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Journal ArticleDOI

Effect of pencycuron on microbial parameters of waterlogged soil

TL;DR: The metabolically activated microbial population was more suppressed compared to the dormant population and the DCM amendment did not seem to have any counteractive effect on the toxicity of pencycuron on the microbial variables.
Abstract: A laboratory study was conducted to monitor the effect of pencycuron [1-(4-chlorobenzyl)-1-cyclopentyl-3-phenylurea] on microbial parameters of alluvial (AL) soil (Typic udifluvent) and coastal saline (CS) soil (Typic endoaquept) under waterlogged condition. Pencycuron at field rate (FR), 2FR and 10FR affected the microbial biomass C (MBC), soil ergosterol content and fluorescein diacetate hydrolyzing activity (FDHA) differentially. The DCM amendment did not seem to have any counteractive effect on the toxicity of pencycuron on the microbial variables. The change in microbial metabolic quotient (qCO2) and microbial respiration quotient (QR), indicated pencycuron induced disturbance at 10FR. Present study revealed that the metabolically activated microbial population was more suppressed compared to the dormant population.
Citations
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Journal ArticleDOI

568 citations

01 Jan 1981
TL;DR: Fluorescein diacetate (FDA) was applied as a vital stain to soil bacteria in pure cultures, sterilized soil, and natural soils as discussed by the authors, and nearly 80% of the isolates were stained.
Abstract: Fluorescein diacetate (FDA) was applied as a vital stain to soil bacteria in pure cultures, sterilized soil, and natural soils. The staining ability of FDA was tested on 111 isolates of soil bacteria in pure cultures in a diluted laboratory medium and in sterilized soil. Nearly 80% of the isolates were stained. In a growth experiment in sterilized soil, FDA was compared to acridine orange (AO). At a given time, when most bacteria were considered metabolically active, the number of FDA-stained bacteria exceeded that stained by AO. The staining efficiency and the simple procedure indicate that the FDA-method is useful for estimating the number of metabolically active bacteria in soil. This was confirmed by examination of ten different soils, where the FDA-method was compared to AO-staining, fluorescein isothiocyanate (FITC)-staining, and plate counts.

151 citations

Journal ArticleDOI
TL;DR: The present finding suggests that the mesorhizobial isolate endowed with multiple properties could be used to facilitate the productivity of chickpea under insecticidestressed soils.
Abstract: An experiment was carried out to determine the plant growth-promoting activities of fipronil- and pyriproxyfen-tolerant Mesorhizobium isolates in the presence and absence of insecticides. The bioremediation and plant growth-promoting potentials of Mesorhizobium isolate (MRC4) was assessed using chickpea as a test crop grown under fipronil- and pyriproxyfen-stressed soils. In this study, the most promising mesorhizobial isolate (MRC4) tolerated fipronil and pyriproxyfen up to a concentration of 1600 μg ml−1 and 1400 μg ml−1, respectively. Isolate MRC4 produced a substantial amount of indole acetic acid (44.3 μg ml−1), salicylic acid (35 μg ml−1), 2,3 di-hydroxybenzoic acid (19 μg ml−1), and exo-polysaccharides (21 μg ml−1) in the absence of insecticides. The plant growth-promoting substances displayed by the isolate MRC4 declined progressively with increasing concentrations of each insecticide. The insecticide tolerant isolate MRC4 was further tested for its effect on chickpea plants grown in fipronil- and pyriproxyfen-treated soils. The insecticide-tolerant isolate MRC4 increased the dry matter accumulation progressively. A maximum increase of 80 (at 600 μg kg−1 soil of fipronil) and 118% (at 3900 μg kg−1 soil of pyriproxyfen) was recorded 135 days after sowing when compared to noninoculated plants treated with the same rates of each insecticide. Moreover, Mesorhizobium isolate MRC4 when used in fipronil- and pyriproxyfen-treated soil also increased symbiotic properties (nodulation and leghaemoglobin content), root N, shoot N, root P, shoot P, seed yield, and seed protein compared to the un-inoculated but treated solely with insecticide. The present finding suggests that the mesorhizobial isolate endowed with multiple properties could be used to facilitate the productivity of chickpea under insecticidestressed soils.

63 citations


Cites background from "Effect of pencycuron on microbial p..."

