Economic Analysis of Anaerobic Soil Disinfestation on Tomato Production in Southwest and North Florida

Chemical soil fumigants (CSF) are widely used for soil disinfestation in horticultural crop production. With the phase-out of methyl bromide due to its impact on ozone depletion, research has focused on developing alternative chemical and biological fumigation methods. Anaerobic soil disinfestation (ASD) is biological method developed to suppress plant parasitic nematodes, weeds and soil borne pathogens. ASD uses a labile organic carbon source like molasses or composed poultry litter (CPL), to stimulate microbial respiration and O₂ consumption in the soil. ASD uses VIF (virtually impermeable film) to seal the soil, thereby limiting gas exchange between soil and air space. ASD uses irrigation to saturate the pore space, which creates anaerobic conditions and enhances the diffusion of byproducts through the soil solution. ASD is environmentally friendly and could result in higher crop than chemical fumigation methods. However its application requires additional labor and increases material costs compared to chemical treatment.

This study evaluates the economic viability of using ASD in tomato production drawing on data produced by two field experiments conducted at the University of Florida Southwest Florida Research and Education Center (SWFREC) in Immokalee and the Plant Science Research and Education Unit (PSREU) in Citra, FL in fall 2015. Each location had one CSF and two ASD treatments in a randomized complete block design. The CSF treatment used Pic-Clor 60 at the rate of 224 kg/ha at both locations. The two ASD treatments used different rates of molasses and CPL, 6.93 m³/ha molasses and 11 Mg/ha CPL were applied for ASD0.5, 13.86 m³/ha molasses and 22 Mg/ha CPL were applied for ASD1.0. The economic analysis focused on differences between the CSF and ASD treatments with regard to land preparation cost, gross return and net return. The land preparation cost per plant was $0.35- $0.38 in CSF and $0.74-$1.31 in ASD treatments. Two ASD treatments in Immokalee generated higher net return than the CSF treatment. Although the commercial viability on ASD in Citra was not obvious, we can still get profit if we sell the Citra’s tomato at Immokalee’s price. The planting date was not the most concerned factor. However the market tomato price changed a lot as time changing. In conclusion, ASD increased yields and can be an economically viable tomato field production method in Florida in most cases.