Induction and Transfer of Enhanced Biodegradation of the Herbicide Napropamide in Soils

✍ Scribed by Walker, Allan; Welch, Sarah J.; Roberts, Steven J.

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 500 KB
• Volume: 47
• Category: Article
• ISSN: 1526-498X
• DOI: 10.1002/(sici)1096-9063(199606)47:2<131::aid-ps401>3.0.co;2-c

✦ Synopsis

In laboratory incubations, the times to 50% loss (DT,,) of a first application of napropamide were approximately 25, 45 and 75 days in soil incubated at 25, 15 and 5°C respectively. When treated for a second time, the DT,, values vere 4, 7 and 15 days at the same temperatures, irrespective of the temperature of the first incubation. This indicates that enhanced degradation of napropamide in soil can be both induced and expressed at low temperature. A mixed microbial culture able to degrade the herbicide to a single degradation product, identified by HPLC retention time as naphthoxypropionic acid, was obtained from a soil capable of rapid degradation. Addition of a sub-sample of this mixed culture to a previously untreated soil introduced rapid degrading ability. When small amounts of soil capable of rapid degradation were added to previously untreated soil, in both the laboratory and the field, the degradation rate of napropamide increased compared with that in unamended soils.