime in and then seed. This has worked well for us without using anything to kill current weeds and grasses.

However, our approach going forward is 1) wait for weeds and grasses to green-up then spray round-up to kill everything. Wait 2-3 weeks and then disc for planting. I am not aware of anything that you can disc in to help with weed control although it could be out there. Keep in mind that I think that any time you disc whether you have sprayed or not you are moving weed and grass seeds around and to the top of the soil that may eventually grow. Hope things go well for you. I am in WV and we are just getting ready to begin our process this weekend. We never plant until the second week of May because of frost. I would suspect in NY you are behind us a some as far as green-up but my place is located in the highest mtns. in our state. Good Luck