Assessment of nitrate adsorption in soils by extraction, equilibration and column-leaching methods

1996 ◽  
Vol 76 (1) ◽  
pp. 49-57 ◽  
Author(s):  
C. G. Kowalenko ◽  
S. Yu
Keyword(s):  
Microbial Growth ◽  
Simulation Models ◽  
Practical Method ◽  
Soil Samples ◽  
Column Leaching ◽  
Microbial Inhibition ◽  
Nitrate Adsorption ◽  
Leaching Methods ◽  
Fraser Valley ◽  
Key Words Nitrate

The possibility of nitrate adsorption in 18 samples representing 11 soil types from the lower Fraser Valley of British Columbia was examined by differential extraction, equilibration and column leaching methods. Contrary to what was expected if nitrate was adsorbed by the soil, more nitrate was extracted by water than by 2 M KCl from some of the samples. Observations in related studies of greater microbial growth in 0.1 and 1.0 than in 2.0 M KCl extracts after more than 1 wk of storage and of different equilibrium results when conducted with and without toluene supported the conclusion that microbial or enzyme activity caused the larger amount of nitrate to be extracted by water than by 2 M KCl. Both equilibration and column leaching methods measured adsorption in some of the soil samples, but the amounts in the various samples by the two methods were not always the same. The equilibration method was analytically more precise than the column leaching method because it was simpler and required fewer measurements, but the column leaching method was considered to match more closely the soil to water ratio that would occur in the field. The equilibrium method found from 0 to 34% adsorption of the nitrate when added at a concentration not exceeding 50 μg N g−1. Further work is required to develop a practical method to meaningfully quantify nitrate adsorption in soils. The presence of nitrate adsorption has important implications for the interpretation of soil nitrogen research data and should possibly be included in nitrogen simulation models. The observation of microbial or enzyme effects on extraction of nitrate from soil shows the importance of using extraction solutions (e.g., those of high salt concentration or that contain a microbial inhibitor) that eliminate that possibility. Key words: Nitrate reactions, anion adsorption, nitrogen process, microbial effect, microbial inhibition

The Interactions of Soil-Borne Microorganisms and DCPA

Weed Science ◽  
1968 ◽  
Vol 16 (4) ◽  
pp. 470-473 ◽  
Author(s):  
B. G. Tweedy ◽  
Nikki Turner ◽  
Miriam Achituv
Keyword(s):  
Adverse Effect ◽  
New York ◽  
Carbon Source ◽  
Microbial Growth ◽  
Bacterial Population ◽  
Degradation Products ◽  
Past History ◽  
Subsequent Treatment ◽  
Soil Samples ◽  
History Of

Soil samples with and without a past history of dimethyl-2,3,5,6-tetrachloroterephthalate (DCPA) treatment were obtained from New York. A third sample was obtained from a field in Colorado where DCPA had been ineffective as a herbicide. The populations of bacteria and actinomycetes in these soils were determined and the actinomycetes were more prevalent in the samples with previous DCPA treatment than in untreated samples. Subsequent treatment resulted in an increase in actinomycete population and little change in bacterial population. In pure culture and in soils, the addition of DCPA had no adverse effect upon microbial growth, and several microorganisms appeared to utilize the herbicide as a carbon source. Two degradation products were methyl-2,3,5,6-tetrachloroterephthalate and 2,3,5,6-tetrachloroterethalic acid.

scholarly journals Antimicrobial activity of Arctium lappa constituents against microorganisms commonly found in endodontic infections

2005 ◽  
Vol 16 (3) ◽  
pp. 192-196 ◽  
Author(s):  
Juliana Vianna Pereira ◽  
Débora Cristina Baldoqui Bergamo ◽  
José Odair Pereira ◽  
Suzelei de Castro França ◽  
Rosemeire Cristina Linhares Rodrigues Pietro ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Microbial Growth ◽  
Diffusion Method ◽  
Arctium Lappa ◽  
Retention Factors ◽  
Antimicrobial Substances ◽  
Chemical Structures ◽  
Microbial Inhibition ◽  
Endodontic Infections

