Advantages and disadvantages of fescue pasture renovation
In the Ozarks, tall fescue thrives as a hardy, insect resistant and drought tolerant grass. However, the type of tall fescue pervasive in many pastures, Kentucky-31, creates toxins that negatively affect some aspects of livestock production. “Kentucky-31, produces toxins that impact livestock production which includes reduced conception rates, milk production, and weaning weights, as well as others,” Sarah Kenyon, PhD, field specialist in agronomy with the University of Missouri, said.
Replacement Options: Producers looking to replace Kentucky 31 tall fescue may choose to plant a novel endophyte tall fescue. “Novel tall fescue, sometimes called ‘friendly,’ contains an endophyte but the endophyte does not produce the toxins resulting in livestock impact,” Kenyon explained.
Additionally, producers may choose to plant an endophyte free tall fescue that contains no toxins, but it is more susceptible to insect infestation, overgrazing and heat. Both the novel endophyte and the endophyte free cultivars have a similar growth cycle as Kentucky 31.
Another replacement option is native warm-season grasses. These varieties typically produce the most forage in June, July and August. The warm-season grasses generally require less fertility compared to cool season grasses. “The native warm season grasses need less nitrogen and, in some cases, less phosphorus and potassium as well because they are deeper rooted and pull up mineral from deeper in the soil profile,” Gene Schmitz, specialist in livestock with the University of Missouri Extension, said. “They also pull up more moisture from deeper in the soil profile.” Schmitz added the native warm season grasses can be very productive and good for grazing and haying.
Advantages: One advantage to renovating pastures is eliminating the potential health risks and negative impacts to livestock that exist with toxin producing fescue. “Research has demonstrated that having 25 percent of the total grazing acres in novel tall fescue can help to alleviate the impacts of fescue toxicosis,” Kenyon stated. “This research is important because it means that farmers do not need to convert all of their tall fescue, but having a portion of their acres, managed correctly, could have a big impact on their overall production.”
Secondly, replacing Kentucky 31 with a forage like a native warm season grass, can enhance several aspects of herd performance. “The advantages are improved animal performance, improved reproduction, gains on stocker cattle, improved breeding rates, improved calf gains and improved stocker gains,” Schmitz, explained.
Additionally, warm season grasses produce additional forage during the hottest time of the year. “Having 15 to 30 percent of the total grazing acres in warm season forages can increase forage yield in the summer months,” Kenyon explained. “Cool-season grasses, like tall fescue, orchardgrass, Kentucky bluegrass, etc. reduce their growth in the summer months. Warm-season grasses have different cell structure that allows them to be most productive in hot temperatures.”
Disadvantages: But there are disadvantages. Tall fescue can be hard to kill. And even after efforts to eradicate the toxic tall fescue it can invade renovated stands. In addition, some fields may simply not be conducive to renovation. The fields may be too steep, the soil too rocky, and terrain unsuitable for other grasses to be planted.
Moreover, the process takes time. During the time of eradication, replanting and growth producers will incur a loss of productivity on those acres. Also, some of the replacement grasses may not be as hardy and drought tolerant as Kentucky 31 tall fescue.
Steps of the Process: There are a variety of ways to eradicate endophyte infected fescue. Extension specialists recommend spraying the infected field with an effective herbicide, seeding a smother crop, and planting a new forage. Then wait for the new forage to grow and produce a full stand.
Other important renovation measures to consider whether producers reseed with a native warm-season grass or a novel endophyte tall fescue variety. First, conduct a soil test and utilize the information to correct soil nutrient deficiencies. Next, institute a weed control plan, both before and after seeding a new forage. “These steps will help with the success of the renovation process and with future productivity of the new forage stands,” Schmitz explained.
Lastly, follow recommended harvest management practices for the renovated acres. Overgrazing or cutting forage plants too short will weaken and shorten the lifespan of the new stands.
Stages of Implementation: When undertaking the task of renovating pastures, implement the transformation in stages to battle loss of productivity and mitigate risk. For example, if a producer wants to renovate 40 acres, then spread the process out over four years transforming 10 acres each year.
