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T K Adhya - One of the best experts on this subject based on the ideXlab platform.
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effect of combine application of organic manure and inorganic fertilizer on methane and nitrous oxide emissions from a tropical Flooded Soil planted to rice
Geoderma, 2014Co-Authors: T K AdhyaAbstract:Abstract Methane and nitrous oxide emissions, their global warming potential, carbon efficiency ratio and related biogeochemical properties of a tropical Soil planted to rice were investigated under different N management [i.e. urea-N (120 kg N ha − 1 ), rice straw (RS) (30 kg N ha − 1 ) + urea-N (90 kg N ha − 1 ), compost (C) (30 kg N ha − 1 ) + urea-N (90 kg N ha − 1 ) and poultry manure (PM) (30 kg N ha − 1 ) + urea-N (90 kg N ha − 1 )]. CH 4 fluxes were increased by 82.7%, 65.1%, 63.4% and 31.9% in RS + urea-N, C + urea-N, PM + urea-N and urea-N, respectively whereas percentage increase in cumulative N 2 O emission was 390.6, 371.8, 315.6, and 253.1 in PM + urea-N, urea-N, C + urea-N and RS + urea-N, respectively over control (no fertilizer amendment). However, increase of GWPs in different manure + urea-N over that of control were 85.5%, 69.2%, 68.8% and 37.6% in RS + urea-N, C + urea-N, PM + urea-N and urea-N, respectively. Microbial biomass carbon (MBC), readily mineralizable carbon (RMC) and fluorescence diacetate (FDA) hydrolysis activity were significantly affected by integrated N-management and followed the order of C + urea-N > PM + urea-N > RS + urea-N > urea-N > control. With considerably high microbial biomass C and microbial activity, high C efficiency ratio, high yield and low greenhouse gas intensity, C + urea-N could be a better option to mitigate CH 4 and N 2 O emissions and to maintain Soil biological quality and yield in tropical paddy.
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effects of rice straw and nitrogen fertilization on greenhouse gas emissions and carbon storage in tropical Flooded Soil planted with rice
Soil & Tillage Research, 2012Co-Authors: P Hattacharyya, T K Adhya, K S Roy, S Neogi, K S Rao, M C MannaAbstract:Abstract Effects of four years of inorganic and organic nitrogen (N) management on the emission of three major greenhouse gases (GHGs): methane (CH 4 ), carbon dioxide (CO 2 ) and nitrous oxide (N 2 O), and on Soil labile carbon fractions such as water-soluble carbon (C, WSC), microbial biomass carbon (MBC), KMnO 4 oxidizable organic carbon (KMnO 4 -C), carbon management index (CMI) and Soil carbon storage were investigated in a Flooded rice ( Oryza sativa L.) field in India. The treatments included an unfertilized control, inorganic nitrogen fertilizer, rice straw + inorganic nitrogen fertilizer and rice straw + green manure. Maximum global warming potential (GWP) (10,188 kg CO 2 equivalent ha −1 ) was determined for the combined application of rice straw and green manure. Total carbon content and carbon storage in the topSoil were significantly increased for the rice straw + inorganic nitrogen fertilizer treatment. The combined application of rice straw and green manure was more effective in increasing WSC, MBC, KMnO 4 -C concentrations and CMI than the inorganic fertilizer treatments, although it increased gaseous carbon emission. The combined application of rice straw and an inorganic fertilizer was most effective in sequestrating Soil organic carbon (1.39 Mg ha −1 ), resulting in a higher grain yield. Therefore, it could be the best option for improving productivity and carbon storage in the rice–rice cropping system.
