Using Cattle to Rehabilitate Rangeland Vegetation and Improve Ecosystem Function (3 yr project)
This project demonstrates managed cattle grazing either maintaining or improving ecosystem function on degraded rangelands by using cattle trained to include invasive species in the their diets, along with using high stocking densities to reduce weedy species and increase natives and/or preferred vegetation. In 2011, multiple changes were made to the project design based on the previous year’s results and to manage for drought, unseasonably cool temperatures, lack of water for livestock and a new regional trail through the pasture. Managing for “mob-grazing” is proving to be very difficult, and changes in vegetation seem due to animal preferences for weeds and their locations.
1. Train city and county staff and participating ranchers in the use of rangeland health assessments to create a team of monitors.
2. Set up demonstration site pastures and manage cattle within them. Pastures will be set up in early June of 2010, 2011 and 2012. Cattle are managed in demonstration pastures for six weeks during each summer, with timing to be selected based on forage growth for each of the three years of the project.
3. Conduct six rangeland health assessments for each of the demonstration areas over the course of three years. This is a total of 72 rangeland health assessments in our 500 acre demonstration pasture. The data from these health assessments will be used to compare changes/improvements in ecosystem function among the different grazing treatments (regular density, high density and control). Pre-grazing rangeland health assessments will be done in early June of each of the three years of the project for all 12 demonstration plots. Post-grazing assessments will be done in September of each year of the project.
4. Develop draft criteria for managing high density grazing including number/pounds of animals per acre and how long animals should be in one pasture based on changes in forage. This criteria will be developed using input from participating ranchers, successful practitioners, available literature and adaptive management during the project. Criteria will begin development in fall 2010 and will be completed by the end of the project in 2012.
5. Create outreach and education materials to share with producers, city and county staff, media, county commissioners, open space advisory boards, NRCS and extension staff and others. These will include results in report form, flyer invitations and handouts for field days, and a video on DVD documenting the project. Results will
also be available on the Boulder County Parks and Open Space and the Livestock for Landscapes web sites. Outreach and education materials will begin development spring 2012 and will be completed by the end of the project in 2012. Results will also be shared at annual meetings of producers with county and city staff.
1. On May 18, 2010, we held a Rangeland Health Assessment training. NRCS staff Josh Saunders and Herman Garcia provided instruction for 24 participants, including staff from Boulder County and City of Boulder Open Space and Mountain Parks and two of the participating ranchers. (All ranchers were invited, but only Babe and Leo Hogan chose to attend.) As part of the training, an assessment was completed on the upper portion of the Mayhoffer pasture. The evaluation site was selected for its usefulness as a training tool, and because there was a reference worksheet available for it. Reference worksheets are not available for other, quite different parts of the pasture. Josh Saunders provided his evaluation sheet and the following review: “I feel that that there was more mortality than drought was causing, also, there appears to be a slightly more build up of litter on the site. I feel that if anything, the nutrient cycling (ecological process) may be stagnating somewhat on this site. If you were planning on upping the stocking density on this site for a short period, I think that it would do it some good.”
Unfortunately, because participating ranchers chose not to attend, our team of monitors is not as well-rounded as we had hoped.
2. The amount of time and when and where the cattle graze has been changed from the six weeks suggested in the proposal due to Boulder County Parks and Open Space (BCPOS) management, weather effects on vegetation and needs of the ranchers providing cattle for the project. In the first year of the project, BCPOS managers wanted widespread grazing through the whole Mayhoffer pasture, except for 100 acres where they sprayed herbicide to reduce diffuse knapweed. With widespread grazing for 12 days early in the growing season, the 80 cow calf pairs would hit bolting knapweed and blooming Dalmatian toadflax. We then confined them to smaller pastures to focus grazing on areas that were particularly weed infested, moving them from pasture to pasture when each plant had been bitten once, and we were seeing some hoof-impact and manure deposition. Cattle spent 16 additional days in the small pasture management.
Overall, 2011 was a difficult year for the project. We were challenged by weather, discovery of rare leopard frogs in one of the stock ponds in the pasture, drought that emptied stock ponds, construction of a parking lot in one corner of the pasture, as well as a section of trail running through, and communication issues among partners. We also encountered fencing problems and high gas prices.
