What is the difference between the Part 395 agriculture exemption and the 100 air mile (short haul) exemption?

Federal Regulations reflect two exemptions in Part 395:  (1) an agriculture exemption, and (2) a 100-air-mile (short haul) exemption. 

The main difference is that with the 100-air-mile exemption, the carrier must maintain time records and the property carrying driver can only work 12 hours with 10 hours separating each 12 hour shift; regardless of the property being hauled. 

With the agriculture exemption, the load must be agricultural products; there are no time record keeping requirements when loaded; but time records must be kept when empty.