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dynamics of changes in methanogenesis and associated microflora in a Flooded alluvial Soil following repeated application of dicyandiamide a nitrification inhibitor
Microbiological Research, 2009Co-Authors: Santosh Ranjan Mohanty, K. Bharati, V. R. Rao, T K AdhyaAbstract:Influence of repeated application of the nitrification inhibitor dicyandiamide (DCD), on CH(4) production and associated microflora in a Flooded alluvial Soil, was investigated in a laboratory incubation study. Application of DCD at the time of Soil incubation resulted in a substantial reduction in CH(4) production (31% over that of untreated control). Second repeat application of DCD, on the contrary, annulled the inhibitory effect on CH(4) production, restoring it to the level of unamended Soil. Application of the third dose of DCD maintained CH(4) production almost to the same extent as that of second application. The alleviation of the initial inhibitory effect of DCD on CH(4) production was linked to the enhanced degradation of DCD following its repeated application to the Flooded Soil. Admittedly, abatement of the initial inhibitory effect of DCD on CH(4) production in Soil repeatedly amended with DCD was also related to the inhibition of CH(4)-oxidizing bacterial population and noticeable stimulation of heterotrophic bacterial population. Results suggest that repeat application of DCD with fertilizer-N to Flooded rice Soils might not be effective in controlling CH(4) production under field condition.
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influence of incorporation or dual cropping of azolla on methane emission from a Flooded alluvial Soil planted to rice in eastern india
Agriculture Ecosystems & Environment, 2000Co-Authors: K. Bharati, Santosh Ranjan Mohanty, V. R. Rao, D P Singh, T K AdhyaAbstract:Abstract Green manures are widely used in rice production and may influence methane efflux (CH 4 ). Influence of application of Azolla ( A. caroliniana Wild.), a widely used biofertilizer for rice ( Oryza sativa L.), on CH 4 efflux from a Flooded alluvial Soil planted to rice, and select Soil and plant variables were investigated in a field experiment at Cuttack, India. Azolla was either incorporated as green manure at the beginning of the experiment or grown as dual crop in the standing water along with the rice crop. Dual cropping of Azolla (equivalent to 30 kg N ha −1 ) in conjunction with urea (30 kg N ha −1 ) effected lowest CH 4 flux (89.29 kg CH 4 ha −1 ). Cumulative CH 4 flux followed the order of urea > Azolla (incorporated) + urea > Azolla (incorporated + dual crop) > no N control > urea + Azolla (dual crop). Growing Azolla had a moderating effect on CH 4 efflux from Flooded Soil through an increase in the dissolved oxygen concentration at the Soil–floodwater interface. Among the different Soil and plant variables studied, Soil redox potential, dissolved oxygen concentration at the Soil–floodwater interface and α-naphthylamine oxidase activity of root base exhibited significant negative relationship with CH 4 flux. In addition, Fe 2+ and ninhydrin reactive nitrogen (NRN) contents of the Flooded Soil exhibited significant positive relationship with CH 4 flux. Results indicated that, dual cropping of Azolla in conjunction with urea considerably reduced CH 4 efflux without affecting the rice yields and can be used as a practical mitigation option for minimizing CH 4 flux from Flooded paddy.
Ronald S Tjeerdema - One of the best experts on this subject based on the ideXlab platform.
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aerobic versus anaerobic microbial degradation of clothianidin under simulated california rice field conditions
Journal of Agricultural and Food Chemistry, 2016Co-Authors: Rebecca A Mulligan, Patrick L Tomco, Megan W Howard, Tabitha T Schempp, Davis J Stewart, Phillip M Stacey, David B Ball, Ronald S TjeerdemaAbstract:Microbial degradation of clothianidin was characterized under aerobic and anaerobic California rice field conditions. Rate constants (k) and half-lives (DT50) were determined for aerobic and anaerobic microcosms, and an enrichment experiment was performed at various nutrient conditions and pesticide concentrations. Temperature effects on anaerobic degradation rates were determined at 22 ± 2 and 35 ± 2 °C. Microbial growth was assessed in the presence of various pesticide concentrations, and distinct colonies were isolated and identified. Slow aerobic degradation was observed, but anaerobic degradation occurred rapidly at both 25 and 35 °C. Transformation rates and DT50 values in Flooded Soil at 35 ± 2 °C (k = -7.16 × 10(-2) ± 3.08 × 10(-3) day(-1), DT50 = 9.7 days) were significantly faster than in 25 ± 2 °C microcosms (k= -2.45 × 10(-2) ± 1.59 × 10(-3) day(-1), DT50 = 28.3 days). At the field scale, biodegradation of clothianidin will vary with extent of oxygenation.
