Effects of regenerative, organic, and conventional soil management and glyphosate on crops’ chemical composition

Project Overview

Project Type: Farmer/Rancher
Funds awarded in 2021: $9,000.00
Projected End Date: 01/31/2023
Grant Recipient: Sumner's Farm, LLC
Region: North Central
State: Missouri
Project Coordinator:
Dr. Walton Sumner, II
Sumner's Farm, LLC

Information Products


  • Agronomic: peas (field, cowpeas), amaranth
  • Vegetables: beets, greens (leafy), okra, radishes (culinary), sweet corn, tomatoes


  • Crop Production: fertilizers, food product quality/safety, no-till, organic fertilizers
  • Education and Training: demonstration
  • Farm Business Management: budgets/cost and returns
  • Pest Management: chemical control, mulches - general
  • Production Systems: organic agriculture
  • Soil Management: composting, organic matter, soil analysis, soil chemistry
  • Sustainable Communities: food quality: nutrient density & heavy metal exposure

    Proposal summary:

    My 2019 SARE FRG explored crops’ nutrient density as a function of soil management. An intense, expensive program to restore trace elements and soil organic matter unexpectedly decreased nickel content across diverse crops, and decreased several heavy metals in amaranth leaves and seeds, compared to conventional fertilization. Effects on selected nutrient compound densities were muted. Weed control using physical methods was challenging.
    High dietary nickel probably exacerbates Systemic Nickel Allergy Syndrome (SNAS), and may contribute to other common diseases. Heavy metal exposure should be minimized.
    Other SARE-sponsored reports suggest that no-till management allows soil microbiomes to supply major and trace elements to annual crops. Concerns exist that glyphosate (Round Up) and chemical fertilizers injure the soil microbiome.
    This proposal will compare 8 crop species grown in 5 soil and weed management conditions (no till field, no till sheet mulch, tilled, tilled with fertilizer, and tilled with fertilizer plus glyphosate), each in two fertilizer conditions (organic versus conventional). Outcome measures include heavy metals in amaranth and nickel in all crops. The main hypothesis is that no till strategies reduce input costs while achieving crop quality comparable to balanced organic amendments: this ecologically sound practice could improve economic viability and social health.

    Project objectives from proposal:

    1. Estimate net profit for each crop in the different weed and fertilizer management strategies (no till, sheet mulch, till, till+glyphosate x organic, conventional fertilizer).
    2. Describe how different weed and fertilizer strategies affect:
    a. dietary nickel exposure from diverse crops.
    b. dietary heavy metal exposures from amaranth leaves and seeds.
    3. Quantify dietary glyphosate and aminomethylphosphonic acid (AMPA) exposure following use for weed control.
    4. Share results in peer reviewed professional publications, conferences, a site tour, and social media.

    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.