EFFECT OF APPLICATION METHODS ON 1,3-DICHLOROPROPENE VOLATILIZATION FROM SOIL UNDER CONTROLLED CONDITIONS

Emissions of fumigants can be an important source of air pollution at soil fumigation sites, and the high emission rates result partly from the use of application methods that are high in volatilization potenti al. In this study, we compared volatilization of fumigant 1,3-dichloro propene (1,3-D) from a sandy loam in 60 cm packed columns after applie d by different methods. The most volatilization was found with injecti on into uncovered soil at a shallow depth (e.g., 56% loss fur the 20-c m injection) and application via surface drip irrigation (>90%). Volat ilization fluxes and cumulative losses, however, rapidly decreased as the injection depth was increased, and the total loss was only 27% for the 40-cm injection. The commonly used polyethylene plastic was ineff ective in reducing the volatilization because of its high permeability to 1,3-D. Water application after the 20-cm injection resulted in sub stantially reduced volatilization, but the least loss (22%) was obtain ed when an emulsifiable formulation of 1,3-D, Telone SL. Has drip-appl ied to the subsurface at 20 cm. Our results indicate that variables mo st influencing 1,3-D volatilization are injection depth and Hater mana gement, By optimizing these variables, application methods,vith low em ission potential can be developed.