Maintaining agroecosystem health in an organic strawberry/vegetable rotation system

Continued growth of organic strawberry and vegetable production in California faces two challenges: soil-borne disease management without use of synthetic chemical fumigants, and fertility management to optimize fertility input use while ensuring protection of vulnerable habitats.
The goal of this project is to demonstrate effects of diverse organic strawberry/vegetable rotations and integrated ecological practices on agroecosystem health.
In 2001, we initiated a replicated on-farm trial at Moss Landing, California with number of years between strawberry crops as the main plot treatment (5 levels) and strawberry cultivar as sub-plots (2 levels). Ecological practices such as biofumigation with broccoli residues and mustard incorporation, compost application, use of vegetables that do not host Verticillium dahliae (spinach and broccoli) as rotational crops, and choosing strawberry cultivars that are less sensitive to disease are used in an integrated manner. While the main treatment effects will be tested after the fifth year, soil health indicators (Verticillium dahliae propagule number, soil inorganic N, and other physicochemical indicators) and agroecosystem health indicators (yield, disease incidence, and nutrient budgets) will be monitored during all five years.