Here is a good example of that:
This bed has produced around 35 kohlrabi so far but as I harvested the last one last week it was time to get it producing again.
I pulled up the plastic, scattered some blood, fish and bone powder, a bit more compost and raked it over.
Then I got my Earthway seeder out and drilled five rows of carrots (two times on each row to make it nice and thick) over the 30 inch bed. That's another 50ft of carrots to harvest in a few months time.
Hopefully the plastic will have killed off lots of the weed seed that was near the surface and because I haven't turned the soil it should have brought any more to the surface. There will be weed pressure but it should be minimal now and by the time the crop grows it, planted close together like this it should form a canopy to keep other weeds suppressed.
I should say that I also heavily watered this bed before I planted the carrots as it had been weeks without rain and the surface was very dry.