My phosphorus is really high as well, and I asked about how to lower it, and all I got was leave it high, eventually rain and crops will slowly make it drop. Also don’t add anymore, so no more 10-10-10 or like fertilizers. You could also plant stuff that uses up high amounts of P&K but unless it is really holding your desired plants back, I don’t see much of a reason to plant something you don’t want, just to fix high numbers.