Options for handling treated soybean seed (including as a cover crop)

Before deciding how to handle treated soybean seed, weigh these options to inform your choice.

Tractor and drill
Photo by Mike Staton, MSU Extension

With only 69% of the soybean acreage in Michigan planted as of June 23, 2019, and the fact that some producers have taken the prevented planting option and put their planting equipment away, there may be a significant amount of treated soybean seed that will not be planted. In some cases, seed companies may not allow returns of treated soybean seed. Producers need to understand their options regarding how to handle treated seed so they can make informed decisions.  Several options are listed below.

Plant the seed for harvest.

While the yield potential for late-planted soybean declines sharply after the end of June (Greater than 40% loss compared to optimal planting timing), some producers may want to plant soybeans with the intention of harvesting them for grain. Producers can mitigate some of the risk associated with very late planting by following the MSU Extension recommendations for late-planted soybeans.

Plant the seed as a cover crop.

Treated soybean seed can be planted as a cover crop on fields where the producer elected to take the prevented planting option. Please see the MSU Extension article titled “Corn and soybeans as cover crops following prevented planting.”

   Be sure to follow these recommendations when planting soybeans as a cover crop:

  • Narrow row spacing (ideally 15 inches or less) combined with increased seeding rates will minimize soil erosion, maximize ground cover and increase biomass production. Increase seeding rates to 150,000 seeds per acre when planting with a planter and increase them by another 20% when planting with a drill. In case of equipment restrictions (e.g. only 30-inch planter available), plant half the seeding rate in normal row direction followed by splitting the rows or planting at an offset (perpendicular or at an angle) from the original row.
  • Soybean from any maturity groups adapted for Michigan can be planted as a cover crop. However, if producing high quality forage is your goal, plant late maturing varieties (maturity group 3-3.5) under extremely delayed planting.  
  • The plant material must be harvested for forage on or after September 1 from prevented planted acreage, ideally before R6 growth stage (seed completely filling the pods on any of the top four nodes on the main stem) for high quality forage. No grain can be harvested from such acreage.
  • Check the labels for seed treatments and any herbicides that were applied to make sure the soybeans can be harvested for livestock feed.

Return the seed to your supplier.

Some seed suppliers will accept returned soybean seed that has been treated and some will not. Please check with you specific seed supplier for details regarding their policy.

Provide the seed to a neighbor that is still planting soybeans.

Producers that have earlier maturing varieties (maturity groups 1.5 to 2.0) and have taken the prevented planting option should consider providing seed to their neighbors who want to plant soybeans for grain harvest, but have varieties considered too late to plant at this time of the year. Earlier maturing varieties are recommended for grain harvest when planting is significantly delayed.

Store the seed over the winter for planting in 2020.

This is probably not a viable option for most producers as soybean seed quality typically declines significantly in storage due to high oil content. In order to maintain seed quality in storage, the seed must be of high quality to begin with and the environment should be controlled to achieve 50 degrees Fahrenheit and 50% relative humidity. Only seed that was tagged with a germination score of 90% or higher should be considered for storage. If a controlled environment is not available, identify a location that offers cool and dry conditions.

Always perform a germination test on a representative sample in the spring prior to planting and adjust planting rates or supplement carryover seed with seed purchased in 2020. Handle the seed as little as possible to avoid mechanical damage to the seed coat and/or embryo. The performance of the original seed treatment will most likely be compromised coming out of storage and retreating the seed is not recommended due to the additional handling required. Do not plant the carryover seed into challenging conditions (early planting, poor seed beds, cold or wet soils). 

Bury or burn the seed.

Follow federal and state regulations on the disposal of treated seed. Burying the seed is an option, but only if allowed by the label and avoid burying near water sources.

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