Yes he does and that is interesting stuff, plants need the cal/mag at the end but they could probably pull a lot of it from their own stores, and too much cal/mag will block the P&K that the plants need at the end, but they also need the cal/mag to move the P&K. I am going to guess its all about balance and Mother Nature is a cruel evil woman. 

Can we replace Mother Nature with Henry Ford? I understand how his stuff works.