Other advantages: summer annuals grow fast, mature quickly and can be harvested for stored feed.
Lewandowski cautions that forage quality for summer annuals is good at the vegetative growth stage but declines quickly once the plant reaches its reproductive stage. Extreme dry conditions or drought can also be a concern.
"Summer annuals can accumulate nitrates in the lower portions of the stems under drought conditions," he says. "To reduce the risk of nitrate toxicity in livestock, producers should reduce nitrogen fertilization and make sure livestock don't graze lower than 8 inches.
"Producers also need to be aware that sorghum, sorghum-sudangrass hybrids and sudangrass all have varying levels of potential for prussic acid poisoning if plants are consumed when they are under stress conditions."
Tips for planting summer annuals:
* Plant summer annuals when the soil temperature is 60 to 65 degrees.
* Plant forage sorghum at 12 to 15 pounds per acre.
* Plant millet, sudangrass and sorghum-sudangrass hybrids at 25 to 35 pounds per acre.
* Plant teff grass at 4 to 5 pounds per acre.
* Plant corn used as forage at about 80,000 kernels per acre and seeded with a grain drill.
* Soil pH should be 6.0 to 6.5, soil phosphorus should be at least 15 parts per million and soil potassium should be 100 to 125 parts per million.
* All summer annuals respond to nitrogen, and best yields will be obtained when 50 pounds of nitrogen per acre is applied before or at planting and then again following each cutting or grazing pass.