Surface application of ammonium thiosulfate fertilizer to reduce volatilization of 1,3-dichloropropene from soil

Atmospheric emission of the soil fumigant 1,3-dichloropropene (1,3-D) is of environmental concern because of its toxicity and carcinogenicity. Thiosul fate fertilizers have been found to rapidly transform 1,3-D in soil to non- volatile ions which are less toxic. We investigated the use of surface appl ication of ammonium thiosulfate (ATS) for reducing 1,3-D volatilization. In packed soil columns, emission of 1,3-D applied by sub-surface injection de creased with increasing ATS application rate and the amount of water used f ar delivering ATS. When ATS was applied in 9mm water at 64g m(-2), total 1, 3-D emission was reduced by 61%. The reduction was 89% when ATS was applied at 193g m(-2). Bioassays showed that ATS application did not affect the ef fectiveness of 1,3-D for controlling citrus nematodes. In field plots where a 1,3-D emulsified formulation was applied via sub-surface drip, surface s pray of ATS reduced 1,3-D emissions by 50%, and by 71% when the surface was also covered with polyethylene film. ATS application had no effect on the efficacy of root-knot nematode control or tomato yields. These results sugg est that surface application of thiosulfate fertilizers may be a feasible a nd effective strategy for minimizing 1,3-D emissions. (C) 2000 Society of C hemical Industry.