See more from this Session: General Soil and Environmental Quality Posters: I
Tuesday, October 18, 2011
Henry Gonzalez Convention Center, Hall C, Street Level
Tarping soil surface with the low permeability film such as totally impermeable film (TIF) is a promising agricultural practice to control fumigant emission. The ability of TIF to retaining fumigants in the soil leads to a potential of using reduced fumigant application rate that still provides good pest control. However, it is not well understood how fumigant fate is affected by the amounts of fumigant in soil that directly link to fumigation efficacy. The objective of this study is to determine fumigant degradation rate as fumigation rates vary in different soils. A series of laboratory incubation experiments have been conducted to study the degradation characteristics of several fumigants including 1,3-dichloropropene (1,3-D), chloropicrin (CP), and dimethyl disulfide (DSMS) at application rates from 10 to 200 mg kg-1 in five soils collected in agricultural fields. Results show that the degradation of these fumigants over time follows pseudo first-order kinetics. Fumigant degradation rate changes significantly with application rates and is also highly depending on the soil properties, suggesting that proper fumigation rate for ensuring satisfactory pest control with the use of TIF tarp is different among soils. The data are useful to optimize fumigation efficacy in soils and economize fumigant use when using TIF tarp to reduce detrimental impact of soil fumigation on the environment.