Annual Crops for Forage: Millets

Millets are annual grasses suitable for grazing, greenchop, or hay. They grow 40–50 inches tall in about 60–90 days. Several types of millet are suitable for Pennsylvania conditions. Pearl millet regrows after harvest, while Foxtail millet does not, and Japanese millet grows best in wet soils. Sudangrass is generally superior to millet, except in the cold, poorly drained soils of northern Pennsylvania.

Teff

Teff is a grass that is tolerant of most soil types and limited rainfall conditions. It establishes and grows rapidly and can produce a hay crop in 9–12 weeks from seeding. Teff hay was initially considered a horse feed, but now it is used more and more for dairy because of its high palatability, digestibility, and ability to produce a crop with limited rain fall.

Seeding Methods

Forage sorghums grow best in warm weather and should be seeded at a uniform depth of 1 to 1.5 inches on a well-prepared seedbed at least 10 to 14 days later than the optimum planting date for recommended adapted corn hybrids. Seed at a rate of 5 to 8 pounds per acre.

Sudangrasses, sudangrass hybrids, sorghum x sudangrass hybrids, and millets do best in warm weather. They should be seeded at a uniform depth of 1 to 1.5 inches on a well-prepared seedbed at least 10 to 14 days later than the optimum planting date for recommended adapted corn hybrids. Later seedings, except for forage sorghums, may be made until about July 15. For suggested seeding rates of these species, refer to Table 1.8-5.

Teff should not be seeded in the spring until the threat of a frost has passed. Seeding at 5 pounds per acre is sufficient, but it must not be seeded deeper than 0.25 inches.

Fertilization

Forage sorghum and the other summer-annual grasses require well-drained soils, except for Japanese millet, which tolerates cold, poorly drained soils. Determine lime and fertilizer needs by soil test. Maintain pH between 6.5 and 7.0 for best results. In the absence of a soil test, use the following as a guide, assuming a medium-fertility soil:

Sorghum. Apply 150-75-75. Apply limestone and fertilizer the same as you would for corn. Do not use row fertilizer when seeding with a grain drill.

Sudangrass and sudangrass hybrids. Apply 50-50-50 per acre. Do not apply fertilizer in contact with the seed. Plow down fertilizer during seedbed preparation. Follow with 50 pounds of nitrogen per acre after first grazing.

Sorghum x sudangrass hybrids. Apply the equivalent of 150-75-75 per acre, 100 pounds of nitrogen at plowdown followed by 50 pounds after the first harvest. Significant amounts of nitrogen may be supplied by previous legume crops. Use Table 1.2-8 to adjust the nitrogen recommendation for the appropriate legume. When a previous legume crop is checked on the Penn State soil test information sheet, this residual nitrogen is taken into account in the recommendations; therefore, no further adjustment is necessary. Plow down fertilizer before seeding to ensure even distribution. Fertilizer in contact with the seed may delay emergence or even prevent germination.

Millet. Apply 40-40-40 per acre and disk in before seeding.

Harvesting

For direct-cut silage:

• Forage sorghums: Soft to medium dough
• Sudangrass and sorghum x sudangrass hybrids: Early head to early bloom
• Millet: Early head to early bloom
• Teff: Early head to early bloom

For greenchop, wilted silage, or hay:

• Sudangrass: At least 18 to 24 inches tall
• Sorghum x sudangrass hybrids: At least 30 inches tall
• Millet: Early head to early bloom
• Teff: Early head to early bloom

For pasture:

• Sudangrass: Rotationally graze at 18 to 24 inches of growth
• Sorghum x sudangrass hybrids: Rotationally graze at 30 inches of growth
• Millet: Rotationally graze at 18 inches of growth
• Teff: not recommended for pastures because it pulls out of the ground easily due to its shallow root system

For faster recovery of summer annuals, leave at least 4 to 6 inches of stubble at harvest time. Sorghum x sudangrass hybrids can be harvested at more immature stages for wilted or low-moisture silage.

Well-cured hay made from the hybrids has fair to good quality; however, field curing can be a serious challenge. When these hybrids are harvested for hay, it is essential to use a hay conditioner.

Special Considerations

If summer annuals have been damaged by severe drought or frost, do not allow animals to graze fields having succulent young short growth, and do not rely on damaged material as the only source of feed. To allow prussic acid content to dissipate, do not graze frosted forage for a week after frosting.

For more detailed information about summer-annual grass production, refer to Agronomy Facts 23: Summer-Annual Grasses for Supplemental or Emergency Forage, available from your local extension office.