Eff ect of Water Seal on Reducing 1 , 3 - Dichloropropene Emissions from Diff erent Soil

712 Soil physical conditions can aff ect diff usion, environmental fate, and effi cacy of fumigants in soil disinfestation treatments. Water seals (applying water using sprinklers to soil following fumigation) can eff ectively reduce fumigant emissions from sandy loam soils. Soil column studies compared the eff ectiveness of water seals in reducing cis-1,3-dichloropropene (1,3-D) emissions from three diff erent textured soils (loamy sand, sandy loam, and loam). Treatments included an untreated control, an initial water seal (9 mm water applied immediately before fumigant injection), and intermittent water seals (initial 9 mm water seal followed by 3 mm at 12 and 24 h). For the loamy sand, instead of the initial water seal treatment, a reducedamount intermittent water seal (initial 3 mm water followed by 1 mm at 12 and 24 h) treatment was tested. Overall emission loss of 1,3-D from the control over 2 wk was 56% for the loamy sand, 51% for the sandy loam, and 43% for the loam. Th e initial water seal reduced total 1,3-D emissions to 46% in the sandy loam and 31% in the loam. Th e intermittent water seals reduced emission loss to 26% for the loamy sand, 41% for the sandy loam, and 21% for the loam. Th e reduced-amount intermittent water seal for loamy sand had little eff ect. Low emission loss was associated with high surface soil water content. None of the water applications reduced gaseous fumigant concentrations. Results indicate that water seal techniques may be able to eff ectively reduce emissions for diff erent soil textures without reducing fumigant concentration in the soil. Eff ect of Water Seal on Reducing 1,3-Dichloropropene Emissions from Diff erent Soil Textures