I sat (virtually) through a local irrigation district board meeting this morning. As you might imagine in a year like this, drought was on everybody's mind, from elected board members to staff to customers. The district has already asked for voluntary water conservation; next month, their board will likely consider mandatory cutbacks. And this district isn't alone - the Browns Valley Irrigation District, for example, has announced that it will end irrigation water deliveries in late August or early September (roughly 45 days earlier than normal). 2021 is shaping up to be an incredibly difficult year.
Given the likelihood that we'll be facing irrigation water reductions at some point this season, we're starting to think about our management options now. What is the best approach for keeping pastures going this year? Are there some things we can do this season to improve pasture survival for next year? Thankfully, some of my UCCE colleagues dove into this topic during the last drought. This publication is especially helpful!
First, we've noticed that the soil profile was very dry by the time we got irrigation water in mid April - and other ranchers have reported similar observations. Ranchers with flood irrigation systems were finding that it took much longer to get water to the end of the field because of these dry conditions. With our pod sprinkler system, it took us two full rotations to get the soil profile full and begin meeting plant demand. Our local irrigation district reported that these dry conditions have resulted in mid-summer irrigation demand - in early May!
With the prospect of water reductions, we need to evaluate the resiliency of the forage species and varieties in our pastures. Some grasses are more drought tolerant than others. At this stage, we can't really do much to shift to a more drought tolerant forage in the midst of the grazing season, but we can adjust our irrigation, fertilization, and grazing strategies to address the needs of the specific species and varieties.
Many foothill and Sacramento Valley pastures go through an annual succession of forages, with cool-season grasses and legumes like tall fescue, orchard grass, and white clover dominating early in the growing season. As temperatures warm, we tend to see more warm-season grasses like dallisgrass and bermuda. With the return of cooler temperatures and longer nights in late summer and early fall, the cool-season often rebound. The warm-season grasses are typically more drought tolerant, as you might imagine. Of the cool-season grasses, species and variety matter. In general, tall fescue seems to be more drought tolerant than orchardgrass, although there are some drought tolerant orchardgrass varieties. Most of our clover varieties, unfortunately, don't have much drought tolerance.
So how should we manage this year? And what can we expect next year? These recommendations are largely adapted from an excellent video produced by my late UCCE colleague, Steve Orloff (click here to view the video):
- Protect plant crowns: avoid grazing below 3" stubble height (and more residual may be better). The plant crown and stubble store sugars and carbohydrates essential for subsequent regrowth. Protecting these plants this fall increases the likelihood that they'll survive into next year.
- Know your pasture plants and pasture soils: prioritize irrigating those fields or portions of fields that can withstand drought. Focus on keeping drought-tolerant forage plants going - the less drought-tolerant plants may need to be replanted regardless of your management. Know where your deeper soils are - in our foothill pastures, these are typically at the foot of slopes. Generally, these deeper soils can hold onto water longer.
- Collect soil samples and target your fertilizer applications: Fall applications of potassium and phosphorous can help stimulate root growth, but it's always helpful to know your baseline fertility. Nitrogen application during drought, however, can concentrate nitrates (and be harmful to grazing livestock).
- Focus on recovery periods: While I think it's ALWAYS critical to vary grazing rotations based on the recovery period of the pasture, drought makes this even MORE important. In short feed years, it's always tempting to come back to a field before it's fully recovered from the last graze. DON'T DO IT! Allowing plants to recover fully will enhance root growth and pasture resiliency.
- Think about next year: If our water shuts off early, we may lose some of our clover - consider over-seeding clover just before the first fall rain. One of the more interesting ideas in the video referenced above was the possibility of planting an annual cereal crop (like triticale) before the water shuts off - and grazing in the fall and again in the spring (assuming something like "normal" winter precipitation). This is something I'll need to think through, but I'm intrigued by the idea.
As always, I'm available to come to your pasture to talk about these options and your specific situation. And we're hoping to do an on-ranch, in-person workshop later this summer to discuss these strategies in more detail. Feel free to contact me at firstname.lastname@example.org or (530) 889-7385!
For many ranchers in the Sierra foothills and Sacramento Valley, irrigated pasture is a critical component of our annual forage calendar. In many ways, irrigated pasture has replaced the historic practice of "following the green" - of taking sheep and cattle to mountain pastures during the summer months. Green summertime forage in the foothills and valley requires irrigation in our Mediterranean climate - and so many of us spend at least part of every day from April through October spreading water across our pastures.
