Download BioX, China 05-09-06 Soybean inoculants may be inconsistent for yield

BioX, China
05-09-06
Soybean inoculants may be inconsistent for yield
BIOX.CN
Despite improvements over the years, soybean inoculants still might be
inconsistent in delivering higher yields in Iowa, according to university and onfarm research.
In Iowa trials, Palle Pedersen, Iowa State University soybean specialist, and
the Iowa Soybean Association (ISA) showed there was no consistent yield
response when using inoculants.
In the 2005 trial near Gilbert, Pedersen says none of the tested inoculants
showed much of a yield increase over the non-inoculated plots.
In 2004, he conducted research on 12 inoculants at two locations.
Only one inoculant at one location showed a significant yield increase over the
non-inoculated soybeans.
THE RESULTS from the ISA on-farm network did not show a response from
soybean inoculants in any of the 17 locations where they tested a product in
2005.
Pat Reeg, ISA field research operations manager, says they used more of
shotgun approach to the research, and this year they will take more of rifle
approach by targeting farm ground that is high in pH and low in phosphorus.
The product they use is a bacteria and fungus.
The bacteria works to increase nitrogen; the fungus works to make phosphorus
available near the roots of the soybean plant.
He says they tried the fungus on corn at 12 sites and it showed a 0.6 of a
bu./acre average increase in yields.
Shawn Conley, Purdue University Extension soybean specialist, reached the
same conclusion in trials he ran in Indiana.
He says his results showed an average boost of one bu./acre by using soybean
inoculants.
There was up to 3 bu./acre improvement.
With inoculants costing $1.30-$2/acre, a benefit of 1 bu./acre would cover the
cost of using the product.
Those results might be lower in Iowa, Conley warns.
Generally, soybean inoculants deliver a more consistent yield response as the
organic matter in the soil is decreased.
Generally, Iowa’s soils have higher amounts of organic matter than Eastern
Cornbelt soils do.
Most Iowa soils have a good population of B. japonicum if soybeans have been
grown in recent years, Pedersen notes.
B. japonicum is the bacteria which helps the soybean plant fix nitrogen.
Despite the results, there might be a place for soybean inoculants.
On the ISU soybean management Web site, which Pedersen operates, he
recommends inoculants be used if the field has been out of soybean production
three to five years.
Inoculants are cheap insurance, he reasons.
Other conditions that might warrant using inoculants in soybeans are:
=the field has never been planted to soybeans;
=the soil pH is below 6.0;
=the soil has a high sand content; and
=the field has been flooded recently.
Conley says it is easy for farmers to test if it is worthwhile to inoculate soybeans.
HE RECOMMENDS they do more than just split a field in half.
He also suggests putting in four- to five-row wide test strips and repeating them
between non-inoculated strips.
A simple yield monitor should be able to detect yield response.
“If there is a yield response, they (yield monitors) should be able to pick it up,”
Conley notes.
He says because not all inoculants are created equal, farmers are advised to
research different products.
Conley recommends farmers look at land-grant university research, such as from
ISU, Missouri and Minnesota.
IN THE near future, he believes soybean inoculants might deliver moreconsistent yield results.
The inoculant industry, such as others, is going through consolidation, which
might improve the performance of the product, Conley reasons.
In addition, he says the industry is changing how inoculants are being handled.
In the past, inoculants were like a peat moss substance farmers had to mix with
soybeans.
In the future, inoculants might come treated on the seed and have a polymer
what would allow farmers a 30-day window to plant. “That way, the farmer does
not have to mess with it,” Conley says.
One soybean inoculant company recently announced its product would allow a
90-planting window.