Article 4169.07 of the Standard Specifications specifies the requirements for straw mulch.
Acceptance of straw mulch for Iowa Department of Transportation projects will be based on certification documentation showing mulch is certified Noxious Weed Seed Free from the Iowa Crop Improvement Association or other state’s Crop Improvement Association (or equivalent association/agency).
Certification documentation is based on the type of documentation issued by the specific state Crop Improvement Association.
The Iowa Crop Improvement Association certification documentation is either a Transit Certificate (starting in 2025) or a certification label.
Each Transit Certificate or certification label issued by the Iowa Crop Improvement Association has a unique number. Contractor shall not submit a Transit Certificate that represents more than the number of bales shown on the certificate. Contractor shall also not submit the same certification label(s) more than once.