scholarly journals The proportion of soil aggregates in dependence on the fraction composition of humic substances

2018 ◽  
Vol 13 (No. 4) ◽  
pp. 193-199
Author(s):  
Tobiašová Erika ◽  
Barančíková Gabriela ◽  
Gömöryová Erika ◽  
Koco Štefan ◽  
Halás Ján ◽  
...  
Keyword(s):  
Humic Substances ◽  
Forest Ecosystems ◽  
Soil Aggregates ◽  
Size Fraction ◽  
Fulvic Acids ◽  
Positive Influence ◽  
Soil Types ◽  
Important Indicator ◽  
Mineral Components ◽  
Stabilizing Element

Humic substances (HS) are an important stabilizing element in the formation of soil aggregates. The experiment included 6 soil types (Haplic Fluvisol, Haplic Chernozem, Cutanic Luvisol, Haplic Cambisol, Haplic Planosol, Rendzic Leptosol), each in four types of ecosystems (forest, meadow, urban, and agro-ecosystems). Soil macroaggregates were separated with the sieve (dry and wet sieve) to size fractions of net aggregates; humic acids (HA) and fulvic acids (FA) were divided into 3(4) fractions: free and bound with mobile R<sub>2</sub>O<sub>3</sub>, bound with Ca<sup>2+</sup>, and bound with mineral components and stable R<sub>2</sub>O<sub>3</sub>. The influence of HA and FA fractions on the proportion of dry-sieved macroaggregates (DSA) and wet-sieved macroaggregates (WSA) was different. Mainly HA bound with polyvalent cations had a positive influence. In the case of HS, their influence depends also on the components with which HA and FA are bound. WSA of the 0.5–1 mm size fraction that is an important indicator of changes in ecosystems, had a higher proportion in the ecosystems influenced by man (agro-ecosystem &gt; urban &gt;) than in the ecosystems close to nature (&gt; meadow &gt; forest ecosystems). The influence of ecosystem was reflected in the proportion of those fractions of DSA and WSA on which the effect of soil type and HS was not shown, and vice versa.  

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 Organic Materials and Their Chemically Extracted Humic and Fulvic Acids as Potential Soil Amendments for Faba Bean Cultivation in Soils with Varying CaCO3 Contents

Horticulturae ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 205
Author(s):  
Ihab M. Farid ◽  
Mohamed A. El-Ghozoli ◽  
Mohamed H. H. Abbas ◽  
Dalia S. El-Atrony ◽  
Hassan H. Abbas ◽  
...  
Keyword(s):  
Humic Substances ◽  
Faba Bean ◽  
Plant Biomass ◽  
Nitrogenase Activity ◽  
Organic Amendments ◽  
Fulvic Acids ◽  
Mineral N ◽  
Randomized Design ◽  
Long Time ◽  
Factor C

Organic amendments are important sources of nutrients that release upon organic matter degradation, yet the stability of these organics in arid and semi-arid regions is relatively low. In contrast, humic substances (HS) are resistant to biodegradation and can keep nutrients in the soil available for the plant over a long time. Combinations between humic substances (HS) and mineral-N fertilizers are assumed to retain higher available nutrients in soils than those recorded for the sole application of either mineral or organic applications. We anticipate, however, that humic substances might not be as efficient as the organics from which they were extracted in increasing NP uptake by plants. To test these assumptions, faba bean was planted in a pot experiment under greenhouse conditions following a complete randomized design while considering three factors: two soils (calcareous and non-calcareous, Factor A), two organics (biogas and compost, Factor B) and combinations of the organics and their extracts (HA or FA) together with complementary doses of mineral-N ((NH4)2SO4) to attain a total rate of 50 kg N ha−1 (the recommended dose for faba bean plants) (Factor C). Results indicated that nitrogenase activity increased significantly due to the application of the used organics. In this respect, compost manure caused higher nitrogenase activity than biogas manure did. Humic substances raised NP-availability and the uptake by plants significantly; however, the values of increase were lower than those that occurred due to the compost or biogas manure. Moreover, the sole application of the used organics recorded the highest increases in plant biomass. Significant correlations were also detected between NP-availability, uptake and plant biomass. This means that HS could probably retain nutrients in available forms for long time periods, yet nutrients released continuously but slowly upon decomposition of organics seemed more important for plant nutrition.

scholarly journals Understanding the Antecedents and Consequences of Green Human Capital

