Agricultural commodities ETFs for my IRA and stock portfolio

In am also long the following two ETFs (Exchange Traded Funds) in my IRA account: MOO and DBA. I am also watching JJA & JJG, but want to see a longer history before buying.

One important factor to consider in selecting an agriculture ETF is whether the ETF tracks the commodities themselves or businesses that grow them. I have noticed that ETFs that track the commodities tend to follow the underlying commodity trend better. The business-based ones tend to show greater sympathy to the stock markets and related indexes. However, the commodities ETFs that track the futures have different tax consequences, especially due to the contango phenomenon in futures. I always do plenty of research into these considerations before deciding which ones to buy.

NEWS:
Also have you heard about Jim Roger's new agriculture ETF (symbol: RJA)? RJA is a much broader-based agriculture ETF, but who better to manage an ETF based upon commodity futures than the master commodities uber-bull, Jim Rogers? His ETF is really taking off and growing very rapidly. I believe his ETFs will be some of the best-performing, without doubt. In fact, his all-commodities ETF (symbol:RJI) is significantly outperforming any other broad-based commodity ETF this year! Jim knows his commodities better than anyone! RJI is the broadest-based commodity ETF of them all, and the results are astounding.