7 steps to better soybean yields
Soybean yields have been knocked in recent years for not keeping pace with corn yields.
“Two years ago, I would have agreed with that,” says Ron Moore, Roseville, Illinois.
In 2010 and 2011, though, Moore's soybean yields bounced back, with bushel-per-acre yields ranging from the upper 50s to the low 80s. The bounceback was a relief during a difficult 2011, as summertime moisture was scant.
Then came the drought of 2012. The year started out fine, with 4 inches of rain falling at the start of May in Moore's area. After that, though, drought relentlessly set in, sending soybean yields south.
What 2013 brings is anyone's guess. Moore plans to maintain practices like no-tilling lighter soils to conserve moisture. That helps soybeans withstand hot and dry conditions like those in 2011 and 2012. Genetics, preemergence herbicides, and fungicides all play a part, too.
“With higher land costs, you have to have higher management,” he says.
Here's a look at some steps to take to snap up future soybean yields.
1. Maximize fertility
Successful soybean production starts the year before. “You need to manage the previous corn crop for maximum yield potential,” says Seth Naeve, University of Minnesota Extension agronomist.
Excellent fertility is key, says Naeve. Soybeans respond well to previous phosphorus, potassium, and sulfur.
2. Pick the best varieties
Select the best-yielding, full-season varieties coupled with appropriate defensive characteristics that you can plant, says Naeve.
“You have to figure out how to get the right variety in the right field,” he adds.
In Moore's case, he tailors varieties to soil types. He plants early to late Group 3 soybeans. Moore sets the bar high for yield; they have to yield in the top one half of varietal tests.
Picking defensive characteristics is key. Moore picks varieties resistant to soybean cyst nematode (SCN), Phytophthora root rot, and brown stem rot. Planting SCN-resistant varieties can help you minimize yield losses on SCN-infested soils.
“You can literally have 40% yield loss with no symptoms,” says Greg Tylka, Iowa State University (ISU) Extension nematologist. A root dig can indicate the telltale SCN sign of little white SCN females on roots.
There have been cases where SCN has clipped yields of SCN-resistant varieties. Reliance on the main genetic source of SCN resistance (PI 88788)may be helping SCN to overcome SCN-resistant varieties. Out of 807 resistant varieties listed by ISU this year, just 18 had a genetic background outside of PI 88788.
“We have lots of varieties to pick from, but the genetic background is not as diverse as we would like it to be,” says Tylka.
For now, Tylka advises farmers to continue planting SCN-resistant varieties on infested soils. In most cases, they still work.
“Cyst-resistant varieties pay dividends twice – with decreases in egg population and yield increases,” he says.
3. Tile wet spots