A tracking device for transported grain. A tracking device for grain
comprises a radio-frequency identification (RFID) tag dimensioned to have
a size approximating surrounding grain. The tag comprises a memory and an
RF communication channel. Data is stored in the memory, comprising at
least a time when the RFID tag was handled with surrounding grain and
information sufficient to determine a location of handling at the time
when the RFID tag was handled with the surrounding grain.