PARENT SESSION
Contributed Oral Session 55: Agroecology: Management
Tuesday, August 9, 1:30 PM - 5:00 PM, Meeting Room 513 A, Level 5, Palais des congrès de Montréal

Whole farm analysis: Monitoring the transition from conventional to organic agriculture.

Smukler, Sean^*,1, Murphee, Liese², Yakota, Ron³, Ramirez, Ireene ¹, Smith, Richard ⁴, Jackson, Louise¹, ¹ University of California, Davis, Davis, CA, USA² California State University Monterey Bay, Monterey, CA, USA³ Tanimura and Antle Inc., Salinas, CA, USA⁴ UC Cooperative Extension, Salinas, CA, USA

ABSTRACT- Due to the inherent complexity of organically-managed agricultural ecosystems, on-farm research is important for understanding ecological processes in actual production systems and providing results that are useful and accessible to farmers. A whole farm analysis enables the evaluation of responses typical of the populations and communities of organisms on actual farms at representative rates (e.g. pest populations and soil properties). Grower participation facilitates the implementation of research, driving the development of questions, design and results. The objectives of the project were to:(1) Monitor changes in crop species and yield, soil organic matter and microbiology, diseases, insects and weeds (2) Design experiments to target specific management and pest problems (3) Track changes in agronomic management, economic issues and decision-making Our interdisciplinary research team employed a transect approach often used in wildland ecological research to study transition from highly-intensive conventional vegetable production to organic production. Permanent transects were established across two ranches at the onset of adoption of organic practices by our cooperator (Tanimura and Antle, Inc., Salinas Valley, CA), and soil and plants were sampled at harvest of most crops. Results from the 3-yr period indicated the following trends: increase in total soil C and in soil microbial biomass, low soil NO₃ pools, adequate crop nutrients, minor disease and weed problems, and sporadic mild insect damage. Changes in management included higher crop diversity, small plantings, drip irrigation, and annual cover crop, compost and manure applications. Using various statistical approaches, we are addressing questions about specific changes through time, and interrelationships between inputs, practices, and measured parameters. Factors contributing to the overall success of the transition to organic production and implications for improvement of the transition process will be discussed.

Key words: agroecology, organic, soil