Testing the potential of seed pellets to improve the soil health in rangelands

Project Overview

Project Type: Graduate Student
Funds awarded in 2022: $28,577.00
Projected End Date: 07/31/2024
Host Institution Award ID: G129-23-W912
Grant Recipient: University of Arizona
Region: Western
State: Arizona
Graduate Student:
Principal Investigator:
Dr. Albert Barberan
University of Arizona


  • Agronomic: grass (misc. perennial)


  • Animal Production: feed/forage
  • Crop Production: biological inoculants, fertilizers, foliar feeding, food product quality/safety, nutrient cycling, nutrient management, organic fertilizers, tissue analysis
  • Education and Training: on-farm/ranch research, youth education
  • Natural Resources/Environment: biodiversity, habitat enhancement, soil stabilization
  • Production Systems: dryland farming
  • Soil Management: soil chemistry, soil microbiology, soil quality/health
  • Sustainable Communities: sustainability measures

    Proposal abstract:

    Soil degradation is a pressing challenge faced by ranchers from the western US. It not only lead to direct economic loss through a decline in forage value but also deteriorated residents’ life quality with increasing air and water pollution. Passive soil health improvement methods such as grazing exclosures are not effective under harsh dryland environments. Active methods such as soil amendment are costly and require extra effort and equipment that are not commonly available for ranchers. Our project plans to test the potential of using seed pellets to improve soil health. Ranchers can integrate soil health management into their routine reseeding process using accessible materials. Seed pellets are increasingly used in dryland restoration to reduce seed loss and facilitate germination. Beneficial microorganisms and soil organic amendment will be added into seed pellets. Both can improve nutrient cycling, stabilize topsoil, enhancing plants’ abiotic stress tolerance and yield. Our on-ranch experiment will be conducted at the barren land of King's Anvil Ranch in Tucson, Arizona, to simulate the reseedling of a degraded plot in rangeland. A simultaneous greenhouse experiment will be conducted to test seed pellets’ lifespan, which is crucial to the feasibility due to the unpredicted precipitation in drylands. We also plan to organize field days, deploy presentations in local meetings and academic conferences, and publish in a peer-review journal and social media, to share our results with stakeholders and popularize the importance of soil health and microorganisms.

    Project objectives from proposal:

    This project seeks to investigate the short-term and long-term benefits of using seed pellets inoculated with soil amendment and/or microorganisms. In the on-ranch experiment, we will measure how plant establishment, forage quantity and quality differ between pelletized and unpelletized seeds. Soil health indicators (soil stability, available water capacity, nitrogen, phosphorus, organic matter, and microbial community composition) will be assessed to determine the effect of seed pellets on soil health. If both forage value and soil health are improved, it will support the feasibility and profitability of the seed pellet method. Results between seed pellets with or without soil amendment and microorganisms can determine the effectiveness of each component. This will allow us to develop a more profitable seed pellet receipt. In the simultaneous greenhouse experiment, we will quantify how the effect of seed pellets decay over time. It will give farmers additional information on how often to apply seed pellets.
    Progress and results of this project will be shared with stakeholders through field days and presentations on producer-organized meetings, workshops, and symposia. We aim to illustrate to stakeholders the importance of soil microorganisms and soil health to sustainable ranching. This work will be submitted to a peer-reviewed journal and used to generate a series of factsheets and blogposts to maximize our work's impact.

    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.