Emission of methyl bromide (CH{sub}3Br) from soil fumigation contributes to stratospheric ozone depletion and imposes adverse toxicological effects on humans. We report the identification of fertilizer ammonium thiosulfate (ATS) as a potentialsurface amendment to reduce CH{sub}3Br volatilization from fumigated soils. In ATS-amended soil, CH{sub}3Br was rapidly degraded to Br{sup}-, with the degradation rate dependent on the ATS: CH{sub}3Br molar ratio and soil temperature. At 20℃, thehalf-life of CH{sub}3Br in an Arlington sandy loam was >5 d, but was reduced to <5 h when 4 molar times of ATS was amended. Greatly reduced CH{sub}3Br emission was observed from soil columns when Thio-Sul, a 60 ATS fertilizer, was applied to the soilsurface at 660 kg ha{sub}{sup}-1. The emission of CH{sub}3Br from the unamended column was 61 of the applied dosage following a 30cm injection, but that from the ATS-treated columns was <10. Field study showed that ATS amendment at 660 kg ha{sup}-1 only had a limited effect on the efficacy for controlling nematodes and weeds. As ATS is an inexpensive fertilizer, the reported approach is promising for field application.
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