What was the occupation of the speaker in After Blenheim?

Kaspar is by profession a farmer. He is a representative of the common mass who holds the romantic view of war. 
 
Kaspar’s occupation is evident in the following lines from the fourth stanza of the poem —

And often when I go to plough,
The ploughshare turns them out!

When Kaspar ploughs the field, he finds skulls of the soldiers who had died in the Battle of Blenheim. These two lines are here actually to state the speaker’s occupation and indicate his social class.

The title of the  poem is very appropriate as the poet discusses the after-effect of the battle fought at a small village Blenheim between the French and the English.