For the last two seasons, G Farms has depended on legal migrant workers to harvest potatoes, onions and watermelons growing in its fields on the outskirts of Phoenix. Now the farm is bearing different fruit: a first-of-its-kind federal lawsuit that federal officials and immigration activists say exemplifies the pitfalls of the nation’s agricultural visa program—as Congress proposes changes to it.This year the U.S. Labor Department took the farm to court, saying its owner, Santiago Gonzalez, underpaid some of its 69 workers by not offering a set, hourly wage and housed them in an “encampment” consisting of yellow school buses and semitrailers that “violated numerous safety, sanitation and fire code regulations.”Janet Herold, the regional solicitor in charge of the case for the Labor Department, called the living situations a “horror show” that could have led to many worker deaths.The case is the first time the department won a preliminary injunction against a farm using the temporary farmworker visa, known as the H2A. A federal judge barred the business from housing the workers in the encampment, forcing it to house them in an apartment complex and an extended-stay motel for the rest of the season.