Evaluation of Crop Rotation for High Value Cool Season Horticultural Crop Production in Organic and Sustainable Systems

Project Overview

Project Type: Research and Education
Funds awarded in 2010: $200,000.00
Projected End Date: 12/31/2014
Region: Southern
State: Georgia
Principal Investigator:
Dr. George Boyhan
University Of Georgia

Annual Reports

Information Products


  • Agronomic: potatoes
  • Fruits: berries (strawberries)
  • Vegetables: broccoli, carrots, onions, peas (culinary)


  • Crop Production: crop rotation, cover crops, nutrient cycling, organic fertilizers
  • Education and Training: extension
  • Farm Business Management: new enterprise development, budgets/cost and returns, agricultural finance, risk management
  • Pest Management: biological control, cultural control
  • Production Systems: organic agriculture
  • Soil Management: green manures, organic matter, soil analysis, nutrient mineralization, soil quality/health
  • Sustainable Communities: local and regional food systems

    Proposal abstract:

    The interest in organic and locally produced food has increased the demand for organic produce grown in the Southeast. However, there is little information available on profitable organic vegetable crop production suitable for the Southeast. Recent SARE-funded focus groups with vegetable growers in Georgia indicated better information on organic techniques that were suitable for medium-sized farms (20 – 150 acres) is needed. Current organic vegetable budgets focus only on one crop. Economic models that encompass the profitability of entire rotations are needed. The purpose of this project is to take a systems approach to evaluate two crop rotations to produce high value certified organic horticultural crops in the Piedmont and Coastal Plain of the Southeast. Crop rotations includes: Rotation 1- Strawberries ?> Soybeans ?> oats/Austrian winter peas ?> Potatoes ?> Sunhemp ?> Onion ?> southernpeas; Rotation 2 – Brassica ?> Sugar snap peas ?> Sudax/Iron Clay Peas ?> Carrots ?> Sugar snap peas ?> Sunhemp ?> Onion ?> Millet. The proposed rotations focus on cool-season high value crops. They were developed with grower input to improve soil quality through cover crop biomass addition, to rotate between crop families to break pest cycles, to use cover crops to supply nitrogen and suppress weeds, and to use cover crops and crop cycles to suppress nematodes. The project will evaluate yield, crop quality, soil quality, disease incidence, and the economics of the two proposed crop rotations at two University Research and Education Centers in the Piedmont and Coastal Plain. The data will be used to develop production recommendations and a production budget for the entire rotation. By developing an economic model to encompass the profitability of the proposed rotations, we hope to demonstrate the importance of a systems approach to sustainable organic production. The results may be particularly useful for conventional growers interested in transitioning to organic production. Grower input will be used throughout the study to evaluate results and recommend solutions to problems encountered. Results will be presented at regional and national horticultural conferences, vegetable growers’ meetings, e.g. Southern Region American Society for Horticultural Science, Georgia Organics Annual Conference, Southern Sustainable Agriculture Working Group, The Southeast Regional Fruit and Vegeable Growers conference, and Deep South Vegetable conference. The study will be integrated into the training for the newly formed Organic Production Team. In addition, results will be posted on the recently developed Sustainable Agriculture webpage (www.SustainAgGa.org). The impact on grower adoption in Georgia will be assessed through county agents on the Organic Production Team. These agents will survey their growers’ current rotations and vegetable crops before the study and again one year after the study is completed. This will provide an index of potential impact throughout the Southeast.

    Project objectives from proposal:

    The overarching objective of the study is to evaluate the profitability and production characteristics of two cool-season vegetable crop rotations in the Piedmont and Coastal Plain physiographic regions. The research will be conducted at University Research and Education Centers that have certified organic land in each region.

    Objective 1 - Develop an econometric model to evaluate the profitability of the two rotations.
    Objective 2 - Evaluate changes in plant nutrient status, crop yield and quality in the two crop rotations. Data on harvest date, yield, and graded yield will be collected for all treatments. Tissue samples will be collected to evaluate plant nutrient status at critical growth stages.
    Objective 3 - Evaluate changes in soil quality in the two crop rotations. Changes in soil quality will be measured using total carbon and nitrogen, potentially mineralizable nitrogen, active carbon, pH, and Mehlich extractable P, K, Ca, Mg, and Zn.
    Objective 4 - Determine disease incidence in the two rotations and on the specific crops grown.
    Objective 5 - Evaluate the research and potential impact, and disseminate results.

    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.