Is Replanting the Right Decision?

Shawn Casteel
Shawn Casteel

Over the weekend, many growers who have been impacted by heavy rains and floods were weighing their options on replanting. Purdue says replanting may not be the best option. Some of the hardest hit fields are in Northern Indiana and, for those growers, replanting corn is simply not an option, according to Dr. Bob Nielsen with Purdue Extension. He recommends a possible application of nitrogen to help the plants recover, if they are still alive. As for soybeans, Dr. Shawn Casteel says replanting is still an option but may not be the best option, “Even if a grower has as little as 60,000 plants per acre, I would not consider replanting.” He added, if a field or parts of a field are completely drowned out, that is a different story.


“We are quickly marching on the end of time to successfully plant soybeans for grain,” said Casteel. “It’s going to be extremely tight.” Whether planting an initial crop or replanting flood-damaged fields, Casteel recommends using a shorter-season variety and planting at least 200,000 seeds per acre. “If soybeans are to be planted for grain harvest, we need to shorten the maturity group by 1.0 unit relative to the full season in your area,” he said. “We will mature about 7 to 10 days faster with that shorter-season variety.”


High seeding rates are needed to “push the plants and first pods higher, produce more nodes on an area basis and canopy faster,” he said. Farmers also need to determine the latest possible planting date for their area. Even shorter-season varieties need about 90 days to mature or be close enough to maturity for harvest. “If the fall freeze is typically October 10, then soybeans need to be replanted and emerged by July 10 to have a chance at producing harvestable grain this fall,” he said. Soil moisture and temperatures should allow soybeans to emerge quickly. Casteel estimates that late planting could produce about 50 to 60 percent of a normal grain harvest.


Casteel said farmers who were unable to get their soybean crops planted this year because of the wet conditions should still consider planting soybeans as a cover crop or look at alternative cover crops to preserve soil nutrients for next year. “We should plant something in these fields and large drowned-out areas to help suppress weeds, take up moisture and nutrients, and stabilize the soil for this year and next year,” he said. There is no need to use a shorter-season variety if the soybeans are planted as a cover crop, he said, because the goal is to produce biomass and ground cover, not grain.