scholarly journals Gone or just out of sight? The apparent disappearance of aromatic litter components in soils

2016 ◽  
Author(s):  
T. Klotzbücher ◽  
K. Kalbitz ◽  
C. Cerli ◽  
P. J. Hernes ◽  
K. Kaiser
Keyword(s):  
Organic Matter ◽  
Lignin Degradation ◽  
Solid Phase ◽  
Mineral Soil ◽  
Data Interpretation ◽  
Water Soluble ◽  
Mineral Surfaces ◽  
Basic Understanding ◽  
Mineral Soils

Abstract. Uncertainties concerning stabilization of organic compounds in soil limit our basic understanding on soil organic matter (SOM) formation and our ability to model and manage effects of global change on SOM stocks. One controversially debated aspect is the contribution of aromatic litter components, such as lignin and tannins, to stable SOM forms. In the present opinion paper, we summarize and discuss the inconsistencies and propose research options to clear them. Lignin degradation takes place step-wise, starting with (i) depolymerisation, followed by (ii) transformation of the water-soluble depolymerization products. The long-term fate of the depolymerization products and other soluble aromatics, e.g., tannins, in the mineral soils is still a mystery. Research on dissolved organic matter (DOM) composition and fluxes indicates dissolved aromatics are important precursors of stable SOM attached to mineral surfaces and persist in soils for centuries to millennia. Evidence comes from flux analyses in soil profiles, biodegradation assays, and sorption experiments. In contrast, studies on composition of mineral-associated SOM indicate the prevalence of non-aromatic microbialderived compounds. Other studies suggest the turnover of lignin in soil can be faster than the turnover of bulk SOM. Mechanisms that can explain the apparent fast disappearance of lignin in mineral soils are, however, not yet identified. The contradictions might be explained by analytical problems. Commonly used methods probably detect only a fraction of the aromatics stored in the mineral soil. Careful data interpretation, critical assessment of analytical limitations, and combined studies on DOM and solid-phase SOM could thus be ways to unveil the issues.

scholarly journals Gone or just out of sight? The apparent disappearance of aromatic litter components in soils

SOIL ◽  
2016 ◽  
Vol 2 (3) ◽  
pp. 325-335 ◽  
Author(s):  
Thimo Klotzbücher ◽  
Karsten Kalbitz ◽  
Chiara Cerli ◽  
Peter J. Hernes ◽  
Klaus Kaiser
Keyword(s):  
Organic Matter ◽  
Lignin Degradation ◽  
Solid Phase ◽  
Mineral Soil ◽  
Data Interpretation ◽  
Water Soluble ◽  
Mineral Surfaces ◽  
Basic Understanding ◽  
Mineral Soils

Abstract. Uncertainties concerning stabilization of organic compounds in soil limit our basic understanding on soil organic matter (SOM) formation and our ability to model and manage effects of global change on SOM stocks. One controversially debated aspect is the contribution of aromatic litter components, such as lignin and tannins, to stable SOM forms. In the present opinion paper, we summarize and discuss the inconsistencies and propose research options to clear them. Lignin degradation takes place stepwise, starting with (i) depolymerization and followed by (ii) transformation of the water-soluble depolymerization products. The long-term fate of the depolymerization products and other soluble aromatics, e.g., tannins, in the mineral soils is still a mystery. Research on dissolved organic matter (DOM) composition and fluxes indicates dissolved aromatics are important precursors of stable SOM attached to mineral surfaces and persist in soils for centuries to millennia. Evidence comes from flux analyses in soil profiles, biodegradation assays, and sorption experiments. In contrast, studies on composition of mineral-associated SOM indicate the prevalence of non-aromatic microbial-derived compounds. Other studies suggest the turnover of lignin in soil can be faster than the turnover of bulk SOM. Mechanisms that can explain the apparent fast disappearance of lignin in mineral soils are, however, not yet identified. The contradictions might be explained by analytical problems. Commonly used methods probably detect only a fraction of the aromatics stored in the mineral soil. Careful data interpretation, critical assessment of analytical limitations, and combined studies on DOM and solid-phase SOM could thus be ways to unveil the issues.

