title: Effect of thiobencarb and pretilachlor on microorganisms in relation to mineralization of C and N in the Gangetic alluvial soil of West Bengal.
abstract: An experiment was conducted under laboratory conditions to investigate the effect of two pre-emergence herbicides, viz., thiobencarb (at 1.5 and 4.5 kg active ingredient (a.i.) ha(-1)) and pretilachlor (at 0.5 and 1.5 kg a.i. ha(-1)), on the growth and multiplication of some microorganisms (bacteria, actinomycetes and fungi) in relation to transformations and availability of C and N in the Gangetic alluvial soil (Typic Haplustept) of West Bengal, India. Application of both the herbicides, in general, significantly increased microbial biomass, resulting in greater retention, mineralization and availability of oxidizable organic C and N in soil, and the stimulations were more pronounced when the herbicides were applied at their lower concentrations (recommended field application rates), more so with thiobencarb, as compared to pretilachlor. Compared to untreated control soil, the application of thiobencarb at lower concentration increased the proliferation of total bacteria, actinomycetes and fungi by 57.3, 36.6 and 55.2%, respectively, and released the highest amount (40.2%) of soluble NO₃(-) in soil, while pretilachlor at field application rate induced the growth and multiplication of bacteria and fungi by 58.3 and 17.6%, respectively. Irrespective of the concentrations, the stimulations were at par for both the herbicides towards the retention of oxidizable organic C, total N and exchangeable NH₄(+) in soil.
authors.affiliation: Department of Agricultural Chemistry and Soil Science, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, 741252, West Bengal, India.
authors.forename: Sourav
authors.initials: S
authors.lastname: Bhowmick
authors.forename: Ritwika
authors.initials: R
authors.lastname: Das
authors.forename: Amal Chandra
authors.initials: AC
authors.lastname: Das
mesh_terms: D000083:Acetanilides; D001419:Bacteria / Q000187:drug effects / Q000254:growth & development; D018533:Biomass; D002244:Carbon / Q000737:chemistry / Q000378:metabolism; D004784:Environmental Monitoring; D005658:Fungi / Q000187:drug effects / Q000254:growth & development; D006540:Herbicides / Q000633:toxicity*; D007194:India; D009584:Nitrogen / Q000737:chemistry / Q000378:metabolism; D018570:Risk Assessment; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000737:chemistry / Q000633:toxicity*; D013859:Thiocarbamates / Q000633:toxicity*
chemical_list: D000083:Acetanilides; D006540:Herbicides; D012987:Soil; D012989:Soil Pollutants; D013859:Thiocarbamates; C118050:pretilachlor; D002244:Carbon; C037925:benthiocarb; D009584:Nitrogen