CHICAGO, Oct 9 (Reuters) - Fertilizer plants, livestock

feed facilities and at least one large flour mill in Florida

closed on Wednesday in preparation for Hurricane Milton's

destructive winds, heavy rain and deadly storm surge.

The Category 4 storm closed in on Florida's west coast as

millions of people along a stretch of more than 300 miles (483

km) of coastline were under evacuation orders ahead of its

expected landfall near Tampa Bay around midnight.

Milton is the second major storm to hit Florida in two weeks

after Hurricane Helene came ashore in the Big Bend region on

Sept. 26 and carved a path of destruction across agricultural

areas of the Southeast.

Fertilizer maker Mosaic said it has idled Florida

operations. The company, which mines phosphate rock in the state

and produces about three-quarters of North America's phosphate

fertilizers, said last week that a facility in Riverview,

Florida, was offline because of a storm surge from Helene.

Milton is expected to affect an even larger number of

Florida phosphate facilities than Helene, said Veronica Nigh,

senior economist for The Fertilizer Institute, an industry

group.

"The lack of processing and phosphate shipments that will

occur as a result of Helene and now Milton will further tighten

the phosphate market," Nigh said.

As much as 42% of U.S. ammonium phosphate, 32% of U.S.

phosphate rock, and half of U.S. wet-processed phosphoric acid

production capacity is located near Tampa Bay, Nigh said. About

40% of all U.S. phosphate fertilizer exports and 27% of total

fertilizer exports go through Port Tampa Bay, she said.

Flour producer Ardent Mills closed its Port Redwing mill

south of Tampa. The facility, opened in 2022, can produce up to

1.8 million pounds of flour a day from imported grain or wheat

grown in the Midwest and Southeast.

Global agribusiness Cargill Inc preemptively

closed its salt-packaging and animal-nutrition facility in

Milton's path, the company said.