This study evaluated in vitro the antimicrobial activity of rough extracts from leaves of Arctium lappa and their phases. The following microorganisms, commonly found in the oral cavity, specifically in endodontic infections, were used: Enterococcus faecalis, Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis and Candida albicans. The agar-diffusion method allowed detection of the hexanic phase as an inhibitor of microbial growth. Bioautographic assays identified antimicrobial substances in the extract. The results showed the existence, in the rough hexanic phase and in its fractions, of constituents that have retention factors (Rf) in three distinct zones, thereby suggesting the presence of active constituents with chemical structures of different polarities that exhibited specificity against the target microorganisms. It may be concluded that the Arctium lappa constituents exhibited a great microbial inhibition potential against the tested endodontic pathogens.

scholarly journals Diseño de un medio para la producción de un co-cultivo de bacterias fosfato solubilizadoras con actividad fosfatasa

2012 ◽  
Vol 17 (1) ◽  
pp. 43 ◽  
Author(s):  
Jimena Paola Angulo-Cortés ◽  
Anamaría García-Díaz ◽  
Aura Marina Pedroza ◽  
María Mercedes Martínez-Salgado ◽  
Viviana Gutiérrez-Romero
Keyword(s):  
Phosphatase Activity ◽  
Microbial Growth ◽  
Culture Media ◽  
Biomass Concentration ◽  
Soil Samples ◽  
Phosphate Solubilizing Bacteria ◽  
Bacterial Strains ◽  
Box Behnken Design ◽  
Phosphate Solubilizing ◽  
Complex Culture

<strong>Objective</strong>. To design a complex culture media for the production of biomass and acid phosphatases from phosphate-solubilizing bacteria isolated from soil. <strong>Materials</strong> <strong>and methods</strong>. Phosphate-solubilizing bacteria were isolated from oil palm crop soil samples and selected on SMRS1 agar, which were then assessed with antagonism tests to verify their aptitude to form a co-culture. A Box-Behnken experimental design was applied to<br />evaluate the effect of each one of the culture media components on the production of biomass and phosphatase enzymes at a laboratory scale. Finally, microbial growth and enzyme production curves were carried out in order to determine their production times. <strong>Results</strong>. Five phosphate-solubilizing bacterial strains were isolated and three of them were selected based on their solubilization indices.These Gram negative strains with bacillus morphology were identified as A, B and C; their solubilization indices were 2.03, 2.12, and 2.83, respectively. According to the ANOVA analyses for the Box-Behnken design, the only factor which had a significant effect on the phosphatase activity (p&lt;0.01) was hydrolyzed yeast, and the formulation that generated the highest biomass concentration and phosphatase activity (p&lt;0.01) contained 10, 15 and 2.5 gL-1 of phosphoric rock, sucrose and hydrolyzed yeast, respectively. After 24 hours of incubation at 100 rpm, the highest values of biomass and phosphatase activity were obtained: 11.8 logarithmic units of CFU and 12.9 phosphatase units. <strong>Conclusion</strong>. We determined that the culture media based on phosphoric rock 10 gL-1, hydrolyzed yeast 2.5 gL-1 and commercial sucrose 15 gL-1 was ideal for the production of biomass and phosphatases by the strains evaluated; likewise, we proved that the hydrolyzed yeast was the only factor significantly influential for the production of phosphatases.<br /><br /><strong>Key words</strong>: bio-inoculants, phosphate solubilizing microorganisms, phosphatase activity, Box Behnken design.

A SURVEY OF DAIRY HERDS IN THE FRASER VALLEY OF BRITISH COLUMBIA TO DETERMINE POSSIBLE CAUSES OF UNSATISFACTORY REPRODUCTIVE PERFORMANCE

1977 ◽  
Vol 57 (3) ◽  
pp. 395-404 ◽  
Author(s):  
R. G. PETERSON ◽  
D. E. WALDERN
Keyword(s):  
British Columbia ◽  
Reproductive Performance ◽  
Artificial Insemination ◽  
Soil Samples ◽  
Dairy Herds ◽  
Return Rates ◽  
Factors Associated ◽  
Preliminary Study ◽  
Fraser Valley ◽  
Feed Samples