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Soil and glass surface photodegradation of etofenprox under simulated california rice growing conditions
Journal of Agricultural and Food Chemistry, 2011Co-Authors: Martice E Vasquez, Thomas M Cahill, Ronald S TjeerdemaAbstract:Photolysis is an important degradation process to consider when evaluating a pesticide's persistence in a rice field environment. To simulate both nonFlooded and Flooded California rice field conditions, the photolytic degradation of etofenprox, an ether pyrethroid, was characterized on an air-dried rice Soil and a Flooded rice Soil surface by determination of its half-life (t(1/2)), dissipation rate constant (k) and identification and quantitation of degradation products using LC/MS/MS. Photodegradation was also characterized on a glass surface alone to rule out confounding Soil factors. Measured photolytic dissipation rates were used as input parameters into a multimedia environmental fate model to predict etofenprox persistence in a rice field environment. Photolytic degradation proceeded at a faster rate (0.23/day, t(1/2) = 3.0 days) on the Flooded Soil surface compared to the air-dried surface (0.039/day, t(1/2) = 18 days). Etofenprox degradation occurred relatively quickly on the glass surface (3.1/day, t(1/2) = 0.23 days or 5.5 h) compared to both Flooded and air-dried Soil layers. Oxidation of the ether moiety to the ester was the major product on all surfaces (max % yield range = 0.2 ± 0.1% to 9.3 ± 2.3%). The hydroxylation product at the 4' position of the phenoxy phenyl ring was detected on all surfaces (max % yield range = 0.2 ± 0.1% to 4.1 ± 1.0%). The air-dried Soil surface did not contain detectable residues of the ester cleavage product, whereas it was quantitated on the Flooded Soil (max % yield = 0.6 ± 0.3%) and glass surface (max % yield = 3.6 ± 0.6%). Dissipation of the insecticide in dark controls was significantly different (p < 0.05) compared to the light-exposed surfaces indicating that degradation was by photolysis. Laboratory studies and fate model predictions suggest photolysis will be an important process in the overall degradation of etofenprox in a rice field environment.
Ruben Kretzschmar - One of the best experts on this subject based on the ideXlab platform.
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mercury mobilization in a Flooded Soil by incorporation into metallic copper and metal sulfide nanoparticles
Environmental Science & Technology, 2013Co-Authors: Anke F Hofacker, Andreas Voegelin, Ralf Kaegi, Ruben KretzschmarAbstract:Mercury is a highly toxic priority pollutant that can be released from wetlands as a result of biogeochemical redox processes. To investigate the temperature-dependent release of colloidal and dissolved Hg induced by flooding of a contaminated riparian Soil, we performed laboratory microcosm experiments at 5, 14, and 23 °C. Our results demonstrate substantial colloidal Hg mobilization concomitant with Cu prior to the main period of sulfate reduction. For Cu, we previously showed that this mobilization was due to biomineralization of metallic Cu nanoparticles associated with suspended bacteria. X-ray absorption spectroscopy at the Hg LIII-edge showed that colloidal Hg corresponded to Hg substituting for Cu in the metallic Cu nanoparticles. Over the course of microbial sulfate reduction, colloidal Hg concentrations decreased but continued to dominate total Hg in the pore water for up to 5 weeks of flooding at all temperatures. Transmission electron microscopy (TEM) suggested that Hg became associated with C...
