The effects of monocrotophos and quinalphos on population and nitrogen-fixing activity of Azospirillum sp.in four agricultural soils were determined in a laboratory study.Concentrations of the two insecticides up to a...The effects of monocrotophos and quinalphos on population and nitrogen-fixing activity of Azospirillum sp.in four agricultural soils were determined in a laboratory study.Concentrations of the two insecticides up to a 5 kg ha^(-1)level were either stimulatory or innocuous to the popula- tion of Azospirillum in the soils.Four successive applications of the insecticides to soils resulted in a significant increase in the population density.Cultures of Azospirillum sp.,isolated from insecticide-treated soils,exhibited greater nitrogen-fixing activity.Three consecutive subcultur- ings of the isolates from insecticide-treated soils had no effect on their nitrogen-fixing activity.1989 Academic Press,Inc.展开更多
文摘The effects of monocrotophos and quinalphos on population and nitrogen-fixing activity of Azospirillum sp.in four agricultural soils were determined in a laboratory study.Concentrations of the two insecticides up to a 5 kg ha^(-1)level were either stimulatory or innocuous to the popula- tion of Azospirillum in the soils.Four successive applications of the insecticides to soils resulted in a significant increase in the population density.Cultures of Azospirillum sp.,isolated from insecticide-treated soils,exhibited greater nitrogen-fixing activity.Three consecutive subcultur- ings of the isolates from insecticide-treated soils had no effect on their nitrogen-fixing activity.1989 Academic Press,Inc.
