Northland Federated Farmers are concerned for the safety of Kawakawa farmer Paul McIntyre as he prepares to go to court in Kaikohe on Friday.

Mr McIntyre, 45, faces two firearms-related charges after he shot and injured one of three men he found trying to steal his quadbike from his Whangae farm on the night of October 20.

The federation's Northland operations director, Bill Guest, said Mr McIntyre had told him he had received threats against his life.

Mr Guest said he understood the threats had come from people associated with the men confronted by Mr McIntyre on his farm, 55km north of Whangarei.

"It's a worry. He's very isolated up there."

Mr Guest said he would advise police of the threats and pass on the federation's concern about Mr McIntyre's safety.

The three men also face two charges, one of trying to steal the farmbike and one of possessing a firearm.

One 29-year-old man from Moerewa has undergone surgery in Auckland Hospital for a shotgun wound.

The three men and Mr McIntyre will all appear in the Kaikohe court on the same day, which Mr Guest thought was unwise.

"That's confrontational," he said.

The Northland federation has begun accepting public and farming community donations to a legal defence fund for Mr McIntyre.

"He's facing a possible maximum of eight years in jail," Mr Guest said.

"This is a serious business and we need a substantial amount of money for his defence."

An initial federation estimate put the cost of the farmer's legal defence at up to $60,000.

Whangarei barrister John Ross has been engaged to represent Mr McIntyre.