Ames, Iowa
March 19, 2009
With soybean production expected
to approach a record 80-million acres in 2009, many growers will
be rotating land back into soybeans after several years of
continuous corn. When doing so, university experts say, growers
should expect significantly depleted populations of
nitrogen-fixing rhizobia bacteria in these soils. To avoid the
performance losses typically associated with inadequate
nitrogen, these experts are recommending that producers
inoculate their soybean seed with fresh rhizobial inoculants.
These naturally occurring rhizobium bacteria release compounds
that cause legumes, such as soybeans, to develop nodules on
their roots. The bacteria move into these nodules where they
grow and multiply. In this protected environment, they also
extract environmental nitrogen from the air and turn it into a
nitrogen form the plant can use to grow and produce a crop.
Commercial inoculants, such as VAULT®, from
Becker Underwood,
use rhizobia strains that are selected for their ability to fix
nitrogen, and, ultimately, increase the yield of the soybean
plant. Without adequate numbers of these highly active fresh
rhizobia, crop performance suffers.
“Typically, fields that have been in continuous corn for several
years will have rhizobium cells, but the populations are very
low and they don’t generate enough nodules to supply adequate
nitrogen for a high-yielding soybean crop,” explains Jim
Beuerlein, professor of agronomy and soybean research and
extension specialist for The Ohio State University. “In this
type of situation, it is very likely that a grower will see a
large yield response from inoculation.”
University studies show that growers normally can expect an
average yield benefit of 2.5 bushels per acre from the use of
inoculants in fields that are rotated to soybeans every other
year. However, the yield benefit often is significantly greater
in fields where soybeans have not been planted in several years,
such as continuous corn or CRP acres.
Charlie Hale, U.S. inoculant product manager for Becker
Underwood, says there is evidence that rhizobia become less
productive, or “lazy,” when exposed to high nitrogen levels, as
is typically the case on ground planted to corn. Rhizobia that
survive in the soil from one year to the next are not
necessarily the best strains when it comes to fixing nitrogen
for the soybean plant.
“As farmers look to reestablish their regular crop rotations and
think about planting more soybeans in 2009, they really need to
make sure they inoculate their soybeans with a fresh,
high-quality rhizobial inoculant,” he says. “This will help
ensure that rhizobia populations are present in the numbers and
strains needed for maximum nitrogen fixation and, ultimately,
greater yield.”
Inoculants offer additional benefits, Hale notes. Well-nodulated
soybeans, for instance, are capable of producing a nitrogen
credit of as much as 120 pounds per acre, although around 40
pounds per acre is more typical. This nitrogen is in the soil,
in a highly stable form, and available for use by the next
year’s corn or small grains crop. This nitrogen also reduces the
amount of costly synthetic nitrogen fertilizer the producer must
purchase in order to produce the following year’s crop, he says.
There is an environmental benefit, too. “The production of
synthetic nitrogen fertilizers generates large volumes of carbon
emissions,” Hale says. “Reducing the need for synthetic nitrogen
fertilizer decreases greenhouse gas emissions. Also, by applying
less nitrogen to their fields, growers lower the risk of
nitrogen leaching into the groundwater.”
Becker Underwood produces three VAULT brand soybean inoculants.
These include VAULT LVL, a low-volume liquid inoculant system
that also includes a biological fungicide for increased disease
protection. Initially introduced as a professionally applied
product, VAULT LVL has recently received approval for on-farm
application by growers. Additional VAULT formulations include
VAULT NP (formerly known as NOD+™) and VAULT SP (sterile peat).
Learn more about VAULT inoculants at
www.BeckerUnderwood.com
or by visiting your local dealer or seed treater. Please call
1-800-892-2013 if you need help locating a dealer in your area.
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. To learn more about its
products, visit the company’s Web site at
www.BeckerUnderwood.com. |
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