RE: Crop Rotation
Good question Rob, there' s lots of good answers, you' ve already got several.
I' ll tell you what I do, though I' m still experimenting with different rotations.
First, I always want to plant corn following clover (or alfalfa if your ph is good enough). This is because of the N content availible the first 2 years of corn. Then If the site is good, I' ll keep corn there 2 more years. In the last 2 years I will have to add more Nitrogen - but its worth it. The corn needs to be sprayed or at least cultivated well until its knee high, this will get rid of any sod build up - after 4 years of corn, a feild is a PLEASURE to prepare again for clover, with little or no sod (grasses) to bust up, and few weeds to contend with. I cultivate rather than spray my corn.
As far as other rotations go - Buckwheat (spring planting) & Rye(fall planting) are often good 1st time plots on plowed sod soils, the roots are extensive, and help break up sod and loosen up the soil for the next year' s clover or legume plot.
We are going to play with two acres of soybeans (follows corn) this year - I' ll probably post on the results. We plan to row plant it in the corn planter, and cultivate like the corn. At last cultivation in August, we will broadcast Rye/clover as a cover crop, and fall food source. Hopefully it will take hold well enough to become a clover plot the next year. At least thats the plan right now
Fall plantings in the North should always be winter hardy ( clover/ rye, rye, clover/winter wheat, etc.) No sense planting soybeans, cowpeas, buckwheat or any other frost intolerant plants in the fall.