Availability and biodegradation of metribuzin in alluvial soils as affected by temperature and soil properties |
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| Authors: | P BENOIT J PERCEVAL† M STENRØD† C MONI† O M EKLO† E BARRIUSO T SVEISTRUP‡ & J KVÆRNER‡ |
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| Institution: | UMR INRA INA-PG, Environnement et Grandes Cultures, Thiverval-Grignon, France;, Plant Health and Plant Protection Division, Bioforsk Norwegian Institute for Agricultural and Environmental Research, Ås, Norway;, and Soil and Environment Division, Bioforsk Norwegian Institute for Agricultural and Environmental Research, Ås, Norway |
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| Abstract: | Herbicide degradation in soils is highly temperature‐dependent. Laboratory incubations and field experiments are usually conducted with soils from the temperate climatic zone. Few data are available for cold conditions and the validation of approaches to correct the degradation rate at low temperatures representative of Nordic environments is scarce. Laboratory incubation studies were conducted at 5, 15 and 28°C to compare the influence of temperature on the dissipation of metribuzin in silt/sandy loam soils in southern and northern Norway and in a sandy loam soil under temperate climate in France. Using 14C‐labelled metribuzin, sorption and biodegradation were studied over an incubation period of 49 days. Metribuzin mineralisation and total soil organic carbon mineralisation rates showed a positive temperature response in all soils. Metribuzin mineralisation was low, but metabolites were formed and their abundance depended on temperature conditions. The rate of dissipation of 14C‐metribuzin from soil pore water was strongly dependent on temperature. In Nordic soils with low organic content, metribuzin sorption is rather weak and biodegradation is the most important process controlling its mobility and persistence. |
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| Keywords: | metribuzin temperature microbial degradation soil solution |
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