More specifically, I'm looking for a side mounted dual placement 1.5" dry/anhydrous ammonia knife like a mini mole with a carbide tip.  
Lange makes what I am looking for, but not side mount, only chisel plow style:  http://www.langesupply.com/Fertilizer-Cultivator-Knives.html
Weise knives on page 3, but I want carbide inserts on the tip:  http://www.wieseindustries.com/documents/reference/June2013_Knife_Catalog_8AF088E81B240.pdf