The last few years have been tough on grass pastures and hay fields and many are not in a good productive condition. Also, reseeding last fall and this spring was not done in a lot of cases due to weather and cost. Considering this, livestock producers may want to consider summer annual grasses to supplement their forages.
These grasses, however, should be considered only as temporary solutions to summer forage needs. They are expensive to produce, difficult to manage and some have a potential for prussic acid and/or nitrate poisoning of livestock. They can, however, if properly managed, provide high yields of good quality forage in a short period and be considered as a substitute for cool season grasses and legumes.
Sudan grass and Sudan grass hybrids are rapidly growing annual grasses of the sorghum family. They are medium yielding and well suited for grazing. They regrow quickly after harvest and can be grazed or cut for hay several times during summer and early fall.
Sorghum x Sudan grass hybrids are more vigorous and higher yielding than Sudan grass. They are more likely to contain toxic levels of prussic acid (especially related to drought, non-killing frost, freezes, and low grazing) and are difficult to cure as hay.
Brown midrib sorghum-sudan grasses contain lower lignin that results in greater intake and increased digestibility than normal midrib types. This should result in increased gains per animal and per acre.
Millets are small-seeded, fast-growing summer annual grasses. They have smaller stems and are more leafy than the sorghum-type plants. Although they are lower yielding and somewhat slower growing, they do not have a problem with prussic acid poisoning. Pearl Millet is higher yielding regrows after harvest if a 5-inch stubble height is left. Dwarf varieties, which are leafier and better suited for grazing, are available.
Teff is a new summer annual that has potential for a summer crop. It is relatively disease free and requires less nitrogen than typical summer grasses. It can be of high nutritive value. Overfertilization should be avoided to prevent lodging of the crop. A little Teff has been grown locally.
These crops can be planted from May 1 until the end of July. Of course, later seeding reduces the number of harvests and total yields. The seed can be broadcast and cultipacked, or seeded with a grain drill into a well-prepared, firm seedbed. Most can also be planted no-till.
No-till planting usually requires the use of a burn down herbicide to control existing vegetation. Residual herbicides usually are not needed since these grasses are very competitive once established and growing. Be sure to follow label directions for any herbicides used.
If a grain drill is used for planting, use the lower rates of seed. Seed sizes may vary. If using small seeds, reduce the amount of seed planted.
Summer annuals need a good supply of nutrients to make high yields. Lime, phosphate, and potash should be applied according to soil test results. Nitrogen is important and should be added at the rate of 60 to 100 pounds per acre at planting time. Additionally, 40 to 60 pounds of nitrogen per acre may be added after each harvest for increased yields.
Another potential summer annual grass that can be grazed is corn. While corn is typically not considered a grazing crop, several farmers in other parts of the state have utilized it in their beef herds.
For more information on summer annual grasses, contact the Extension Office and ask for publication AGR. 88, Producing Summer Annual Grasses in Kentucky.