A lot of the manure in NC  is put on hay ground.    I know someone in NC  with 3 lagoons.  Their lagoons are inspected  multiple times a year  by:  Smithfield and  the NC  agency,(I think  Enviromental Dept).   They have to send in manure samples,  soil samples  and lengthy  manure application  records are kept.    I don't  doubt it would stink at times  to have it sprayed into the air.   Also,  there are rules for dead disposals too.    Most have compositing facilities for deads.    Buzzards,  Eagles and coyotes  know where they are.