SAGE Open ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 215824402098886
Author(s):  
Yin Ma ◽  
Shih-Chih Chen ◽  
Athapol Ruangkanjanases
Keyword(s):  
Job Satisfaction ◽  
Human Capital ◽  
Big Five ◽  
Structural Equation ◽  
Positive Impact ◽  
Positive Influence ◽  
Equation Modeling ◽  
Outcome Variable ◽  
Big Five Personality ◽  
Important Indicator

Green human capital (GHC) is regarded as one of the primary attributes individuals need to develop in the era of environmental degradation. Many existing studies indicate that it is probably an important indicator of employees’ satisfaction in the workplace. Thus, based on trait theory and ability–motivation–opportunity theory, the current study examines the antecedents and outcomes of GHC among 630 employees from the manufacturing and service companies in Guangdong Province. The research employs Big Five personality and green training as the predictors of GHC, and job satisfaction as the outcome variable. Partial least squares structural equation modeling is used to analyze the data. The findings show that, in Big Five personality domains, only agreeableness and openness have a positive as well as significant impact on the individuals’ GHC, and that green training also has a positive influence on the GHC. GHC has a positive impact on the employees’ job satisfaction. The research findings and managerial implications are then discussed in detail.

scholarly journals Modified Humic Substances as Soil Conditioners: Laboratory and Field Trials

Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 150
Author(s):  
Natalia A. Kulikova ◽  
Alexander B. Volikov ◽  
Olga I. Filippova ◽  
Vladimir A. Kholodov ◽  
Nadezhda V. Yaroslavtseva ◽  
...  
Keyword(s):  
Humic Substances ◽  
Soil Aggregates ◽  
Field Tests ◽  
Performance Testing ◽  
Field Trials ◽  
Soil Conditioner ◽  
Model Soil ◽  
Substrate Induced Respiration ◽  
And Performance ◽  
Survival Of Seedlings

The paper is devoted to the development and performance testing of a soil conditioner based on leonardite humic substances (LHS) modified with 3-aminopropyltriethoxysilane (APTES). The modified HS were obtained by adding APTES to LHS solution at different mass ratios of LHS and APTES, followed by the investigation of siloxane structures using 31Si NMR spectroscopy. The Urbic Technosol was used as a model soil. The size and amount of water-stable soil aggregates were estimated using wet sieving and laser diffraction, respectively. Toxicity was evaluated by monitoring microbial substrate-induced respiration (SIR) and seedling bioassay. Laboratory column experiments demonstrated an increase in water-stability of the 3–5 mm soil aggregates after LHS-APTES application. Field tests showed an increase in the average weighted diameter of micro aggregates (from 59 to 73 μm) and water-stable macroaggregates (from 1.6 to 2.9 mm) due to the LHS-APTES amendment. A substantial increase in SIR from 5 to 9 mg CO2 (kg h)−1 was detected. Better survival of seedlings was observed. The obtained beneficial results indicate that APTES-modified HS can be successfully used as a soil conditioner. The formation of extended siloxane networks was suggested as the main mechanism of the observed improvement in the structure of the amended soils.

Bioavailability of a nonylphenol isomer in dependence on the association to dissolved humic substances

2004 ◽  
Vol 50 (5) ◽  
pp. 277-283 ◽  
Author(s):  
R. Vinken ◽  
A. Höllrigl-Rosta ◽  
B. Schmidt ◽  
A. Schäffer ◽  
P.F.-X. Corvini
Keyword(s):  
Humic Acid ◽  
Carbon Source ◽  
Humic Substances ◽  
Organic Compounds ◽  
Sole Carbon Source ◽  
Equilibrium Dialysis ◽  
Fulvic Acids ◽  
Degrading Bacterium ◽  
Bacterium Strain ◽  
Dissolved Humic Substances

Humic substances are important environmental components since they represent a very large part of organic compounds on earth. According to many reports, dissolved humic substances are a determinant parameter for the bioavailability of xenobiotic compounds. For the present bioavailability studies, two kinds of dissolved humic substances, a commercially available humic acid and fulvic acids isolated from peat were used. As the relevant xenobiotic, a defined branched nonylphenol isomer, 4(3′,5′-dimethyl-3′-heptyl)-phenol (p353NP) was synthesised according to Friedel-Crafts alkylation. Equilibrium dialysis studies were implemented in order to investigate the association between 14C-labelled p353NP and dissolved humic substances. The biodegradability in the presence of dissolved humic substances was examined in experiments with the nonylphenol degrading bacterium strain Sphingomonas TTNP3 and with p353NP as sole carbon source. The results showed that p353NP-humic acid associates were formed in high amounts, whereas no adducts with fulvic acids occurred. In the degradation studies with Sphingomonas TTNP3, no effects of dissolved humic substances on the bioavailability of p353NP could be observed. It was assumed that the association between nonylphenol and humic acids occurs rapidly and is reversible. Thus, the formation of "labile" complexes did not influence biodegradation rates, which were quite low.

