WING, N.D. — The Wagner family farmstead in central North Dakota could have been lifted from a Grant Wood painting: bales of hay rest on a gently sloping hill, cattle graze near a bright blue pond, green tendrils of durum and sunflowers peek out of the dirt.

The Wagners fear that all of this could someday be under threat from big, impersonal corporations. It is a concern that is expected to drive them, and other North Dakotans, to the polls on Tuesday to vote on a referendum that would make it possible for companies to buy up farms like theirs.

Starting in 1932, North Dakota law barred nonfamily corporations from owning farmland or operating farms. But that changed in March of last year when the state Legislature passed a bill that would relax the corporate farming ban and Gov. Jack Dalrymple signed it into law.

Citizens protested the new law, with the state’s farmers union at the forefront, which led to the referendum that voters will face on Tuesday. The law was set to take effect last August, but its fate rests on the outcome of the referendum.