An extended winter drought throughout the Southeast and severe drought conditions in the spring and summer in the lower South may create a need for alternative grazing for livestock in 2007.
Warm season grasses can fill this void, providing relatively high quality forage from late June until September.
Advantages of warm season grasses include fast germination and emergence, rapid growth, and high productivity. Many of these grasses can be grazed heavily and excess growth can be harvested as silage for hay.
Disadvantages include high cost of establishing and maintaining summer grasses.
Many varieties are noted for low stand counts, especially in periods of low moisture in the late spring and early summer months.
Often profitability of beef cow herds is determined by the amount of pasture available during summer months. Optimum early season growth of cool season grasses is wasted because cattle producers cannot stock heavy enough to take advantage of this growth. Warm season grasses could fill this void and provide a means for higher stocking rates in the summer months.
Researchers at Virginia Tech's Southern Piedmont Research and Education Center are looking at three potential warm season grasses that could provide high quality grazing for cattle producers in the upper Southeast.
Among the most promising is Caucasian bluestem. This warm season grass produces grazing from mid-May in North Carolina to early June in central Virginia. It can grow in soil with pH as low as 5.2, medium phosphorus and potash and less nitrogen than needed for cool season grasses or bermudagrass.
The big advantage for Caucasian bluestem is its ability to grow for long periods of time under drought conditions. Its major drawback is poor seed quality and reduced germination.
Switchgrass is a fast growing, tall growing warm season perennial grass. It is native to much of the U.S. and in Colonial days grew in vast patches throughout the Southeast. It's high dense growth was often a hazard to early American settlers, many of whom lost cattle, even children in the dense growth.
It has been tested extensively for use as biomass. In Alabama, switchgrass was tested by Alabama Power Company to power hydroelectric-generating plants. It can produce high quality cattle feed, but must be grazed rotationally, but not closer than 12 inches.
Switchgrass breaks winter dormancy in April throughout much of the Southeast and can provide grazing in May. In addition to grazing, it provides excellent wildlife habitat and erosion control.
Compared to bermudagrass, switchgrass fertility requirements are fairly low. However, seed dormancy can be low and needs to bebroken by wet chilling the seed prior to planting.
TEF is an annual warm season grass native to Africa. It is grown as a grain crop throughout Africa, providing as much as two-thirds of the human food supply in that impoverished area.
It has a low, massive fibrous root system, which ideally adapts it to a wide range of climatic conditions, including drought. TEF also produces high volume crops on marginal land, making it suitable to many areas of the Southeast.
TEF can have a double benefit in that it produces both grain for human consumption and forage for cattle grazing. It has produced forage yields up to six tons per acre with protein content in the 10-15 percent range.
One of the by-products of a heightened emphasis on developing biomass for alternative fuel production may be development of additional grass crops to offset weather-related or economic-driven shortages of forage for low cost animal nutrition.