Gary Green, 52, was today jailed for 16 months after pleading guilty to breaching health and safety over the incident which led to the death of Harry Whitlam.
A court heard Green’s eyes were glazed and he still appeared drunk when he was arrested shortly after the incident, which took place at 9.15am at Swithens Farm, Rothwell, on the morning of August 9 2013.
Green, of Robin Hood, Wakefield was found to be more than twice the drink drive limit at the time of the incident.
After the tragedy Green claimed to have drunk four pint of beer and to cans before going to bed the previous evening.
But Leeds Crown Crown heard how an expert estimated that Green would have consumed 13 pints between the hours of 10pm and 2am.
Judge Guy Kearl, QC, told Green, who has two previous convictions for drink driving, that his behaviour had been a “flagrant disregard” for the law.
Harry, from East Ardsley, died from his injuries after being struck by the vehicle as Green was reversing the tractor, which had a tank of slurry attached.
The judge said: “This collision could and should have been avoided by the defendant keeping a proper lookout and observations.
“That was not the only cause of the collision.
“In my judgement, had he not been affected by alcohol, his ability to carry out such observations would have been greater.”