scholarly journals Fertigation of ‘BRS Princesa’ banana with humic substance and saponin-based plant extracts

Revista CERES ◽  
2017 ◽  
Vol 64 (4) ◽  
pp. 392-398
Author(s):  
Diego Magalhães de Melo* ◽  
Eugênio Ferreira Coelho ◽  
Raul Castro Carriello Rosa ◽  
Ana Lucia Borges ◽  
Djalma Barbosa dos Santos ◽  
...  
Keyword(s):  
Humic Substances ◽  
Humic Substance ◽  
Plant Extract ◽  
Plant Extracts ◽  
Block Design ◽  
Fulvic Acids ◽  
Growth And Yield ◽  
Randomized Block Design ◽  
Number Of Leaves ◽  
Banana Cultivar

ABSTRACT The use of humic substances and plant extract has been increasing mainly in organic crop systems without scientific-based recommendations. Research is necessary to evaluate the feasibility and the recommendations of these substances. The objective of this work was to evaluate the effect of humic substances (humic and fulvic acids) applied by fertigation with and without saponin-based plant extracts on growth and yield of ‘BRS Princesa’ banana. The experiment was carried out using the banana cultivar ‘BRS Princesa’, at a spacing of 2.0 × 2.5 m, fertigated by drip irrigation in a Dystric Densic Xantic Ferralsol, at the Recôncavo da Bahia, Brazil. Treatments consisted of five doses of humic substances (0.0; 70; 105; 140, and 210 L ha-1cycle-1) applied with and without a saponin-based plant extract in a randomized block design in split-plot scheme. The following growth variables were evaluated: number of leaves, pseudostem height, pseudostem diameter, and length and width of the third leaf. The number of fruits/hand and hands/bunch, hand and bunch yield, and length and fruit diameter of the second central hand were evaluated during harvest. The doses of humic substances influenced only pseudostem height. Hand yield, as well as fruit length and diameter of ‘BRS Princesa’ banana were higher in plants fertigated with humic substance and plant extract in comparison with plants fertigated with only humic substance.

scholarly journals Influence of humic substances on the landfill leachate biodegradability with a focus on temporal seasonality

2021 ◽  
Author(s):  
Wagner Guadagnin Moravia ◽  
Victor Rezende Moreira ◽  
Yuri Abner Rocha Lebron ◽  
Liséte Celina Lange ◽  
Míriam Cristina Santos Amaral
Keyword(s):  
Humic Substances ◽  
Landfill Leachate ◽  
Fulvic Acids ◽  
Biologic Treatment ◽  
Adequate Treatment ◽  
Tropical Regions ◽  
Treatment Techniques ◽  
Biological Treatments ◽  
Lowry Method ◽  
The Cost

Abstract The high resilience to biological treatments from the landfill leachate is generally associated with the presence of humic substances (HS). The brown color characteristic of this effluent is also related to these substances. Landfill leachate with low biodegradability can make biological treatments unfeasible, which can drive up the cost for the treatment of large leachate volumes. In this context, this research aimed to characterize the leachate in different seasonal periods, and verify the influence of HS species on the biodegradability of the effluent to assist in the selection of adequate treatment techniques. The HS quantification was performed using the modified Lowry method and speciation through fractionation according to the molar masses of the HS species. The tropical regions can be the precursor for the rapid stabilization of biodegradable organic matter. The warmer climate contributed to a reduced BOD/COD ratio (0.03) and the predominance of compounds of lower mass (e.g.: fluvic acids). The tests showed an HS concentration of 26.9% of the total COD in the raw leachate in the rainy season, which increased to 37.3% in the dry season. Approximately 70% of HS species refer to fulvic acids, a fraction identified as having the highest biologic treatment resilience.

scholarly journals Soil Pollution vs. Soil Collembola as a Bioindicator: A review

