- Author: Daniel K Macon
Barb goatgrass (Aegilops triuncialis L.) is a winter annual grass native to the Mediterranean region and western Asia. According to a UCANR publication, it was introduced to Sacramento and El Dorado Counties via the importation of cattle from Mexico. And it is a growing problem on annual rangelands here in the Sierra Foothills. In some ways, I think of this invasive grass as "medusahead on steroids" - barb goatgrass spikes and joints (seedheads) disperse by attaching to animals, humans, and equipment. I often see new infestations along roads or walkways. Barb goatgrass forms dense stands with a rapidly establishing root system, making it extremely competitive with other annual grasses and forbs. In some areas, barb goatgrass reduces forage quality and quantity by as much as 75 percent - and because livestock tend to avoid the plant (and graze more desirable forages), it can spread rapidly.
Carol and Andy Kramer, who operate a sheep and cattle ranch in Nevada County, have been fighting barb goatgrass for several years. Most recently, they've been working with the Natural Resource Conservation Service (NRCS) through an Environmental Quality Incentives Program contract focused on goatgrass control. Over the course of the last 9 months, Carol and Andy have been working with the Placer Resource Conservation District (RCD) and UCCE to experiment with using prescribed fire to reduce goatgrass and re-invigorate native grasses.
Research suggests that burning goatgrass for two consecutive years offers "excellent control." Sounds pretty straightforward, right?! Not so fast! Fire is an effective control method when most of the fine fuel has dried sufficiently to carry the fire, but when the goatgrass seedheads are still attached to the stem - in other words, in late spring or early summer, when everyone is starting to get nervous about fire in the foothills!
A quick aside about using prescribed fire as a range improvement tool. When I started working with ranchers in California in the early 1990s (when I was just out of college, working for the California Cattlemen's Association), prescribed fire had largely gone out of vogue. This was partly a result of increasing worries about liability, and partly, as I recall, a shift in focus and attitude within the California Department of Forestry and Fire Protection (which became officially known as CalFire in the early 2000s). Today, after a decade of increasingly catastrophic wildfires (and the accelerating spread of invasive weeds like barb goatgrass), prescribed fire is making a comeback - thanks to efforts of many of my UCCE colleagues, RCD staffers and contractors like Cordi Craig and Chris Paulus (who led this effort), and especially of landowners like Carol and Andy!
Obviously, with something as complicated as prescribed burning, you don't simply wake up one June morning and say, "Hey, this would be a great day to light the back pasture on fire!" Carol and Andy (along withCordi and Chris, andUCCE) began planning for this burn last winter. As fire professionals,Cordi and Chris recommended putting a "black line" around the 1.5 acres ofgoatgrass during the winter months, whenCALFIRE burn permits are not required. Carol and Andy invested in water tanks and other equipment, and spent much of the winter and early spring pile burning and creating fire lines. Working together, we also burned several adjacent units to remove ground and ladder fuels in the areas surrounding thegoatgrass site.
Then we all waited! We needed the underlying fuel to be dry enough to burn, but we also needed the goatgrass to hold onto its seedheads. And we needed the right weather conditions. With the wet, cool spring we had in 2023, these conditions didn't arrive until July - well into fire season. This meant that we also needed a permit from CalFire. I've lived and worked in CalFire's NEU unit (which covers Placer, Nevada, and Yuba Counties) - and worked with and around ranchers - for nearly 30 years. I wasn't aware of CalFire ever allowing a rancher to do a prescribed fire for range improvement (or any other reason) in July. But thanks to the Kramer's persistence and Cordi and Chris's experience and knowledge, we received permission to do the burn on July 13.
Carol and Andy started the fire around 9am that morning - temperatures were hovering around 80F, and the relative humidity was just over 50%. Amazingly, we had difficulty getting the vegetation to burn - even as temperatures rose and humidity dropped over the course of the morning. By midday, we'd burned all we could burn, and began mopping up (making sure the fire was completely out).
Walking through the burn, I was amazed by the variability in burn intensity. Some of the goatgrass seedheads were completely consumed; others looked like they had not been exposed to fire at all. Carol collected seedheads from before the burn, as well as singed and apparently unsinged seedheads, to see if there will be any difference in germination (we'll keep you posted). We also started thinking about next year's burn.
One of the biggest challenges in burning for a second consecutive year, I expect, will be whether there is enough fine fuel (other grasses, pine needles, dry leaves, etc.) to carry the fire through the goatgrass. Visiting the site two weeks ago, I was impressed to see native blue wildrye starting to grow in the blackened burn unit (even with very little precipitation since the fire) - we'll be anxious to see what happens once we've had a germinating rain. Even so, we are considering broadcasting a quick-growing, early maturing annual grass (like soft chess (Bromus hordeaceus) this fall so that we have more receptive fuel next spring.
I think we all learned a great deal about the logistics of using fire to manage goatgrass (thanks to Cordi and Chris) - and about the challenges of using prescribed fire during fire season. One of the side benefits, from my perspective, is the demystification of fire generally. This was not a scary burn, even though it happened in the middle of July! While this was partly due to the conditions on the day of the burn, the work that Carol and Andy did to prepare (with Cordi and Chris's guidance) over the many months leading up to July 13 made it successful and safe. We're all looking forward to next year's fire!
