A farming leader from Chagford turned over part of his cattle shed to cannabis growing because he thought it would make him more money that rearing beef.
John Shears is a former National Farmers' Union chairman who fell for the 'crackpot' scheme in the hope of making enough money to install new cattle grids on his land.
He hoped to be paid £3,000 a year rent for the use of a cattle shed and outbuildings at Chagford but ended up losing money when three successive crops failed.
He was caught with 187 plants with a potential yield of almost £50,000 when police raided the farm last year.
They found so much cannabis growing they had to call in reinforcements from Plymouth to remove it all, Exeter Crown Court was told.
Shears agreed to allow the cannabis farm on his land after being approached by a man he met at a point to point meeting in Devon in 2011 and when police raided the barns they found a young drug user tending the crop.
The case has ruined the reputation of Shears, who is a leading figure in local politics and was a member of the Dartmoor National Park Authority until recently.
Shears, 70, of Lower Nattadon Farm, Chagford, admitted allowing the cultivation of cannabis on his premises on May 5, 2014.
Daniel Perryman, of Exeter Road, Kingsteignton, admitted production of cannabis.
Shears was jailed for six months, suspended for 12 months and Perryman was jailed for 20 months, suspended for two years by Recorder Miss Julia Clayton.
She told Shears: "You expected a substantial financial gain even if it did not materialise. You have been respected in the community and have given a number of years of public service, often on a voluntary basis."
Sean Brunton, prosecuting, said police found the cannabis growing after visiting Nattadon Farm last year.
He said:"Police from Okehampton attended and found Shears, who was the land owner. He indicated they would find cannabis in various barns and outbuildings. There was quite a considerable hydroponic set up and other police from the Plymouth support group were called in.
"One outhouse had two compartments and a cattle barn had been divided into four growing areas one of which was described as a drying room.
"Another 36 plants and 32 seedlings were found in another building and the total number was 187 along with two mother plants. The police analyst estimated a potential yield of 7.5 kilograms with a value of just under £50,000.
"Both defendants were present and police found a book, which was said to be a bible of indoor marijuana horticulture, in Perryman's car.
"Shears explained to police he was primarily a beef farmer and lived in a four bedroomed house which was in need of repair. He also ran a haulage business.
"He said although he had joked about growing cannabis in the past, he had been approached by a man at a point to point meeting and it was agreed he would pay £3,000, the cost of electricity and 20 per cent of the value of the yield.
"He said the first crop was planted in early 2011 and killed by frost, the second died because it was too hot, the third crop did not take and the fourth was the one seized by the police.
"He said he did it for money to try to keep his farm business afloat and was told he would get 20 per cent of £25,000 but had lost money because he had only received £3,600 but not been paid for the electricity, which cost £5,000.
"He told the police he had been a fool to get involved in it."
Mr David Evans, for Shears, said he regrets having anything to do with the scheme, in which his only role was to act as landlord.
He said: "He has never been in trouble before and knows this was utterly foolish. It may be he had some financial difficulties with the farm, where he had a small beef herd.
"He hit on this crackpot scheme to get money to install cattle grids, an issue which was hotly disputed on the National Park group.
"He has been attached to the land all his life. A prison sentence would entirely destroy his livelihood. He has positive qualities and is active locally.
"He is highly regarded and respected and his involvement in this folly has damaged his reputation. He did not make any money out of it. He was not living the life of Reilly."
Warren Robinson, for Perryman, said he was drawn into the venture through his own cannabis use and the only reward he expected to receive was a personal supply of the drug.
He has sought help to give up since his arrest and is now in work as well as acting as carer for his parents. A defence expert estimated the likely yield as being worth only £20,000.
Shears is a former chairman and vice chairman of the Devon branch of the National Farmers' Union. He was also a member of the Dartmoor National Park Authority, where he was appointed by the Environment Secretary.
He served on committees dealing with Standards, Audit and Governance, Planning and Sustainable Development, and Park Management and had been given leave of absence from his duties.