Here in the foothills, these pastures do more than feed livestock. Large blocks of green vegetation provide landscape-scale firebreaks that protect rural residential communities. These pastures support a great deal of wildlife, as well - I consistently see wild turkeys, blacktail deer, song birds, and hawks (just to name a few species) on our pastures near Auburn. At least to me, a well managed irrigated pasture is a cool, green jewel amidst the summer-time brown of our foothill landscapes.
Truly productive irrigated pastures don't simply appear once we start applying water, though. No matter how much I water the annual grasses that grow on our rangelands, these plants have to die each year - that's what makes them annuals! Establishing irrigated pasture is similar to planting an other permanent crop - it requires soil preparation, infrastructure development, fertilizer application, and seeding of perennial forage species (like orchard grass, fescue, and clover).
Once planted, irrigated pasture requires careful management, as well. Our irrigation system is designed to put enough water in 24 hours onto the pasture to meet plant needs for ten days (in other words, our irrigation "sets" are for 24 hours, and our "rotation" brings us back to the same location in the pasture every ten days). We also manage our grazing carefully - matching our rest periods with the growth rate of our forage. When the grass is growing rapidly in the springtime, we can graze the same paddock every 25 days; in the heat of the summer when grass growth slows, our rest periods are longer to allow the plants to re-grow before we graze them again. And to protect water quality, we try not to irrigated underneath the livestock.
Obviously, the decision to establish irrigated pasture - or to incorporate it into our production systems - must include economics! Establishing pasture - even one that will last for 20-plus years - requires significant investment. Once established, we have to pay for water, depreciate our equipment, pay for labor, PAY OURSELVES!
This spring, I collaborated with Don Stewart at the Ag Issues Center at UC Davis to update two cost studies specifically analyzing foothill irrigated pasture. Click on the links below to access them:
On a related note, I'm also collaborating with Dr. Leslie Roche, Cooperative Extension Specialist in Rangeland Management at UC Davis, along with a number of other farm advisors throughout Northern California, on a research project examining a variety of irrigated pasture management strategies. We're looking at grazing management, water management, forage production, soil health, and a variety of other parameters - stay tuned for more information on this project as well!
Now I need to go out and move water....
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 email@example.com.
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.
We have a variety of livestock and pasture-focused workshops scheduled this spring! Check out the links for more information.
Penn Valley, CA
Co-sponsored by the Nevada Irrigation District and the Nevada County Resource Conservatory District, this FREE workshop will focus on soil management, irrigation systems, and pasture management. Participants must pre-register – contact Kaycee Strong at (530) 273-6185 ext. 244 or firstname.lastname@example.org.
Learn how to set up and manage a small-to-medium-sized shearing facility for small flocks. Participants will learn about sheep handling, shearing preparation, wool handling, and wool marketing. (Note: this is not a shearing school). Register at: http://ucanr.edu/woolhandling&shearingmanagement.
UC Sierra Foothill Research and Extension Center, Browns Valley, CA
This day-long workshop will include presentations on managing soils and forage, decision tools and strategies for managing livestock during drought, and climate data and visualization tools to support on-ranch planning. Register at: http://sfrec.ucanr.edu/?calitem=445275&g=62869
Shone Farm, Santa Rosa Junior College, Santa Rosa, CA
This 2-day, hands-on grazing school provides participants with practical, field-based experience in applying the principles of managed grazing on rangelands. Participants will learn to estimate carrying capacity and graze periods, as well as develop grazing plans and monitoring systems. For more information, go to: http://cesonoma.ucanr.edu/?calitem=446449
This one-day workshop will focus on the business practices and logistics planning essential to managing an effective and profitable targeted grazing business. UCCE Livestock and Natural Resources Advisor Dan Macon has managed medium-and large-scale targeted grazing projects in the Sierra Foothills and Sacramento Valley. Other speakers will include current contractors and grazing experts. Register at https://ucanr.edu/sites/Livestock/?calitem=450512&g=93567.
Stay up to date on other workshops and events at https://ucanr.edu/sites/Livestock//span>
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)
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/span>/span>