Multi-Species Cover Crops Control Weeds and Improve Fertility in Organic No-Till Fields

Project Overview

Project Type: Farmer/Rancher
Funds awarded in 2010: $18,000.00
Projected End Date: 12/31/2012
Region: North Central
State: North Dakota
Project Coordinator:
Linda Grotberg
Prairie Farm Pilot Project


  • Agronomic: corn, millet, oats, rapeseed, rye, spelt, sunflower, wheat, grass (misc. perennial), hay
  • Animals: bovine, poultry, goats
  • Animal Products: dairy


  • Animal Production: parasite control, animal protection and health, grazing - continuous, free-range, grazing management, livestock breeding, manure management, mineral supplements, grazing - multispecies, pasture fertility, preventive practices, range improvement, grazing - rotational, housing, stockpiled forages, stocking rate, watering systems, winter forage, feed/forage
  • Crop Production: windbreaks
  • Education and Training: decision support system, demonstration, display, farmer to farmer, focus group, mentoring, networking, on-farm/ranch research, study circle, workshop, youth education, technical assistance
  • Energy: bioenergy and biofuels, energy conservation/efficiency, energy use, solar energy
  • Farm Business Management: whole farm planning, new enterprise development, budgets/cost and returns, marketing management, agritourism
  • Natural Resources/Environment: carbon sequestration, biodiversity, habitat enhancement, indicators, soil stabilization, wetlands, wildlife
  • Pest Management: allelopathy, biological control, competition, cultural control, economic threshold, eradication, field monitoring/scouting, genetic resistance, mulches - killed, mulches - living, mating disruption, physical control, prevention, sanitation, smother crops, mulching - vegetative, weather monitoring, weed ecology
  • Production Systems: agroecosystems, holistic management, organic agriculture, permaculture, transitioning to organic, integrated crop and livestock systems
  • Soil Management: earthworms, soil analysis, composting, nutrient mineralization, soil microbiology, soil chemistry, organic matter, soil physics, soil quality/health
  • Sustainable Communities: community planning, infrastructure analysis, leadership development, local and regional food systems, partnerships, public participation, analysis of personal/family life, community services, social capital, social networks, social psychological indicators

    Proposal summary:

    The Problem: The intense use of chemical fertilizers, herbicides, fungicides, pesticides, and tillage to keep the ground black by industrial agriculture has produced soil that is depleted in minerals, nutrients, and organic matter. This kind of soil does not have the ability to support the microbial life needed to rebuild and restore fertility and health. The seed bank of annual and perennial weeds and soil condition in these fields makes weed pressure the number one challenge to continuous organic no-till farming.

    The Importance of the Problem: The Food, Conservation, and Energy Act (FCEA) of 2008 identified assistance to organic producers as a top priority for EQIP. Due to their importance to organic systems and significant environmental benefits, the NRCS Chief has identified 6 core conservation practices for priority ranking and increased program support.

    These core conservation practices include no-till and multi-species cover crops. Susan Samson-Liebig, Soil Quality Specialist, USDA-NRCS, writes, “The use of cover crops has generated a lot of interest and there is much we have yet to learn. From a soils standpoint, we are very interested in soil biology in particular, under these systems and the effect cover crops have on select soil properties as well as carbon sequestration. We need demonstration sites to collect information to help better understand what works and what does not.”

    The Problem Solving Plan: Multispecies cover crops in an organic no-till system are an essential tool for weed control as well as restoring fertility and soil microbial life. Our plan will encompass three control sites: The Jack and Helen Olson Farm, which is certified organic and is beginning to use multi- species cover crops and conservation tillage in Organic EQIP. The Mark and Joan Gehlhar Farm, which is a conventional conservation tillage grain and custom grazing livestock farm. The Bethany Prairie Farm will be the demonstration site on eleven fields for organic no-till practices and multi-species cover crop mixes. The other farms involved in the project will test and record the findings of the organic, cover crops, and no-till treatments applicable to those farms, as well as compare their standard practices with those initiated at Bethany Prairie.

    Organic no-till field studies to suppress weeds and increase fertility will include one or more of the following treatments on each of the Bethany Prairie fields:
    Crop rotations that include high residue producing crops, to maintain 90 percent residue cover on the surface after seeding or include cover crops planted immediately following harvest of low residue producing crops

    Continuous organic no-till for all crops and cover crops in the planned rotation that is part of the organic system plan
    Deep mulch that is the result of continuous no-till, rolling winter rye using the Rodale roller/crimper, or grazing only 50 percent of cover crops or aftermath

    Winter crops and crops with natural allopathic characteristics to naturally suppress weeds

    Multi-species cover crops growing continuously by planting immediately after the crop is harvested or as a companion to the grain crop

    Mob grazing weeds immediately before or after planting grain or cover crops

    Termination of cover crops using non-chemical methods such as flail mowing, roller crimper and frost kill

    Clipping weeds such as Canadian thistle and wild mustard in growing grain and cover crops with a CRP style cutter instead of flail mowing or grazing

    Spreading chaff and chopping straw with the combine to provide an even soil covering

    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.