U.S. Sen. Bill Nelson has been many things over the years. State legislator. Congressman. Astronaut. Insurance commissioner.

In Brevard County, he is a gentleman farmer.

Thanks to a half-dozen cows that graze Nelson’s 55 acres on the Indian River, he saved $43,000 in property taxes last year.

Nelson does not live there or own the cows. He leases the land, at no cost, to a cattle operation. Nelson says he gets to preserve undeveloped land while providing for a waning industry.

Yet the small herd has saved Nelson big taxes. The land has a full market value of $2.7 million, but the county tax collector uses the agricultural value of $210,000. That reduced Nelson’s tax bill in 2011 to $3,696.

When Nelson has sold parts of the agriculture land, he did so at full market value. In some states he would have had to return part of the tax break. Not Florida, which has one of the country’s most generous agricultural classifications.

Nelson’s situation is legal but nonetheless cuts to a long-running debate over Florida’s “greenbelt” law, originally intended to give farmers a break as the state modernized.

Enacted in 1959, it has proven to be a lucrative shelter exploited by developers who park a few cows, beehives or crops and reap the tax benefits until they are ready to turn a profit.

The farming family of former U.S. Sen. Bob Graham grazed heifers in Miami Lakes on land planned for development because of the tax benefit. “We would be silly not to,” Stu Wyllie, a Graham Companies official, told The Miami Herald in 2005.

Nelson spokesman Dan McLaughlin said any comparison to developers is preposterous. “Bill is not a major company or mega-developer with some hidden agenda to buy, develop or resell acreage.”

The senator said Tuesday in an interview that he is being treated as the law provides and that it accomplished the goal of keeping land open.

“I pay all the taxes owed on the pasture land,” Nelson said. “This pasture has been in my family since 1924 and it’s been a cow pasture since 1950.”

Nelson, 69, likes to tell the story of how he, as a boy, sold a herd of purebred Santa Gertrudis to pay for college. He once lived on the land but sold the home in 1998, three years after moving to Tallahassee when he was elected state treasurer and insurance commissioner.

In 1999, the agricultural classification was removed when an inspector from the property appraiser’s office found no cattle and the property overgrown with pepper plants, according to records.

Nelson, who was running for Senate for the first time, saw his tax bill shoot up to more than $26,000 from about $4,500. He challenged the ruling with the local value adjustment board but lost. The dispute went to court and Nelson regained the tax protection.

Today, about five or six cows roam Nelson’s land. They are owned by a farmer in Melbourne who has lease agreements with several landowners. The farmer gets use of the land in exchange for maintenance, while Nelson and the other property owners get the tax break.

Nelson’s property may never have draw attention but over the years he has put some of it up for sale, netting at least $1.4 million. Three of the five lots were not classified as agriculture, according to records he provided to the Times. Two others were agriculture, as is a sixth lot he currently has for sale at about $540,000. On those, he has gotten the benefit of low taxes before selling at market value.