COMPARISON OF REAGENTS FOR SOIL ORGANIC MATTER EXTRACTION AND EFFECT OF H ON SUBSEQUENT SEPARATION OF HUMIC AND FULVIC ACIDS

Soil organic matter is known as an important condition for the mobility of trace elements in soils, their geo- chemical migration and availability to plants. However, various components of soil organic matter have differ- ent effect on these processes due to their signifi cant differences in structure and properties. Aim. To establish the role of humic and fulvic acids in the process of formation of microelement mobility in soils and their accu- mulation in plants. Methods. A model experiment with sand culture was used to investigate the release of trace elements from preparations of humic and fulvic acids and their uptake by oat plants. Results. It was found that among biologically needed elements humic acids are enriched with iron, fulvic acids – with zinc, and copper distribution between these two groups of substances may be characterized as even. These elements have un- equal binding power with components of soil organic matter, as evidenced by their release into the cultivation medium and accumulation in plants. In the composition of fulvic acids zink has the most mobility – up to 95 % of this element is in the form, accessible for plants; the lowest mobility was demonstrated by copper in the composition with humic acids, for which no signifi cant changes in the concentration of mobile forms in the substrate and in the introduction to the test culture were registered. Despite signifi cantly higher iron content in humic acids, the application of fulvic acids in the cultivation medium provides a greater increase in the con- centration of mobile forms of this element. Conclusions. The results confi rm the important role of organic sub- stances of fulvic nature in the formation of zinc and iron mobility in the soil and their accumulation in plants.

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A method for isolating soil organic matter after the extraction of humic and fulvic acids

Organic Geochemistry ◽

10.1016/j.orggeochem.2006.07.007 ◽

2007 ◽

Vol 38 (1) ◽

pp. 140-150 ◽

Cited By ~ 21

Author(s):

A. Baglieri ◽

A. Ioppolo ◽

M. Nègre ◽

M. Gennari

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Fulvic Acids ◽

Humic And Fulvic Acids

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

Agronomy ◽

10.3390/agronomy11061067 ◽

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.

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Glomalin – an interesting protein part of the soil organic matter

Soil and Water Research ◽

10.17221/29/2019-swr ◽

2020 ◽

Vol 15 (No. 2) ◽

pp. 67-74 ◽

Cited By ~ 7

Author(s):

Vítězslav Vlček ◽

Miroslav Pohanka

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Arbuscular Mycorrhiza ◽

Mycorrhizal Fungi ◽

Biological Diversity ◽

Agricultural Practices ◽

Arbuscular Mycorrhizal ◽

Fulvic Acids ◽

Soil Parameters ◽

Citrate Buffer

The negative effects of the current agricultural practices include erosion, acidification, loss of soil organic matter (dehumification), loss of soil structure, soil contamination by risky elements, reduction of biological diversity and land use for non-agricultural purposes. All these effects are a huge risk to the further development of soil quality from an agronomic point of view and its resilience to projected climate change. Organic matter has a crucial role in it. Relatively significant correlations with the quality or the health of soil parameters and the soil organic matter or some fraction of the soil organic matter have been found. In particular, Ctot, Cox, humic and fulvic acids, the C/N ratio, and glomalin. Our work was focused on glomalin, a glycoprotein produced by the hyphae and spores of arbuscular mycorrhizal fungi (AMF), which we classify as Glomeromycota. Arbuscular mycorrhiza, and its molecular pathways, is not a well understood phenomenon. It appears that many proteins are involved in the arbuscular mycorrhiza from which glomalin is probably one of the most significant. This protein is also responsible for the unique chemical and physical properties of soils and has an ecological and economical relevance in this sense and it is a real product of the mycorrhiza. Glomalin is very resistant to destruction (recalcitrant) and difficult to dissolve in water. Its extraction requires specific conditions: high temperature (121°C) and a citrate buffer with a neutral or alkaline pH. Due to these properties, glomalin (or its fractions) are very stable compounds that protect the soil aggregate surface. In this review, the actual literature has been researched and the importance of glomalin is discussed.

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Chemical characterization and infrared spectroscopy of soil organic matter from two southern brazilian soils

Revista Brasileira de Ciência do Solo ◽

10.1590/s0100-06832003000100004 ◽

2003 ◽

Vol 27 (1) ◽

pp. 29-39 ◽

Cited By ~ 28

Author(s):

D. P. Dick ◽

J. H. Z. Santos ◽

E. M. Ferranti

Keyword(s):

Organic Matter ◽

Infrared Spectroscopy ◽

Soil Organic Matter ◽

Chemical Characterization ◽

Fulvic Acids ◽

Alkaline Treatment ◽

Hydrophobicity Index ◽

Elemental Analyses ◽

Brazilian Soils

Soil organic matter from the surface horizon of two Brazilian soils (a Latosol and a Chernosol), in bulk samples (in situ SOM) and in HF-treated samples (SOM), was characterized by elemental analyses, diffuse reflectance (DRIFT) and transmission Fourier transform infrared spectroscopy (T-FTIR). Humic acids (HA), fulvic acids (FA) and humin (HU) isolated from the SOM were characterized additionally by ultraviolet-visible spectroscopy (UV-VIS). After sample oxidation and alkaline treatment, the DRIFT technique proved to be more informative for the detection of "in situ SOM" and of residual organic matter than T-FTIR. The higher hydrophobicity index (HI) and H/C ratio obtained in the Chernosol samples indicate a stronger aliphatic character of the organic matter in this soil than the Latosol. In the latter, a pronounced HI decrease was observed after the removal of humic substances (HS). The weaker aliphatic character, the higher O/C ratio, and the T-FTIR spectrum obtained for the HU fraction in the Latosol suggest the occurrence of surface coordination of carboxylate ions. The Chernosol HU fraction was also oxygenated to a relatively high extent, but presented a stronger hydrophobic character in comparison with the Latosol HU. These differences in the chemical and functional group composition suggest a higher organic matter protection in the Latosol. After the HF treatment, decreases in the FA proportion and the A350/A550 ratio were observed. A possible loss of FA and condensation of organic molecules due to the highly acid medium should not be neglected.

