Compost for Carbon Sequestration on Irrigated Pasture

Progress report for OW20-358

Project Type: Professional + Producer
Funds awarded in 2020: $49,746.00
Projected End Date: 12/31/2023
Host Institution Award ID: G345-20-W7901
Grant Recipient: Colorado State University Extension
Region: Western
State: Colorado
Principal Investigator:
Retta Bruegger
Colorado State University Extension
Dr. Megan Machmuller
Colorado State University
Seth Urbanowitz
Colorado State University Extension
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Project Information


Climate change threatens the viability of ranching and farming and poses impacts to society as a whole. Simultaneously, a disconnect between research and application by ranchers diminishes the ability of both to respond in an adaptive way. We propose to test a potential intervention for sequestering carbon, while integrating ranchers into the research process. Compost applications on rangelands and pasturelands may provide a win-win scenario for producers and society. Research indicated a 1-time application of compost increased soil organic matter content, enhanced plant growth, and contributed to climate change mitigation in California’s rangelands (Silver et al 2018). Though promising, these results are untested in western Colorado, an area with substantial soil and climatic differences from the locations of the original trials. Research and outreach will be integrated in this project. Producers and stakeholders will participate directly in research through iterative meetings where they will assist in interpretation of the data analyses and ultimately help develop recommendations based on the findings. The project outcomes include 1) recommendations in terms of the appropriateness of the practice for western Colorado pasturelands based on our findings, and 2) an engaged group of stakeholders who have direct experience participating in a scientific process.

Project Objectives:

Research Objectives

  1. Test the efficacy for western Colorado pastures of compost application using field trails, replication, and controls by 2023.
  2. Test the efficacy of a 1-time compost application to increase grass productivity.
  3. Test the efficacy of a 1-time compost application to sequester carbon and increase soil organic matter.
  4. Test the impact of a 1-time compost application on species composition.

Outreach Objectives

  1. Assemble a stakeholder group of producers and interested parties to advise, contribute and comment on research activities. Stakeholders will meet 3-5 times over the course of the project. We will meet 1) before the initial application of compost, 2) at the end of the first field season to assess how things went, and 3) after field results have been analyzed to interpret and discuss finding, and consider barriers and advantages to implementation, and develop recommendations.
  2. Present findings at the annual Delta Soil Health Conference (February each year in Delta, CO), Pasture Plot Field day (October every year in Hotchkiss, CO), and the Field Day at the Fruita Agricultural Experiment Station (summer/ fall).
  3. Compose article for the Small Acreage newsletter for spring 2022 (Circulation 6,000).
  4. Produce infographics and social media posts on the practice which we can post to our websites ( and and other affiliates including Global Rangelands: and social media outlets (Facebook: @ColoradoStewardship and Instagram: coloradostewardship) by summer 2022.


Click linked name(s) to expand/collapse or show everyone's info
  • Lanny Denham - Producer
  • Mike Higuera - Producer
  • Cynthia Houseweart - Producer
  • Tom Kay - Producer
  • Lowell King - Producer
  • Ken Lipton - Producer
  • Steve Woodis - Producer


Materials and methods:

Objectives 1-4

In order to complete our research objectives (Objective 1-4), we will conduct the experiment at 2 sites in western Colorado. Potential sites are the Fruita Research Station (through Co-PI Urbanowitz), and a local producer, Ken Lipton, has offered the use of his pastures near Ridgeway, CO for the second.  We will use a randomized complete block design that includes 3 blocks consisting of treatment (compost addition) and control plots oriented in 25 by 60-meter strips and separated by at least 5 meters. There will be 12 plots total (2 sites x 3 blocks per site x 2 plots per block (treatment and control). We will sample each plot 1 and 2 years after compost application (24 total).

In each plot, we will dig a profile sampling at 4 depths: 0-10 cm, 10-30 cm, 30-50 cm, and 50-100 cm (Ryals et al 2014, Silver et al. 2018). We will collect soil samples and measure total carbon/nitrogen stocks, soil texture, and soil health metrics (plant-available nutrients, water holding capacity). At each plot, we will also sample above-ground biomass production using the clip-and-weigh method (Coulloudon et al 1998), and vegetation composition using the line point intercept method (Herrick et al. 2005). Finally, we will sample utilization before and after grazing each year of the experiment.

For analyses, we compare several dependent variables on treatment and control plots. Specifically, we will quantify total carbon/nitrogen stocks, inorganic nitrogen, plant biomass production and plant species composition on treatment plots (compost applied) compared to controls. Analysis methods will ultimately depend on experimental design and approach, but will likely be ANOVA, analyzed in R.

