PORT SULPHUR, La. -- For the past decade, something eerie has taken place here. The ground is getting saltier and saltier.

Patty Vogt, a sturdy 49-year-old farm owner who's herded cattle and lived off planting oranges all her working life, looks at her citrus trees and sees what an untrained eye doesn't: Death.

"It should be full and green and full of oranges," she says, a few weeks before harvest.

Salt -- lots of it -- lies 3, 4 feet underground. Scientists say all the salt is tied to Louisiana's bigger problem: Coastal land loss.

As the marsh goes, the sea gets closer -- the ground saltier.

But the hundreds of citrus growers here aren't about to plow their trees under and say goodbye to a 200-year-old tradition.

Research scientists are tinkering with salt-tolerant and salt-resistant root stocks. Dwarf trees with shallower roots are in style. Pumping and draining the salt has caught on.

Since Jesuit priests in the 1790s first stuck orange seeds into this "black land," as Vogt and the other folk call the rich alluvial soil on the banks of the Mississippi River south of New Orleans, orange growers have overcome pests, storms, freezes and diseases.

"This is one we might not be able to solve," says Wayne Bourgeois, the main researcher at the Louisiana State University AgCenter Citrus Research Station. "We might not be able to find tried and true solutions. We might just be able to keep our heads above water."

"Last year I had oranges on my trees for the first time in about six years. I hate to get too doggone optimistic about it, but it gives encouragement," said Gerald Ragas, a 70-year-old farmer in Buras, down the road a few miles from Vogt.

He's a fan of draining the salt away. Perforated drainage pipe -- 1,100 feet of it -- runs along the rows of his navel orange trees to keep the water table low and the salt from reaching the roots.

"Citrus needs dry feet," said Alan Vaughn, the AgCenter county agent who talks with citrus farmers up and down this stretch of land, lends his ear to their woes and spreads the word of scientific advances.

"These guys are desperate, they're saying they'll try anything," Vaughn said.

Orange production isn't increasing, and that shouldn't happen with oranges, he said. As a tree gets older, it should hang with more fruit.

Once salt clusters around the deep tap roots, nutrients can't get up and the tree begins to die. Last year, dozens of Vogt's 3,000 trees dried up and died because of salt.

"I was picking 10 50-pound boxes on these trees, now I'm lucky to get three and a half," she said.

Farmers on this narrow strip of land between the Mississippi and the Gulf first noticed something strange around 1992.

"Right before the oranges got ripe, all the leaves started falling, all the trees were barren in this one little section, and it kept expanding," Ragas recalls.

Soil and leaf tests pinpointed the culprit, and researchers worked on how to save the $7 million citrus harvest.

They can't do much to stop the salt from getting in. They can't do much about the 25 square miles of marsh vanishing under the sea each year. They can't pad the coast with the 1,900 square miles of marsh already lost since 1930.

Louisiana's loss of wetlands is the byproduct of decades of human industriousness, and millions of dollars are spent each year to stop the erosion.

The hundreds of miles of levees built to save towns and cities from floods straightjacketed the Mississippi, and kept it from flooding its banks and replenishing the marshes with sediment. A starved marsh sinks.

Dredges chewed through the marsh to drill for oil and natural gas, opening up the "trembling prairie" -- as these vast wetlands are sometimes called -- to the Gulf's salt water.

"It's tragic how much of the marsh land has washed away," Ragas said.

Farmers are adjusting.

"Nothing's stagnant in this industry. What we were doing 30 years ago won't necessarily work," Vaughn said.

That's where the drains and pumps, dwarf trees and new root stocks come into play.

But maybe not for Vogt.

She's no fan of laying drainage -- it's too costly. Dwarf trees, a few feet off the ground? Nope, not for Vogt, who carries with her four generations of citrus growing know-how. She remembers 30- to 40-foot trees when she was growing up, and believes they ought to stay that way.

"If I plant any more trees, I'm going to plant them on high beds," she says, before heading back to her roadside fruit stand she works with her brother.