They have quite a diversity of crops, and I suspect that they have some idea of crop-rotation.
The years of mowing are arranged in the crop-rotation to provide for as many harvests as promise immediate profit.
Clover-growing, crop-rotation, using animal manures, those are their inventions.
In a crop-rotation containing corn and wheat, the corn-stubble land is left unbroken until May or June, and then plowed.
Here are two systems of crop-rotation as practiced at one or more agricultural experiment stations.