Plant soybeans early to increase yields. Planting earlier also allows the soybeans to make full use of the sunshine it needs to produce.
That was one of the messages that a tag team of Jim Specht, University of Nebraska agronomist, and Paul Jasa, UNL extension engineer, had for growers attending Soybean Management Field Days last week at four locations around the state: Doniphan, Weeping Water, Osmond, and Genoa. Other topics included nutrient management; emerging disease, insect and weed threats; and pricing and financial decisions.
"Plant earlier but do it right!" says Specht. "Planting early is one of the lowest cost things you can do to increase soybean yields."
Specht advises not to plant soybeans any earlier than two weeks before the average last frost day for the area. There's no need to pay close attention to soil temperatures, he says. Modern soybean varieties are bred to survive in cold soils.
Soybeans planted after April 25 usually don't yield as well as earlier-planted beans, according to UNL research. Later-planted soybeans may be taller than earlier-planted soybeans, but that's because the stems are longer between nodes. But the earlier soybeans will have more nodes, and it's the nodes that determine yield.
Planting earlier also saves water, says Jasa. Soybeans that canopy earlier, reduce moisture evaporation from the soil, whether the water came from rainfall or irrigation.
If yours soybeans are the first planted in the area, you may have a problem with bean leaf beetles. Compensate by selecting varieties that flower later, says Specht.