In the fight against invasive cheatgrass in the western United States, a low-cost solution is emerging for ranchers and land managers. Research from the USDA's Agricultural Research Service (ARS) and the University of Nebraska–Lincoln (UNL) shows that precisely timed livestock grazing can help manage cheatgrass infestations while potentially improving cattle weight gains.
Cheatgrass, an annual grass native to Eurasia, has become one of the most problematic invasive species in the western U.S. It outcompetes native vegetation in the spring and, after completing its growth cycle, dries into fine fuels during summer, leading to more frequent and widespread wildfires. This invasive species not only threatens ecosystem biodiversity but also poses significant challenges for ranchers and land managers.
The study, published in the journal Rangeland Ecology & Management, identified a critical window of opportunity for targeted grazing. This window, lasting approximately 38 days in the spring, varies depending on the year and location. During this period, cattle can effectively graze cheatgrass, reducing its seed production and competitiveness against native species.
The key to successful targeted grazing lies in observing cheatgrass growth rather than adhering to strict calendar dates. Researchers found that cattle consistently prefer to graze cheatgrass from when it reaches four inches in height until it completes flowering and its seeds begin to harden. This flexible approach allows ranchers to adapt their grazing strategies to the unique conditions of each season and location.
The study, conducted over four years in mixed-grass prairie sites in Nebraska and Wyoming, revealed that spring targeted grazing can reduce cheatgrass seed production by up to 77% compared to summer grazing. This significant reduction in seed production can help break the cycle of cheatgrass dominance, allowing native species to reclaim their territory over time.
By reducing cheatgrass density, targeted grazing can also lower the risk of wildfires, a growing concern in the cheatgrass-dominated western landscape. Cheatgrass dries out quickly, providing a fuel source for wildfires, but when its growth is curbed early, the overall fire risk diminishes. Furthermore, as native plants have a chance to re-establish themselves, the biodiversity of these ecosystems can improve, enhancing rangeland health.
The findings of this study offer a promising path forward for ranchers and land managers grappling with cheatgrass infestations. By implementing targeted grazing strategies, they can potentially reduce the need for costly herbicide treatments while simultaneously improving forage quality for their livestock.
The research further suggests that spring targeted grazing can lead to favorable cattle weight gains due to higher crude protein and energy content in their diets during this period. This dual benefit of ecological restoration and improved cattle performance makes targeted grazing an attractive option for ranchers looking to optimize their land management practices.
It's important to note that successful implementation requires careful observation and flexibility. Ranchers must be prepared to adjust their grazing schedules based on cheatgrass growth patterns, which can vary from year to year. This adaptive approach may require some initial investment in time and resources, but the long-term benefits to both the ecosystem and cattle operations could be substantial.
As climate change continues to alter environmental conditions, targeted grazing could become an increasingly valuable tool in the fight against invasive species. By working in harmony with natural growth cycles, ranchers and land managers can play a crucial role in restoring and maintaining healthy rangeland ecosystems while potentially improving their bottom line.
