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The kinetics of linuron and metribuzin decomposition in soil using different laboratory systems
Author(s) -
HANCE R.J.,
HAYNES R. A.
Publication year - 1981
Publication title -
weed research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.693
H-Index - 74
eISSN - 1365-3180
pISSN - 0043-1737
DOI - 10.1111/j.1365-3180.1981.tb00100.x
Subject(s) - chemistry , decomposition , polyethylene , kinetics , incubation , diffusion , metribuzin , zero order , chromatography , analytical chemistry (journal) , first order , environmental chemistry , thermodynamics , mathematics , biochemistry , biology , organic chemistry , ecology , physics , quantum mechanics , weed control
Summary: Rales of linuron and metrihuzin breakdown in soil were studied in four laboratory systems: fresh soil incubated in polyethylene bags; air‐dry soil resetted and incubated in polyethylene bags; complete soil cores; a perfusion apparatus. The apparent order of reaction. estimated using a power rate equation, varied from 0.45 to 2.90 and was not consistent with respect either to the compounds or the incubation methods. It is possible that diffusion controlled processes may be involved in producing this variation. The results of six of the eight experiments could be fitted to the first order rate equation ( P = 0.01). When the first order model was statistically valid, half‐life times were within 50% of the time for 50% disappearance calculated wiih the power rate expression but there were differences up to five‐fold in the times for 90% disappearance, calculated by the two methods. It is suggested that decomposition experiments giving orders of reaction greater than I require verification in more than one experimental system