scholarly journals Organic Matter Causes Chemical Pollutant Dissipation Along With Adsorption and Microbial Degradation

2021 ◽  
Vol 9 ◽  
Author(s):  
A. Vilhelmiina Harju ◽  
Ilkka Närhi ◽  
Marja Mattsson ◽  
Kaisa Kerminen ◽  
Merja H. Kontro
Keyword(s):  
Organic Matter ◽  
Microbial Degradation ◽  
Mineral Soil ◽  
Organic Soil ◽  
Organic Soils ◽  
First Response ◽  
Chemical Pollutant ◽  
Mineral Soils ◽  
Soil And Sediment

Views on the entry of organic pollutants into the organic matter (OM) decaying process are divergent, and in part poorly understood. To clarify these interactions, pesticide dissipation was monitored in organic and mineral soils not adapted to contaminants for 241 days; in groundwater sediment slurries adapted to pesticides for 399 days; and in their sterilized counterparts with and without peat (5%) or compost-peat-sand (CPS, 15%) mixture addition. The results showed that simazine, atrazine and terbuthylazine (not sediment slurries) were chemically dissipated in the organic soil, and peat or CPS-amended soils and sediment slurries, but not in the mineral soil or sediment slurries. Hexazinone was chemically dissipated best in the peat amended mineral soil and sediment slurries. In contrast, dichlobenil chemically dissipated in the mineral soil and sediment slurries. The dissipation product 2,6-dichlorobenzamide (BAM) concentrations were lowest in the mineral soil, while dissipation was generally poor regardless of plant-derived OM, only algal agar enhanced its chemical dissipation. Based on sterilized counterparts, only terbutryn appeared to be microbially degraded in the organic soil, i.e., chemical dissipation of pesticides would appear to be utmost important, and could be the first response in the natural cleansing capacity of the environment, during which microbial degradation evolves. Consistent with compound-specific dissipation in the mineral or organic environments, long-term concentrations of pentachloroaniline and hexachlorobenzene were lowest in the mineral-rich soils, while concentrations of dichlorodiphenyltrichloroethane (DTT) and metabolites were lowest in the organic soils of old market gardens. OM amendments changed pesticide dissipation in the mineral soil towards that observed in the organic soil; that is OM accelerated, slowed down or stopped dissipation.

Obvious and less obvious processes of aggregate formation in soil

2021 ◽  
Author(s):  
Hans-Jörg Vogel ◽  
Mar­ia Balseiro-Romero ◽  
Philippe C. Baveye ◽  
Alexandra Kravchenko ◽  
Wilfred Otten ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Structure ◽  
Solid Phase ◽  
Pore Space ◽  
Imaging Techniques ◽  
Mineral Soil ◽  
Aggregate Formation ◽  
Conceptual Approach ◽  
Soil Matrix ◽  
Biophysical Processes

<p>Soil structure, lately referred to as the ''architecture'' is a key to explain and understand all soil functions. The development of sophisticated imaging techniques over the last decades has led to significant progress in the description of this architecture and in particular of the geometry of the hierarchically-branched pore space in which transport of water, gases, solutes and particles occurs and where myriads of organisms live. Moreover, there are sophisticated tools available today to also visualize the spatial structure of the solid phase including mineral grains and organic matter. Hence, we do have access to virtually all components of soil architecture.</p><p>Unfortunately, it has so far proven very challenging to study the dynamics of soil architecture over time, which is of critical importance for soil as habitat and the turnover of organic matter. Several largely conflicting theories have been proposed to account for this dynamics, especially the formation of aggregates. We review these theories, and we propose a conceptual approach to reconcile them based on a consistent interpretation of experimental observations and by integrating known physical and biogeochemical processes. A key conclusion is that rather than concentrating on aggregate formation in the sense of how particles and organic matter reorganize to form aggregates as distinct functional units we should focus on biophysical processes that produce a porous, heterogeneous organo-mineral soil matrix that breaks into fragments of different size and stability when exposed to mechanical stress.  The unified vision we propose for soil architecture and the mechanisms that determine its temporal evolution, should pave the way towards a better understanding of soil processes and functions.</p>

