Heaney employs a solid structure in his poem to emphasise the role of hard work on the farm and how this contributes to his admiration towards his father
Neat, stable structure mirrors the well ploughed fields the poem references
Could be Heaney commenting on how he is able to achieve a similar level of perfection, just through the manipulation of words rather than physical soil
Tight structure may reflect the claustrophobic, tight-knit environment that Heaney was brought up in