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EFFECT OF PARAQUAT ON MICROBIAL ACTIVITIES IN SOILS *
Author(s) -
TU C. M.,
BOLLEN W. B.
Publication year - 1968
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.1365-3180.1968.tb01398.x
Subject(s) - paraquat , nitrification , chemistry , loam , soil water , environmental chemistry , organic matter , incubation , nitrogen cycle , agronomy , zoology , nitrogen , ecology , biology , biochemistry , organic chemistry
Summary. When paraquat was added to four different soils, nitrification was not appreciably affected but ammonification of soil organic‐matter nitrogen was slightly retarded. Carbon dioxide evolution as well as oxygen consumption was used as an index of metabolic activity of soil micro‐organisms and paraquat had a stimulatory effect at higher concentrations. Oxidation of added sulphur was slightly depressed. Paraquat decreased both the total mould and bacterial populations in Chehalis silt loam. After 30 days incubation the percentages of Streptomyces and Penicillia were markedly increased by most treatments but were little affected in Chehalis silt clay and Woodburn soils. Except for the temporary suppression of nitrification, paraquat had no significant influence on general microbial activities of importance to soil fertility. Some bimodal effects or toxicity inversions were observed with intermediate concentrations. Effet du paraquat sur les activités microbiennes dans les sols