The Organic Church (aka the Soil Association) was invented in the 1940s by Lady Eve Balfour, a Suffolk lady reminiscent of Margaret Rutherford, who proposed that all farmers, butchers and bakers should be nationalised, and a former Indian civil servant called Sir Albert Howard, a man who believed that compost was the answer to most agricultural problems. The church remained for 30 years a small, tightly knit band of believers who, with shining eyes and sandaled feet, sought to convert the non-believing farmers, who themselves were just beginning to experience the joys - and increased profits - of fertilisers, fungicides and pesticides. To finance the church, the Soil Association sold indulgences, pieces of paper certifying that farmers were in a state of grace and thus could rightfully call themselves organic.
But then a strange thing happened. A series of food scares, including foot and mouth, mad cow disease and genetic modification - or "frankenfood" as it was called by more hysterical brethren - gave the organic missionaries the causes they had been lacking. So successful was the organic church in proselytising that sales of organic food grew massively - and so did the demand.

That explains why, one sunny day, a disgustingly successful (but entirely fictitious) Range Rover-driving, pesticide-using Lincolnshire vegetable grower realised that perhaps there was money to be made by growing organic potatoes. So he went along to the organic Vatican, and filled in all the right forms. He also waited three years, during which he grew clover in those fields. Eventually the magic moment came and he started to produce vegetables that were certified organic. He sold them to Waitrose and made a bucket of dosh - so much dosh that even his not-so-bright Lincolnshire neighbours noticed and they too applied to be baptised. Although they kept all the rules laid down by the organic Vatican, in their heart of hearts they did not think of it as a religion.

The organic cardinals were thrilled. Every day more farmers queued up to receive their organic baptism. But under the surface all was not well in the college of organic cardinals. One evening, after a solemn high tea of Duchy Originals, one of the brethren whispered that some of these new converts were committing the sin of bigness. They may have converted to the organic religion, he said, but their fields were not cosy little plots surrounded by hedges in which blackbirds chirped and beetles frolicked. On the contrary; they were often - and here he paused before uttering one of the foulest words in the organic catechism - "prairies".

There was a gasp from the assembled group of scarlet-clad princes of the church. The dissenting cardinal now felt more confident. "And what is more," he continued "their tractors are often 200 horsepower, they use enormous industrial irrigation equipment and their copper sulphate (organic, of course) is sprayed through 36-metre booms."

At this point another cardinal, possibly emboldened by a glass of organic ginger wine, had the temerity to mention that the director of the Soil Association had recently sanctified an organic fish farm in Scotland. It was impossible to believe that this band of disciples could countenance the vile and unnatural practice of fish farming.

On the contrary, he was told, fish farming was a fact of life - albeit a regrettable one - in the 21st century. It was therefore right and proper and profitable for the Organic Church to sell indulgences to fish farms - always providing they adhered to the rules religiously.

Hell hath no fury like a theologian scorned, and so the argument rapidly became so bitter that several of the cardinals threw their scarlet hats on to the replica of Sir Albert's original compost heap and flounced out of the organic Vatican in low dudgeon.

Thus appeared the first tiny crack in the hitherto monolithic facade of the Soil Association. Maybe today, somewhere in the hills of Somerset or Selkirk, a latter-day Luther is waiting to nail his theses to a barn door. If and when this happens, the organic Vatican will surely seek to defend itself in the traditional manner. It will summon a diet of Worms. Organic worms, of course.

· Oliver Walston is a Cambridgeshire cereal farmer  owalston@thriplow-farms.co.uk