Advancing Cover Crop Knowledge: Assessing the Role of Plant Diversity on Soil Change

Project Overview

Project Type: Graduate Student
Funds awarded in 2018: $25,000.00
Projected End Date: 03/31/2020
Grant Recipient: Montana State University
Region: Western
State: Montana
Graduate Student:
Principal Investigator:
Dr. Perry Miller
Montana State University


  • Agronomic: wheat


  • Crop Production: cover crops, fallow, nutrient cycling, nutrient management, water management
  • Education and Training: on-farm/ranch research, participatory research
  • Natural Resources/Environment: biodiversity, soil stabilization
  • Production Systems: dryland farming
  • Soil Management: nutrient mineralization, organic matter, soil analysis, soil chemistry, soil microbiology, soil physics, soil quality/health
  • Sustainable Communities: local and regional food systems

    Proposal abstract:

    In low rainfall areas of the northern Great Plains cover cropping is appropriately aimed at
    greening the summer fallow period, which is an economically risky practice. Over time, soils
    may improve sufficiently so that the increased crop return outweighs the cost of cover crops. The
    proposed study was begun in 2012 (SARE Project SW11-099) at two on-farm sites in Montana
    to compare different plant functional groups’ effects on soil properties. Eleven treatments are
    included in this replicated plot-scale study, including paired plant species representing four plant
    functional groups (brassicas, fibrous rooted, nitrogen fixing, and tap rooted crops) in various
    combinations and sole pea and chemical fallow as controls. The experimental design provides a
    unique opportunity to test each functional group, whereby 1) each group appears separately as
    four functional group treatments (‘presence’), 2) they appear together in a complete mixture, and
    3) the complete mixture minus each functional group (‘absence’). Due to the semi-arid climate,
    more time is required to see soil differences. We seek supporting funding to complete the final
    soil sampling in spring 2019, after four cycles of cover crops, in association with my M.Sc.
    thesis. This should have allowed enough time to elapse for a battery of biological, chemical, and
    physical soil assessments to be differentiated by functional group and what that does to the
    subsequent wheat quality. This research will fundamentally discover the role of functional
    groups within cover crop mixtures, and allow for more strategic design of cover crop seed mixes
    for targeted soil improvement. By making this research widely available, producers will be
    provided valuable information regarding methods of sustainable soil management. If soil benefits
    from long-term cover cropping can be proven to offset the short term economic loss, then this
    more sustainable management technique can be more easily adopted into our agricultural

    Project objectives from proposal:

    Soil and Agronomic Objectives
    1. To investigate how biomass production compares among the ten cover crop treatments
    included in this study.
    2. To measure how plant functional groups affect biological, chemical, and physical soil
    properties, and subsequent wheat yields and protein, differently.
    Educational Implications
    3. To increase local producer knowledge of the value, or lack there-of, for cover crop
    mixtures compared with less diverse cover crops for biomass production, soil water and
    nitrogen use, and change in biological, chemical, and physical soil properties.
    • Pre- and post-presentation mini-surveys will be used to measure changes in local
    producer knowledge at a 2018 field day to be held at either the Amsterdam or
    Conrad project site.
    4. To provide producers with information regarding the potential benefits of alternative
    cover crops through scientific publications, extension publications, popular press articles,
    social media, public presentations, and research summaries and factsheets.
    • The number of viewers at each presentation will be tracked to assess the impact of
    presentations on producers and others present. The number of people who “like”,
    “follow” or “view” the information provided on social media will also be tracked.
    The results of this research will provide fundamental knowledge on the ability of different plant
    functional groups to change soil properties distinctly. This base knowledge will be helpful in
    optimizing strategies for deploying cover crop mixtures over time and to serve specific functions
    to the soil.

    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.