Floodwaters have brought up many issues for South Dakota farmers this year. As water recedes slowly, I’ve been working with growers to help find options for alternative crops that could be planted in drowned out row crop fields. A couple weeks ago, I published an article mentioning several factors to consider before planting alternative crops as “Plan B.” This week, we’ll focus on soybeans.

One of the most common questions I’ve heard this last couple weeks is regarding filling in dead spots in soybean fields. If you’re familiar with pre-emerge herbicides (especially those for soybeans), you likely know that you may be quite limited in what can be planted in crop-failure areas this time of year if a pre was put down this spring.

As always, you should check the label on all pesticides applied to the field, before considering filling in the dead spots. Keep in mind that if a herbicide is not labelled for livestock use, this needs to be taken into consideration as well before forage is considered.

If you would like to try replanting soybeans for grain, be aware that the odds of obtaining a profitable yield are very slim this late in the season. At this point in the year for much of South Dakota, group 0.0 beans should be considered to have enough time to make grain before frost hits this fall. Early maturity groups can be hard to find, and typically, very little yield is expected (<10bu/ac).

Another alternative to consider is planting soybeans for forage. It is not an extremely common practice in this area, but soybeans actually originally made their way here as a forage crop as a legume with decent feed quality. In fact, a study in the early 2000s in WI demonstrated that it is possible to produce greater than 4 ton/acre of soybean forage containing 20% CP, 30% ADF, and 40% NDF in the Arlington, Wis., area.

For the purpose of forage beans, look for a very long maturing variety if possible (4.0+). This would allow the plant to put on more leaves and have more overall foliage before trying to put on a bean.

The advantage to forage soybeans is that producers already have the equipment and should be able to harvest a reasonable forage crop for cattle via grazing, ensiling, or haying. In addition, having a crop growing in otherwise dead areas is of advantage to your soil health, versus no living root or cover.

It is also possible to feed spring-planted soybean crop that has failed to mature/make mature grain (but is not dead); however, it’s important to remember that although the soybean plant makes a good forage option, the actual soybean grain itself requires caution when feeding. Green soybeans may be used as a protein supplement for cattle, or heat treated to before feeding to swine. Soybean plants tend to have a fair amount of tannin in them, so allowing access to no other feed (in a grazing or other feeding situation) could cause potential bloat issues; therefore, mixing in rations or limit grazing/strip grazing and/or providing other grazing feed sources is more ideal.

Soybeans before the R5 stage have been consumed by cattle in several cases with minimal issues, but after this maturity, it is likely unsafe to allow cattle to graze or consume the crop on it’s own. More mature soybeans (R5+) require feed processing blending/testing to ensure feed safety as bloat issues can occur.

When utilizing soybean hay, there may be a fair amount of inert matter found in bales that can affect palatability, so blending or grinding may be necessary. Soy straw can also be a feed ingredient if added appropriately to a ration. Ensiling may also be effective if timing and equipment allow, often this practice may require additional moisture (water or other crops blended in the pile) as well. Adding soylage to a feed ration will require consultation with an animal nutritionist. In most cases, when building a ration, it is recommended to keep soybean forage at 50% or less of the total dry matter to avoid too much vegetable oil in the feed.

If you have large drown-out areas where soybeans have died this summer and herbicides are limiting your replant options, consider trying late-maturing soybeans as cattle feed this year. Be sure to check your herbicide labels, speak with your crop insurance agent, and consult an animal nutritionist before getting started.

Another issue many have seen this year is flooded round bales; flash flooding caused many growers to lose bales or experience bale damage this summer. Although it can be a devastating loss, in many cases flooding renders these bales nearly useless as flood waters can contain many toxins. In some cases, if a bale was in moving water for a short period of time, growers may consider testing the bale for toxins, or rolling off spoiled portions of a bale before feeding; but, caution should be taken as tests may not represent the entire bale area and excess moisture may have caused additional bale spoilage.

It is understandable that a grower would not want to dispose of hay after putting several hours into putting it up; however, molds, toxins from floodwater, and potential caramelization/combustion issues, make these bales a hazard and likely unsafe for feeding.