The victim was apparently attacked at his farm in Beromünster on Tuesday afternoon before police were notified that a person had been seriously injured.
When officers and an ambulance arrived the farmer was already dead.
He suffered from cuts and stab wounds, police said.
Officers arrested the farmer's 30-year-old son on the spot.
Police said they retrieved the alleged murder weapon, a knife.
Investigators are still looking into what happened.
But according to a neighbouring farmer, the father and son had a violent altercation, the Blick newspaper reported.
The 64-year-old was counting on taking his retirement and was planning on tuning his farm over to the son of his sister, according to the report.
This led neighbours to believe that a question of inheritance was at the origin of the dispute.
The son arrested, however, is not a farmer but a car mechanic.
His father also has another son, Blick said.