As a patent attorney in an area heavily involved in agriculture, I do a lot of work with agricultural machinery. The World Ag Expo in Tulare, CA is a great way to keep up with advancements in agriculture, from machinery to biotechnology to computer software systems.
This year's show is February 14th through 16th at the International Agri-Center. A full schedule of events can be found here. If you've never been to the show, it is well worth the trip.