2010 ◽  
Vol 2 (5) ◽  
pp. 1-11
Author(s):  
Atreyee Sahana
Keyword(s):  
Organic Matter ◽  
Soil Health ◽  
Soil Formation ◽  
Terrestrial Ecosystems ◽  
Soil Types ◽  
Natural Soil ◽  
Natural Health ◽  
Arthropod Fauna ◽  
Mineral Components ◽  
Inorganic Mineral

Soil is the foundation of all life activities in terrestrial ecosystems. Soil micro arthropod groups (less than 2 mm in size) like Acari and Collembola comprise more than 90% of arthropod fauna in most soil types. They majorly help in soil formation by breaking up the organic matter and mixing it up with inorganic mineral components. Among them, various species of Collembola have been proved to be effective bioindicator tool to measure soil health either it is polluted or not by its several characteristics in temperate countries. Therefore, in today’s world where pollution in soil by various agents is a baffling issue like other environmental pollutions, these natural soil inhabitants can make a hope to measure the natural health of soil.

scholarly journals An approach to identify soil types by using hydraulic conductivity values

2018 ◽  
Vol 2 (1) ◽  
pp. 43-51
Author(s):  
Maritha Nilam Kusuma ◽  
Wahyono Hadi ◽  
Budisantoso Wirjodirdjo ◽  
Yulfiah Yulfiah
Keyword(s):  
Water Treatment ◽  
Hydraulic Conductivity ◽  
Preliminary Analysis ◽  
Soil Types ◽  
Main Role ◽  
Important Indicator ◽  
Pre Treatment ◽  
Constant Head ◽  
Soil Filtration

Water treatment in Indonesia still uses coagulant to reduce the contaminant. Therefore, an infiltration gallery is required as the pre-treatment before conventional water treatment conducted. Infiltration gallery is a natural technology for absorbing or filtrating the contaminant. The hydraulic conductivity plays the main role in soil filtration. There are many types of soil with different hydraulic conductivities. In infiltration gallery method it is important to identify the hydraulic conductivity value as the preliminary analysis because it is the important indicator to show the ability of soil to flow the water from one side to other sides when filtrating the contaminant. The slower the conductivity is, the better the quality of the water will be. The method used in this study was the Constant head Permeameter. The result of this study shows that the same type of soil type has different hydraulic conductivities.

Mean residence times and characteristics of humic substances extracted from a Taiwan soil

2001 ◽  
Vol 81 (3) ◽  
pp. 299-307 ◽  
Author(s):  
M C Wang ◽  
S H Chang
Keyword(s):  
Humic Substances ◽  
Soil Profile ◽  
Fulvic Acids ◽  
Spectroscopic Properties ◽  
Residence Times ◽  
Spin Resonance ◽  
Profile Depth ◽  
Mean Residence Times ◽  
High Degree ◽  
C Nmr

Humic substances are well known for their long-term persistence in soil environments. The relationship between the mean residence times (MRT) and characteristics of humic substances extracted from a soil with highorganic matter (OM) content in Taiwan was investigated. The MRTs of the soil organic matter (SOM) and its humic substances extracted from the soil samples taken from three depths (0–20, 40–60, and 70–150 cm) of a soil profile were determined by 14C-dating procedures. Moreover, the humic substances were subjected to elemental analysis and investigation by electron spin resonance (ESR), Fourier transform infrared (FTIR), and solid-state 13C nuclear magnetic resonance (13C NMR) spectroscopies. The ranges of the MRT of fulvic acids (FA) (MW < 1000), FA (MW > 1000), humic acid (HA) (MW > 1000), and humins (MW > 1000) were 143 ± 110 to 1740 ± 60, 213 ± 120 to 1690 ± 200, 253 ± 60 to 2200 ± 40, and 293 ± 40 to 2173 ± 70 yr, respectively. The higher standard deviations of the means of determined MRTs of FA (MW < 1000) and FAs (MW > 1000) may be due to their lability. Further, the MRTs of the FAs (MW < 1000), FAs (MW > 1000), HAs (MW > 1000), and humins (MW > 1000) increased with increasing soil profile depth, indicating the slow biological and chemical degradations of humic substances in the deeper layers. The elemental composition and spectroscopic properties of FTIR, 13C NMR, and ESR of humic substances did not change significantly with their MRTs. The MRTs in the range observed in this study were apparently long enough to render humic substances a high degree of chemical stability. Key words: Humic substances, mean residence times, ESR, FTIR, 13C NMR, humin

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