Need to do the P&K balance sheet, work out how much P&K is removed in baled straw and compare its value to bought-in replacement fertiliser.
I'll stop there, been lambasted by straw merchants too often in the past.
Forgive my OAP's cynicism, but a weed that has the potential to make arable farming unsustainable can be (partially) controlled by a chemical that has the potential to make arable farming unsustainable.
From my occasionally involvement with chalk farmers I know there has been more than one who decided that, since soil comes from erosion of the bedrock, ploughing up the chalk would eventually make more soil.
I expect they're still waiting.