It is. But there's also the "how large is the rotation?"

There's the typical cash crop rotation: corn to soy. This has the advantage of cash crop and cash crop. These are both well known and the differences in weather over the course of a growing season are minimized - if its a drought year, you've got the appropriate hybrid. If its a wet year, you've got the appropriate hybrid. Very predictable.

Adding wheat into the rotation helps. http://www.cornandsoybeandigest.com/make-wheat-work http://www.agriculture.com/crops/wheat/adding-wheat-to-cnsoy... - but then this also means different equipment to harvest and a different market.

When one goes to the idealistic organic the cycle could be: corn, beans, reddish, onion, melon, sunflower, broccoli, carrots, tomatoes. Rather extreme, but an example. Also note that onions and garlic can be mixed, as can peans and beans... but that is the idea.

This works nicely for the home garden plots but when trying to rotate with hundreds of acres of fields its a bit more challenging. Instead of two or three means of harvest its nine different types of plants - tomato harvest is completely unlike corn harvest. Furthermore, it means that the farmer is a bit more at the mercy of the weather (great year for corn, but you've planted radishes because you just had corn two years ago and would need some pesticides or go to a GMO variety of corn... and that's not organic anymore) and the markets (there's no demand for the things that are in the next three seasons in the harvest - do you skip forward four?).