Acceleration of 1,3-dichloropropene degradation by organic amendments and potential application for emissions reduction

Emissions of the fumigant 1,3-dichloropropene (1,3-D) can result in degradation of air quality in certain areas. The high emission potential of 1,3-D is caused by its rapid diffusion and comparatively slow degradation in soil. One approach to reduce the emission is to enhance the surface soil's capacity to degrade 1,3-D. We investigated the capability of two organic amendments, a composted manure (CM) and a biosolid-manure mix (BMI), to accelerate 1,3-D degradation in soil. Degradation of 1,3-D was significantly enhanced in amended soils compared to the unamended soil, and the degree of acceleration varied with the type as well as the rate of amendment. Compost manure was more effective in stimulating 1,3-D degradation than the less decomposed BM; even at an amendment/soil ratio as low as 1:40 (w/w), degradation in the CM-amended soil was two times faster than that in the unamended soil. The acceleration in CM-amended soils was a combined result of enhanced chemical and microbial degradation, since sterilization only partially reduced the enhanced degradation. The reduction of 1,3-D emissions by surface application of organic amendments was illustrated in a column experiment: 1,3-D emission loss after injection at 30 cm was 30% from an unamended Arlington sandy loam (a coarse-loamy, mixed, thermic Haplic Durixeralf), but decreased to only 16% in the column containing 5% CM in its top 5-cm layer.