Summer Annual Forages Following a Failed Wheat Crop

Summer annual forage test plot - Aaron Berger
Figure 1. Foxtail millet is a summer annual frequently grown for hay in the Nebraska Panhandle.

Summer Annual Forages Following a Failed Wheat Crop

According to the USDA, hay stocks for the United States were the second lowest they have been for the last 25 years in December of 2018, with the only other lower year being December of 2012. There will be very little carryover hay this year in Nebraska due to the severe winter weather conditions. This sets up a scenario where annual forages may play an important role in providing forage for cattle producers this year.

Proso Millet
Figure 2. Field of proso millet, one of several summer annual forages that might be planted this spring.

In the Nebraska Panhandle, there are situations where the winter wheat crop is in poor condition due to winterkill. Where this is the case, producers may want to consider either salvaging the wheat crop with grazing or for hay, and/or terminating the wheat and planting a summer annual for forage production. Visit with your crop insurance agent when evaluating the options of what to do with a wheat crop that is in poor condition.

For much of the state, there is a full soil moisture profile in place. Additionally, the NOAA Climate Prediction Center is forecasting that much of Nebraska will have above average precipitation May through July. These conditions lend themselves to the establishment and production of summer annual forages.

Summer annual forages have varying attributes that fit different management practices. Forage yield and quality will depend on soil fertility, moisture, growing conditions and stage of maturity at harvest. Summer annual forages are the most water use efficient and drought tolerant of the annual forages. Forage sorghum, sudangrass, forage sorghum x sudangrass hybrids, foxtail millet, pearl millet, proso millet, and teff are all options for Nebraska producers, depending on their forages needs and how the crop will be harvested. The summer annual forage that is the best fit will depend on the production system and goals of the producer.

Growing Summer Annual Forages

Summer annual forages should be planted once soil temperatures reach 55°F to 60°F to ensure rapid germination. In western Nebraska, soils typically reach these temperatures in mid-May to early June. Summer annual forages can be planted through mid-July and still have acceptable yields. When grown under dryland conditions, annual forages tend to yield one to three tons per acre when moisture and soil fertility are adequate.

Summer annuals can be harvested by direct grazing, windrow grazing, chopping for silage, or harvesting for hay. These forages can grow and mature rapidly, making it challenging to graze or harvest the crop at optimum times. The beef.unl.edu website has a number of articles, webinars, and NebGuides on planting, grazing or harvesting annual forages.

Toxicity Concerns

Two types of toxicity are possible with these forages: nitrate poisoning and prussic acid poisoning. Nitrate poisoning is most likely to occur when forage is harvested or grazed after the plant has undergone stressful growing conditions and nitrate conversion to amino acids (protein) is reduced. In western Nebraska this is most likely caused by drought, hail, or frost. Nitrate poisoning can occur in forage that is directly grazed, but is more likely to occur when forage is harvested as hay and then fed. Testing forages prior to cutting and after they have been harvested can help producers identify potential nitrate risk and manage accordingly.  

Prussic acid does not occur freely in normal, healthy plants, but can occur when plant tissues are damaged due to chopping, chewing by animals, or frost. Sorghum-sudan and sudan grass hybrids carry this risk. If planning to graze a sorghum-sudan or sudan grass hybrid, plant varieties with low prussic acid potential. Millets or teff are not a risk for prussic acid poisoning.

For more information on growing and utilizing summer annual forages, please see these Nebraska Extension NebGuides: