Anaerobic soil disinfestation: Nutrient cycling and potential environmental impact

Authors: DI GIOIA, FRANCESCO - Pennsylvania State University; Hong, Jason; OZORES-HAMPTON, MONICA - University Of Florida; ZHAO, XIN - University Of Florida; WILSON, CHRIS - University Of Florida; Albano, Joseph; LI, ZHOUNA - University Of Florida; Pisani, Cristina; GUO, HAICHAO - Noble Research Institute; PAUDEL, BODH - University Of Florida; BUTLER, DAVID - University Of Tennessee; Rosskopf, Erin

Submitted to: Acta Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/20/2019
Publication Date: 2/27/2020
Citation: Di Gioia, F., Hong, J.C., Ozores-Hampton, M., Zhao, X., Wilson, C., Albano, J.P., Li, Z., Pisani, C., Guo, H., Paudel, B., Butler, D., Rosskopf, E.N. 2020. Anaerobic soil disinfestation: Nutrient cycling and potential environmental impact. Acta Horticulturae. https://doi.org/1270.

Interpretive Summary: Few alternatives to methyl bromide soil fumigation are not dependent upon the use of a broad-spectrum chemical. Anaerobic soil disinfestation (ASD) is a non-chemical alternative to soil fumigation based on the combined concepts of biofumigation, biosolarization, soil saturation, and forced shifts in the microbial community that are highly dependent upon soil temperature, moisture, and the availability of a labile carbon source. Adoption by specialty crop producers has been limited due to multiple reasons. Impediments to adoption include the use of transparent film during treatment, which must be replaced. This issue was addressed through research which established that the use of opaque totally-impermeable film limited gas exchange, resulting in effective treatment. To determine if nutsedge control could be improved, ASD was successfully combined with one pre-emergent herbicide. Lower rates of organic amendments can be used for fall production and composted yard waste is a potential replacement for the use of composted poultry litter in ASD treatments.

Technical Abstract: Anaerobic soil disinfestation (ASD) is a pre-plant biological soil disinfestation technique proposed for the simultaneous control of soil-borne pathogens, nematodes, and weeds in several horticultural crops grown in conventional and organic systems. The technique is applied amending the soil with a labile carbon (C) source, tarping the soil with totally impermeable film, and irrigating the soil to saturation. The rapid shift of redox potential stimulates the growth of anaerobic microorganisms and the anaerobic decomposition of the C source with the consequent production of metabolites (organic acids, aldehydes, alcohols, ammonia, and volatile organic compounds) results in the suppression of many soil-borne pathogens and pests. The temporary change of soil microbial population, redox potential and pH occurring during ASD may also have an impact on nutrient cycling, thereby affecting soil fertility, availability of nutrients for the crop, and potential loss of nutrients into the environment. Understanding the nutrient dynamics and the factors influencing the availability and/or loss of nutrients during and after ASD treatment is critical for the sustainable application of this technique on a large-scale. The objective of this work is to review the factors governing the nutrient cycling in relation to ASD treatment, discuss potential solutions to optimize the crop nutrient management and minimize the risks of nutrient loss, and identify future research priorities. While there are concerns about N2O emission and nutrient leaching, the results of previous studies and of on-going research activities conducted at multiple sites, suggest that the risks of nutrient loss are not higher than those associated with standard chemical soil fumigation practices. Instead, there is clear evidence that ASD has both short- and long-term effects on the soil fertility, and excluding some risks of phytotoxicity at transplanting, ASD has been demonstrated to have positive effects on plant growth and crop yield performances.