scholarly journals Gas‐Diffusivity based characterization of aggregated agricultural soils

2020 ◽  
Vol 84 (2) ◽  
pp. 387-398 ◽  
Author(s):  
J. R. R. N. Jayarathne ◽  
T. K. K. Chamindu Deepagoda ◽  
Timothy J. Clough ◽  
M.C.M. Nasvi ◽  
Steve Thomas ◽  
...  
Keyword(s):  
Agricultural Soils ◽  
Gas Diffusivity

scholarly journals Characterization of Soil Organic Matter Individual Fractions (Fulvic Acids, Humic Acids, and Humins) by Spectroscopic and Electrochemical Techniques in Agricultural Soils

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1067
Author(s):  
Aleksandra Ukalska-Jaruga ◽  
Romualda Bejger ◽  
Guillaume Debaene ◽  
Bożena Smreczak
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Humic Substances ◽  
Humic Acids ◽  
Agricultural Soils ◽  
Fulvic Acids ◽  
Sorption Properties ◽  
Aliphatic Chains

The objective of this paper was to investigate the molecular characterization of soil organic matter fractions (humic substances (HS): fulvic acids-FAs, humic acids-HAs, and humins-HNs), which are the most reactive soil components. A wide spectrum of spectroscopic (UV–VIS and VIS–nearIR), as well as electrochemical (zeta potential, particle size diameter, and polydispersity index), methods were applied to find the relevant differences in the behavior, formation, composition, and sorption properties of HS fractions derived from various soils. Soil material (n = 30) used for the study were sampled from the surface layer (0–30 cm) of agricultural soils. FAs and HAs were isolated by sequential extraction in alkaline and acidic solutions, according to the International Humic Substances Society method, while HNs was determined in the soil residue (after FAs and HAs extraction) by mineral fraction digestion using a 0.1M HCL/0.3M HF mixture and DMSO. Our study showed that significant differences in the molecular structures of FAs, Has, and HNs occurred. Optical analysis confirmed the lower molecular weight of FAs with high amount of lignin-like compounds and the higher weighted aliphatic–aromatic structure of HAs. The HNs were characterized by a very pronounced and strong condensed structure associated with the highest molecular weight. HAs and HNs molecules exhibited an abundance of acidic, phenolic, and amine functional groups at the aromatic ring and aliphatic chains, while FAs mainly showed the presence of methyl, methylene, ethenyl, and carboxyl reactive groups. HS was characterized by high polydispersity related with their structure. FAs were characterized by ellipsoidal shape as being associated to the long aliphatic chains, while HAs and HNs revealed a smaller particle diameter and a more spherical shape caused by the higher intermolecular forcing between the particles. The observed trends directly indicate that individual HS fractions differ in behavior, formation, composition, and sorption properties, which reflects their binding potential to other molecules depending on soil properties resulting from their type. The determined properties of individual HS fractions are presented as averaged characteristics over the examined soils with different physico-chemical properties.

scholarly journals Isolation and characterization of Bacillus thuringiensis (Ernst Berliner) strains indigenous to agricultural soils of Mali

2015 ◽  
Vol 10 (28) ◽  
pp. 2748-2755 ◽  
Author(s):  
Kassogue Adounigna ◽  
Maiga Kadia ◽  
Traore Diakaridia ◽  
Hamadoun Dicko Amadou ◽  
Fane Rokiatou ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Agricultural Soils ◽  
Isolation And Characterization

scholarly journals Isolation and characterization of phosphate solubilizing bacteria from agricultural soils for a potential use in cultivating Capsicum frutescens

2020 ◽  
Vol 10 (2) ◽  
pp. 5161-5173
Keyword(s):  
Plant Growth ◽  
Agricultural Soils ◽  
Pot Experiment ◽  
Available Phosphorus ◽  
Phosphate Solubilizing Bacteria ◽  
Capsicum Frutescens ◽  
Isolation And Characterization ◽  
Insoluble Form ◽  
Phosphate Solubilizing

Phosphorus (P) is one of the essential macronutrients needed for the plant growth, other than nitrogen and potassium. Most phosphorus remains as insoluble form in soils and the plants only can uptake the phosphorus nutrient in soluble forms. Phosphate solubilizing bacteria (PSB) dissolves the phosphorus and make it available for plants. In this study, Soil samples were collected and screened for PSB on PK medium. PSB colonies with the highest phosphate solubilization ability were chosen and used for studying its rhizosphere effect on Capsicum frutescens by pot experiment.. It was evidenced that selected PSB strain could solubilize phosphate in PK medium and modified PK broth. Besides, it provided available phosphorus for plants and enhanced the plant growth in pot experiment.

scholarly journals Characterization of Physically Fractionated Wollastonite-Amended Agricultural Soils

Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 635
Author(s):  
Aashvi Dudhaiya ◽  
Fatima Haque ◽  
Hugo Fantucci ◽  
Rafael M. Santos
Keyword(s):  
Inductively Coupled Plasma ◽  
Agricultural Soils ◽  
Mineral Carbonation ◽  
X Ray Diffraction ◽  
Silicate Mineral ◽  
Inductively Coupled ◽  
Natural Silicate ◽  
Inorganic Content ◽  
Plasma Mass Spectrometry

Wollastonite is a natural silicate mineral that can be used as an agricultural soil amendment. Once in the soil, this mineral undergoes weathering and carbonation reactions, and, under certain soil and field crop conditions, our previous work has shown that this practice leads to accumulation of inorganic carbon (calcium carbonate). Mineral carbonation is the carbon sequestration approach with the greatest potential for sequestration capacity and permanency. Agricultural lands offer vast areas onto which such minerals can be applied, while benefiting crops. This work illustrates a technique to separate wollastonite-containing soils into different fractions. These fractions are characterized separately to determine organic and inorganic content, as well as to determine the chemical and mineral composition. The aim is to detect the fate of wollastonite in agricultural soils, and the fate of weathering/carbonation products in the soil. The soils used in the study were collected from soybean and potato farmlands in Southern Ontario, and from an experimental pilot plot. Soil fractionation was done using sieving, and soil fractions were analyzed by a calcimeter, X-ray diffraction, and loss-on-ignition. Acid digested samples were measured by Inductively Coupled Plasma Mass Spectrometry. Carbonates and wollastonite were enriched by fractionation.

Characterization of (R/S)-mecoprop [2-(2-methyl-4-chlorophenoxy) propionic acid]-degrading Alcaligenes sp. CS1 and Ralstonia sp. CS2 isolated from agricultural soils

2001 ◽  
Vol 3 (4) ◽  
pp. 288-293 ◽  
Author(s):  
Christopher W. Smejkal ◽  
Tatiana Vallaeys ◽  
Fabian A. Seymour ◽  
Sara K. Burton ◽  
Hilary M. Lappin-Scott
Keyword(s):  
Propionic Acid ◽  
Agricultural Soils

scholarly journals Characterization of S-Triazine Herbicide Metabolism by a Nocardioides sp. Isolated from Agricultural Soils

2000 ◽  
Vol 66 (8) ◽  
pp. 3134-3141 ◽  
Author(s):  
Edward Topp ◽  
Walter M. Mulbry ◽  
Hong Zhu ◽  
Sarah M. Nour ◽  
Diane Cuppels
Keyword(s):  
Agricultural Soils ◽  
Sole Source ◽  
Bacterial Strains ◽  
Corn Production ◽  
Whole Cells ◽  
Carbon And Nitrogen ◽  
Cell Extracts ◽  
Hydrolytic Reaction ◽  
Central Canada

ABSTRACT Atrazine, a herbicide widely used in corn production, is a frequently detected groundwater contaminant. Nine gram-positive bacterial strains able to use this herbicide as a sole source of nitrogen were isolated from four farms in central Canada. The strains were divided into two groups based on repetitive extragenic palindromic (rep)-PCR genomic fingerprinting with ERIC and BOXA1R primers. Based on 16S ribosomal DNA sequence analysis, both groups were identified as Nocardioides sp. strains. None of the isolates mineralized [ring-U-14C]atrazine. There was no hybridization to genomic DNA from these strains usingatzABC cloned from Pseudomonas sp. strain ADP or trzA cloned from Rhodococcus corallinus. S-Triazine degradation was studied in detail inNocardioides sp. strain C190. Oxygen was not required for atrazine degradation by whole cells or cell extracts. Based on high-pressure liquid chromatography and mass spectrometric analyses of products formed from atrazine in incubations of whole cells with H2 18O, sequential hydrolytic reactions converted atrazine to hydroxyatrazine and then to the end productN-ethylammelide. Isopropylamine, the putative product of the second hydrolytic reaction, supported growth as the sole carbon and nitrogen source. The triazine hydrolase from strain C190 was isolated and purified and found to have a Km for atrazine of 25 μM and a V max of 31 μmol/min/mg of protein. The subunit molecular mass of the protein was 52 kDa. Atrazine hydrolysis was not inhibited by 500 μM EDTA but was inhibited by 100 μM Mg, Cu, Co, or Zn. Whole cells and purified triazine hydrolase converted a range of chlorine or methylthio-substituted herbicides to the corresponding hydroxy derivatives. In summary, an atrazine-metabolizingNocardioides sp. widely distributed in agricultural soils degrades a range of s-triazine herbicides by means of a novel s-triazine hydrolase.

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