Went on a bit of a cover crop tour yesterday near Homer, Illinois. Some of our grower-users are the best cover crop folks around. One of their friends planted this in radish and rye grass.
What's amazing, though, is that it had rained almost 6 inches in the past 5 days - you can see the flooded (non-cover crop field in the background). This field, while saturated, had unbelievable internal drainage.