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multi metal contaminant dynamics in temporarily Flooded Soil under sulfate limitation
Geochimica et Cosmochimica Acta, 2009Co-Authors: Frankandreas Weber, Andreas Voegelin, Ruben KretzschmarAbstract:Abstract In many river basins, floodplain Soils have accumulated a variety of metal contaminants, which might be released during periods of flooding. We investigated the dynamics of copper, cadmium, lead, zinc, and nickel in a contaminated freshwater floodplain Soil under a realistic sulfate-limited flooding regime in microcosm experiments. We found that most contaminants were initially mobilized by processes driven by the reductive dissolution of Fe(III) and Mn(IV, III) (hydr)oxides. Subsequently, bacterial sulfate respiration resulted in the transformation of the entire available sulfate (2.3 mmol/kg) into chromous reducible sulfur (CRS). Cu K-edge X-ray absorption fine structure (XAFS) spectroscopy revealed that the Soil Cu speciation changed from predominantly Cu(II) bound to Soil organic matter (SOM) intermittently to 14% metallic Cu(0) and subsequently to 66% copper sulfide (CuxS). These CuxS precipitates accounted for most of the formed CRS, suggesting that CuxS was the dominant sulfide phase formed in the Flooded Soil. Sequential metal extractions, in agreement with CRS results, suggested that easily mobilizable Cd was completely and Pb partially sequestered in sulfide precipitates, controlling their dissolved concentrations to below detection limits. In contrast, Zn and Ni (as well as Fe) were hardly sequestered into sulfide phases, so that micromolar levels of dissolved Zn and Ni (and millimolar dissolved Fe(II)) persisted in the reduced Soil. The finding that Cu, Cd, and Pb were sequestered (but hardly any Zn, Ni, and Fe) is consistent with the thermodynamically predicted sulfide ladder following the increasing solubility products of the respective metal sulfides. The observation that Cd and Pb were sequestered in sulfides despite the presence of remaining SOM-bound Cu(II) suggested that the kinetics of Cu(II) desorption, diffusion, and/or CuxS precipitation interfered with the sulfide ladder. We conclude that the dynamics of multiple metal contaminants are intimately coupled under sulfate limitation by the relative thermodynamic stabilities and formation kinetics of the respective metal sulfides.
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contaminant mobilization by metallic copper and metal sulphide colloids in Flooded Soil
Nature Geoscience, 2009Co-Authors: Frankandreas Weber, Andreas Voegelin, Ralf Kaegi, Ruben KretzschmarAbstract:Colloids, such as submicrometre mineral particles or bacterial cells, can act as carriers enhancing the mobility of poorly soluble contaminants in subsurface environments. Spectroscopic and microscopic analysis of Flooded Soils suggests that copper colloids and metal sulphide colloids increase the concentration of contaminants in waterlogged Soils. Colloids, such as submicrometre mineral particles or bacterial cells, can act as carriers enhancing the mobility of poorly soluble contaminants in subsurface environments1,2. In sulphate-reducing Soils and sediments, metal sulphide precipitation has been proposed3,4,5,6 to generate contaminant-bearing sulphide colloids, which could transport contaminants traditionally thought to be immobilized by metal sulphide formation7. However, direct evidence for such a process is lacking. Here, we report the composition and morphology of pore-water colloids formed in contaminated floodplain Soil when Flooded with synthetic river water over a four-week period. We show that, on flooding, bacteria dispersed in the pore water mobilize copper by inducing biomineralization of metallic copper(0). We suggest that copper(0) crystals form by disproportionation of copper(I), which is released by copper-stressed bacteria to maintain copper homeostasis8,9. Sulphate reduction, which started on the fourth day of flooding, resulted in the mobilization of cadmium and lead, which were partitioned to copper-rich sulphide colloids showing two types of morphology: bacterium-associated ∼50–150-nm-diameter hollow particles formed through copper(0) transformation, and dispersed <50 nm nanoparticles, probably formed through homogeneous precipitation. The slow deposition of both types of sulphide colloid ensured elevated contaminant concentrations in the pore water for weeks. Our findings imply that colloid formation can enhance contaminant release from periodically sulphate-reducing Soils and sediments, potentially polluting surface- and groundwaters.
