Transition to Organic Vegetable Production by Large-Scale Conventional Farmers

Project Overview

Project Type: Research and Education
Funds awarded in 2001: $123,399.00
Projected End Date: 12/31/2004
Matching Non-Federal Funds: $128,246.00
Region: Western
State: California
Principal Investigator:

Annual Reports


  • Vegetables: broccoli, cauliflower, celery, greens (leafy), onions
  • Additional Plants: herbs


  • Crop Production: cover crops, double cropping, fallow, fertigation, municipal wastes, nutrient cycling, organic fertilizers, application rate management, tissue analysis
  • Education and Training: technical assistance, demonstration, display, extension, farmer to farmer, on-farm/ranch research
  • Farm Business Management: budgets/cost and returns, agricultural finance, risk management
  • Pest Management: biological control, botanical pesticides, competition, cultural control, disease vectors, economic threshold, field monitoring/scouting, physical control, prevention, trap crops, weed ecology
  • Production Systems: transitioning to organic, agroecosystems, integrated crop and livestock systems
  • Soil Management: green manures, organic matter, soil analysis, nutrient mineralization, soil quality/health
  • Sustainable Communities: partnerships, public participation, sustainability measures


    Whole-farm analysis showed that flexible management techniques and careful planning helped large-scale California vegetable farmers convert successfully to organic production. Participatory research involved monitoring of 81 points on two ranches for three years. Biodiversity-based management included many crop species, cover crops, and insectary strips. No increase in disease, insect pests, or nutrient deficiency occurred during the transition. Soil quality improved due to higher microbial biomass and less potential for nitrate leaching. In specific experiments, yard-waste compost had similar effects as manure-based compost, and brassica cover crops caused no decline in mycorrhizal colonization or crop nutrient content. Organic transition was clearly viable in the midst of a conventional farming area.

    Project objectives:

    Our objectives were to: 1) Monitor changes in crop species and yield, soil organic matter and soil microbiology, diseases, insects, and weeds during the three-year organic transition. 2) Design experiments to target specific management and pest problems as they arise. 3) Track changes in agronomic management, economic issues, and decision-making. And, 4) disseminate findings via field days, public meetings, workshops, and publications.

    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.