Researchers use pigs to root out problem weeds

Back before chemical pesticides and herbicides, farmers had to come up with ways to kill the weeds that took over their fields. One method used "back in the day" was letting pigs loose in fields that were not being used for crops for a season and allowing the pigs to do what they do naturally: dig up the roots of weeds and fertilize the land.

In the last year, Greg MacDonald, a weed science researcher with the University of Florida's Institute of Food and Agricultural Sciences, decided to give the method a try to combat nutsedge, a weed that looks like grass and is so resilient it can sprout up through plastic row-crop coverings and even the plastic lining of above-ground pools.

"It forms huge numbers of tubers per plant and comes back year after year," MacDonald said.

After Dr. Daniel Colvin, the director of the Plant Science Research and Education Unit in Citra suggested it, MacDonald built pens and brought in domesticated pigs.

"Old-timers were practicing these methods, but nobody's ever done any research on it," Colvin said, recalling the farmers he knew as a boy using the pigs after the summer peanut crop had been picked. "You'd come in the next year and have almost no weeds at all."

In addition to feeding them regular swine feed, the pigs were allowed to root up the tubers in fields that had been heavily infested with this major weed.

"In the last year, they reduced the nutsedge by 48 percent," MacDonald said.

He could calculate the reduction by pulling multiple soil samples throughout the field, counting the number of tubers in the sample before they moved in the pigs and then three months later.

This method of weed control could be used in organic farms, he said. And while he did not test for fertilizer levels in the soil, MacDonald said it is certainly an added benefit.