Depends on how you define "cycle" though. It's quite possible to use Roundup on the ground to first kill the weeds, then wait some time for the glyphosate to di

Depends on how you define "cycle" though. It's quite possible to use Roundup on the ground to first kill the weeds, then wait some time for the glyphosate to disintegrate, then plant the crop. Or just use weedkiller on areas outside the planted crop, in order to stop weeds from spreading from outside.