3 Pa.C.S. § 6809

For the purpose of determining the commercial value to be applied under section 6808 (relating to plant nutrient deficiency), the department shall determine and publish annually a notice transmitted to the Legislative Reference Bureau for publication in the Pennsylvania Bulletin stating the values per pound of total nitrogen, available phosphate and soluble potash in fertilizers in this Commonwealth. The values published in the Pennsylvania Bulletin shall take effect July 1 of each year and be used in determining and assessing penalty payments.