Nutrient Content of Field-grown Organic Heirloom Tomatoes as Influenced by Poultry Compost and Mychorrhizae Application

Safety and healthfulness of produce relate to several factors, including fruit nutrient content. Fruit nutrient content can be influenced by the growing medium and soil additives such as poultry composts. In this 2012 field study, the objective was to determine whether poultry compost and vesicular arbuscular mycorrhizae (VAM) affected the nutrient content of organically produced heirloom tomato (Lycopersicon esculentum) fruits. Tomato cultivars, Debarao Plum (DP) and Brandywine Red (BR) were transplanted at the field site and subjected to four treatments; control, VAM, poultry compost, and VAM + poultry compost.  Ripe fruits were analyzed for the nutrients; sulfur, phosphorus, calcium, aluminum, zinc, iron copper, arsenic, and lead. The amendments did not have a significant effect on fruit nutrient concentrations except for sulfur, which was the lowest (0.13%) in DP fruits from the VAM treatment. Cultivar, DP had higher levels of calcium than BR, with values ranging from 0.12% for DP to 0.09% for BR. Copper levels of DP fruits were generally lower than BR fruits across treatments, and ranged from 7.0 ppm for DP to 9.8 ppm for BR. Total arsenic and lead levels ranged from 0.8 to 1.0 ppm and 0.0 to 0.1ppm, respectively. These nutrient results indicate that the soil amendments used in this study did not pose a food safety risk factor to tomato fruits of Debarao Plum and Brandywine Red.