The effect of over 50 years of liming on soil aluminium forms in a Retisol

2019 ◽  
Vol 157 (1) ◽  
pp. 12-19 ◽  
Author(s):  
Z. Kryzevicius ◽  
D. Karcauskiene ◽  
E. Álvarez-Rodríguez ◽  
A. Zukauskaite ◽  
A. Slepetiene ◽  
...  
Keyword(s):  
Soil Profile ◽  
Soil Acidity ◽  
Solid Phase ◽  
Water Soluble ◽  
Total Water ◽  
Clay Particles ◽  
Ph Values ◽  
Exchangeable Al ◽  
Limed Soil

AbstractThe aim of the current study was to evaluate the effect of long-term (56 years) liming on changes in soil pH and aluminium (Al) forms in the soil profile compared with an unlimed soil in a sandy moraine loam of a Dystric Glossic Retisol. Long-term liming had a significant influence on soil acidity of the whole profile, causing increased pH values in the following horizons to 120 cm depth: the ploughing horizon (Ahp), where humus accumulates; the eluvial horizon (E), from which clay particles are leached; a horizon having retic properties and predominantly coarser-textured albic material (E/B); and a horizon with retic properties and predominantly finer-textured argic material (B/E). In the solid phase, non-crystalline Al in limed soil decreased in the Ahp horizon; meanwhile a decrease in total organically bound Al (Alp) and organo–Al complexes of low to medium stability was detected in the deeper El and ElBt horizons. High-stability Al complexes with organic matter were the predominant form of Alp in the unlimed and limed whole soil profile. The concentration of total water-soluble Al ranged from 0.61 to 0.80 mg/l in the limed soil profile but 0.62–1.15 mg/l in the unlimed soil. The highest concentration of exchangeable Al was determined in the upper horizons of the unlimed soil profile and the concentration decreased significantly in the same horizons of the limed soil profile. Long-term liming promoted changes in Al compounds throughout the soil profile.

Salt Composition of Clay Soils and Its Variation with Long-term Water Filtration in Republic of Kalmykia

2018 ◽  
Vol 9 (1) ◽  
pp. 130
Author(s):  
Anatoly A. DORDZHIEV ◽  
Anatoly G. DORDZHIEV ◽  
Mergen M. SANGADZHIEV ◽  
Leonid M. RUBEKO ◽  
Victor A. ONKAEV
Keyword(s):  
Solid Phase ◽  
Sandy Loam ◽  
Exchange Process ◽  
Water Soluble ◽  
Water Filtration ◽  
Clay Soils ◽  
Salt Composition ◽  
Daily Work ◽  
The Republic

Knowledge of soils types in a certain area allows to predict the stability of the system. Therefore, the purpose of the work is to determine the salt composition of clayey soils and its variation with long-term water filtration, for example, the Republic of Kalmykia. For a detailed study of the topic, the authors carried out various experiments that were based on physico-chemical analyzes of samples and monoliths selected from different regions of Kalmykia. For this, water-soluble salts found in clay soils were considered. Basically, these are three groups: readily soluble, mildly soluble and hardly soluble. Chemical analyzes of chloride, sulphate and carbonate salts of sodium, potassium, magnesium and calcium were conducted on the basis of the Kalmyk State University. Separately attention was paid to the ion-exchange process and, in particular, to the transition from the solid phase to the pore solution. In connection with the strong mineralization of groundwater in the republic, the monoliths are mineralized to 10-20 g / l and in terms of chemical composition, chloride-sodium and sulfate-chloride. Calcium carbonates and gypsum are considered separately depending on the depth of the monolith. On the basis of the experiments carried out, plots of the dependence were plotted in different mineral constituents. It has been established that in gypsum and gypsum-bearing rocks the correlation coefficients for loam and sandy loam are low. The desalinization factor is more than 50%, and the desalinization is uneven in all monoliths taken from different depths. In sandy loam these parameters are lower by 20%. Separately, the parameters of exchange of mineral, disperse composition and the presence of organic substances are considered. The results will allow engineers, designers, practitioners and students to use the results in their daily work.

