Looking out the window this morning it sure doesn’t seem like mid May. The weather has been cool and wet for the most part and hasn’t allowed planting to progress as many would have liked. The forecast for the next 10 days looks to be warmer and drier, meaning that planting will be in full swing. I’m sure the crop on everyone’s mind right now is corn. Getting corn acres in is important, but don’t forget that planting your soybeans early is a key to maximizing yield. If you have access to two planters, using one to plant soybeans may pay off big in the long run.
According to UNL Agronomy professor Jim Specht a rule of thumb for increasing soybean yields is to “Have the soybean canopy green to the eye by the 4th of July.” Early planting has proven to increase yield for a number of reasons. One can be attributed to capturing solar radiation early in the growing season. If the crop is out of the ground early it will have more time to capture the energy of sunlight and convert carbon dioxide into carbohydrates, protein, and oils, all adding up to increased yield (Figure 1).
Figure 1. Comparison of development of soybeans planted at four dates in late June 2003 and 2004. The signs indicate when the 4-row strips were planted. (Photo courtesy of Jim Specht, UNL)
An earlier planting date will also increase yield by adding more nodes per plant. Once a soybean puts on its first trifoliate leaf, it will add one node every 3.75 days. This is relatively independent of temperature so those later planted beans will likely not “catch up” in terms of number of nodes developed. Nodes are where the plant flowers put on pods so more nodes = more pods and more pods = more yield. UNL research has shown anywhere from a 1 to 10 bushel per acre increase by planting soybeans early depending on spring weather conditions with an average increase of 3 bushels per acre over the last 7 years. After May 1, producers lose between 1/4 and 5/8 of a bushel per day that soybean planting is delayed.
If your operation has the equipment, try planting some soybeans along-side your corn this growing season. Some of the most successful farmers are those who think outside the box and are willing to try new approaches in their farming operations. Come harvest, early planted soybeans might just pay dividends.