This is a badge bit (BB) that is part of the PEP curriculum. Completing this BB is part of getting the sand badge in Gardening.
Chop and Drop is a method that stacks several functions. It cuts out growth that you either don't want or was intended to be cut. It mulches areas with that growth to smother undesirables. It transfers nutrients from the chopped plants to the desirable plants being mulched.
Usually, 3 square feet of area would be chopped to fully smother-mulch 1 square foot.