ISSN:
1432-0703
Source:
Springer Online Journal Archives 1860-2000
Topics:
Energy, Environment Protection, Nuclear Power Engineering
,
Medicine
Notes:
Abstract The disappearance of the herbicide, Avadex (40% diallate), from five agricultural soils (differing in either pH, carbon content, or nitrogen content), incubated under sterile and non-sterile conditions, was followed for a period of 20 weeks. Avadex was rapidly lost from microbiologically active soils, with over 50% of the applied (2.5 ppm) dosage disappearing within four weeks; losses from sterile soils were much slower with recoveries of over 50% after 20 weeks. Incubation of soil with Avadex to which14C-labeled diallate had been added resulted in rapid formation of14CO2 from microbiologically active samples and only very slow14CO2 formation from sterile samples. Substantial quantities of radioactivity were retained as unextractable residues in both sterile and non-sterile soils after seven days incubation. From these data it was concluded that the disappearance of the herbicide from non-sterile soils was mainly due to microbial degradation and to binding of diallate or its metabolites as residues to undefined soil components. Losses from sterile soils were attributed to both binding of residues and to a slow chemical degradation. Avadex degradation by pure cultures was studied using representative fungi isolated from the five soils. Of the fungi tested,Phoma eupyrena, Penicillium janthinellum, andTrichoderma harzianium could degrade at least 20% of the applied (2.5 ppm) herbicide after ten days incubation. Degradation of Avadex in soil cultures ofT. harzianum was found to be slower than degradation in liquid nutrient cultures.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02221010
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