In a preliminary study of reproductive performance of 261 dairy herds in the Lower Fraser Valley of British Columbia for the period 1966 through 1970, mean non-return rate was 4.7% less in 1970 than in the previous 4 yr. In February 1972, factors associated with the reproductive performance of 68 herds in the same region were studied in greater detail. Herd non-return rates for 1971 were estimated from artificial insemination (AI) unit records. Feed samples, soil samples, feed intakes, and herd production levels were obtained for each period. The results indicated that differences in mineral nutrition between herds were associated with reproductive performance. The Cu/Mo ratio in silage was the most important factor, with increases in Cu relative to Mo being associated with low herd non-return rates. Other minerals found to be important included the Cu/Mo ratio in hay and grain, Cu in hay, Mo and Se in grain, Ca and P in silage and the variability of soil Mg levels. The type of forage fed was also important, with herds receiving diverse rations having higher conception rates than those restricted to one type of silage and/or hay.

scholarly journals Adsorption of nitrate as a groundwater pollutant by soil particles

2006 ◽  
Vol 34 ◽  
pp. 141-146
Author(s):  
Chieko Nakayama ◽  
Yoshinori Tanaka
Keyword(s):  
Nitric Acid ◽  
Breakthrough Curve ◽  
Amorphous Material ◽  
Soil Column ◽  
Soil Samples ◽  
Nitrate Contamination ◽  
Nitrate Content ◽  
Batch Test ◽  
Column Test ◽  
Nitrate Adsorption

This study discusses nitrogen adsorption in several soil samples of the Kanto loam collected from two locations in the Kanto plain. Their chemical properties were assessed on each of the soil samples as well as on pure allophane clay by instrumental analysis using batch and soil column tests. Nitrogen-nitrate adsorption by soil samples was determined by a 10-hour batch test using a nitric acid solution of 0.14 mmol. A saturation column test was conducted to obtain a breakthrough curve and calculate the coefficients of dispersion and retardation. The extent of nitrate adsorption in soil samples was confirmed by percolation with 0.14 mmol nitric acid through columns packed with the soil sample and silicate sand. In the batch test, it was found that the amount of nitrate adsorption was greater in allophane-rich volcanic ash soils with the amount of nitrate adsorption increasing under conditions of low pH. The breakthrough curve determined by the column test showed that the coefficient of retardation increased in allophane-rich soils. Adsorption of nitrates by Kanto loam soils was thus found to be dependent upon the content of allophane and amorphous material in the soil. Since the positive charge of allophane has the potential to reduce the nitrate content in groundwater, it can be effectively applied to reduce nitrate contamination in groundwater.

scholarly journals MICROBIAL CONTROL IN WHITE CACTUS PEAR WITH BIOPOLYMERIC COATING OF CHITOSAN, CANDELILLA WAX AND THYME ESSENTIAL OIL

2019 ◽  
Vol 42 (3) ◽  
pp. 201-207
Author(s):  
Daniel J. Valle-Ortiz ◽  
Adalberto Gómez-Cruz ◽  
Alma D. Hernández-Fuentes ◽  
Salvador Valle-Guadarrama
Keyword(s):  
Weight Loss ◽  
Essential Oil ◽  
Shelf Life ◽  
Microbial Growth ◽  
Microbial Control ◽  
Thymus Vulgaris ◽  
Cactus Pear ◽  
Microbial Inhibition ◽  
Low Weight ◽  
Microbial Development

White cactus pear (Opuntia albicarpa L.) undergoes decay by pathogens in postharvest, which limits its shelf life. The objective of this study was to evaluate coatings based on chitosan (Q), candelilla (Euphorbia antisyphilitica Zucc.) wax (Cw) and thyme (Thymus vulgaris L.) essential oil (Eo) to reduce microbial development on the cactus pear and increase shelf life. Emulsions based on Q, Eo, and Q+Eo were applied on freshly harvested cactus pear fruits, which were stored for 18 days at 22 ºC. Treatments with Q also incorporated Cw. Controls were uncoated fruits (Ct). Microbial inhibition was assessed through bacterial counting in culture plate, in addition to the appearance of the fruit on a visual scale 1 to 5, where 1 corresponded to appalling and 5 to excellent. Fruits with the Q+Eo treatment had an appearance close to 4 at the end of the storage, followed by those with Q, Eo, and T, which obtained a score of 1. The lowest weight loss occurred when Cw was used. With a coating of Q (2 %), Eo (2000 ppm) and Cw (5 %) microbial growth was reduced by 98.4 %, allowing a shelf life of at least 18 days at 22 ºC, with good appearance and low weight loss in fruits.

