Richard Taylor, Extension Agronomist; rtaylor@udel.edu
Since barley harvesting has already begun in Kent County, I would encourage anyone who has not planted their full-season soybeans to place a high priority on planting them. Soybean prices are some of the best in recent memory, so keep the following tips in mind to help maximize yields.
On soils with a history of crusting and when planting in conditions too dry for germination, avoid planting too deep since a heavy downpour can easily cause the soil to seal over before the soybeans emerge. Shallower planted soybeans seem to be able to break through the crust more easily than deep planted beans.
Even in dryland fields I like to shoot for about 175,000 pure live seed per acre as my target population. When seed to plant was expensive and the price you received for the beans you harvested was low, reduced populations made economic sense. With today’s prices, I think targeting for higher yield potential is worth the extra seed cost.
Plant as early as possible for full-season beans. Yield potential quickly declines as we move further and further into June. For double-crop soybeans, again planting as quickly after barley or wheat harvest as possible is best although be sure you are placing the seed in the soil and not on top of small grain straw where they possibly will die during germination from lack of moisture or an inability to peg themselves into the soil. If the field is so dry you can’t place the seed properly, your best choice will be to wait for rain to soften the ground and allow fast germination.
Once soybeans have emerged, scout them frequently for micronutrient deficiency, especially in fields that showed micronutrient deficiency on the small grain crop. Again, as with corn, the micronutrient you should be most concerned with is manganese (Mn). To maximize yields, apply Mn in a foliar spray as soon as you spot the characteristic interveinal chlorosis on the newly emerging leaves. You can confirm deficiency with either or both a soil test and a whole plant or leaf tissue test. If plants are very young when Mn deficiency shows up, you may need two foliar applications of Mn as manganese sulfate or a chelated Mn.