scholarly journals Long-term measurements of carbonaceous aerosols in the Eastern Mediterranean: evidence of long-range transport of biomass burning

2008 ◽  
Vol 8 (18) ◽  
pp. 5551-5563 ◽  
Author(s):  
J. Sciare ◽  
K. Oikonomou ◽  
O. Favez ◽  
E. Liakakou ◽  
Z. Markaki ◽  
...  
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Long Range ◽  
Biomass Burning ◽  
Water Soluble ◽  
Long Range Transport ◽  
Crete Island ◽  
Yearly Average ◽  
Range Transport

Abstract. Long-term (5-year) measurements of Elemental Carbon (EC) and Organic Carbon (OC) in bulk aerosols are presented here for the first time in the Mediterranean Basin (Crete Island). A multi-analytical approach (including thermal, optical, and thermo-optical techniques) was applied for these EC and OC measurements. Light absorbing dust aerosols were shown to poorly contribute (+12% on a yearly average) to light absorption coefficient (babs) measurements performed by an optical method (aethalometer). Long-range transport of agricultural waste burning from European countries surrounding the Black Sea was shown for each year during two periods (March–April and July–September). The contribution of biomass burning to the concentrations of EC and OC was shown to be rather small (20 and 14%, respectively, on a yearly basis), although this contribution could be much higher on a monthly basis and showed important seasonal and interannual variability. By removing the biomass burning influence, our data revealed an important seasonal variation of OC, with an increase by almost a factor of two for the spring months of May and June, whereas BC was found to be quite stable throughout the year. Preliminary measurements of Water Soluble Organic Carbon (WSOC) have shown that the monthly mean WSOC/OC ratio remains stable throughout the year (0.45±0.12), suggesting that the partitioning between water soluble and water insoluble organic matter is not significantly affected by biomass burning and secondary organic aerosol (SOA) formation. A chemical mass closure performed in the fine mode (Aerodynamic Diameter, A.D.<1.5μm) showed that the mass contribution of organic matter (POM) was found to be essentially invariable during the year (monthly average of 26±5%).

scholarly journals Density fractions versus size separates: does physical fractionation isolate functional soil compartments?

2012 ◽  
Vol 9 (7) ◽  
pp. 8405-8447 ◽  
Author(s):  
C. Moni ◽  
D. Derrien ◽  
P.-J. Hatton ◽  
B. Zeller ◽  
M. Kleber
Keyword(s):  
Organic Matter ◽  
European Beech ◽  
Mineral Surfaces ◽  
Density Fractionation ◽  
Adsorbed State ◽  
Density Fractions ◽  
Physical Fractionation ◽  
Comprehensive Picture ◽  
Mineral Soils ◽  
Decomposition Pathway

Abstract. Physical fractionation is a widely used methodology to study soil organic matter (SOM) dynamics, but concerns have been raised that the available fractionation methods do not well describe functional SOM pools. We also examine the question whether physical fractionation techniques isolate ecologically meaningful, functionally relevant soil compartments. In this study we explore whether the kind of information that aggregate density fractionation (ADF) and particle size-density fractionation (PSDF) yield on soil OM dynamics is method-specific, similar, or complimentary. We do so by following the incorporation of a 15N label into mineral soils of two European beech forests a decade after its application as 15N labelled litter. Both density and size-based fractionation methods suggested that OM became increasingly associated with the mineral phase as decomposition progressed, within aggregates and onto mineral surfaces. Our results suggest that physical fractionation methods do isolate ecologically relevant functional soil subunits. However, scientists investigating specific aspects of OM dynamics are pointed towards ADF when adsorption and aggregation processes are of interest, whereas PSDF is the superior tool to research the fate of particulate organic matter (POM). Some methodological caveats were observed mainly for the PSDF procedure, the most important one being that fine fractions isolated after sonication can not be linked to any defined decomposition pathway or stabilisation process. This also implies that historical assumptions about the "adsorbed" state of carbon associated with fine fractions need to be re-evaluated. Finally, this work demonstrates that establishing a comprehensive picture of whole soil OM dynamics requires a combination of both methodologies and we offer a suggestion for an efficient combination of the density and size-based approaches.

