1099-MISC For Rents Paid...Self-Employment?

I will be receiving a 1099-MISC for rents received on farm equipment I own.  The company issuing the 1099-MISC said that the amount would be reported in Box 1 (Rents).  I simply bought the equipment for a passive investment for the lease/rental income.  Will the IRS see this as self-employment income since it is reported on a 1099-MISC?  This seems to be a gray area, especially with the income being reported in Box 1.