That determination Martin comes from Washingtion D.C. from the now retired national agronomist.  Some guy from Georgia.  There is a concerted effort by acedamia to debunk this "ruling" with the rotary harrow's and aerway type of machines as well as other machines like the turbo till that just "scratch" the surface.  It is interesting that MD has somehow gotten around this??  I do know that MD has been one of the states working hard on getting the "rule" changed though so maybe they were granted some sort of pilot project?

On topic, with P becoming such a big player in regulations now (at least in PA), I would encourage all who want to use poultry manure to look at P balancing more than N.  If you spread poultry for N needs you will get P out of whack real quick.  Look at the poultry litter as your P source primarily and N source secondary.