Soybean inoculation

Today I ran across a 2010 article on soybean inoculation.  Bradyrhyzibium japonicum help soybeans to fix nitrogen from the air.  In the past it has been common practice to inoculate soybeans with the bacteria.  Inoculants were studied over the midwest from 2000 to 2008.  The probability of break even was 59% in Nebraska, 25% in Minnesota and Indian and 4% in Iowa.  The probability of achieving break even status was even less if soybeans had been grown recently.  In fields where soybeans have not been produce the payoff is big with almost a 15 bushel per acre increase in yield.  If you are breaking out pasture, or going to soybeans after many years of continuous corn I would say inoculate.  If you are in a corn soybean rotation, inoculations will probably not pay.