Andreas Voegelin - One of the best experts on this subject based on the ideXlab platform.
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mercury mobilization in a Flooded Soil by incorporation into metallic copper and metal sulfide nanoparticles
Environmental Science & Technology, 2013Co-Authors: Anke F Hofacker, Andreas Voegelin, Ralf Kaegi, Ruben KretzschmarAbstract:Mercury is a highly toxic priority pollutant that can be released from wetlands as a result of biogeochemical redox processes. To investigate the temperature-dependent release of colloidal and dissolved Hg induced by flooding of a contaminated riparian Soil, we performed laboratory microcosm experiments at 5, 14, and 23 °C. Our results demonstrate substantial colloidal Hg mobilization concomitant with Cu prior to the main period of sulfate reduction. For Cu, we previously showed that this mobilization was due to biomineralization of metallic Cu nanoparticles associated with suspended bacteria. X-ray absorption spectroscopy at the Hg LIII-edge showed that colloidal Hg corresponded to Hg substituting for Cu in the metallic Cu nanoparticles. Over the course of microbial sulfate reduction, colloidal Hg concentrations decreased but continued to dominate total Hg in the pore water for up to 5 weeks of flooding at all temperatures. Transmission electron microscopy (TEM) suggested that Hg became associated with C...
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multi metal contaminant dynamics in temporarily Flooded Soil under sulfate limitation
Geochimica et Cosmochimica Acta, 2009Co-Authors: Frankandreas Weber, Andreas Voegelin, Ruben KretzschmarAbstract:Abstract In many river basins, floodplain Soils have accumulated a variety of metal contaminants, which might be released during periods of flooding. We investigated the dynamics of copper, cadmium, lead, zinc, and nickel in a contaminated freshwater floodplain Soil under a realistic sulfate-limited flooding regime in microcosm experiments. We found that most contaminants were initially mobilized by processes driven by the reductive dissolution of Fe(III) and Mn(IV, III) (hydr)oxides. Subsequently, bacterial sulfate respiration resulted in the transformation of the entire available sulfate (2.3 mmol/kg) into chromous reducible sulfur (CRS). Cu K-edge X-ray absorption fine structure (XAFS) spectroscopy revealed that the Soil Cu speciation changed from predominantly Cu(II) bound to Soil organic matter (SOM) intermittently to 14% metallic Cu(0) and subsequently to 66% copper sulfide (CuxS). These CuxS precipitates accounted for most of the formed CRS, suggesting that CuxS was the dominant sulfide phase formed in the Flooded Soil. Sequential metal extractions, in agreement with CRS results, suggested that easily mobilizable Cd was completely and Pb partially sequestered in sulfide precipitates, controlling their dissolved concentrations to below detection limits. In contrast, Zn and Ni (as well as Fe) were hardly sequestered into sulfide phases, so that micromolar levels of dissolved Zn and Ni (and millimolar dissolved Fe(II)) persisted in the reduced Soil. The finding that Cu, Cd, and Pb were sequestered (but hardly any Zn, Ni, and Fe) is consistent with the thermodynamically predicted sulfide ladder following the increasing solubility products of the respective metal sulfides. The observation that Cd and Pb were sequestered in sulfides despite the presence of remaining SOM-bound Cu(II) suggested that the kinetics of Cu(II) desorption, diffusion, and/or CuxS precipitation interfered with the sulfide ladder. We conclude that the dynamics of multiple metal contaminants are intimately coupled under sulfate limitation by the relative thermodynamic stabilities and formation kinetics of the respective metal sulfides.
