Fall Flooding Damage to Soybeans

Field Facts written by DuPont Pioneer Agronomy Sciences

Types of Flooding Damage

Soybeans are very susceptible to flood damage in the fall, with lodging, shattering, and low quality grain being the most likely issues. Yield may be reduced by each of these problems.

  • Lodging – Soybeans have little resistance to flowing water, so lodging is a likely result where water rapidly enters or leaves the field. Even non-flowing water can kill or weaken roots and leave soybeans susceptible to future lodging.
  • Shattering – When soybeans are mature, splitting of pods and loss of seeds (“shattering”) increases with repeated cycles of wetting and drying. Prolonged wetting due to submersion may amplify shattering losses.
  • Grain quality reductions are inevitable with prolonged submersion of soybean pods. Issues include:
    • Sprouting in the pod if soybean seeds have dried below 50% moisture and imbibe water to increase back above 50% moisture (soybeans are very near to 50% moisture at physiological maturity, or growth stage R7).
    • Diseases may be introduced into pods and seeds by flooding. Diseased and discolored soybean seeds can incur dockages at the elevator.
  • Yield losses can result from several factors:
    • Shattering before or during harvest
    • Severe lodging that limits harvest of plants or pods
    • Silt and debris that reduce harvest of lower pods
    • Sprouting and diseases that reduce seed weight
    • Damage to soybean plants prior to maturity, resulting in smaller seeds
      (see Appendix 1.)

Management of Flooded Soybeans

  • Scout fields thoroughly to identify the type and extent of flooding damage. Continue monitoring fields closely through the pre-harvest period to optimize harvest timing and minimize yield and quality losses.
  • Manage field areas separately – Most fields will not be uniformly affected by flooding. Where practical, consider harvesting flooded and non-flooded field areas separately, as one harvest date may not be optimal for the whole field.
  • Separate grain from flooded and non-flooded fields or field areas, as quality, storage life and marketing channels may be very different from these sources.
  • Early harvest – Fields with severe flooding damage will likely benefit from early harvest to avoid further shattering, lodging and quality problems.

Shattering in Soybeans Due to Repeated Wetting and Drying.


  • Delaying harvest of minimally damaged fields is a viable strategy for preventing or reducing soil compaction. Allowing fields to dry adequately to minimize compaction must be balanced with the risk of harvest losses.
  • Pursue crop insurance claims for heavily damaged fields or field areas. Contact your crop insurance provider before harvesting field so he/she can submit a notice of loss. It will be important to clearly document any flooded areas for insurance or disaster relief assistance claims.

Storing Flood-Damaged Soybeans

A general rule of grain storage is to avoid mixing good quality and poor quality grain. This is especially true for soybeans with quality deterioration due to flooding. Sprouted, disease damaged, and discolored soybeans may lower soybean grade and incur dockage at the elevator. These quality impairments will also lower storage life, often significantly.

To help prevent contamination and extend storage life, clean bins, areas around bins and all grain handling equipment before putting grain in storage. Aerate grain to equalized temperatures throughout the grain mass. Hot spots need to be eliminated by stirring and cooling or removing grain from the bin.

A normal soybean crop should be at 13% for a 6-month storage period, and 12% for 12 months of storage. For lower quality soybeans, experts suggest drying grain one or two points below that required for a normal crop, monitoring grain closely while in storage (at least twice monthly), and in some cases, storing this grain for only six months rather than a year.


Appendix 1. Soybean growth stages and approximate seed moisture, days to maturity and yield loss from plant damage or death that stops seed development before full maturity.

Stage R6 – Full Seed Stage

  • “Green bean” stage – bean fills pod cavity
  • Seed Moist. ~75 – 80%
  • ~25 days remaining until full maturity
  • Yield Loss ~ 20 – 35%

Stage R6.5 – Mid-way from Full Seed to Maturity

  • Pod/seed color between green and yellow
  • Seed Moist. ~65-70%
  • ~16-18 days remaining until full maturity
  • Yield Loss ~ 10 – 15%

Stage R7 – Beginning Maturity Stage

  • All green color lost from seeds and pods
  • Seed Moist. ~55 – 60%
  • ~8 – 10 days remaining until full maturity
  • Yield Loss ~ 0 to 5%

Soil Sampling for Management Excellence

Soil sampling is right around the corner, will you be sampling this year? If you have been debating soil sampling or investing elsewhere, ask yourself three questions. How long has it been since past soil testing on your fields? If this is over four years ago, we recommend sampling to reset our fertilizer recommendations for the fields. Secondly, what will I do when my P and K levels fall to a point of yield reduction by mining of nutrients? Soil mining is a technique used by many growers on low price years; but, I advise to test before attempting to cut back on P and K. We know that both P and K have a buffering capacity of building, so once mined the amount of fertilizer to reset levels to optimum can become quite uneconomic. Lastly, ask yourself if your yields being removed from fields have matched the recommendation rate of fertilizer being applied to the field. If these two values have not matched, moreover if the yield removal is greater than the fertilizer applications, areas of mining may be occurring without your knowledge. I highly recommend sampling for this reason alone, before levels fall too low to support the crop planted. 


