Compost application on rangeland in the semi-arid southwest for increased soil C storage and forage production

Project Overview

FW20-363
Project Type: Farmer/Rancher
Funds awarded in 2020: $19,981.00
Projected End Date: 04/01/2023
Host Institution Award ID: G355-20-W7900
Grant Recipient: Polk’s Folly Farm
Region: Western
State: New Mexico
Principal Investigator:
Zachary Withers
Polk’s Folly Farm

Commodities

  • Agronomic: grass (misc. annual), grass (misc. perennial)
  • Animals: bovine

Practices

  • Animal Production: range improvement
  • Soil Management: composting, soil analysis

    Summary:

    In the semi-arid Southwest, rangeland restoration is needed to ensure economically  viable agricultural operations in light of historical mismanagement of rangeland and climate change. Compost application to croplands and rangelands in mesic environments has proven successful to increase forage production and soil carbon storage, essential for soil water-holding capacity. Here we propose leveraging current compost production at Polk’s Folly Farm to assess the efficacy of compost application to rangeland for increased forage production and soil carbon storage at two semi-arid sites in New Mexico (annual precipitation ~ 460 mm). Polk’s Folly Farm and Sol Ranch collaborated with the Quivira Coalition and New Mexico Tech to assess this method at two sites with native plant communities using three application rates and a control. After one year, ranches saw improved aboveground biomass, methane uptake, and infiltration rate with compost addition. In order to provide a comprehensive picture of project efforts to producers, Polk’s Folly Farm created an economic case study of on-farm compost production. Additionally, the team held two field-days featuring the experiments and Polk’s Folly Farm and Sol Ranch discussed their experiences on Quivira Coalition’s podcast. Results were presented at the annual REGENERATE conference, where the largest attendee group is producers. Assessing the efficacy of this nationally recognized method for increasing soil carbon storage and forage production in semi-arid sites will inform producers, agencies, and technical service providers’ management decisions.

    Project objectives:

    Objective 1: Determine best methods and economic feasibility of compost production on Polk’s Folly Farm

    • Produce compost with a C:N >11 appropriate for rangeland application [4,6]
      • Polk’s Folly Farm, Eva Stricker (technical advisor), Benjamin Duval (researcher)
    • Open-source, free economic case study of compost production
      •  Polk’s Folly Farm, Eva Stricker, Benjamin Duval

    Objective 2: Determine appropriate compost application rate 

    • Establish 3 application rates (1/4, 1/2, and 1") and a control plot in experimental plots
      • Polk’s Folly Farm, Sol Ranch, and Eva Stricker

    Objective 3: Determine compost application effect on soils and plant communities

    • Soil sampling and analyses at pre-treatment (year 1) and years 2 and 3. Plant community monitoring at pre-treatment and years 2 and 3. 
      • Lead: Eva Stricker, all team members participate
    • Analyze and interpret data for presentation at 2021 and 2022 REGENERATE Conference
      • Eva Stricker and Benjamin Duval

    Objective 4: Producer focused engagement in experimental setup and the WSARE grant application process

    • Experimental design and compost application field-day
      • Eva Stricker, Polk’s Folly Farm, and Sol Ranch
    • Podcast about WSARE Farmer/Rancher Research and Education Grant process for producers
      • Polk’s Folly Farm and Sol Ranch 
    • Presentation of results at 2021 and 2022 REGENERATE Conferences
      • Eva Stricker, Polk’s Folly Farm, and Sol Ranch
    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.