The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
A. C. Favre - One of the best experts on this subject based on the ideXlab platform.
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Small-Scale Spatial Variability of Atrazine and Dinoseb Adsorption Parameters in an Alluvial Soil
Journal of Environmental Quality, 2008Co-Authors: A. Mermoud, Jean M. F. Martins, D. Zhang, A. C. FavreAbstract:Soil sorption processes largely control the environmental fate of herbicides. Therefore accuracy of sorption parameters is crucial for accurate prediction of herbicide mobility in agricultural Soils. A combined experimental and statistical study was carried out to investigate the small scale spatial variability of sorption parameters for atrazine and dinoseb in Soils and to establish the number of samples needed to provide a value of the distribution coefficient (Kd) next to the mean, with a given precision. The study explored sorption properties of the two herbicides in subsurface samples collected from four pits distributed along a transect of an Alluvial Soil; two to four samples were taken at very short distances apart (about 30 cm), at each sampling location. When considering all the data available, the distribution coefficients were found to be normally and log-normally distributed for atrazine and dinoseb, respectively; the coefficients of variation were relatively high (close to 50% for dinoseb and 40% for atrazine). When analyzed horizon by horizon, the data revealed distribution coefficients normally distributed for both herbicides, whatever the Soil layer, with lower coefficients of variation. The Kd values were shown to vary considerably between samples collected at very short distance (a few centimeters), suggesting that taking a single Soil sample to determine sorption properties through batch experiments can lead to highly unrepresentative results and to poor sorption/mobility predictions.
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Small-Scale Spatial Variability of Atrazine and Dinoseb Adsorption Parameters in an Alluvial Soil
Journal of Environmental Quality, 2008Co-Authors: A. Mermoud, D. Zhang, Jean Martins, A. C. FavreAbstract:Received for publication June 7, 2007. Soil sorption processes largely control the environmental fate of herbicides. Therefore, accuracy of sorption parameters is crucial for accurate prediction of herbicide mobility in agricultural Soils. A combined experimental and statistical study was performed to investigate the small-scale spatial variability of sorption parameters for atrazine and dinoseb in Soils and to establish the number of samples needed to provide a value of the distribution coefficient (Kd) next to the mean, with a given precision. The study explored sorption properties of the two herbicides in subsurface samples collected from four pits distributed along a transect of an Alluvial Soil; two to four samples were taken at about 30 cm apart at each sampling location. When considering all the data, the distribution coefficients were found to be normally and log-normally distributed for atrazine and dinoseb, respectively; the CVs were relatively high (close to 50% for dinoseb and 40% for atrazine). When analyzed horizon by horizon, the data revealed distribution coefficients normally distributed for both herbicides, whatever the Soil layer, with lower CVs. The Kd values were shown to vary considerably between samples collected at very short distance (a few centimeters), suggesting that taking a single Soil sample to determine sorption properties through batch experiments can lead to highly unrepresentative results and to poor sorption/mobility predictions.
T K Adhya - One of the best experts on this subject based on the ideXlab platform.
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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.
A. Mermoud - One of the best experts on this subject based on the ideXlab platform.
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Small-Scale Spatial Variability of Atrazine and Dinoseb Adsorption Parameters in an Alluvial Soil
Journal of Environmental Quality, 2008Co-Authors: A. Mermoud, Jean M. F. Martins, D. Zhang, A. C. FavreAbstract:Soil sorption processes largely control the environmental fate of herbicides. Therefore accuracy of sorption parameters is crucial for accurate prediction of herbicide mobility in agricultural Soils. A combined experimental and statistical study was carried out to investigate the small scale spatial variability of sorption parameters for atrazine and dinoseb in Soils and to establish the number of samples needed to provide a value of the distribution coefficient (Kd) next to the mean, with a given precision. The study explored sorption properties of the two herbicides in subsurface samples collected from four pits distributed along a transect of an Alluvial Soil; two to four samples were taken at very short distances apart (about 30 cm), at each sampling location. When considering all the data available, the distribution coefficients were found to be normally and log-normally distributed for atrazine and dinoseb, respectively; the coefficients of variation were relatively high (close to 50% for dinoseb and 40% for atrazine). When analyzed horizon by horizon, the data revealed distribution coefficients normally distributed for both herbicides, whatever the Soil layer, with lower coefficients of variation. The Kd values were shown to vary considerably between samples collected at very short distance (a few centimeters), suggesting that taking a single Soil sample to determine sorption properties through batch experiments can lead to highly unrepresentative results and to poor sorption/mobility predictions.
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Small-Scale Spatial Variability of Atrazine and Dinoseb Adsorption Parameters in an Alluvial Soil
Journal of Environmental Quality, 2008Co-Authors: A. Mermoud, D. Zhang, Jean Martins, A. C. FavreAbstract:Received for publication June 7, 2007. Soil sorption processes largely control the environmental fate of herbicides. Therefore, accuracy of sorption parameters is crucial for accurate prediction of herbicide mobility in agricultural Soils. A combined experimental and statistical study was performed to investigate the small-scale spatial variability of sorption parameters for atrazine and dinoseb in Soils and to establish the number of samples needed to provide a value of the distribution coefficient (Kd) next to the mean, with a given precision. The study explored sorption properties of the two herbicides in subsurface samples collected from four pits distributed along a transect of an Alluvial Soil; two to four samples were taken at about 30 cm apart at each sampling location. When considering all the data, the distribution coefficients were found to be normally and log-normally distributed for atrazine and dinoseb, respectively; the CVs were relatively high (close to 50% for dinoseb and 40% for atrazine). When analyzed horizon by horizon, the data revealed distribution coefficients normally distributed for both herbicides, whatever the Soil layer, with lower CVs. The Kd values were shown to vary considerably between samples collected at very short distance (a few centimeters), suggesting that taking a single Soil sample to determine sorption properties through batch experiments can lead to highly unrepresentative results and to poor sorption/mobility predictions.
