Forage growers may be reluctant to include native grasses in their grazing system because they have heard that grazing management for these species can be difficult. In practice, how much of an issue is this? Based on the work we have conducted at UTIA – and the experience of several producers who have been managing native grass pastures for a number of years – not near as much as you may have been led to believe.
Native grasses require better management than endophyte-infected tall fescue and bermudagrass, both of which can tolerate close grazing – up to a point. The reason for this difference is that natives, because they are tall-growing, cannot tolerate persistent, close defoliation. On the other hand, short-term overgrazing rarely creates long-term problems for native grass pastures, although it will increase weed pressure and temporarily reduce forage production as with any forage crop. Thus graziers must be prepared to monitor and adjust stocking on native pastures more often than what they may have been used to with some of our other common forage grasses.
Despite the need to monitor pasture condition more often, natives can really be pretty simple to graze. In our trials, we have used a simple, 3-paddock rotation, moving cattle every 3-10 days (a week is pretty typical) quite effectively. In this system, we normally enter a paddock at about 24-28 inch canopy height and pull off at about 14 inches. If you prefer not to use a rotational system, continuous grazing maintaining adequate canopies (about 16-18 inches, depending on species) for eastern gamagrass and a big bluestem/indiangrass blend has worked well in our trials. Lowland switchgrass, because of its strong growth surge in late spring/early summer, may not lend itself to this type of continuous grazing. When overgrazing does occur, providing a rest period of a few weeks is all that is normally needed to correct the situation. Stands that have been severely impacted require longer periods of rest to recover.
I recently visited some farms where lowland switchgrass has been grazed for 21 years (two different farms) and about 5 years (a third farm). In each case, the switchgrass is still vigorous and relatively clean. I asked each producer how difficult this species has been for them to manage. The answer in each case was that they had not had any difficulty at all. On one farm, the producer was rotating a large group of cow-calf pairs through about 140 acres of switchgrass in 10-acre paddocks. On another farm, the producer was using a smaller group of cattle but leaving them on the pasture for longer periods – several weeks at a time – and then rotating them off to another pasture. In most cases, the biggest challenge was simply keeping enough pressure on the grass to keep it in optimum condition.
The bottom line is that if you are willing to pay more attention to your pastures, native grasses are not difficult to manage and can contribute to improved summer forage production. For more information on native grass forages, see UT Extension publication series SP731 on line at http://nativegrasses.utk.edu/publications/default.htm.