Effect of Monocrotophos and Quinalphos on Soil Population and Nitrogen-Fixing Activity of Azospirill

• 作 者: V.RANGASWAMY P.B.B.N.CHARYULU K.VENKATESWARLU
• 机 构: Department of Microbiology Sri Krishnadevaraya University,Anantapur 515003,India,Department of Micro
• 出 处: Biomedical and Environmental Sciences
• 发表日期: 1989年04期
• 关键词: agricultural successive isolates consecutive subsequent untreated fertility lett

The effects of monocrotophos and quinalphos on population and nitrogen-fixing activity ofAzospirillum sp.in four agricultural soils were determined in a laboratory study.Concentrationsof 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 resultedin a significant increase in the population density.Cultures of Azospirillum sp.,isolated frominsecticide-treated soils,exhibited greater nitrogen-fixing activity.Three consecutive subcultur-ings of the isolates from insecticide-treated soils had no effect on their nitrogen-fixingactivity.1989 Academic Press,Inc.

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 (1) were either stimulatory or innocuous to the popula tion of Azospirillum in the soils. Flow of applications of the insecticides to soils resulted in a significant increase in the population density. Cultures of Azospirillum sp., isolated frominsecticide-treated soils, demonstrated greater nitrogen-fixing activity. Three consecutive subcultures of the isolates from insecticide-treated soils had no effect on their nitrogen-fixing activity. 1989 Academic Press, Inc.