Countersue the City of East Lansing for violating First and Fourteenth Amendment rights.
Suing personally the government officials who violated his rights is the only way this nonsense will stop.
That's the ticket. Also, in addition to suing the city, sue all "individuals" responsible for violating this farmer's 1st amendment rights.
Beyond suing in civil court there may be the possibility of criminal prosecution. If criminal laws were broken in denying the farmer his rights - insist that the DA prosecute the criminals.