Does long-term soil warming affect microbial element limitation? A test by short-term assays of microbial growth responses to labile C, N and P additions

2020 ◽  
Author(s):  
Chupei Shi ◽  
Carolina Urbina Malo ◽  
Ye Tian ◽  
Shasha Zhang ◽  
Marilena Heitger ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Nutrient Limitation ◽  
Microbial Growth ◽  
Soil Samples ◽  
Growth Responses ◽  
Soil Warming ◽  
Soil C ◽  
Soil Microbial ◽  
Limiting Nutrients

&lt;p&gt;Human activities have caused global warming by 0.95 &amp;#176;C since the industrial revolution, and average temperatures in Austria have risen by almost 2 &amp;#176;C since 1880. Increased global mean temperatures have been reported to accelerate carbon (C) cycling, but also to promote nitrogen (N) and phosphorus (P) dynamics in terrestrial ecosystems. However, the extent of warming-induced increases in soil C, N and P processes can differ, causing an eventual uncoupling of biogeochemical C, N and P cycles, and leading to altered elemental imbalances between available plant and soil resources and soil microbial communities. The altered dynamics in soil C and nutrient availability caused by increased soil temperature could shift the growth-limiting element for soil microorganisms, with strong repercussions on the decomposition, mineralization and sequestration of organic C and nutrients. The latter relates to the conservative cycling of limiting elements while elements in excess are mineralized and released at greater rates by microbial communities.&lt;/p&gt;&lt;p&gt;Despite the many laboratory and in situ studies investigating factors that limit soil microbial activity, most of them explored nutrient addition effects on soil respiration or soil enzyme activities. A critical assessment, however, clearly indicated the inappropriateness of these measures to deduce growth-limiting nutrients for soil microbes. Similar to studies of plant nutrient limitation, unequivocal assessment of soil microbial element limitation can only be derived from the response of microbial growth to element amendments. To our knowledge this has not been performed on soils undergoing long-term soil warming.&lt;/p&gt;&lt;p&gt;In this study, we therefore investigated the effect of long-term soil warming on microbial nutrient limitation based on microbial growth measurements in a temperate calcareous forest soil. Soil samples were taken from two soil depths (0-10, 10-20 cm) in both control and heated plots in the Achenkirch soil warming project (&gt;15 yrs soil warming by + 4 &amp;#176;C). Soil samples were pre-incubated at their corresponding field temperature after sieving and removal of visible roots. The soils were amended with different combinations of glucose-C, inorganic/organic N and inorganic/organic P in a full factorial design, the nutrients being dissolved in &lt;sup&gt;18&lt;/sup&gt;O-water. After 24 hours of incubation, microbial growth was measured based on the &lt;sup&gt;18&lt;/sup&gt;O incorporation into genomic DNA. Nutrient (co)limitation was determined by comparing microbial growth responses upon C and nutrient additions relative to unamended controls. Basal respiration was also measured based on the increase in headspace CO&lt;sub&gt;2&lt;/sub&gt;, allowing to estimate microbial C use efficiency (CUE). The fate of C and nutrient amendments was finally traced by measurements of inorganic and organic extractable and microbial biomass C, N and P. This study will thereby provide key insights into potential shifts in limiting nutrients for microbial growth under long-term soil warming, and into concomitant effects on soil C and nutrient cycles.&lt;/p&gt;

The Application of Quantitative Risk Assessment to Microbial Food Safety

1998 ◽  
Vol 61 (5) ◽  
pp. 640-648 ◽  
Author(s):  
DAVID JOHN VOSE
Keyword(s):  
Risk Assessment ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Food Safety ◽  
Probability Distributions ◽  
Simulation Models ◽  
Practical Method ◽  
Assessment Model ◽  
Quantitative Risk Assessment ◽  
Suitable Model

