Planting into a clean seed bed is very important.  Keeping it clean is extremely important.  I like 3 residuals and at least that many modes of action in the burn down and pre emerge.  I like to prevent as many from sprouting as possible.  A 2 inch weed is a 6 inch out of control weed in days.

I can't till, my soil is too erodible so I rely on my chemical program heavily.

This has been a primary reason my yields have went up, not flat or down.

Ed Winkle