All of the major farm equipment makers have now publicly declared how they’ll meet the interim Tier IV diesel engine off-road air emissions standards that take effect next January. And the things that are certain are:

• Farmers will have a choice between two distinct diesel engine technologies.
• Whichever high-horsepower tractor a farmer chooses, it’s going to be significantly more expensive. 

These two factors along with growing uncertainty about farm commodity prices in the coming year…