Prairie farmers are struggling to seed this year because of excess moisture in fields. (CBC)

The Canadian Wheat Board has released a grim preliminary crop forecast because of what it calls unprecedented wet weather across the Prairies.

Excess rain has washed away the hope of seeding for many farmers, said Bruce Burnett, the board's director of weather and market analysis.

He estimates three million to five million hectares could go unplanted this year in Western Canada.

The amount of wheat put into the ground will be the smallest since 1971, and the barley crop is also looking at its lowest seeding since 1965.

Burnett says the situation is particularly bad in Saskatchewan, where many fields have been flooded by record rainfall.

He says that's bound to have a significant impact on crop production, because Saskatchewan is such a big agricultural area — the province has 41 per cent of Canada's arable land — but Manitoba and Alberta are struggling as well.

Walter Finlay, who farms in the Souris area southwest of Brandon, Man., has only managed to get seed into two-thirds of his fields.

And large sections of those fields that have been seeded are flooded over.

Finlay has not been able work his land for nearly two weeks now. All he can do is shrug his shoulders and wait.

"There is nothing you can do about it," he said. "You just try and suck it up and continue on."

Oilfields affected

The rain has also slowed work in southwestern Manitoba's oilfields.

Muddy roads and waterlogged land are making it challenging to move equipment and service oil rigs, said Lawrence Stovin, who operates an oil field maintenance company.

Oil companies have been forced to set aside their trucks and rent Caterpillar tractors to haul service equipment to the rigs. The machines cost more than $100 an hour to rent, Stovin said.

The conditions, however, have provided his company with some economic benefit. His crews are keeping busy pumping standing water off the saturated land.

With files from The Canadian Press