Crop rotation

Whilst working at St Luke's University in 2017, the Twelfth Doctor was meant to give a lecture on crop rotation. However, he opted to give one on space instead. (TV: Oxygen) Crop rotation was one of the mundane subject to which Squire Sherringford Holmes devoted his extraordinary intelligence working the old Holmes farmstead, to the exasperation of his brother Mycroft. (PROSE: All-Consuming Fire)