Farms for City Children, the educational project set up by Michael Morpurgo, the children's laureate, wants to recruit a teacher to work as a school manager on its Devon farm.
The role will involve conducting farm-based lessons - and mucking in with the mucking out.
Jane Feaver, chief executive, said: "There is slime and cow dung in the farmyard and most people are revolted when they turn up.
"We need someone who understands cows, sheep and poultry. They have to have a real passion for the countryside, rather than thinking it will be like The Good Life."
Mr Morpurgo set up the company in 1976 to give city children a taste of farm life. More than 3,000 pupils visit its three farms each year.
The farm school manager's day starts at 7.30am, and finishes with hillside star-gazing 12 hours later. In between, lessons vary between history, geography and practical science.
"Reproduction of animals can be a hard subject to teach," said Ms Feaver.
"But seeing a cow being artificially inseminated is a pretty graphic lesson."
And there is an unpredictability to the day that may surprise even the most jaded teacher.
Heather Tarplee, farm school manager for the Gloucestershire farm, said:
"The toilets could stop working or the pigs could get out. You have to deal with all of it and still make sure the children wash their hands before they go inside."
But for Ms Tarplee, a former teacher, there are rewards unlike those found in the classroom. "Many children have never set eyes on farm animals before," she said. "One child saw a calf and thought it was a wolf. Another was scared to walk past a cat. So when they stick their fingers in a calf's mouth, you can see their confidence grow."
Sarah Nunn, assistant head at Charles Dickens primary, in south London, has taken pupils to the farm for three years. She said: "Coming here can be daunting. The pigs are enormous, and run at you. And the cows are huge, with horns that sway in the light.
"But the managers are fearless. You pick that up very quickly, and it boosts your confidence."