Pervasive cheatgrass has long posed a threat to ranchers and their communities in the Intermountain West. Edging out native perennials and taking over entire rangelands, the annual weed compromises forage value for livestock, destabilizes soil, increases risk of wildfire and diminishes wildlife habitat.
“We’ve reached a point where a lot of times we can’t directly reseed natives into the environment. The soils have been changed” by years of dominance by cheatgrass, says Blair Waldron, a plant geneticist with the USDA Agricultural Research Service in Utah.
But there is new hope in forage kochia, a perennial shrub that Waldron and his colleagues have demonstrated is a stiff competitor against cheatgrass in semi-arid environments and provides excellent, protein-rich forage for cattle that can improve stocking rates. Another promising strategy lies in grass-legume mixes, also a subject of Waldron’s research.
In four years of SARE-funded research, Waldron, Utah State University Beef Extension Specialist Dale ZoBell and others demonstrated forage kochia’s adaptability to semi-arid western rangelands. They found pastures combining kochia and crested wheatgrass yielded six times more forage than comparison plots of crested wheatgrass alone, largely due to kochia’s tolerance of drought. This in turn means the rangelands with kochia could support 1.38 animals per acre, while the traditional rangelands could support only 0.24 animals per acre.
In previous research, they demonstrated the profitability of this nutritious blend: Grazing cattle on kochia and crested wheatgrass from November through January cost participating ranchers 25 percent less than feeding alfalfa hay, and resulted in similar body condition scores.
“We concluded these cows that were on forage kochia were near optimal for calving and rebreeding,” Waldron says.
By establishing forage kochia on rangeland damaged by invasive weeds, less land would be needed to manage more beef cattle. This allows other land to rest, Waldron says. Additionally, because kochia is perennial, it can act as a barrier against wildfires that feed off dead annual weeds.
Waldron has begun a more recently funded SARE project to further expand a rancher’s toolbox, by exploring the potential of grass-legume pastures to meet nitrogen needs while promoting environmental stewardship. Says Waldron, “In the mid-1950s pastures had legumes, but legumes in pastures have become a thing of the past.”
Through on-farm research in southern Idaho and Utah starting in 2011, Waldron and his team plan to compare grass monocultures with low- and high-tannin grass-legume mixtures, anticipating that high-tannin legumes may reduce potential problems with excess nitrogen in a grazing system. They hope to develop recommendations for which species and grass-legume ratios optimize a ranch’s economic and environmental sustainability.
Waldron’s focus now is on different varieties of the shrub, a widespread forage in its native Central Eurasia. One promising variety leads to yields almost double the variety he has been promoting and grows nearly a foot taller, making it more accessible in deep snow.
View a video presentation by Waldron discussing his forage kochia research.