1. Notice of such proceedings shall be given by one publication in a newspaper having a general circulation in each county in which any part of the property sought to be condemned is located. Such publication shall be at least 20 days and not more than 30 days prior to the date set for the hearing on the validity of the proceedings.
2. Such notice shall be in substantially the following form (the blanks being appropriately filled):
3. Notice of such proceedings shall also be given:
(a) By posting a copy of the notice designated in subsection 2 in conspicuous places on the real property sought to be condemned.
(b) By filing a copy thereof in the office of the clerk of the court in which such proceedings are pending.
(c) By filing a copy thereof in the proper office or offices for the filing of lis pendens in each county in which any part of the real property is situated.
4. Such publication, posting and filing shall constitute a legal and sufficient notice to all persons having any interest in or lien upon the property described in the notice. The filing of such notice in the county office shall also be a constructive notice of the proceeding to any person who subsequently acquires any interest in or lien upon the property, and the petitioner shall take all property condemned under this chapter free of the claims of any such person.