Harvesting drought-stressed soybeans for forage
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EmailFeeding drought-stressed soybeans to livestock is an option, but make the decision carefully.
Some soybean producers may be considering harvesting severely drought-stressed soybean fields for forage this summer. This is not an easy decision and producers should consider the value of the soybean grain compared to the value of the soybean forage. Other considerations include impacts on crop insurance payments, federal disaster aid and feeding restrictions for all pesticides applied to the soybeans.
Value of soybean grain versus value of soybean forage
Estimating the potential grain yield of drought-stressed soybeans is very difficult. This is because plants that have retained more than 50 percent of their leaves have the potential to produce a good grain yield as long as significant rain occurs before they stop producing flowers (early August). Be patient and assess the grain yield potential in mid-August. At this time, if more than 50 percent of the leaves have been lost, the plants have stopped producing flowers and few pods are present, grain yield will be very low.
A reasonable estimate of the dry matter yield for drought-stressed soybean forage would be 1.5 tons per acre. According to the feed tables in the Nutrient Requirements of Dairy Cattle, soybean silage harvested at early maturity contains 17.4 percent crude protein (equivalent to mature alfalfa hay), 1.29 NEL 3X Mcal/Kg (equivalent to mid-maturity alfalfa hay), 46.6 percent NDF (equivalent to mature alfalfa hay) and 5.7 percent ether extract or oil content (about 2.5 times the amount in alfalfa hay). These values will change with the development stage of the crop. This is especially true for the ether extract or oil content. Because the oil is in the seeds, larger, more mature seeds will increase the oil content.
Impacts on crop insurance
The key message here is communicate closely with your crop insurance agent before taking any actions such as harvesting the crop for forage (including grazing) or destroying the crop and planting an alternative forage crop. Failure to communicate with your agent prior to these actions will result in a loss of indemnity payments.
USDA program eligibility
Contact your localUSDA Farm Service Agency office to determine how harvesting the field for forage or replanting to an alterative forage crop will affect USDA program eligibility.
Pesticide feeding restrictions
Soybeans treated with the following herbicides can be harvested as feed and fed to livestock:
- Boundry
- Dual II Magnum/Parallel
- First Rate
- IntRRo/Microtech
- Prowl H2O/Prowl
- Sencor
- Sharpen
- Trifluralin
- Basagran
- Glyphosate
- Poast/Poast Plus
Always read and follow information listed on these product labels regarding feeding treated crops. The Poast/Poast Plus labels are a good example of why this is important because they state that treated soybeans can be harvested for hay, but not for silage. Soybeans treated with herbicides other than those listed above cannot be harvested as feed and fed to livestock.
Soybeans treated with the insecticides listed in Table 1 can be harvested as feed and fed to livestock. Soybeans treated with insecticides other than those listed in Table 1 cannot be harvested as feed and fed to livestock. As always, carefully check and follow the product label.
Table 1. Insecticides having specific statements on their labels that allow harvesting treated soybeans for livestock feed.
|
Product |
Active ingredient |
Forage and hay pre-harvest interval (PHI) |
|
Baythroid XL |
cyfluthrin |
15 days for dry vines (hay) and green forage |
|
Bifenture EC |
bifenthrin |
No specific statement on label |
|
Brigade 2EC |
bifenthrin |
No specific statement on label |
|
Dimethoate |
dimethoate |
Some formulations - do not graze within five days of last application. Other formulations list no specific statement on label. |
|
Intrepid |
methoxyfenozide |
7 days for hay or forage |
|
Lannate LV & SP |
methomyl |
3 days for forage, 12 days for dry hay |
|
Leverage 2.7 |
imidacloprid/ cyfluthrin |
45 days for dry vines (hay), 15 days for green forage |
|
Leverage 360 |
imidacloprid/ cyfluthrin |
15 days for dry vines (hay) and green forage |
|
Radiant SC |
spintoram |
No specific statement on label |
|
Sevin |
carbaryl |
14 days for grazing or harvest for forage |
Source: Christina DiFonzo, MSU Extension field crop entomologist
Soybeans treated with the fungicides listed in Table 2 can be harvested as feed and fed to livestock. Soybeans treated with fungicides other than those listed in Table 2 may not be harvested as feed and fed to livestock. As always, carefully check and follow the product label.
