An Alberta man died after his crop dusting plane crashed in a field west of Rose Valley, Sask. on Friday morning.

Rose Valley is about 116 kilometres east of Humboldt.

RCMP have not released the name of the 31-year-old pilot, but said he was pronounced dead at the scene.

Dale Whitford, a volunteer fire chief in Rose Valley, said he saw the aftermath of the crash.

"Basically in a nose-dive position, [the plane] crashed direct into the ground," Whitford said. "Front part of the plane demolished fairly badly."

The Transportation Safety Board is investigating the crash. It said he was flying a Piper PA-25.

This is the third crop dusting plane to crash this week in Saskatchewan. The pilots in the first two crashes were able to walk away without injuries.