- Vegetables: tomatoes
- Crop Production: nutrient cycling, organic fertilizers
- Education and Training: extension, on-farm/ranch research
- Pest Management: chemical control, field monitoring/scouting
- Soil Management: organic matter, soil analysis, soil microbiology, soil chemistry, soil quality/health
Agricultural transition from methyl bromide has led to a resurgence of diseases caused by soilborne pathogens, especially wilt caused by Fusarium oxysporum f.sp. lycopersici (Fol). Addition of organic matter through the application of composts and management of pH by liming may reduce the incidence of Fusarium wilt during commercial production of tomatoes on sandy, acidic soils. In addition, the application of organic composts may improve soil physical, biological and chemical properties, which improves plant nutrient uptake and suppression of certain plant diseases. The goal of this study was to determine the effect of compost and lime on soil organic matter, the soil microbial community, including Fusarium spp., and the incidence and severity of diseases caused by soil borne pathogens, such as Fol. Composted yard waste and lime were added to the soil during bedding operations at a commercial tomato field in Florida. We evaluated soil microbial populations, Fol. populations, soil organic matter content and nutrient status and soil CO2 flux over two production seasons. Data collection is planned for an additional growing season in 2011.
Project objectives from proposal:
The objective of this study is to determine the effect of compost and lime on soil organic matter, the soil microbial community, including Fusarium spp., and the incidence and severity of diseases caused by soil borne pathogens, such as Fol. Specifically, the proposed treatments will directly evaluate the effect of compost and lime amendments on the severity of Fusarium wilt, soil microbial community structure and soil organic matter.
In addition, we will evaluate the effect of compost amendments on soil organic matter under Florida’s humid sub-tropical climate. Increases in soil organic matter can improve nutrient cycling, increasing water holding capacity and sequester carbon. We will also determine the effect of the proposed treatments on the availability of essential plant nutrients, especially Ca and Mg. Both Ca and Mg can form complexes with dissolved organic carbon and be leached from the soil when composts are applied. Losses of Ca and Mg from soils can lead to abnormal fruit development (blossom end rot) and large yield losses.
Results from this study will give Pacific Tomato Growers (Mr. Whiddon) and the greater grower community guidance in the use of soil amendments and soil pH management. The information collected as part of this project will be invaluable to Mr. Whiddon and other organic growers in the southeastern U.S., where few options for the management of soilborne disease and pest problems are available. This research is part of a long-term effort by both UF investigators to identify cost-effective cultural practices that reduce the need for chemical pesticides and fertilizers by improving soil conditions that enhance soil microbial populations and activity. Such practices are sustainable, environmentally benign and have practical applications for conventional and organic crop production in Florida and other southeastern states.