With many farmers in Iowa and other states eager to try growing industrial hemp, the Iowa Department of Agriculture and Land Stewardship (IDALS) and other organizations last week urged the U.S. Department of Agriculture (USDA) to revise its proposed rules to make growing the crop more practical and predictable.

“There are some uncertainties and inconsistencies in the federal regulatory framework, and those issues need to be addressed,” said Iowa Agriculture Secretary Mike Naig....