The Collaborative International Dictionary of English v.0.48:

Plowgate \Plow"gate`\, Ploughgate \Plough"gate`\, n.
   The Scotch equivalent of the English word plowland.
   [1913 Webster]

         Not having one plowgate of land.         --Sir W.
                                                  Scott.
   [1913 Webster] Plowhead