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contaminant mobilization by metallic copper and metal sulphide colloids in Flooded Soil
Nature Geoscience, 2009Co-Authors: Frankandreas Weber, Andreas Voegelin, Ralf Kaegi, Ruben KretzschmarAbstract:Colloids, such as submicrometre mineral particles or bacterial cells, can act as carriers enhancing the mobility of poorly soluble contaminants in subsurface environments. Spectroscopic and microscopic analysis of Flooded Soils suggests that copper colloids and metal sulphide colloids increase the concentration of contaminants in waterlogged Soils. Colloids, such as submicrometre mineral particles or bacterial cells, can act as carriers enhancing the mobility of poorly soluble contaminants in subsurface environments1,2. In sulphate-reducing Soils and sediments, metal sulphide precipitation has been proposed3,4,5,6 to generate contaminant-bearing sulphide colloids, which could transport contaminants traditionally thought to be immobilized by metal sulphide formation7. However, direct evidence for such a process is lacking. Here, we report the composition and morphology of pore-water colloids formed in contaminated floodplain Soil when Flooded with synthetic river water over a four-week period. We show that, on flooding, bacteria dispersed in the pore water mobilize copper by inducing biomineralization of metallic copper(0). We suggest that copper(0) crystals form by disproportionation of copper(I), which is released by copper-stressed bacteria to maintain copper homeostasis8,9. Sulphate reduction, which started on the fourth day of flooding, resulted in the mobilization of cadmium and lead, which were partitioned to copper-rich sulphide colloids showing two types of morphology: bacterium-associated ∼50–150-nm-diameter hollow particles formed through copper(0) transformation, and dispersed <50 nm nanoparticles, probably formed through homogeneous precipitation. The slow deposition of both types of sulphide colloid ensured elevated contaminant concentrations in the pore water for weeks. Our findings imply that colloid formation can enhance contaminant release from periodically sulphate-reducing Soils and sediments, potentially polluting surface- and groundwaters.
Peter Christie - One of the best experts on this subject based on the ideXlab platform.
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Solid-solution partitioning and thionation of diphenylarsinic acid in a Flooded Soil under the impact of sulfate and iron reduction
Science of The Total Environment, 2016Co-Authors: Meng Zhu, Haibo Zhang, Lijuan Zhang, Jing Wei, Yongming Luo, Peter ChristieAbstract:Diphenylarsinic acid (DPAA) is a major organic arsenic (As) compound derived from abandoned chemical weapons. The solid-solution partitioning and transformation of DPAA in Flooded Soils are poorly understood but are of great concern. The identification of the mechanisms responsible for the mobilization and transformation of DPAA may help to develop effective remediation strategies. Here, Soil and Fe mineral incubation experiments were carried out to elucidate the partitioning and transformation of DPAA in anoxic (without addition of sulfate or sodium lactate) and sulfide (with the addition of sulfate and sodium lactate) Soil and to examine the impact of sulfate and Fe(III) reduction on these processes. Results show that DPAA was more effectively mobilized and thionated in sulfide Soil than in anoxic Soil. At the initial incubation stages (0-4weeks), 6.7-74.5% of the total DPAA in sulfide Soil was mobilized likely by sorption competition with sodium lactate. At later incubation stage (4-8weeks), DPAA was almost completely released into the solution likely due to the near-complete Fe(III) reduction. Scanning transmission X-ray microscopy (STXM) results provide further direct evidence of elevated DPAA release coupled with Fe(III) reduction in sulfide environments. The total DPAA fraction decreased significantly to 24.5% after two weeks and reached 3.4% after eight weeks in sulfide Soil, whereas no obvious elimination of DPAA occurred in anoxic Soil at the initial two weeks and the total DPAA fraction decreased to 10.9% after eight weeks. This can be explained in part by the enhanced mobilization of DPAA and sulfate reduction in sulfide Soil compared with anoxic Soil. These results suggest that under Flooded Soil conditions, Fe(III) and sulfate reduction significantly promote DPAA mobilization and thionation, respectively, and we suggest that it is essential to consider both sulfate and Fe(III) reduction to further our understanding of the environmental fate of DPAA.