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Membrane fouling propensity after adsorption as pretreatment in rainwater: a detailed organic characterisation

Water Science & Technology ◽

10.2166/wst.2008.522 ◽

2008 ◽

Vol 58 (8) ◽

pp. 1535-1539 ◽

Cited By ~ 1

Author(s):

L. Sabina ◽

B. Kus ◽

H.-K. Shon ◽

J. Kandasamy

Keyword(s):

Molecular Weight ◽

Organic Matter ◽

Membrane Fouling ◽

Membrane Filtration ◽

Building Blocks ◽

Fulvic Acids ◽

Humic And Fulvic Acids ◽

Removal Efficiencies ◽

Hydrophilic Compounds ◽

Hydrophobic Fraction

Organic characterisation in rainwater was investigated in terms of dissolved organic carbon (DOC) and molecular weight distribution (MWD) after powdered activated carbon (PAC) adsorption. PAC adsorption was used as pretreatment to membrane filtration to reduce membrane fouling. The MW of organic matter in rainwater used in this study was in the range of 43,000 Da to 30 Da. Each peak of organic matter consisted of biopolymers (polysaccharides and proteins), humic and fulvic acids, building blocks, low MW acids (hydrolysates of humic substances), low MW neutrals and amphiphilics. Rainwater contained the majority of hydrophilic compounds up to 72%. PAC adsorption removed 33% of total DOC. The removal efficiencies of the hydrophobic and hydrophilic fractions after PAC adsorption were 50% and 27%, respectively. PAC adsorption was found to preferentially remove the hydrophobic fraction. The majority of the smaller MW of 1,100 Da, 820 Da, 550 Da, 90 Da and 30 Da was removed after PAC adsorption. The MFI values decreased from 1,436 s/L2 to 147 s/L2 after PAC adsorption. It was concluded that PAC adsorption can be used as a pretreatment to membrane filtration with rainwater.

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Sustainability/resilience of soil organic matter components in an Argentinean arid region .

Spanish Journal of Soil Science ◽

10.3232/sjss.2013.v3.n1.05 ◽

2014 ◽

Vol 2 ◽

Author(s):

Carolina Vázquez ◽

Laura Noe ◽

Adriana Abril ◽

Carolina Merlo ◽

Carlos Romero ◽

...

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Humic Substances ◽

Humic Acids ◽

Arid Region ◽

Management Practices ◽

Agricultural Soils ◽

Fulvic Acids ◽

Soil Sustainability ◽

Undisturbed Site

This short communication presents a novel approach to determining the soil sustainability of productive practices in an Argentinean arid region, using the resilience degree of soil organic matter components. The study was conducted in four sites of the Arid Chaco region of the Cordoba province: one undisturbed site, two sites with livestock (with total and with selective clearing) and one site with agriculture. In each site three soil samples were taken and total soil organic matter, fulvic and humic acids, and non-humic substances were analyzed. Variations of each component (%) between each productive practice and the undisturbed site were calculated in order to establish the resilience degree. The livestock soils showed: a) moderate resilience for non-humic substances, b) low resilience for organic matter and humic acids, and c) no resilience for fulvic acids. The agricultural soils showed: a) low resilience for total organic matter and non-humic substances, and b) no resilience for fulvic and humic acids. We conclude that this approach is a powerful tool for establishing management practices according to each particular situation, allowing improved productivity in arid regions.

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Comparison of soil organic matter composition under different land uses by DRIFT spectroscopy

Plant Soil and Environment ◽

10.17221/11/2021-pse ◽

2021 ◽

Vol 67 (No. 5) ◽

pp. 255-263

Author(s):

Saven Thai ◽

Lenka Pavlů ◽

Václav Tejnecký ◽

Petra Vokurková ◽

Shahin Nozari ◽

...

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Molecular Mass ◽

Forest Soil ◽

Fulvic Acids ◽

Land Uses ◽

Drift Spectroscopy ◽

Organic Matter Composition ◽

Diffuse Reflectance Infrared ◽

Soil Organic Matter Composition

The study aimed to estimate and characterise soil organic matter under different land uses (cropland, grassland, and forest) and soil depths. The soil organic matter composition of the soil was assessed by diffuse reflectance infrared spectroscopy (DRIFT). Humic and fulvic acids (HAs, FAs) were extracted from soils and their compositions were evaluated by DRIFT. Low molecular mass organic acids content was also measured. Our result revealed that the largest differences of the spectra in the composition of organic matter were observed in the upper parts of the soil profile. The forest soil spectra had more intense aliphatic bands, carboxylic, and CH bands than spectra of grassland and cropland soils. The difference of HAs spectra was at 3 010 to 2 800/cm where the most intensive aliphatic bands were in forest soil HAs, followed by grassland and cropland soil HAs. The grassland topsoil FAs spectrum differs most from the other land uses. It has lower peaks around 1 660–1 600/cm and 1 200/cm than cropland and forest. The concentration of low molecular mass organic acid (LMMOA) was the highest in the forest soil and the most abundant acid was citrate.

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