I read a paper from Oregon State on hop fertilizer research and application. I've also had discussions regarding phosphorus additions during "flowering" and it seems from what I understand, Nitrogen needs of the plant are ginormous, phosphorus not so much. A dose of bone meal to the soil at the first signs of burs seems to be adequate. Potassium given in moderate levels throughout the season from a balanced schedule will suffice.
IMHO, Hops grow like weeds. Most people use prepared soil and a basic feeding schedule for fertilizer, as long as they don't get over watered, or contract a virus, the plant will acclimate and thrive.