Farm Rents-Government Payments

Did they get a 1099-G? Did they have to apply for this? And, is this considered a Grant (which will have a specific name and purpose)?

In general, taxable grants are part of Other Income on the entity's filing form (Form 1040, 1065) unless this is their activity/purpose (file Schedule C, C-EZ, E, or F or Form 4835). In such situations, the taxpayer would instead report the taxable or deductible amount allocable to the activity on that schedule or form.

For instance, there is a WI farmer grant that the landlord would not be entitled to, and might have applied in error.

Sounds like the traditional farm subsidies, not any new "grant" from recent legislation.  I think you have to figure out how to pound a square peg into a round hole.  I would put the cash rent on Schedule F, line 8, and the payments on LIne 4a.  Enter all the expenses on Schedule F, also.  Let the net flow through to Line 5 of the 1065. There are some deductions that have to be taken or elected on the partner level, so details will have to be provided on the K-1's.  But this is just my educated guess -- there may be some IRS guidance somewhere, on how they want you to show it.