Here is a link to an interesting press release from John Deere. They are going to use biodiesel.
http://www.deere.com/en_US/newsroom/2005/releases/farmersandranchers/050201_biodiesel.html

Yeah I just read that in one of the farm magazines we get. Good for them but b2 isn't that much. Probably more for the PR than anything right now.

It is suprising what a 1 to 2 % mixture of biodiesel will do for lubrication, injector cleanliness, and over all engine smoothness. Not to mention the public relations.

I bet part of why they are doing it is the new 20 series tractors are using high pressure common rail injection and they have had a few injector problems with them.