Table 2. Fungicides having specific statements on their labels that allow harvesting treated soybeans for livestock feed.
|
Product |
Active ingredient |
Forage and hay pre-harvet interval (PHI) |
|
Alto 100 SL |
cyproconazole |
14 days for grazing forage (no information on hay) |
|
Headline |
pyraclostrobin |
21 days for hay and 14 days for forage |
|
Headline SC |
pyraclostrobin |
21 days for hay and 14 days for forage |
|
Priaxor |
fluxapyroxad + pyraclostrobin |
21 days for hay and 14 days for forage |
|
Quadris |
azoxystrobin |
0 days for hay and forage |
|
Quadris Xtra |
azoxystrobin + cyproconazole |
14 days for hay and 14 days for forage (when 6.8 fl. oz. per acre or less has been applied) |
|
Quilt |
azoxystrobin |
0 days for hay and forage |
Source: Martin Chilvers, MSU Extension field crop pathologist
Harvesting for hay
Harvesting soybean forage for silage is preferred over baling it as dry hay because ensiling retains more dry matter during harvest and storage. However, it is possible to make high quality hay from soybeans in the R3 to R5 growth stages. There are lots of leaves at these stages and the pods are less likely to shatter during mowing and raking operations. Use a roller-type mower conditioner set to lay the hay in a wide swath and leave about 4 inches of stubble. When dry, slowly and gently rake the swath into a windrow in the morning when humidity levels are higher to avoid leaf loss. Invert the windrows after several hours of good drying conditions and bale in the early evening to avoid further leaf loss.
Harvesting for silage
The crop can be harvested from R3 to R6. Soybeans harvested at R3 to R5 will produce high quality forage and have lower oil content than those harvested at R6. The higher oil content may cause fermentation problems. However, soybeans harvested at R6 will produce more dry matter. Mow the crop with a mower conditioner equipped with roller crimpers. Experience from Wisconsin indicated that flail conditioners cause more damage and dry matter loss than roller conditioners. As with alfalfa, soybeans should be allowed to wilt in the field to 65 percent moisture before chopping.
Determining the whole plant moisture content is critical to achieving proper fermentation. Collect representative samples from the chopper and use the microwave method to determine whole plant moisture levels before chopping each field. Adjust the chopper to produce a 3/8-inch cut to improve packing.
Feeding soybean hay
Soybean hay has a tendency to cause bloat in cattle, so it should be fed carefully. Mix the soybean hay with grass hay or fill the cattle up on grass hay prior to feeding soybean hay. Horses can safely consume soybean hay if it is baled and stored properly.
Feeding soybean silage
Feed quality of soybean silage is equivalent to alfalfa haylage. Soybean silage is less palatable than haylage or corn silage. However, it can make up 15 to 20 percent of a dairy ration without impeding animal intake or milk production. The exception is when the soybeans are harvested after the R6 stage is reached as more seed (higher oil content) is present, which can affect fermentation and palatability.
Harvesting soybeans for forage is an individual decision and should be given careful consideration. Be patient and wait until early to mid-August to make the final decision as soybeans can recover from drought stress if significant rainfall occurs before August.
References:
- D. Undersander, K. Jarek, T. Anderson, N. Schneider and L. Milligan. A Guide to Making Soybean Silage, Plant Management Network, 2007.
- S. Johnson, J. Dunphy and M. Poore. Soybeans as Forage for Grazing, Hay or Silage, North Carolina State University, 2007.
- S. Barnhart and A. Lenssen. Alternatives for Drought-Damaged Soybeans - Bean Crop or Forage, Iowa State University, Integrated Crop Management News, 2012.
- C. Sprague. Weed Control Guide for Field Crops, MSU Extension Bulletin E-434, 2012.
- Nutritional Requirements of Dairy Cattle, National Research Council, 2001.
This article was produced by the SMaRT project (Soybean Management and Research Technology). The SMaRT project was developed to help Michigan producers increase soybean yields and farm profitability. SMaRT is a partnership between MSU Extension and the Michigan Soybean Checkoff program.
Additional information:
- MSU Extension’s Drought Resources