While the human participants struggled with all of these things, our cow colleagues just continued to do the job they had been hired for. They did an excellent job targeting the most weed-infested areas of the pasture, whether or not the electric fence was in place. When I returned in August and again in September, I could not find a single Dalmatian toadflax plant that had not been grazed, and diffuse knapweed had been significantly grazed early in the season. They have also continued to increase the variety of their diets, even when not confined in smaller pastures. They were originally trained to eat late-season diffuse knapweed and Dalmatian toadflax. They have continued eating both of these species. Cattle show a marked preference for the north end of the pasture where diffuse knapweed is concentrated, and at the end of the 2011 grazing season every toadflax in the pasture had been grazed. To this diet they have added every other plant in pasture. The list of plants includes rabbit brush, broom snakeweed, sagebrush, mullein, field bindweed, rose bushes, Louisiana sage, fringed sage, pigweed, wild licorice, wormwood sagewort, plains milkweed, fetid marigold, curlycup gumweed, lambsquarters and more.
The drought and resulting livestock water issues altered the amount of time cattle could be in the pasture, and where they could graze. Timing of grazing and number of cattle was adjusted as well based on results from 2010. We built a one-mile stretch of electric fence to keep the cows from crossing the new regional trail and from accessing the stockponds with the leopard frogs. We also fenced several smaller pastures on the north end of Mayoffer. On May 30, we put 150 cow-calf pairs in the remaining 300 acres of the pasture. Cows concentrated themselves in the heavily weed-infested area on the southern end of the pasture where two stockponds provided water. When the ponds were emptied, cattle were allowed access to the northern end of the pasture where they could water from an irrigation ditch. Cattle grazed through June 25. We put twenty pairs in a small diffuse knapweed heavy pasture August 22 – August 31. I had hoped to be allowed to put the cattle back in this area of the pasture on August 3 to regraze the diffuse knapweed in its late season bloom, but coordination with the County was delayed. By the time cattle were allowed into the pasture, the plant was no longer palatable, and they did not graze it.
One of the best results to come out of this summer was evidence that grass is returning to replace weed species in the southern portion of the pasture. Participating ranchers are excited by the increase in sideoats grama in the pasture, and it is clear that there is more grass overall throughout the pasture. The amount of diffuse knapweed in the northern part of the pasture seems to be decreasing somewhat, though it is difficult to tell if this is a result of grazing or the dry winter. Rob Alexander, our Boulder County Parks and Open Space representative, says that he is very pleased with the progress in the pasture.
3. As noted in #1, we do not have adequate reference sites for the different areas of the pasture so rangeland health assessments are difficult to conduct. I am working with NRCS to resolve some issues so that further assessments can be completed.
4. We are still in the process of developing criteria. It is clear that how vegetation responds to weather each year will make it difficult to manage this kind of system and will dramatically affect criteria development.
5. Outreach materials will begin development in 2012.
Impacts and Contributions/Outcomes
-Increased forage production due to enhanced ecosystem health
When cows eat weeds, forage available is automatically increased. As for increased production, we are seeing some increases already in sideoats grama in the pasture. It is too soon to see what else might increase.
-Ability to extend the grazing season
This depends more on the willingness of ranchers and land managers to change the way they operate. Currently I am finding that they are happy with the way things are.
-Support for grazing from non-agriculturalists who see the benefits to their values that livestock can provide
City of Boulder Open Space and Mountain Parks is working on a project to develop a Boulder brand for natural beef raised on city and county open space. City Councilman Macon Cowles said that developing a Boulder brand of natural beef would help further the city’s goal of promoting local food production.
-Reduced weed management costs
It goes without saying that when cows eat weeds, costs for managing them with herbicides or other control methods are decreased.
2536 N. 95th St.
Boulder, CO 80301
Office Phone: 3036669808
11919 Hwy 93
Boulder, CO 80303
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2303 S. 104 St.
Broomfield, CO 80020
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Ag Resources Manager
Boulder County Parks and Open Space
5201 St Vrain Rd.
Longmont, CO 80503
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10473 Arapahoe Rd.
Lafayette, CO 80026
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Longmont, CO 80503
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natural Resource Specialist
City of Boulder Open Space and Mountain Parks
P.O. Box 791
Boulder, CO 80306
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1226 S. Cherryvale Rd.
Boulder, CO 80303
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