The recent dry spell followed by recent torrential rains has forced many herders and farmers to make tough decisions quickly. Planting summer annual grasses can help you overcome summer fodder shortages. According to Dr. Vanessa Corriher-Olson, Texas AgriLife Extension in Overton, summer grasses can be very useful because they grow quickly, tolerate drought, respond well to fertilizers and water, and are more nutritious than warm season perennial forages. solution to meet summer forage needs. They can be expensive to produce, difficult to manage and could poison livestock with nitrates and/or prussic acid.
Despite these inherent disadvantages, summer annuals can be a great option in dry years. Summer annual grasses that can be grown in Texas include: Pearl millet (Pennisetum americanum) Forage sorghum (Bicolor Sorghum) Sudangrass sorghum hybrids, Sudan grass (Bicolor Sorghum) and Crabgrass (Digitaria sanuinalis). These forages can be valuable in a global forage system. Each of these grasses has unique growth characteristics and must be managed appropriately for optimal production.
Pearl millet is suitable for sandy, acidic soils floors. It can be planted in the spring by broadcast or by sowing ½ to 1 inch seeds deep in a prepared seedbed. The shortest varieties such as Tifleaf I, II and III are more leafy and fewer stems. Under grazing, these shorter grasses may be easier to handle than the larger types. Taller varieties can produce more dry matter per acre than the dwarf types. Also avoid grazing or mowing pearl millet short, because it can kill the stand. If you leave 4 to 6 inches of plant stubble after harvest, pearl millet will regrow. The medium can be harvested again in about 4 to 6 weeks. You can graze cattle on Tifleaf cultivars until frost because pearl millet does not do not contain harmful levels of prussic acid. However, it can cause nitrate poisoning.
Sorghum grains grow 3 to 5 feet and are not normally considered fodder because they produce relatively little dry product. question. However, several types of fodder sorghum have been developed. Forage sorghums can reach 8 to 13 feet large and produce a substantial amount of dry matter. Forage sorghums grow best in fertile, well-drained soils that have good water retention capacity. It’s the most drought tolerant of the warm season annuals listed here. Forage sorghums are the best used in a single cut of hay when the plants are in bloom or in the early mushy stage. These sorghums have large stems; crush them with a trimmer/conditioner will make them dry faster.
Sorghum-sudan hybrids grow from 4 to 7 feet tall, have smaller stems and dry faster than forage sorghums. Sorghum-sudan hybrids can produce more than any other summer annuals. These hybrids can be used for pasture or silage, but they are difficult to dry for hay. If used for grazing, let the sorghum-sudans grow back to 24 inches tall before reintroduction of livestock. Do not allow horses to graze sorghum-sudans because they contain an unidentified toxin that can cause spinal cord degeneration and even paralysis. Some sorghum-sudan hybrids and forage sorghum cultivars are susceptible to day light duration. These photosensitive strains can support more consistent growth over a longer growing season because they remain vegetative until September, until day length is less than 12 hours.
Sudan grass is a fast-growing, warm-season annual that can produce good forage, but generally not as much as sorghum-sudangrass hybrids. True Southern Grass has thin stems and regrows quickly after to be grazed. Sudan grass needs fertility well-drained soil. Two plantations 4 to 6 weeks apart will provide fodder throughout Summer. Varieties with brown midribs are preferred because they have less lignin and are more digestible than other varieties. In general, sorghums have total digestible nutrients values from 53 to 60 percent and gross protein concentrations of 9 to 15 percent.
silage or hay is easier to dry when the the plants are in the start-up stage (have not produced a seed head); however, the yield and the sugar content that quickly ferments silage are more important at the soft dough stage (when the seed is soft). Use a conditioner to crush the rods to ensure the drying of the hay rapidly.
Crabgrass is commonly considered a weed, but it can be a high quality summer forage. Crabgrass grows best in well-drained soils and, if allowed to reach the seeds stage, can reseed year after year. Crabgrass fodder has excellent quality and palatability, but yield varies depending on soil fertility and rainfall. Crabgrass hay normally heals longer slower than Bermuda grass but more quickly than sorghum-sudan hybrids or pearl millet. It is best to use this fodder in a rotational grazing system.
Summer annuals need proper fertilizer to produce well. Add lime, phosphorus and potassium depending on the soil test recommendations. Nitrogen is also important; apply for 60 to 100 pounds per acre to green at the top. If you anticipate additional harvests, you can apply 40 to 60 pounds of nitrogen per acre after each to harvest. Hot season annuals require that you are preparing soil, plant seeds and fertilize every year. Considering the price of diesel, seeds, fertilizers, and irrigation, it might not be economical for planting and managing annuals.
If there is not enough rain during the summer to produce enough hay, winter annuals can option. Warm season annual forages work well in open field situations whenever you want for planting annual winter fodder for grazing. The growing seasons for cold and warm season annuals are complementary and allow for a slight overlap in seasonal production.
Millet and sorghum-sudan plants can accumulate nitrates during drought. When conditions are dry, test the grass before leaving the cattle to graze. Millet and sorghum-sudan plants can be harvested as green chop, silage or hay; nitrates will persist in forages cut for hay.
As for grazing, you must test the green chop to prevent prussic acid and/or nitrate poisoning. If you suspect the hay has a high nitrate content levels, have samples tested. Recent experiences with Johnson Grass as forage grown under severe dry conditions this year have also raised concerns about its toxicity. It is always recommended to test it before using it or letting livestock graze.
For more information on this or any other agricultural topic, please contact the Hopkins County Extension Office at 903-885-3443 or email me at [email protected]