Improving vegetable yield, profit, and quality of life on urban farms with a new biobased, compostable weed barrier for narrowly spaced crops

Project Overview

FNC24-1407
Project Type: Farmer/Rancher
Funds awarded in 2024: $15,000.00
Projected End Date: 02/15/2026
Grant Recipient: Frogtown Farm
Region: North Central
State: Minnesota
Project Coordinator:

Commodities

  • Vegetables: beets, carrots, cucurbits, greens (leafy), greens (lettuces), onions, radishes (culinary)

Practices

  • Crop Production: varieties and cultivars, water management
  • Education and Training: demonstration, farmer to farmer, mentoring, on-farm/ranch research, participatory research, youth education
  • Farm Business Management: labor/employment
  • Natural Resources/Environment: soil stabilization
  • Pest Management: mulches - general
  • Sustainable Communities: local and regional food systems, public participation, quality of life, urban agriculture

    Proposal summary:

    Hand weeding vegetables is time
    consuming and back-breaking, particularly in narrowly spaced
    crops like leafy greens, carrots, and green onions. Many urban
    farmers and gardeners have full-time jobs off the farm and tend
    their crops in the evenings and on weekends, which makes the
    opportunity cost of hand weeding particularly severe. Common
    alternatives to hand weeding in these crops include stale seed
    bedding, flame weeding, and tillage with harrow and tine weeders;
    however, stale seed bedding displaces valuable time in an already
    short Minnesota growing season and flame weeding and tillage are
    time-sensitive, only partially effective, and can cause
    significant crop damage. For most of our crops, mulching is the
    most promising option for lasting weed suppression during the
    growing season, but traditional plastic mulch films and
    geotextile fabrics are not feasible for narrowly spaced crops
    because the number of planting holes required compromises the
    integrity and function of the barrier. In addition, plastic-based
    films and fabrics can contaminate soil and must be removed and
    landfilled at the end of their useful life. We need a viable
    biobased, mulching strategy to eliminate hand weeding in narrowly
    spaced crops on our farms. 

    Project objectives from proposal:

    RootThru

    Toward the goal of eliminating
    hand weeding in narrowly spaced, high density vegetable crops, we
    will test the RootThru Weed Barrier in comparison to our current
    weed management practices. RootThru is a composite geotextile
    fabric made from two sustainable, 100% plant-based materials –
    paper and corn. RootThru is unique from other weed barriers
    because we can plant our seeds directly on the barrier and the
    seedlings grow and root through it; and yet, weed growth is
    effectively suppressed below the barrier. Unlike plastic-based
    weed barriers, RootThru is biobased and can be taken to a
    composting facility after field removal instead of the
    landfill. 

    RootThru is installed by
    following these four steps: 1) prepare the soil by removing weeds
    and creating furrows for seeds; 2) unroll the weed barrier onto
    the soil, form fabric into furrows, and secure the edges with
    soil or landscape staples; 3) plant seeds into furrows directly
    on the fabric or into a layer of weed-free compost or soil mix;
    4) cover seeds with additional compost or soil mix and irrigate
    daily until seeds have germinated and rooted through the fabric.
    Once established, RootThru eliminates the need for hand weeding
    and frees time and energy to create value elsewhere on the
    farm.  

    We received free sample rolls of
    RootThru in July 2023 to test at Frogtown Farm and Kilimo
    Minnesota Farm in carrot, radish, turnip, sweet corn, jute, and
    collard greens. Results were promising and individual growers
    were enthusiastic about the product. Nura Ahmed, a long-time
    grower at Frogtown Farm said, “I couldn’t believe it, there are
    no weeds [in my jute crop] …that is really amazing!” Given the
    initial anecdotal success of RootThru, we would like to expand
    its use on our farms and quantify the potential benefits for our
    farms and share those results with other growers. 

    In 2024, we will establish field
    research and demonstration trials at Frogtown Farm and Kilimo
    Minnesota - Lino Lakes Farm to compare the RootThru Weed Barrier
    with existing farmer weed management practices (including straw
    mulching, hand weeding, and tine weeding). We will use a
    mother-baby experimental design whereby there is one controlled,
    replicated “mother” trial at Frogtown Farm and at least 3
    non-replicated “baby” trials at each farm. Baby trials will be
    valuable for providing additional replication of treatments in
    the mother trial (additional validation) and for demonstrating
    the technology under real-life conditions (thereby improving the
    potential for farmer adoption). In the mother trials, RootThru
    will be compared to a combination of mechanical and hand weeding
    across three replicated, randomized experimental
    plots. 

    At the end of the experiment,
    RootThru will be removed from the field and delivered to a
    commercial composter, Specialized Environmental Technologies
    (SET) in Rosemount, MN. SET will also provide the compost
    necessary for the trials, demonstrating the full circularity and
    sustainability of the RootThru system (whereby compost produced
    from RootThru in one season can be used to grow crops in RootThru
    in subsequent seasons). 

    Data collection plans from these
    field trials are summarized in the “Measuring Results” section
    below.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and should not be construed to represent any official USDA or U.S. Government determination or policy.