LAW - The law that established soil science registration is in Indiana Code (ic) 25-31.5:
http://www.in.gov/legislative/ic/code/title25/ar31.5/ (source: in.gov)
RULE - The rule that spells out the details of carrying out the law is 307 IAC:
http://www.in.gov/legislative/iac/T03070/A00010.PDF (source: in.gov)
Proposed Rule (Readoption of 307 IAC 1):
http://iac.iga.in.gov/iac/irtoc.htm?lsayear=21&lsadoc=234&view=list&ldn=Y (source: iac.iga.in.gov)