>>2107797>Legumes growing produce will not add nitrogen to your soil until you kill and bury them.This isn't true. I've planted a row of kale where peas had been before and another row 1m beside that and the pea row grew much better. It has to do with bacteria that the legumes feed that make nitrogen more bioavailable.
Cut them off at the base and leave the roots in the soil (you should do this with most plants you pull out)