I also wonder exactly these same things. I'm not sure how to find out the answers though? I would assume that the emergency reserves would have been expensive

I also wonder exactly these same things. I'm not sure how to find out the answers though? I would assume that the emergency reserves would have been expensive to maintain, with high amounts of spoilage. I'm guessing that someone involved simply said, "Hey, you know, the free market has millions of tons of grain for sale right now. If there was an emergency, we could just buy what we need! Let's sell this pile of spoiling grain and just hang onto the cash! Cash will only increase in value, while grain is a depreciating asset." But what they failed to realize (in my opinion) is that in times of famine (due to things like global warming or whatever), the free market's grain prices will skyrocket, and the grain reserves on the free market will most likely dwindle before we even realize there is an emergency. I would like to see them stockpiling a constantly rotating reserve of grain, with old grain being constantly sold off, and new grain constantly being bought (to limit spoilage waste). If they did that, they could isolate our grain reserves and ensure the army had food to distribute even when times were tough and grain prices were extremely high.