Thanks, we plow because in side by side trials which we conducted the plowing always yielded at least 10 bu. more than a disk ripper.  The nitrogen also gets tied up in you stocks if you don't turn it over.  Another reason is that with a plow you can come in hours behind the combine and do an excellent job.

One pass is smooth enough to plant into if we already had our N put on (I think collegeboy does it one pass, correct me if I'm wrong???)  But since there is voids and cracks in the plowed ground we have to make a quick pass over it to apply 32% and chemicals, if the chemical is buried too deep it will do no good. 

We actually have considered buying a big harrow and going over the ground in the fall with that which would make it one pass in the spring.

We do not run crumblers, just three-bar coil tine harrows.