- Author: Dan Macon
Smutgrass, in my experience, is a complicated, opportunistic weed, by which I mean there neither seems to be any single factor that contributes to its spread, nor any single management technique that leads to its eradication. Smutgrass seeds require bare ground, sunlight, and warm temperatures (68°F to 95°F) to germinate. Management practices (like pasture harrowing), or pests (like gophers) that lead to bare ground may provide a toehold for smutgrass establishment.
We have grazing exclosures established on several irrigated pastures on the eastern edge of the Sacramento Valley. The grazed portions of these pastures have significant smutgrass populations; the exclosures, where the forage grows all season without being removed, have little or none. To me, this suggests that getting the grazing right on our pastures may be part of the answer. If we can graze our pastures to 4-6" of stubble height, and then allow sufficient time for the desirable forage plants to regrow before we graze again, perhaps we can allow these "good" plants to outcompete smutgrass. On paper, this sounds easy; out in the pasture, it requires us to vary our graze periods and (more importantly) rest periods based on the growth rate of the pasture. Our rest period in June might be 25 days; in August it might be 40 days! Not every operation is set up to accommodate this variability.
We have noticed that dry ewes are more likely to graze smutgrass than lambs, particularly early in the season. Other producers have observed that goats will graze smutgrass. Davy et al. suggests that this may be related protein levels and digestibility. Clipping (or grazing) can maintain smutgrass in a more vegetative state, increasing palatability and nutritional value.
But even where we get the rest periods and graze periods right for the plants we want, we may still have smutgrass. Irrigation inefficiencies may favor smutgrass in some cases. Josh Davy and Betsy Karle found that smutgrass was significantly decreases on a pasture where irrigation was changed from a 14-day rotation to a 7-day rotation (with corresponding increases in more desirable grasses). I've noticed on the pastures that we irrigate for sheep that we seem to have more smutgrass in areas where shallower soils or lower water pressure results in less than optimal irrigation (in other words, we can't get enough water on these sites to maintain sufficient soil moisture in our 12-day irrigation rotation). And since our system is designed to run on 24-hour sets and 12-day rotations, we don't have a great deal of flexibility when in comes to addressing our smutgrass problem by adjusting our irrigation schedule.
Some producers in our region regularly clip their pastures to avoid eye problems and keep forage in a more vegetative condition. Research shows that repeated mowing can decrease the diameter of individual plants but increase the density of the stand. Mowing may also spread seed. On the other hand, mowing may maintain the nutritional quality of smutgrass further into the summer (which may improve its palatability for livestock).
Finally, glyphosate (RoundUp) may be a viable control option. A rotary wiper allows the operator to adjust the height of the wiper drum above the desirable pasture plants and "wipe" the herbicide directly on the smutgrass plants. This application should occur shortly after grazing (so that the desirable plants are lower than the smutgrass). According to Davy et al., "glyphosate should be applied after flowering when the plants are translocating sugars back to the roots or below-ground reproductive structures (generally late summer and early fall). Managing Smutgrass on Irrigated Pastures contains a helpful guide to using glyphosate with a rotary wiper. The Tahoe Cattlemen's Association has a wiper that is available for rent through Far West Rents and Ready Mix in Lincoln. If you'd like help learning to use the wiper, contact me at (530) 889-7385 or at dmacon@ucanr.edu.
Weeds are often a symptom of a management problem, rather than the actual "disease" - if we don't address the underlying issue (in the case of smutgrass this may be grazing management, irrigation management, or other factors), the problem is likely to reoccur. And with a weed like smutgrass that seems to be so opportunistic, eradication may be especially difficult. Controlling it (rather than eradicating it) maybe the most cost-effective option.
- Author: Dan Macon
Registration is now open for several livestock-focused workshops offered by the University of California Cooperative Extension!
2019 Cattlemen's Symposium - March 20, 2019 (9am - 1pm)
Lincoln, CA
Co-sponsored by the Tahoe Cattlemen's Association, the 2019 Cattlemen's Symposium will feature presentations on Genetic Improvement in Beef Cattle by Dr. Alison VanEenennaam of UC Davis, Cattle Marketing and Added-Value Programs by Dr. Tina Saitone of UC Davis, Managing Cattle Health by Dr. Gaby Meier of the UC Davis School of Veterinary Medicine, and Managing Smutgrass on Irrigated Pasture by Josh Davy of UC Cooperative Extension.
The cost is just $15 per person and includes lunch! Register at http://ucanr.edu/2019cattlesymposium.
Livestock Protection Tools Field Day - March 29, 2019 (8:30am - 12pm)
Penn Valley, CA
Are you interested in learning about techniques for protecting your livestock from predators? Curious about nonlethal livestock protection tools but concerned about costs and effectiveness? Join UCCE for this hands-on field day. Our keynote speaker, Cat Urbigkit, operates a sheep and cattle ranch in western Wyoming. She'll share her experiences using livestock guardian dogs and other tools to protect livestock from wolves and other predators in extensive rangeland environments. The field day will also feature demonstrations of turbo-fladry, electric fencing systems, game cameras, low-cost GPS collars for livestock guardian dogs, and other tools. Wildlife Services specialists will cover preserving a livestock kill site, and George Edwards, executive director of the Montana Livestock Loss Board, will discuss compensation programs.
Please note: This field day is focused on on-the-ground solutions to predator losses in commercial ranching settings. The intended audience is commercial ranchers. We will be hosting a similar workshop for agency and nonprofit staff, as well as interested public, later in Spring 2019 – stay tuned for details.
No charge for this workshop! Please RSVP at http://ucanr.edu/livestockprotectiontoolsnevadaco
