Preparing fields for winter

I have prairie hay and bale once a year.  Then I keep knock it down after all the grasses seed.

 

1. I have rows of heavy grass clippings from my bushhogging job.  WIll these rows rot and disappear before next spring or do I need to rake and bale this stuff to get it off the grass underneath?

 

2.  Once I take care of task 1 above, how short do you cut the field for winter, or do you cut it at all??

 

Thanks

Preparing fields for winter