AMES, Iowa -- More than 5 inches of rainfall were recorded in Coles County, Illinois, last week. Reports of 4 1/2 inches from May 13-16 were common in Crawford County, Illinois.

Crop farmers in those locations plus many others in Indiana, Ohio and other areas of the eastern Corn Belt are facing critical planting delays due to flooded fields which may cause some to consider switching acres from corn to soybeans if conditions don't rapidly improve.

As of May 17, only 24 percent of the anticipated corn acreage and 6 percent of the soybeans had been planted in Indiana, compared to the 5-year average of 83 percent and 49 percent respectively. Growers in Illinois had planted only 20 percent of their projected corn and 1 percent of their planned soybean acreage. That compares to the 5-year averages of 92 percent and 50 percent respectively. Ohio farmers were in a little better shape with 39 percent of the corn crop and 17 percent of the soybeans planted compared to the 5-year average of 82 percent and 57 percent respectively.

Those numbers contrast to the more favorable conditions in the western Corn Belt where, for example, corn planting in Iowa is 90-percent complete and soybean planting is 41-percent complete, close to the normal 5-year averages.

The adverse weather which has delayed corn planting in many states east of the Mississippi River could have a significant negative impact on soybean yields in those areas as well, says Charlie Hale, U.S. inoculants product manager for Becker Underwood.

Because of the current soil saturation, plus the severe flooding that inundated millions of those same acres last spring and summer, agronomic experts say critically important rhizobia populations in these soils will be significantly reduced. "Soaked fields causing planting delays of this magnitude are particularly vulnerable to rhizobia loss," says Jim Beuerlein, professor of agronomy and soybean research and extension specialist for The Ohio State University.

"The saturation and flooding that we've seen across wide areas of Illinois and Indiana and other parts of the eastern Corn Belt, both this spring and last year, can create an anaerobic soil environment that will kill most rhizobia in as little as two to five days," Beuerlein says. "Our recommendation is certainly for soybean growers in those areas to go ahead and inoculate their soybean seed even if they haven't in previous years."

Without inoculating those fields, Beuerlein says, soybean farmers could be sacrificing significant yield and profit potential. Inoculating soybean seed with fresh rhizobia bacteria at planting may take a bit of extra effort but will help reestablish important rhizobia populations in the soil and improve nitrogen fixation and yield potential.

"Over time, waterlogged fields can gradually become reinoculated through small amounts of soil moved by wind, water, machinery, insects and animals," Beuerlein says. "Still, I would not advise growers to rely on that method for this year's planting. My recommendation is they take matters into their own hands and inoculate their soybeans with one of the highly effective and inexpensive rhizobial products available to them," he notes.

University studies and independent trials have consistently shown an approximate two bushel per acre yield benefit from the use of all inoculants, concludes Becker Underwood's Hale.

"But the potential benefits in fields like those in Illinois, Indiana and other areas of the eastern Corn Belt that have been waterlogged all spring could be much higher, especially for those producers who use a fresh inoculant having a guaranteed high rhizobia count," he says. "That's really the only way to immediately overcome the loss of native rhizobia caused under these excessive moisture conditions."

Becker Underwood, Inc., founded in 1982, is an international developer of bio-agronomic and specialty products. In addition to being the leading manufacturer of seed coatings and colorants, the company is also the leading global producer of inoculants, beneficial nematodes, and a wide range of agricultural and horticultural products.

SOURCE: Becker Underwood.