  • ...After application, a large portion of insecticides accumulate in the top soil layer (0-10 cm) and exert deleterious effects on microbial diversity (Das et al. 2005) thereby leading to a loss in soil fertility (Pal et al. 2006)....

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  • ...2005) thereby leading to a loss in soil fertility (Pal et al. 2006)....

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Journal ArticleDOI
TL;DR: Of the various concentrations of the two insecticides, pyriproxyfen showed comparatively more severe toxicity to pea plants by decreasing plant biomass, symbiotic attributes, nutrients (nitrogen and phosphorus) uptake, seed yield and grain protein over the uninoculated control.

48 citations

Book ChapterDOI
01 Jan 2011
TL;DR: The present review focuses on the role of naturally occurring rhizosphere microbes involved in degradation or transformation of insecticides.
Abstract: Modern application of insecticides belonging to different chemical families to boost agricultural productivity has led to their accumulation in soils to levels that affect, directly and indirectly, soil enzyme activities and physiol-ogical characteristics of nontarget soil microflora including plant growth-promoting rhizobacteria, and, consequently the performance of crop plants. Various biological strategies can be applied for removing toxic substances, including insecticides, from the environment and are collectively known as bioremediation. Among biological approaches, the use of microbes with degradative ability is considered the most efficient and cost-effective option to clean pesticide-contaminated sites. The present review focuses on the role of naturally occurring rhizosphere microbes involved in degradation or transformation of insecticides.

29 citations


Cites background from "Effect of pencycuron on microbial p..."

  • ...This study revealed that the metabolically activated microbial population was more suppressed compared to the dormant population ( Pal et al. 2006 )....

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  • ...Subsequently, abnormally high concentrations of insecticides may lead to a considerable loss in soil fertility ( Pal et al. 2006 )....

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References
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Journal ArticleDOI
TL;DR: In this paper, the effects of fumigation on organic C extractable by 0.5 m K2SO4 were examined in a contrasting range of soils and it was shown that both ATP and organic C rendered decomposable by CHCl3 came from the soil microbial biomass.
Abstract: The effects of fumigation on organic C extractable by 0.5 M K2SO4 were examined in a contrasting range of soils. EC (the difference between organic C extracted by 0.5 M K2SO4 from fumigated and non-fumigated soil) was about 70% of FC (the flush of CO2-C caused by fumigation during a 10 day incubation), meaned for ten soils. There was a close relationship between microbial biomass C, measured by fumigation-incubation (from the relationship Biomass C = FC/0.45) and EC given by the equation: Biomass C = (2.64 ± 0.060) EC that accounted for 99.2% of the variance in the data. This relationship held over a wide range of soil pH (3.9–8.0). ATP and microbial biomass N concentrations were measured in four of the soils. The (ATP)(EC) ratios were very similar in the four soils, suggesting that both ATP and the organic C rendered decomposable by CHCl3 came from the soil microbial biomass. The C:N ratio of the biomass in a strongly acid (pH 4.2) soil was greater (9.4) than in the three less-acid soils (mean C:N ratio 5.1). We propose that the organic C rendered extractable to 0.5 m K2SO4 after a 24 h CHCl3-fumigation (EC) comes from the cells of the microbial biomass and can be used to estimate soil microbial biomass C in both neutral and acid soils.

9,975 citations


"Effect of pencycuron on microbial p..." refers methods in this paper

  • ...Microbiological Assays The MBC was determined by fumigation extraction method[19] followed by determination of K2SO4 extractable C.[20] Biomass C was estimated as:...

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Book
01 Jan 1961
TL;DR: In this paper, the biological processes that take place in the soil and their importance to soil fertility, plant growth, and environmental quality are investigated from both descriptive and functional viewpoints, including microbial ecology, the carbon and nitrogen cycles, mineral transformation, and ecological interrelationships.
Abstract: Characterizes soil microflora from descriptive and functional viewpoints; considers the biological processes that take place in the soil and their importance to soil fertility, plant growth, and environmental quality. Deals with the biochemical basis for soil processes, including microbial ecology, the carbon and nitrogen cycles, mineral transformation, and ecological interrelationships.

