The document discusses several Irish cultural references that appear in the early poetry of Seamus Heaney, including: 1) Peat (or turf), an important fuel source in Ireland that Heaney uses as a metaphor for digging deep into himself creatively. 2) Traditional farming practices like flax production, horse-drawn ploughing, and potato harvesting that were part of Irish rural life. 3) How these references reflect Heaney's upbringing on a farm in Northern Ireland and his exploration of Irish identity in his poetry.