World food demand is expected to double by 2050 from levels in 2000.  At the same time, agriculture prognosticators suggest the only environmentally sustainable alternative to meet that demand is to at least double productivity on fertile, non-erodible soils already in crop production.

Illinois soybean farmers may want to capitalize on that outlook by testing novel ways to boost soybean yields on fertile Illinois soils through the 2010 Yield Challenge.

“The 2010 Yield Challenge provides the opportunity for farmers to experiment with ways to improve soybean yields.  Data will be collected on all products and practices, so when large yield increases occur, the practices can be analyzed,” says Vince Davis, University of Illinois Extension specialist.  “A survey during our 2009 Corn and Soybean Classic found that one-third are frustrated with yields and half of respondents say yields are not increasing fast enough.”

USDA average yield data show that yields since 1926 have gone up about 34 bushels per acre in a linear trend.  Davis and others suggest that’s because breeders are doing a good job selecting for improvements and yield stability.  Others suggest the genetic yield potential of soybeans may be  more than 100 bushels per acre, but weather stresses, insects and diseases limit potential.

“We struggle with yields in the southern part of the state.  They are much below what we can do in other parts of Illinois, maybe because double-cropping brings the averages down in some cases,” he says.  “We need a total management approach to increase Illinois soybean yields.  We need to focus more on the agronomics.  For example, planting date is key.  Soybeans must have canopy coverage before flowering or otherwise farmers definitely lose some yield potential.”

University of Illinois plant breeders are working on genetic opportunities to increase yields as well.  Illinois soybean breeder Brian Diers says researchers are using genetic markers in breeding to make the selection process more efficient and possibly lead to greater yield gains.

“We use genetic markers to study genes that control yield,” explains Diers.  “A challenge is that yield is a very complex trait with many genes controlling it.  That makes it much more difficult to understand than disease resistance or composition in soybeans.”

Randy Nelson, USDA Agricultural Research Service scientist, says, “I have been incorporating new genetic diversity for 30 years.  Thirteen years ago, we made our first release.  Our most recent releases are much higher yielding than the first,” he says.  “Brian and I use the material to see what exotic germplasm is contributing to better yields by genetically mapping yield contributions from the germplasm.  By identifying DNA markers linked to increased yield, we may make it easier to increase yield but the results we are finding are not going to double yield.”

“With new technology, we will likely find ways to increase yields more rapidly,” Diers adds.  “But it is unlikely we will find a magic bullet that will double yields under normal agronomic practices.  If you plot out historic trends, we would not expect the national average to reach 100 bushels per acre until 2180.  With new technology, we hope it will happen much more quickly.”