Farmers may want to plant summer annuals to boost forage supply
April’s untimely freeze reduced the state’s available forage supply. Since then, drought has hindered recovery of pastures and hayfields. For livestock producers who must decide soon whether to sell animals or find alternate feed, the N.C. Department of Agriculture and Consumer Services suggests planting summer annual forages.
NCDA&CS regional agronomists Bill Yarborough and Tim Hall are advising growers to consider crops like sorghum-sudangrass hybrids or pearl millet, but also recommend they consult with a specialist about potential fertilization hazards.
Sorghum-sudan usually produces higher yields than pearl millet, except on sandy soils, where pearl millet is better suited. Under attentive management, either crop could provide supplemental feed throughout the summer. The grasses can be planted conventionally or no-till.
“In Western North Carolina, hay and forage production is down 30 to 60 percent,” Yarborough said. “The damaged crops are all cool-season grasses and will not recover now, even if it rains. Forage like sorghum-sudan is good for hay or grazing and will grow throughout the summer even with limited rainfall. Under optimum conditions, it could be 12 inches high and ready for grazing within 28 days.”
Yarborough and Hall caution growers to avoid over-fertilization during drought. Fertilizer will not produce a favorable growth response without moisture. In addition, there is the danger that unusually high levels of nitrates may accumulate in the forage. High levels of nitrate can be fatal to cattle.
“High nitrates in forage occur when there is not enough rain for the crop to metabolize the nitrogen it takes up. My advice would be to apply about 50 pounds of nitrogen per acre at planting,” Hall said. “More nitrogen could be applied in mid-summer, but only if we get enough rainfall to produce a growth response.”
Hall also advises caution when grazing animals on drought-stressed sorghum-sudan. “When sorghum-sudan is very young or when it has wilted under stress, it may be toxic due to a build up of prussic acid,” Hall said. “Even if this is the case, however, the forage can still be safely used for hay or silage.”
Growers who want to try summer annuals should plant as soon as enough moisture is available and discuss their situation with an agricultural consultant. NCDA&CS regional agronomists can provide advice on how to adjust fertilization based on the crop and local conditions. It helps if the grower has a recent soil test report for the field being planted, preferably one received within the last year or two.
NCDA&CS Field Services has 13 regional agronomists who give advice on sampling, liming and fertilization and help evaluate suspected problems. For contact information, go to www.ncagr.com/agronomi/rahome.htm or call the division office at (919) 733-2655.