Disappearance of Residual Fen valerate from Sugarcane Trash as Affected by Trash Placement in Soil

Abstract

In laboratory study, we characterized the disappearance of residual fenvalerate [(R8)-a-cyano-3-phenoxybenzyl (R8)-2- (4-chlorophenyl)-3-methylbutyrate) from sugarcane trash as affected by trash placement in soil. There was no preferential disappearance of either enantiomeric pair of optical isomers (RR, 88). Total fen valerate recovery after 12 wk of incubation in the dark at -0.3 bar water potential under CO2-free air was about 46, 41, 58, 63, and 14%, respectively, for the soil only, trash-only, surface-applied, incorporated, and layered soil/sugarcane trash treatments. Fenvalerate disappearance appeared to be a microbial process in all treatments and, in the latter three treatments, to be directly related to the level of microbial activity as measured by total respiratory CO2 evolution.