US Department of Agriculture (USDA)
The USDA uses Grants.gov as a submission portal for most proposal submissions. They have their own specific USDA Grants.gov Submission Guide, which you must adhere to when submitting a USDA grant through Grants.gov. Unfortunately, a lot of the application requirements are only found in this guide, not in the solicitation itself. Failure to include all documents requested in the Submission Guide may lead to your proposal being returned without review.
The USDA is also starting to use ezFedGrants as a portal for submissions, as well as for post award management. Like the eRA Commons, it does interface with Grants.gov for proposal management and tracking.