Every tractor, combine, swather, sprayer, whatever ya got is T4B to T4F in NAFTA - same as a Class 8 tractor and diesel pickups, etc. It's been that way for a while. That regulates particulates to a certain size and NOx to a very low level. Stage 5 in the EU is lower and I was reading up on Stage 6 and it's easy to see what the end goal is. The papers state that new technology will just come out of a unicorn's butt to meet the regs.
I stand by what I stated earlier - what's going to power big Ag equipment when they mandate zero emissions? A Quadtrac holds 450 gallons of diesel - that's over 18000 kWh. At .254kWh/kg, 71,000kg for that battery pack for a 620hp tractor that grosses out at 28,000kg when fully ballasted. I ain't seen a battery pack or big enough hydrogen tank to replace that yet.