""" “I can do 480 watts for six minutes [on a standard 2km rowing ergometer test]. In cycling I can hold like 470-480 watts for 20 minutes. So yeah, that’s a big gap, obviously,” he said when referring to the differences between power measurement compared between rowing and cycling. One of the factors in the difference between power output is that while cycling requires consistent power throughout the entire duration, the recovery phase of the rowing stroke generates no power, effectively meaning that for a third to a half of the testing duration, zero power is produced. """

This falsifies your claim that rowing burns more calories per minute than cycling.