On Farm Research to Quantify the Value of Cover Crops for Nutrient Crediting

Project Overview

Project Type: Partnership
Funds awarded in 2016: $30,000.00
Projected End Date: 05/01/2019
Grant Recipient: Minnesota Department of Agriculture
Region: North Central
State: Minnesota
Project Coordinator:
Spencer Herbert
Minnesota Department of Agriculture
Aicam Laacouri
Minnesota Department of Agriculture


  • Agronomic: corn, soybeans


  • Crop Production: cover crops, nutrient cycling, tissue analysis
  • Education and Training: demonstration, farmer to farmer, on-farm/ranch research, workshop
  • Farm Business Management: budgets/cost and returns
  • Natural Resources/Environment: biodiversity, soil stabilization, carbon sequestration
  • Soil Management: green manures, organic matter, soil analysis, nutrient mineralization, soil chemistry, soil microbiology, soil quality/health

    Proposal abstract:

    This project aims to engage and support farmers that are currently using cover crops and work with them to share information with other local farmers. There has been much research and discussion about implementing cover crops and the benefits to soil health, however, this study will measure and quantify some of the benefits of cover cropping. We will work with four farmers in southern Minnesota, all of whom are experienced in cover cropping. These four individuals, working with their local conservation districts, are key members of the Freeborn County Soil Health Team. Their group aims to promote beneficial soil health practices by hosting field days, collecting data, and educating other farmers who are interested in cover crops. These farmers are eager to learn how their cover cropping practices improve soil health, and want technical assistance to quantify soil health, plant health, and economic parameters. Participating farmers have asked for help collecting local data to guide them in quantifying the physical and economic benefits that the practice is providing. In this study, we will quantify one potential benefit that cover crops provide; their ability to scavenge, recycle, and release nutrients for subsequent cash crops.

    Project objectives from proposal:


    1. Monitor nutrient levels throughout the cover crop life cycle to establish a procedure for properly crediting cover crop nutrients for subsequent cropping years. If this can be done successfully, there is potential to reduce fertilizer inputs. Reduced fertilizer inputs would save the farmer money and could potentially reduce nutrient losses that are impacting water quality.
    2. Generate high quality data for this specific geographic area, soils, and climate.
    3. Provide education and outreach through field days, fact sheets, handouts, etc. This will help local farmers make more informed management decisions regarding cover crops.


    Research Activities

    The main goal of the study is to quantify the ability of cover crops to scavenge nutrients from the soil, and release those nutrients as “credits” for subsequent cash crops. Plant and soil parameters will be monitored in an attempt to quantify these values. Non-treatment, control areas will be monitored for the same parameters, providing baseline data for comparison.

    - Each of the four participating farmers will select one corn field and one soybean field in each year of the study. There will be four corn fields and four soybean fields studied each year.


    - Cover crops will be applied according to the farmers’ normal management methods. Each farmer
    will utilize the same management methods from field to field and year to year, but application
    method, application timing, and cover crop specie(s) selection may vary between farmers.

    - Cover crops will be applied across the entire field, with strategically sized and placed control areas.

    - The parameters measured will include:
    o Cover crop biomass
    o Cover crop nutrient content (tissue sample analysis)
    o Soil nitrate
    o Comprehensive soil nutrient levels (standard composite soil samples)
    o Infiltration rates
    o Compaction
    o Cash crop stand counts
    o Cash crop yield
    o Management and financial information

    The combination of biomass measurements and tissue sample analysis will provide an estimate on the
    total amount of each analyzed nutrient assimilated in the cover crop stand. Periodic soil nitrate
    samples will allow us to track when nitrogen is being released by the terminated cover crop. Other
    parameters measured will help to gauge the effects on soil health and existing cash crop.


    Participating farmers will share their results and experience through a minimum of four
    individual or combined field days and outreach events. The Freeborn Soil Health Team, which
    cooperating farmers participate in, has a presence in the local farming community and holds annual
    spring and fall field days. Fact sheets and educational materials will be developed and distributed at
    local and regional events. Lessons from this study will be shared through a number of local media
    distributions including newsletters and newspapers.

    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.