Objective 5

An innovative part of this grant will be the involvement of the stakeholder group in developing recommendations based on the research findings (Objective 5).  The ‘stakeholder group’ will consist of involved ranchers, Extension agents, and interested parties from the Natural Resources Conservation Service and Conservation Districts. This group will assemble 3-5 times over the course of the experiment to make decisions, provide feedback and evaluate progress. At the end of the project, we will ask this group to assist us in interpreting the results of the analyses and developing recommendations for practice. R. Bruegger has facilitated several groups doing citizen and participatory science (Bruegger et al. 2016A, Bruegger et al. 2016B). We will employ methods of structuring conversations detailed in Bruegger et al. and elsewhere to enhance discussion. For example, in one project, Bruegger et al. 2016(A and B) assembled a group of ranchers, county weed managers, Extension, NRCS and others to co-design, conduct and interpret an experiment on a topic of local concern. We met over 3 years in a local café to share results, plan, and interpret results. In the final meeting, after researchers presented results from analyses, we asked each member to individually reflect in response to prompts such as “I observe…..”, “I am surprised by…”, “I think the results mean…because………” etc. We then used these responses as the basis of a conversation to further interpret results, and ultimately integrated feedback into recommendations based on the findings. In this proposal, we will apply similar methods to directly involve stakeholders in interpretation of research. Producers play a critical role in evaluating the risks and benefits of adopting a new practice and are ultimately the ones managing land. Thus, integrating their knowledge and perspective into the project design and interpretation is essential. In this project, producers will be a part of developing the recommendations based on the research findings.

For our outreach objectives (Objectives 4-6), the methods are described below under “Educational Outreach Activities and Materials.”

Research results and discussion:

We have completed first year data collection, but we have 2 more seasons of data collection. Thus, no results at this time (3/29/22). 

Participation Summary
9 Producers participating in research

Research Outcomes

No research outcomes

Education and Outreach

40 Consultations
3 Curricula, factsheets or educational tools
1 Tours
7 Workshop field days

Participation Summary:

8 Farmers participated
1 Ag professionals participated
Education and outreach methods and analyses:

Consultations - 40

We consulted with farmers and ranchers, and others, via regular updates, meeting invitations, incidental interactions, and phone calls to coordinate the implementation of the experiment on local ranches. 

Curricula, factsheets or educational tools - 7

We have sent out 4 official educational tools so far to producers and participants on this project. The first, in June 2020, was a scope of work covering the timeline, commitment and goals of the project. This was a reiteration of the submitted proposal, but served to remind people of the experiment, and invite people to participate.

At a stakeholder meeting in June 2020, producers identified compost quality as a concern. To this end, we sampled 4 large, industrial composters in the Montrose/Delta/Mesa County area for salts, nitrogen and other nutrients and chemical characteristics. Some producers were interested in Fungal:Bacteria ratio, which we also tested for. We created a report from these results, which was distributed to each cooperating ag producer on the project, as well as customized copies were sent to each compost producer. 

In March 2021, we sent out a second education tool to the involved producers on the project, which was a summary of the work we've done so far, and explanation of how we integrated their feedback (gathered at meetings) and built upon it to move forward with the project. it also summarized the decisions made so far, and the timeline on the experiment. 

Workshop / field days - 7


Given the COVID-19 pandemic, we were not able to meet in person, but we did host 2 virtual meetings with stakeholders, the first in June 2020, and the second in September 2020 to discuss and get their input in to the experiment. These meetings were attended by those who wrote support letters for the project, and a few other interested parties. At the initial meeting in June 2020, critical discussions were around 1) compost quality, and 2) locations of plots. Based on this input, we undertook testing of compost, and we also changed one plot location so the pasture would be more representative of regional practices.  In March 2021, we joined an outdoor meeting of farmers/ ranchers in the Delta County area who were interested in composting. We have no results from the experiment yet (we won't until 2023), but we were able to connect with other producers interested in compost application. Compost Data Handout WSARE Compost Data WSARE Sept 2020 Meeting Slides

Compost Data Handout

2.26.2021 Compost Stakeholder write-up

In July of 2021, we hosted an Ag Field day in collaboration with the Colorado Department of Agriculture. We did not have results from the project, but they were interested in visiting the plot and learning about the experiment. 


We hosted a webinar meeting for stakeholders involved in the project to give us feedback and for them to learn about work that's been done. 

2022.04.11 WSARE Compost Update

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.