D. Zhang - One of the best experts on this subject based on the ideXlab platform.
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Small-Scale Spatial Variability of Atrazine and Dinoseb Adsorption Parameters in an Alluvial Soil
Journal of Environmental Quality, 2008Co-Authors: A. Mermoud, Jean M. F. Martins, D. Zhang, A. C. FavreAbstract:Soil sorption processes largely control the environmental fate of herbicides. Therefore accuracy of sorption parameters is crucial for accurate prediction of herbicide mobility in agricultural Soils. A combined experimental and statistical study was carried out to investigate the small scale spatial variability of sorption parameters for atrazine and dinoseb in Soils and to establish the number of samples needed to provide a value of the distribution coefficient (Kd) next to the mean, with a given precision. The study explored sorption properties of the two herbicides in subsurface samples collected from four pits distributed along a transect of an Alluvial Soil; two to four samples were taken at very short distances apart (about 30 cm), at each sampling location. When considering all the data available, the distribution coefficients were found to be normally and log-normally distributed for atrazine and dinoseb, respectively; the coefficients of variation were relatively high (close to 50% for dinoseb and 40% for atrazine). When analyzed horizon by horizon, the data revealed distribution coefficients normally distributed for both herbicides, whatever the Soil layer, with lower coefficients of variation. The Kd values were shown to vary considerably between samples collected at very short distance (a few centimeters), suggesting that taking a single Soil sample to determine sorption properties through batch experiments can lead to highly unrepresentative results and to poor sorption/mobility predictions.
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Small-Scale Spatial Variability of Atrazine and Dinoseb Adsorption Parameters in an Alluvial Soil
Journal of Environmental Quality, 2008Co-Authors: A. Mermoud, D. Zhang, Jean Martins, A. C. FavreAbstract:Received for publication June 7, 2007. Soil sorption processes largely control the environmental fate of herbicides. Therefore, accuracy of sorption parameters is crucial for accurate prediction of herbicide mobility in agricultural Soils. A combined experimental and statistical study was performed to investigate the small-scale spatial variability of sorption parameters for atrazine and dinoseb in Soils and to establish the number of samples needed to provide a value of the distribution coefficient (Kd) next to the mean, with a given precision. The study explored sorption properties of the two herbicides in subsurface samples collected from four pits distributed along a transect of an Alluvial Soil; two to four samples were taken at about 30 cm apart at each sampling location. When considering all the data, the distribution coefficients were found to be normally and log-normally distributed for atrazine and dinoseb, respectively; the CVs were relatively high (close to 50% for dinoseb and 40% for atrazine). When analyzed horizon by horizon, the data revealed distribution coefficients normally distributed for both herbicides, whatever the Soil layer, with lower CVs. The Kd values were shown to vary considerably between samples collected at very short distance (a few centimeters), suggesting that taking a single Soil sample to determine sorption properties through batch experiments can lead to highly unrepresentative results and to poor sorption/mobility predictions.
Pramod K Aggarwal - One of the best experts on this subject based on the ideXlab platform.
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effects of dicyandiamide farmyard manure and irrigation on crop yields and ammonia volatilization from an Alluvial Soil under a rice oryza sativa l wheat triticum aestivum l cropping system
Biology and Fertility of Soils, 2002Co-Authors: B Banerjee, H Pathak, Pramod K AggarwalAbstract:Volatilization of NH3 from Soil is a major N-loss mechanism that reduces the efficiency of applied N fertilizers, and causes environmental pollution. Strategies are needed to reduce the loss. The influences of dicyandiamide (DCD), farmyard manure (FYM) and irrigation on NH3 volatilization from an Alluvial Soil in rice (Oryza sativa L.)-wheat (Triticum aestivum L.) cropping system was studied using the acid trap method. The loss of NH3 in the rice-wheat system ranged from 38.6 kg N ha–1 from the unfertilized Soil to 69.0 kg N ha–1 in the treatment with urea+DCD. Substitution of 50% N provided through urea by FYM reduced NH3-N volatilization by 10% in rice and wheat as compared to the urea treatment. Application of DCD increased NH3 volatilization in wheat by 7% but in rice it had no effect. The irrigation level had no effect on NH3 volatilization in rice but fewer irrigations with fewer splits of N in wheat resulted in higher NH3 volatilization. Application of DCD and FYM with urea had similar effects on grain yield and N uptake by rice and wheat as that of the urea treatment. The study showed that integrated use of organic manure and chemical fertilizer has the potential to reduce the loss of N due to volatilization and thereby minimize environmental pollution. Nitrification inhibitors, which are reported to be useful in increasing the N-use efficiency by reducing the leaching and denitrification losses of N, however, may increase N loss due to volatilization.