2,728 citations

Book ChapterDOI
TL;DR: In this paper, the chemistry of submerged soils is discussed and the role of lake, estuarine, and ocean sediments as reservoirs of nutrients for aquatic plants and as sinks for terrestrial wastes.
Abstract: Publisher Summary This chapter discusses the chemistry of submerged soils. The chemical changes in the submerged materials influence: (a) the character of the sediment or soil that forms, (b) the suitability of wet soils for crops, (c) the distribution of plant species around lakes and streams and in estuaries, deltas, and marine flood plains, (d) the quality and quantity of aquatic life, and (e) the capacity of lakes and seas to serve as sinks for terrestrial wastes. The single electrochemical property that serves to distinguish a submerged soil from a well-drained soil is its redox potential. The redox potential of a soil or sediment provides a quick, useful, semiquantitative measure of its oxidation–reduction status. Two recent developments have stimulated interest in the chemistry of submerged soils: the breeding of lowland rice varieties, with a high yield potential, and the pollution of streams, lakes, and seas, by domestic, agricultural, and industrial wastes. The chemistry of submerged soils is valuable: (a) in understanding the soil problems, limiting the performance of high-yielding rice varieties, and (b) in assessing the role of lake, estuarine, and ocean sediments as reservoirs of nutrients for aquatic plants and as sinks for terrestrial wastes.

2,651 citations


"Effect of pencycuron on microbial p..." refers background in this paper

  • ...Waterlogging often alters physico-chemical and microbiological processes,[13] which might alter the fate of pesticides in that situation....

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  • ...Further, the microorganisms had to face the stress of oxygen depletion along with other detrimental influences of waterlogging,[13] which caused further reduction in MBC....

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Book
01 Jan 1995
TL;DR: Quality Control and Quality Assurance in Applied Soil Microbiology and Biochemistry in applied soil microbiology and biochemistry and field methods.
Abstract: (Chapter Headings): Introduction. Quality Control and Quality Assurance in Applied Soil Microbiology and Biochemistry. Soil Sampling, Handling, Storage, And Analysis. Enrichment, Isolation and Counting of Soil Microorganisms. Estimation of Microbial Activities. Anaerobic Microbial Activities in Soil. Enzyme Activities. Micorbial Biomass. Community Structure. Field Methods. Bioremediation of Soil. Subject Index.

2,125 citations


"Effect of pencycuron on microbial p..." refers methods in this paper

  • ...Reliable biomass measurements by this method can be obtained in soils of widely different physico-chemical properties, which are waterlogged and recently amended with organic matter.[19] These conditions prevailed herein....

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  • ...Microbiological Assays The MBC was determined by fumigation extraction method[19] followed by determination of K2SO4 extractable C....

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Journal ArticleDOI
TL;DR: In this article, metabolic quotients for CO2 and microbial-C-loss were studied on soil microbial communities under long-term monoculture (M) or continuous crop rotations (CR).
Abstract: Metabolic quotients for CO2C (qCO2C) and microbial-C-loss (qD) were studied on soil microbial communities under long-term monoculture (M) or continuous crop rotations (CR). Under defined laboratory conditions the mean qCO2C (unit CO2C unit−1 Cmic h−1) of different microbial biomasses from 17 M systems amounted to 1.097 μg CO2qCO2CC as compared to 0.645 μg CO2C of microbial biomasses from 19 CR systems. The 1.7 times higher CO2C release per unit biomass and time of microbial biomasses from M systems was significantly different at the P =0.001 level. In addition, microbial C-loss in samples from M or CR plots was followed for 5 weeks. Again, mean qD per unit microbial biomass and time was 1.6 times higher (P = 0.01) for microbial biomasses from M systems (0.301 μg C, 14 soils) when compared with CR systems (0.188μg C, 14 soils). These differences were not related to soil texture, Corg or pH of these soils. The effects of environmental influences (soil management) on the microbial pool in terms of a changing energy demand are discussed.

993 citations


"Effect of pencycuron on microbial p..." refers background in this paper

  • ...The effect can force microbes to utilize a large part of their energy budget for maintenance, thus reducing mineralization activity.[30] As a result, more CO2 is evolved per unit microbial biomass....

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  • ...Anderson and Domsch[8,30] and Beelen and Doelman[4] proposed that the respiration rate per unit microbial biomass, termed as qCO2, is a more sensitive indicator of toxic effects of xenobiotic compounds than the respiration rate or the amount of microbial biomass alone....

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