The McKenzie family has been farming within the 50km zone of Melbourne for all its 80 years.

Alan McKenzie says he has a simple message for the hundreds of new farmers set to be "trapped" within a mooted 100km zone of Melbourne.

"Your lives are about to change forever," he said.

"People with no idea about farming will be telling you what to do."

The McKenzie family has been growing oilseeds and cereal crops and raising a beef herd on today's 160ha farm between Bulla and Sunbury to Melbourne's north.

Mr McKenzie says he has five planning overlays on top of those normal controls plus "Green Wedge" planning controls over his property.

A member of the Victorian Farmers' Federation land use committee, Mr McKenzie says there were a lot of words written in the planning proposal on right to farm but no action.

"Farmers are being seen as fair game to whatever industry they want.

"There are no still right to farm laws proposed to be made into law as part of this."

Mr McKenzie said if the Melbourne planners were serious about protecting farmland why were housing subdivisions still happening right around Melbourne on prime farm country?

"We can't build a second house on this farm, if we want to replace our present house there will be all sorts of approvals.

"This is the sort of control coming to all those farmers within 100km, they have to make themselves aware of it.

"Planners need to seek more advice from those of us with skin in the game."