They are joined by Rushden and Diamonds who were beaten by Port Vale.
Wycombe Wanderers and Notts County had already been relegated.
Scunthorpe will not face the long trip to Torquay last season after the Gulls pipped Huddersfield to the final automatic promotion spot.
Their 2-1 win over Southend moved them above the Terriers, who could only draw at Cheltenham.
Huddersfield will now face Lincoln in the play-offs, with Mansfield playing Northampton.