Climate mitigation through soil carbon sequestration: increasing soil resilience and plant productivity on rangelands through compost application

Project Overview

GW19-202
Project Type: Graduate Student
Funds awarded in 2019: $24,766.41
Projected End Date: 10/31/2020
Host Institution Award ID: G156-20-W7503
Grant Recipient: Western State Colorado University (doing business as Western Colorado University)
Region: Western
State: Colorado
Graduate Student:
Major Professor:
Dr. Jennie DeMarco
Western Colorado University
Major Professor:
Amy Honan
Western Colorado University

6/18/2020: Extended end date per approved NCE request from PI and student. - Jen vS

Information Products

Commodities

  • Agronomic: clovers, grass (misc. perennial)
  • Additional Plants: native plants

Practices

  • Animal Production: feed/forage, grazing management, range improvement, rangeland/pasture management
  • Crop Production: drought tolerance, irrigation, nutrient cycling, nutrient management, water management, water storage
  • Education and Training: demonstration, networking, on-farm/ranch research, participatory research, workshop
  • Farm Business Management: risk management, value added, whole farm planning
  • Natural Resources/Environment: carbon sequestration, soil stabilization
  • Pest Management: mulches - general
  • Production Systems: holistic management
  • Soil Management: composting, organic matter, other, soil analysis, soil chemistry, soil microbiology, soil physics, soil quality/health
  • Sustainable Communities: local and regional food systems, partnerships, sustainability measures

    Proposal abstract:

    Title: Climate mitigation through soil carbon sequestration: increasing soil resilience and plant productivity in rangelands through compost application

                Climate change has already shifted the climate and precipitation levels in Colorado, making it hotter and drier. Due to these changes, ranchers are more inclined to improve their soil’s health, specifically the water holding capacity (WHC). By increasing the WHC of soil, ranchers can expect positive effects of increasing plant productivity. Soil’s WHC is extremely important in arid climates where ranchers rely upon flood irrigation during the spring and early summer. Once the irrigation is shut off, the water needs to sustain the grasses throughout the growing season until harvest. Typically, ranchers in the West harvest three cuts of hay during the season. In Gunnison, due to the short growing season of 62 days, ranchers only get one. Ensuring that single cut of hay is as productive as possible is of vital importance to the ranchers whose livelihoods depend upon that yield. Improving the soils WHC by increasing the soil’s organic matter (SOM) content has shown to promote plant productivity (Deng et al., 2016). Through the application of compost, the amount of SOM content can be increased (Hudson, 1994). This project addresses three questions related to soil health:

    1) How does the application of compost increase the C sequestration potential of rangelands in this specific climate?
    2.) Does compost additions enhance SOM to increase the soil’s WHC?
    3) Does this amendment improve the infection percentages of plant roots by arbuscular endomycorrhizal fungi?

    These questions will be addressed by conducting research on 4 ranches where we will monitor the effects from 2 inches of compost addition on rangeland’s soil health. Expected outcomes are increased soil health, improved soil WHC, and increased soil C storage.

    Project objectives from proposal:

    The goal of this research is to provide ranchers and rangeland managers with site specific research on how compost amendments in this climate impact their soil water holding capacity. This will be achieved by improving the soil health, specifically the SOM and endomycorrhizal contributions to soil structure i.e. the creation of soil aggregates.

     

    With additions of compost to rangelands we expect to:

    1. Increase soil health, specifically looking at water holding capacity.
    2. Increase plant productivity.
    3. Increase endomycorrhizal infection percentage.
    4. Foster increased soil carbon sequestration.

     

    In addition (objective 5), we will assess ranchers’ needs and interests in improving soil health and to share results of this study the community in order to inform future land management practices.

    To achieve objective 1 (increase soil health), we will quantify differences in soil pH, moisture content, organic matter, bulk density, and nutrients between rangelands sites treated with compost versus untreated sites. To determine the soil’s water holding capacity, two tests will be conducted on soil samples: field capacity and wilting point.  The water available for plant growth is the difference between field capacity water content and wilting point water content.

    To achieve objective 2 we will measure the plant biomass differences between the treatment sites and control.

    To achieve objective 3 we will measure the percent infection rate of grass roots with endomycorrhizal fungi.

    To achieve objective 4 we will be quantifying the amount of carbon that has been sequestered in the soil in the treated and compare it to control sites.

    To achieve objective 5 we will put on two soil health workshops specifically on rangelands for the local agriculture community. Panel on soil health, research results and info-graphics of key points of the workshop information. Education of Gunnison producers on soil sustainability in this way is crucial for soil conservation and ecological health. 

    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.