Organic Wheat Intercropping Trials and Outreach

Project Overview

Project Type: Farmer/Rancher
Funds awarded in 2010: $15,000.00
Projected End Date: 12/31/2010
Region: Western
State: Oregon
Principal Investigator:
Sarahlee Lawrence
Rainshadow Organics


  • Agronomic: wheat


  • Crop Production: cover crops, crop rotation, double cropping, intercropping
  • Education and Training: demonstration, extension, farmer to farmer, mentoring, networking, on-farm/ranch research, youth education
  • Farm Business Management: new enterprise development, feasibility study, whole farm planning
  • Natural Resources/Environment: biodiversity
  • Production Systems: transitioning to organic, holistic management, organic agriculture
  • Soil Management: green manures, organic matter, soil analysis



    We addressed the issue of meeting the nutrient needs of a large-scale organic grain crop while suppressing competitive weeds. We focused on a systems approach versus the use of expensive organic-approved fertilizer input. In India, there are native legumes that resemble clover that they have traditionally grown as a permanent cover crop with their grain crops. We wanted to know if we could mimic that symbiotic relationship that the legume has with the crop here in Central Oregon. We wanted to know if we could find a legume that would not overwhelm our wheat, but still suppress the weeds, and produce a yield that was financially acceptable. We hoped that our research would bridge the organic gap for our agricultural community.

    Many farmers are skeptical of organic farming because they can only relate by substituting their conventional practices with similar organic inputs. Simply substituting fertilizers with organically certified ones is cost prohibitive and does not nurture the soil. Fighting the weed wars is discouraging at best. We sought to show that our companion planting could get adequate yields that make it worthwhile to farm organically (taking the increased worth of organic products into consideration), with more people will consider switching to organic.

    We used a 25-acre transitional organic field planted in soft white spring wheat, then cross-drilled five different clover varieties at two different seeding rates, replicated three times, with a total of 33 test strips including three control strips. We kept careful track of irrigation and ultimately harvested a portion of each test strip. We ran several tests, which I describe below. Along the way, we had a field day and have submitted our data to Oregon State University for their annual agricultural publication.

    I cannot say that the clover showed any statistical significance in the production of the wheat, but as I have learned with organic farming, sometimes the benefits are not immediate. All of the clovers coexisted with the wheat, and the grain yield was acceptable across the board. We had very few weeds, but we did have a good stand of clovers after harvest, which was the most significant success of our research.

    Project objectives:

    1. To find a cover crop that provides nitrogen for grain production without overwhelming the grain. Which cover crop works best with the grain?

    2. To determine which cover crop provides the best competition for early weeds, because the cover crop will feed the weeds as well. So, the cover crop must shade the weeds. Which cover crop works best against the weeds?

    3. To find the optimum seeding rates for the companion planted crops.

    4. To share with our agricultural community a cost-effective, systems approach to growing adequate organic grain yields.

    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.