BATON ROUGE, La. (AP) -- High prices for fertilizer and low prices for other crops could boost this year's acreage 20 percent from last year, says LSU AgCenter soybean specialist Ron Levy.

"I would say we're going to be somewhere around 1.2 million acres," he said Tuesday. That would be up 20 percent over the 996,700 acres planted last year in Louisiana.

Levy said the high cost for fertilizer has moved some corn acreage into soybeans, and cotton acreage is moving to soybeans because cotton prices are low.

He says that soybean prices are good, exceeding $14 a bushel for the entire month of April on the Chicago Board of Trade.

The optimum planting window ends May 10, but around two-thirds of the crop is already planted, Levy said. "We could use a rain now to finish planting."

There is concern that the warm winter could result in more insect and disease pressures for soybeans, he said.

He said he is seeing a slight increase in acreage for Liberty Link soybeans because of concerns over weed resistance to glyphosate, the active ingredient in Roundup and other Roundup-like herbicides. But he said most farmers are sticking with Roundup Ready varieties.

Liberty Link soybeans allow use of a herbicide with an active ingredient called gufosinate, which can kill glyphosate-resistant weeds, said Jim Griffin, LSU AgCenter weed scientist.

"Liberty Link is new, so they are looking at how it would fit in their weed-control program. We will have to wait and see if acreage will increase as producers get comfortable using this new technology," Levy said.

Copyright 2012 The AP.