FATE OF A SULFONYLUREA HERBICIDE IN AN ALLUVIAL SOIL, AS SHOWN BY EXPERIMENTAL DEGRADATION OF PYRIMIDINE-2-C-14-LABELED RIMSULFURON

The distribution of Pyrimidine-2-C-14-labeled rimsulfuron applied to a sandy calcareous alluvial soil, among evolved (CO2)-C-14 and soil com ponents was studied under laboratory conditions. Total (CO2)-C-14 rele ased accounted for 0.2 and 2.1 % of the applied C-14 for abiotic and b iotic assays, respectively. High recoveries of C-14 under extraction o f tetrahydrofuran and water from soil samples indicated that most of t he rimsulfuron and its possible metabolites were available for leachin g and degradation. Non extractable residues were mainly located in the 0-50 mu m fraction and were formed in lower amounts in the abiotic as says. Copyright (C) 1996 Elsevier Science Ltd