scholarly journals Long-term measurements of carbonaceous aerosols in the eastern Mediterranean: evidence of long-range transport of biomass burning

2008 ◽  
Vol 8 (2) ◽  
pp. 6949-6982 ◽  
Author(s):  
J. Sciare ◽  
K. Oikonomou ◽  
O. Favez ◽  
Z. Markaki ◽  
E. Liakakou ◽  
...  
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Long Range ◽  
Biomass Burning ◽  
Water Soluble ◽  
Long Range Transport ◽  
Crete Island ◽  
Yearly Average ◽  
Range Transport

Abstract. Long-term (5-yr) measurements of Black Carbon (BC) and Organic Carbon (OC) in bulk aerosols are presented here for the first time in the Mediterranean Basin (Crete Island). A multi-analytical approach (including thermal, optical, and thermo-optical techniques) was applied for these BC and OC measurements. Light absorbing dust aerosols have shown to poorly contribute (+17% on a yearly average) to light absorption coefficient (babs) measurements performed by an optical method (aethalometer). Long-range transport of agricultural waste burning from European countries surrounding the Black Sea was shown for each year during two periods (March–April and July–September). The contribution of biomass burning to the concentrations of BC and OC has shown to be rather small (20 and 14%, respectively, on a yearly basis), although this contribution could be much higher on a monthly basis and is expected a high intra and inter annual variability. By removing the biomass burning influence, our data revealed an important seasonal variation of OC, with an increase by almost a factor of two for the Spring months of May and June, whereas BC was found to be quite stable throughout the year. Preliminary measurements of Water Soluble Organic Carbon (WSOC) have shown that the monthly mean WSOC/OC ratio remains stable throughout the year (0.45±0.12), suggesting that the partitioning between water soluble and water insoluble organic matter is not significantly affected by biomass burning and secondary organic aerosol (SOA) formation. A chemical mass closure performed in the fine mode (Aerodynamic Diameter, A.D.<1.5 μm) showed that the mass contribution of organic matter (POM) was found to be essentially invariable during the year (monthly average of 26±5%).

scholarly journals Influence of long-term application of organic and inorganic fertilizers on soil properties

2014 ◽  
Vol 60 (No. 7) ◽  
pp. 314-319 ◽  
Author(s):  
T. Šimon ◽  
A. Czakó
Keyword(s):  
Organic Matter ◽  
Farmyard Manure ◽  
Water Soluble ◽  
Hot Water ◽  
Cattle Slurry ◽  
Organic C ◽  
Soluble C ◽  
Organic And Inorganic Fertilizers ◽  
Total Organic C

This study assesses the effect of long-term (59 years) application of organic and inorganic fertilizers on soil organic matter and enzyme activity. Total organic C, total organic N, hot water soluble C, microbial biomass C and dehydrogenase activity were evaluated in soil from the long-term field experiment in Prague-Ruzyně (Orthic Luvisol, clay loam). Total organic C and N increased significantly in soils treated with organic fertilizers (farmyard manure, compost) and in soils with a combination of organic and mineral NPK fertilizers (manure + NPK, compost + NPK, cattle manure + straw + NPK) compared to soil treated with inorganic fertilizer, cattle slurry + straw and non-fertilized control. Farmyard manure significantly increased hot water soluble C compared to the control. Dehydrogenase activity was significantly increased by all treatments compared to control. The results indicate that additions of organic matter from various sources differ in the effects on soil organic matter and biological activity. The effect of manure was the most favourable; long-term application of cattle slurry + straw is rather similar to mineral fertilization.

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