Results 171 to 180 of about 16,177 (209)
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Rate constants for nitrification and denitrification in soils
Radiation and Environmental Biophysics, 1976Rate constants for reactions in flowing solutions in soil can be calculated from extents of reactions as functions of depth, rates of flow, effective biomass of microbes and independent measurements of hydrodynamic dispersion. Constants have been calculated from data in the literature and are shown to be arbitrary unless all of these quantities have ...
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Decomposition rate of dicyandiamide and nitrification inhibition
Communications in Soil Science and Plant Analysis, 1989Abstract Degradation of dicyandiamide (DCD) was assayed in laboratory studies at 8, 15, and 22 C in a Decatur silt loam and in a Norfolk loamy sand. Dicyandiamide was very short lived at 22 C, with half‐lives of 7.4 and 14.7 days in the Decatur and Norfolk soils, respectively. In the Norfolk soil at 8 C, half‐life increased to 52.2 days.
K. F. Bronson +2 more
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Measurement of in situ rates of nitrification in sediment
Microbial Ecology, 1980A method has been developed for the measurement of nitrification rates in intact sediment cores without disturbing the concentration gradients of oxygen and ammonium. N-serve (2-chloro-6-trichloromethyl-pyridine), a specific inhibitor of the autotrophic ammonium oxidation, was injected into a 0-2 cm surface layer of the sediment (20 ppm) and added to ...
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Nitrification Potential and Factors Governing the Rate of Nitrification in Lake Kinneret
Oikos, 1977number of nitrifying bacteria initially present in the sample. This finding allowed the calibration of the NP measurements in terms of number of nitrifying bacteria. The fluctuations of the NP values were compared with the nitrification actually occurring in the lake. A concomitant decrease of NP in the sediment and increase of the NP in the lake water
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Microbial Ecology, 1984
A method for measuring rates of nitrification in intact marine sediment cores has been modified and adapted for use in freshwater sediments. The technique involves subsampling a sediment core into minicores. Half of these cores are treated with an inhibitor of chemolithotrophic nitrification and, after incubation, differences in ammonia and nitrate ...
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A method for measuring rates of nitrification in intact marine sediment cores has been modified and adapted for use in freshwater sediments. The technique involves subsampling a sediment core into minicores. Half of these cores are treated with an inhibitor of chemolithotrophic nitrification and, after incubation, differences in ammonia and nitrate ...
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Measurement and Distribution of Nitrification Rates in the Oceans
2011Nitrification is the process that converts ammonium to nitrate and thus links the regeneration of organic nitrogen to fixed nitrogen loss by denitrification. The first step, oxidation of ammonia to nitrite, is performed by a phylogenetically restricted group of proteobacteria (ammonia-oxidizing bacteria, AOB) and Crenarchaea (ammonia-oxidizing archaea,
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High rate partial nitrification treatment of reject wastewater
Journal of Bioscience and Bioengineering, 2010Partial nitrification (PN) treatments on reject wastewater were carried out. Dissolved oxygen concentration was limited by controlling air flowrate, which was the main operational strategy in this study. Stable PN performance was obtained during continuous operation for 80 days, with a maximum nitrogen loading rate (NLR) of 4.2 kg-N m(-3) day(-1) and ...
Jiachun, Yang +6 more
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A method for the measurement of nitrification rates in water
Water Research, 1978Abstract This paper describes a very sensitive method for the evaluation of nitrification rates requiring only short incubation times (3–6 h) and applicable to all aquatic media. It is based on the measurement of dark [ 14 C]-bicarbonate incorporation inhibited by N -serve, an inhibitor of nitrification.
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The rates of nitrification of peat soils in British Guiana
The Journal of Agricultural Science, 1954A study has been made of some of the nitrogen fractions of the pegasse soils of British Guiana in virgin and exhausted conditions, that is, before and after cropping.1. Preliminary field experiments on the virgin and exhausted soils adduced strong evidence in support of the complaints made by farmers that the productivity in yields of the pegasse soils
H. Paul, M. A. A. Shariff
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Soil Research, 2004
Abstract. The nitrification inhibitor dicyandiamide (DCD) has recently been shown to be effective in reducing nitrate leaching from grazed pasture soils. The objective of this study was to determine the influence of temperature and application rate on the effectiveness of DCD in nitrification inhibition.
H. J. Di, K. C. Cameron
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Abstract. The nitrification inhibitor dicyandiamide (DCD) has recently been shown to be effective in reducing nitrate leaching from grazed pasture soils. The objective of this study was to determine the influence of temperature and application rate on the effectiveness of DCD in nitrification inhibition.
H. J. Di, K. C. Cameron
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