Walt,
The big AG's at the CBOT is what I'm referring to. That's where the money is.
Look at today's activity in the big three: Corn, Wheat and Soybeans. 10 cent move down, then back up. Same tick value as the ES ($12.50/tick). Margins are comparable too.
Need I say more? Here's a couple of CBOT seminars to whet your appetite:
CBOT - Why Stock Index Futures Traders Will Love Trading Corn, Wheat & Soybeans
CBOT - Trading the Grains: Tools for Spotting Profit Opportunities
The .pdfs attached on those pages should also provide additional insight for you.