Quantitative risk assessment (QRA) is rapidly accumulating recognition as the most practical method for assessing the risks associated with microbial contamination of foodstuffs. These risk analyses are most commonly developed in commercial Computer spreadsheet applications, combined with Monte Carlo simulation add-ins that enable probability distributions to be inserted into a spreadsheet. If a suitable model structure can be defined and all of the variables within that model reasonably quantified, a QRA will demonstrate the sensitivity of the severity of the risk to each stage in the risk-assessment model. It can therefore provide guidance for the selection of appropriate risk-reduction measures and a quantitative assessment of the benefits and costs of these proposed measures. However, very few reports explaining QRA models have been submitted for publication in this area. There is, therefore, little guidance available to those who intend to embark on a full microbial QRA. This paper looks at a number of modeling techniques that can help produce more realistic and accurate Monte Carlo simulation models. The use and limitations of several distributions important to microbial risk assessment are explained. Some simple techniques specific to Monte Carlo simulation modelling of microbial risks using spreadsheets are also offered which will help the analyst more realistically reflect the uncertain nature of the scenarios being modeled. simulation, food safety

Nitrate leaching and adsorption in a krasnozem from Redland Bay, QLD. I. Leaching of banded ammonium nitrate in a horticultural rotation

Soil Research ◽  
1976 ◽  
Vol 14 (2) ◽  
pp. 171 ◽  
Author(s):  
AS Black ◽  
SA Waring
Keyword(s):  
Ammonium Nitrate ◽  
Nitrate Nitrogen ◽  
Vertical Movement ◽  
Soil Samples ◽  
Lateral Movement ◽  
Time Intervals ◽  
Water Balance Equation ◽  
Cover Cropping ◽  
Nitrate Adsorption ◽  
Bean Crop

Ammonium nitrate at a rate of 165 kg nitrogen ha-l was placed in bands 76 cm apart in a krasnozem. The fertilized plots were either kept bare or cropped using a horticultuial rotation. Soil samples were collected at various time intervals to a depth of 300 cm. The amount of leachate was estimated from the water balance equation and the relative movement of nitrate with water determined. Of the mineral nitrogen initially in the soil, 72% (201 kg nitrogen ha-1) remained as nitrate between the depths of 40 and 120 cm following a bean crop. Prolonged cover cropping with oats decreased the amount of nitrate to less than 44 kg nitrogen ha-1 (< 2 mg nitrate nitrogen kg-1) in the surface 160 cm of the profile. In the bare plots, nitrate movement per 10 mm of leachate decreased with depth, lateral movement was gradual, and vertical movement was concentration dependent below 160 cm. These results are discussed in terms of the direction of water flow, soil structural properties and nitrate adsorption.

scholarly journals Retention of Nitrate and Phosphate in Soil and their Subsequent Uptake by Plants

1970 ◽  
Vol 43 (1) ◽  
pp. 67-76 ◽  
Author(s):  
MS Islam ◽  
SM Ullah ◽  
TH Khan ◽  
SM Imamul Huq
Keyword(s):  
Key Words ◽  
Plant Uptake ◽  
Column Leaching ◽  
Ipomoea Aquatica ◽  
Ph Values ◽  
Phosphate Retention ◽  
Leaching Experiment ◽  
Set Up ◽  
Key Words Nitrate

A laboratory based column leaching experiment was set up to study the retention of nitrate (NO3- ) and phosphate (PO43-) in three Bangladesh soils (Ghatail, Tejgaon and Sonatola) and their subsequent uptake by plants (Ipomoea aquatica). The investigation showed that the higher the clay contents, the higher was the retention of NO3- and PO43- by the soils and the lesser was their transfer into the growing plants. Again the higher the pH values in soils, the lower was the retention of NO3- and PO43- elements retained in the soils and the higher was the transfer of the elements into the growing plant. Retention of nitrate and phosphate followed the order: Ghatail>Tejgaon> Sonatola while the transfer to plant was in the order Sonatola>Tejgaon>Ghatail. Key Words: Nitrate, Phosphate, Retention, Leaching, Plant Uptake. DOI: 10.3329.bjsir.v43i1.858 Bangladesh J. Sci. Ind. Res. 43(1), 67-76, 2008

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