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United States Department of Agriculture

Agricultural Research Service

Title: Remediation of Halogenated Fumigant Compounds in the Root Zone by Subsurface Application of Ammonium Thiosulfate

Authors
item PAPIERNIK, SHARON
item Ernst, Frederick - UC RIVERSIDE, CA
item DUNGAN, ROBERT
item Zheng, Wei - UC RIVERSIDE, CA
item Guo, Mingxin - UC RIVERSIDE, CA
item YATES, SCOTT

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: January 23, 2003
Publication Date: November 1, 2003
Citation: Papiernik, S.K., Ernst, F.F., Dungan, R.S., Zheng, W., Guo, M., Yates, S.R. 2004. Remediation of halogenated fumigant compounds in the root zone by subsurface application of ammonium thiosulfate. Chap. 13. In: Gan, J.J., Zhu, P.C., Aust, S.D., and Lernley, A.T., editors. Pesticide Decontamination and Detoxification. Washington, DC: American Chemical Society. p. 169-179.

Interpretive Summary: Fumigants are used for the control of a broad range of pests in high-cash-value crops. Because of their high volatility, a large fraction of the applied mass may be volatilized from the soil surface following application. Strategies to reduce fumigant emissions are needed to prevent adverse human or environmental health impacts. Some emission-reduction strategies increase fumigant concentrations in the soil, which could cause air or groundwater contamination or phytotoxicity to the crop planted following fumigation. Previous research has shown that fertilizers containing thiosulfate compounds, including ammonium thiosulfate (ATS), react with and detoxify some fumigant compounds in soil and water. In these experiments, we investigated the potential for subsurface application of ATS to reduce fumigant concentrations in the root zone, preventing off-site transport following soil fumigation. Results indicated that the fumigants 1,3-dichloropropene and propargyl bromide were dissipated more rapidly in soil receiving ATS application compared to those receiving water only. For methyl isothiocyanate, a fumigant that does not undergo reaction with ATS, application of ATS had no impact on the rate of dissipation in soil. These results suggest that subsurface application of ATS may be useful for the removal of fumigants and other pesticides from the root zone.

Technical Abstract: Fumigants are used for control of nematodes, fungi, weeds, and insects in high-cash-value crops. Because of their high volatility, a large fraction of the applied mass may be volatilized from the soil surface following application. Emission reduction strategies are needed to prevent adverse human or environmental health impacts. Some emission-reduction strategies, such as tarping the soil surface with impermeable plastic, increase containment of fumigants in the soil. The resulting fumigant residues could cause atmospheric contamination once the tarp is disrupted, groundwater contamination if leaching is allowed, or phytotoxicity to the crop planted following fumigation. Previous research has shown that thiosulfate compounds, including ammonium thiosulfate (ATS), abiotically react with and detoxify halogenated fumigants in soil and water. In these experiments, we investigated subsurface application of ATS to reduce fumigant concentrations in the root zone, preventing off-site transport following fumigation. Results indicated that the halogenated fumigants 1,3-dichloropropene and propargyl bromide were dissipated more rapidly in soil receiving ATS application compared to those receiving water only. For methyl isothiocyanate, a non-halogenated fumigant that does not undergo reaction with ATS, application of ATS had no impact on the rate of dissipation in soil. These results suggest that subsurface application of ATS may be useful for the root-zone remediation of halogenated compounds.

Last Modified: 9/29/2014
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