Looking past the decision process of soil sampling is the utilization of sampling. Growers utilizing precision variable rate applications can help reduce low levels in fields, by placing heavy amounts of P and K in places that will take the fertilizer along with limiting the amount of fertilizer spread on areas of the field with a minimal response to excess fertilizer. Utilizing yield data for proper P and K VR recommendations can lead to an increase in yields in future years, and can help re build soils from yield removals of years past, all while reducing the chances of a mining situation. This means that a proper VR application will include proper planing with your agronomist and Yieldpoint Specialist together. The team at CHS Larsen is trained in providing the right guidance for your fields by analyzing your yields and comparing these to soil test results to build an application that is right for your operation. Call your Agronomist or YieldPoint Specialist today and ask about how soil sampling and variable rate applications can help you be more profitable.  

Save Input Costs

No matter the crops you grow it is important to know what your soil fertility is.  Having soil sampling done by our CHS YieldPoint™ Team, can help you, the grower, apply the correct amount of nutrients based on your soil sampling results. With these results you are able to increasing your economic return per acre. Unfortunately, with crop prices low it’s very important to keep your inputs low when possible. Producers can realize a significant savings by reducing or eliminating unnecessary nutrient applications based on their sampling results. Contact our CHS YieldPoint™ Team, to schedule a time to do your soil sampling.

by Olivia Wagenson, CHS YieldPoint™ Specialist

Benefits of Post-Emergence Soil-Applied Herbicide

The difference between drift and volatilization


Getting the most out of an herbicide application not only includes maximizing efficacy, but also minimizing damage caused by herbicides. Being aware of what can go wrong and how to avoid it can lead to effective, on-target herbicide applications and help growers have a successful growing season – without the distress and loss caused by applications gone awry.

Two threats to herbicide applications are drift and volatilization. While they may seem similar, they are quite unique and require different attention to ensure that neither occur. (more…)

Nitrogen Stress and Rain

This week’s rain has been a blessing and a stressor together. With regards to the rain, I shift my summertime thoughts of weed and pest management to that of Nitrogen. Today’s corn crop ranges from v2-v7 and at this stage has taken up 5-10% of its total nitrogen need, meaning we have a lot of nitrogen to still take up this summer. This week’s rain ranged from 2-5 inches dependent on location. This was roughly 15-30% of the total rainfall this season, meaning nitrogen flow could be quite high in fields with a lower ability to hold its nitrogen. We know that the transient flow of nitrogen is quickly moving due to its negative charge and only moves in a vertical plane through the soil, so as the fields begin to dry out later this week, keep an eye on fields yellowing or showing signs of nitrogen stress that could affect yields if the bulk of your nitrogen has been applied already.

by Alex Yost, YieldPoint™ Specialist

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Spring is Right Around the Corner

With the planting season around the corner , have all the preparations been made to have maximize your profitability. Will you get a return on your investments and have we made the decisions that will create positive results?  We can’t control the weather , what it does or does not do. We do control planting our seed in the right places at the right population, using the right crop protection products and making the right fertilizer decisions. Getting our equipment up to date and ready to hit the fields when they are fit to plant. There are a lot of variables deciding return on investments and profitability .We need to make the right choices that put us in the situation to sustain positive results. Contact your CHS Larsen Agronomist and YieldPoint Specialists to help you maximize your profitability so when planting gets here you are ready knowing the decisions we control are done and now it’s up to mother nature.

Matt McKown, Agronomy Sales Manager

Annual Seed Pick-Up Days


It is time for CHS Larsen Cooperative’s annual “Seed Pick-Up Days.”  We have scheduled Thursday, March 22nd and Friday, March 23th.  Pick-up times will be from 10:00 am until 4:00 pm at the New London Main office warehouse.

Please call us at 920-982-1111 ASAP to let us know if you will be picking up your seed order, this will allow us to have your seed order sorted and ready for you.  If you will not be picking up your order, please call and arrange a delivery time at NO CHARGE if delivered before April 27th.  Each order delivered after April 27th will be considered “In-Season” and will be charged the normal delivery charge of $55.00.

As an added bonus for picking up your seed, a free gift will be given for each order picked up on these days!!

Sandwiches and beverages will be available throughout the day.

 We truly want to “Thank you” for supporting and placing your trust in CHS Larsen Cooperative’s Agronomy Department.  We look forward to seeing you at “Seed Pick-Up Days.”

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