Agriculture is under attack – or at least that’s what proponents of an upcoming Missouri ballot measure are telling voters.

Voters will decide next month on a “right to farm” amendment, which dozens of supporters such as the Missouri Farm Bureau describe as a defense against undue restrictions for family farmers. For one thing, farmers say they wouldn’t have to worry about so-called nuisance lawsuits over the bad odor that comes with the business.

But the right-to-farm campaign has also caught the attention of national animal welfare groups, who argue that the effort would protect giant factory farms like the ones operating the 22 large-scale dog-breeding businesses in Missouri.

The Humane Society of the United States – which recently gave $375,000 to the effort – called for more regulation and described Missouri as the “puppy mill capital of America.” It warned that foreign companies would be given “absolute authority” over the state’s land and animals.

“By forbidding any state rules to regulate agriculture, Measure 1 allows big agribusiness to write its own rules with no oversight,” a statement from the Humane Society reads.

Before the Humane Society’s contribution, the opposition campaign had raised just $46,000 compared to the half-million dollars raised by supporters of the right-to-farm measure, according to the Kansas City Star.

The right-to-farm is written into every state constitution across the country. But agriculture groups across the Midwest have sought more protections in recent years as they face pressure from opponents of genetically modified crops and other large-scale farming practices.

North Dakota passed a right-to-farm ballot measure in 2012 by a two-thirds vote. That law protects a farmer’s right “to employ agricultural technology, modern livestock production and ranching practices.” Indiana lawmakers have added the right to “agricultural or commercial production of meat, fish, poultry or dairy products.”

If the campaign is successful in Missouri, the state constitution would be amended to read that a person’s right to “engage in farming and ranching practices shall be forever guaranteed.” (An earlier version included the word “modern” but was ultimately scrapped to help rally support among smaller farmers.)

Allan Rowland, who farms 2,300 acres in southeast Missouri, said the amendment will ensure that he can continue using certain kinds of fertilizer.

“[It would] protect me from the environmental groups that seem to think the way we farm today is not correct,”  Rowland told KFVS News. “This is a good way of life out here. It’s tough a lot of times, but I don’t know of any better way of life.”