All Is Not Lost

A portion of the Agtegra trade territory was hit with bad storms recently, resulting in crop damage, especially in the central area.
“High winds sandblasted many of the crops,” says Brad Ruden, Agtegra Agronomy Technical Services Manager. “There was a significant amount of soil moved around.”
Now that there has been time to assess the damage, many producers are wondering what to do with crop stands that remain in the fields, particularly if the crop is soybeans.
Soybeans Are Tough
Soybeans are a tremendously resilient crop, according to Ruden. Even after a severe weather event completely removes the crop’s leaves, soybeans can often bounce back. “Soybeans have an axillary bud wherever a leaf attaches to the stem, including at the base of the unifoliate leaves and even at the cotyledons,” Ruden says. “If any of these buds remain, the plant will send out a new shoot.”
Where these buds are located is important. If soybeans are cut off below the cotyledons, then they will not recover. If they are cut off above the cotyledons, then there is a chance they might regrow. If soybeans are going to recover, it will take a few days for them to start sending out new shoots.
Evaluating Your Soybean Stands
“One of the toughest conversations now may involve plant stand evaluations,” says Ruden. “Soybeans can look really damaged after a high wind and dust event.” Ruden adds that if there are at least 75,000-85,000 remaining live plants in a stand, then yield losses should be minimal. “Losses start increasing significantly after that level at lower populations,” he clarifies.
Stand uniformity is important, as well. Soybeans will compensate for gaps of two feet or less. Gaps larger than two feet may contribute to lower yields. See the table below.

When evaluating a plant stand, Ruden says that the best method is measuring the plants in 1/1000 of an acre of a row and replicating this reading as many times as necessary to be comfortable that you’ve measured a good representation of the stand.
Row lengths for 1/1000 of an acre are as follows:

  • 15 inch rows: 34 feet, 10 inches
  • 20 inch rows: 26 feet, 2 inches
  • 30 inch rows: 17 feet, 5 inches
Difficult Decisions
Some farmers may be asking themselves whether or not they should replant. Ruden agrees that it’s a tough call. “After the remaining plant stand is evaluated, the first step should be to include crop insurance in the conversation,” Ruden says. “Crop insurance must be contacted in order to release a field for replanting.”
The second step is to determine whether replanting seed is even available. Your seed supplier will be able to answer that question.
“It’s not too late to replant soybeans, but we are now at a point where maximum yield potential is somewhat reduced,” Ruden says. See the table below.

There are many other considerations that growers might pursue, such as interseeding soybeans. Ruden cautions that many seed companies would discourage this practice. “Interseeding soybeans into an existing plant stand can cause a lot of damage to the remaining seedlings in the field,” he says. “Remember, soybeans grow above ground, and if they have emerged, their stems are quite brittle.”
How the soybeans were planted plays a factor, too. If the beans were drilled versus rowed and how much of that crop will be run over with the planter and tractor should also be considered when deciding about interseeding as well. 
It may be tempting to till the field and start over, but Ruden also cautions against this. “The effect of tillage on pre-emergence herbicides will really reduce their efficacy, plus further dry the soil,” he says. “In general, no-till is recommended.”
Ruden says that if farmers are looking for a clean slate, the preferred method is chemically destroying the remaining crop to start over.
What About Herbicides Already Sprayed?
Many growers had already sprayed their fields with pre-emergence herbicides, so they are unsure what to do. “The general opinion from me and the many experts I contacted is that we would not recommend re-spraying fields until post-emergence,” Ruden says. “It is difficult, at best, to determine how much soil actually blew off of a field, unless there are gullies formed in the field.” 
“We need to follow label restrictions. I also would not want to double up those chemistries on an acre, especially in lighter soils or areas that may remain dry.”
Ruden recommends leaving the remaining herbicide and adjusting your post-emergence plan to early post and adding in a residual product to fill the gap.