|DI GIOIA, FRANCESCO - University Of Florida|
|OZORES-HAMPTON, MONICA - University Of Florida|
|ZHAO, XIN - University Of Florida|
|THOMAS, JOHN - University Of Florida|
|WILSON, PATRICK - University Of Florida|
|LI, ZHUONA - University Of Florida|
|SWISHER, MARILYN - University Of Florida|
Submitted to: Agriculture, Ecosystems and Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/18/2017
Publication Date: 3/1/2017
Citation: Di Gioia, F., Ozores-Hampton, M., Zhao, X., Thomas, J., Wilson, P., Li, Z., Hong, J.C., Albano, J.P., Swisher, M., Rosskopf, E.N. 2017. Anaerobic soil disinfestation impact on soil nutrients dynamics and nitrous oxide emissions in fresh-market tomato. Agriculture, Ecosystems and Environment. 240:194-205. https://doi.org/10.1016/j.agee.2017.02.025.
Interpretive Summary: Anaerobic Soil Disinfestation (ASD) is a non-chemical approach to treating soil for the management of soilborne pathogens and weeds. The method involves the incorporation of a microbially-available carbon source, in this case molasses, saturating the soil, and covering with an impermeable film. The current approach to ASD in FL includes the application of composted broiler or layer litter, which serves as a source of plant nutrients. The process causes the soil environment to become anaerobic for a short period of time. The application of nitrogen and carbon to the soil has the potential to result in nutrient loss to the environment. The reported study evaluated the partitioning of plant nutrients in plants, movement into the soil, and release of nitrous oxide in to the air. Tomato plants grown using ASD accumulated a higher level of many plant nutrients. Soil in plots treated with ASD retained more immobilized nitrogen than did soil in fumigated plots but and resulted in increased nitrous oxide release at transplanting, while the fumigated plots generated more nitrous oxide during the treatment period than did the ASD plots. The potential for leaching phosphorous and potassium was higher in ASD treated plots, but the loss of nitrogen was not as significant.
Technical Abstract: Anaerobic soil disinfestation (ASD) is proposed as a pre-plant, non-chemical soil disinfestation technique to control several soilborne phytosanitary issues. Limited information is available on the impact of ASD on soil fertility, plant growth, and potential nutrient loss. The objectives of the current study were to evaluate the effects of ASD applied using composted poultry litter (CPL) and molasses as amendments, on soil redox potential, pH, temperature, soil nutrient content, plant biomass and nutrient accumulation, nitrous oxide (N2O) emissions and preliminary information on potential for nutrient leaching. A field study was conducted on fresh-market tomato (Solanum lycopersicum L.) at two sites, Immokalee and Citra, FL, comparing ASD applied using a mix of CPL at the rate of 22 Mg ha-1 and two rates of molasses [13.9 (ASD1) and 27.7 m3 ha-1 (ASD2)] as a carbon-source to chemical soil fumigation (CSF). ASD treatment had a significant impact on soil redox potential, but did not affect soil pH or temperature. Soil treatment did not affect nitrous oxide emissions from intact polyethylene mulched beds at either location. Emissions ranged from 0 to 0.378 µg m-2 h-1 and from 8.8 to 39.8 µg m-2 h-1 in Immokalee and Citra, respectively. However, on day 21 after punching holes in the polyethylene film to transplant, N2O emissions ranged from 1.56 to 4.83 and from 303.4 to 1480.1 µg m-2 h-1 in Immokalee and Citra, respectively. Emissions were higher in ASD than in CSF plots in Citra, but not in Immokalee. Molasses and CPL used in ASD treatments increased soil nutrients, increasing the risks of nutrient (particularly P and K) losses into the environment. Therefore, pre- and post-planting nutrient management should be adjusted to take into account the nutrients provided through the molasses and CLP application. ASD applied using CPL and molasses at the rates tested increased soil fertility and nutrient availability, increasing the potential risk of P and K leaching, while there is no clear evidence of an increased risk of N loss with ASD compared to CSF.