Soil organic matter stabilization at the pluri-decadal scale: Insight from bare fallow soils with contrasting physicochemical properties and macrostructures

Geoderma ◽  
2016 ◽  
Vol 275 ◽  
pp. 48-54 ◽  
Author(s):  
Remigio Paradelo ◽  
Folkert van Oort ◽  
Pierre Barré ◽  
Daniel Billiou ◽  
Claire Chenu
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Physicochemical Properties ◽  
Organic Matter Stabilization ◽  
Decadal Scale ◽  
Bare Fallow

scholarly journals Priming and substrate quality interactions in soil organic matter models

2013 ◽  
Vol 10 (3) ◽  
pp. 2089-2103 ◽  
Author(s):  
T. Wutzler ◽  
M. Reichstein
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Balance Model ◽  
Levels Of Abstraction ◽  
Substrate Quality ◽  
Substrate Limitation ◽  
Energy Limitation ◽  
Bare Fallow ◽  
Different Levels

Abstract. Interactions between different qualities of soil organic matter (SOM) affecting their turnover are rarely represented in models. In this study, we propose three mathematical strategies at different levels of abstraction to represent those interactions. By implementing these strategies into the Introductory Carbon Balance Model (ICBM) and applying them to several scenarios of litter input, we show that the different levels of abstraction are applicable at different timescales. We present a simple one-parameter equation of substrate limitation that can straightforwardly be implemented into other models of SOM dynamics at decadal timescale. The study demonstrates how substrate quality interactions can explain patterns of priming effects, accelerate turnover in FACE experiments, and the slowdown of decomposition in long-term bare fallow experiments as an effect of energy limitation of microbial biomass. The mechanisms of those interactions need to be further scrutinized empirically for a more complete understanding. Overall, substrate quality interactions contribute to both understanding and quantitatively modelling SOM dynamics.

scholarly journals Integrating plant litter quality, soil organic matter stabilization, and the carbon saturation concept

2015 ◽  
Vol 21 (9) ◽  
pp. 3200-3209 ◽  
Author(s):  
Michael J. Castellano ◽  
Kevin E. Mueller ◽  
Daniel C. Olk ◽  
John E. Sawyer ◽  
Johan Six
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Litter Quality ◽  
Plant Litter ◽  
Carbon Saturation ◽  
Organic Matter Stabilization

A molecular dynamic study of Soil Organic Matter stabilization mechanisms

2021 ◽  
Author(s):  
Edgar Galicia-Andrés ◽  
Yerko Escalona ◽  
Peter Grančič ◽  
Chris Oostenbrink ◽  
Daniel Tunega ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Humic Substances ◽  
Clay Mineralogy ◽  
Metal Cations ◽  
Dense Matter ◽  
Chemical Degradation ◽  
Molecular Graphics ◽  
Organic Matter Stabilization ◽  
Reactive Surfaces

<p>It is well known that some fractions of soil organic matter (SOM) can resist to physical and (bio)chemical degradation which can be attributed to factors ranging from molecular properties to the preference for digesting other molecular species by microorganisms. Some mechanisms, by which organic matter is protected, are often referred to as: physical stabilization through microaggregation, chemical stabilization by formation of SOM-mineral aggregates, and biochemical stabilization through the formation of recalcitrant SOM.</p><p>Protection mechanisms are responsible for the accumulation process of organic carbon, reducing the exposure of organic matter and making it less vulnerable to microbial, enzymatic or chemical attacks. In these mechanisms, water molecular bridges and metal cation bridges play a key role. Cation bridges serve as aggregation sites on humic substances, forming dense matter, in comparison to systems where bridges are missing. This effect is enhanced in systems with cations at higher oxidation states.</p><p>By using the modeler tool developed in our group (Vienna Soil–Organic–Matter Modeler, VSOMM2) (Escalona et al., 2021), we generated aggregate models of humic substances at atomistic scale reflecting the diversity in composition, size and conformations of the constituting molecules. Further, we built models of organo-clay aggregates using kaolinite and montmorillonite as typical soil minerals. This allowed a systematic study to understand the effect of the surrounding environment at microscopic scale, not fully accessible experimentally.</p><p>Molecular simulations of the adsorption process of SOM aggregates on the reactive surfaces of led to two observations: 1) the humic substances aggregates were able to interact with the reactive surfaces mainly via hydrogen bonds forming stable organic matter-clay complexes and 2) the aggregates subsequently lost rigidity and stability after metal cations removing, consequently leading to a gradual loss of humic substance molecules, evidencing the role of metal cations in the protection mechanism of soil organic matter aggregates and possibly explaining its recalcitrance (Galicia-Andrés et al., 2021).</p><p>References</p><ul><li>Escalona, Y., Petrov, D., & Oostenbrink, C. (2021). Vienna soil organic matter modeler 2 (VSOMM2). Journal of Molecular Graphics and Modelling, 103, 107817. https://doi.org/10.1016/j.jmgm.2020.107817</li> <li>Galicia-Andrés, E., Grančič, P., Gerzabek, M. H., Oostenbrink, C., & Tunega, D. (2021). Modeling of interactions in natural and synthetic organoclays. In I. C. Sainz Diaz (Ed.), Computational modeling in clay mineralogy.</li> </ul>

scholarly journals Biological and physicochemical processes and control of soil organic matter stabilization and turnover

2006 ◽  
Vol 57 (4) ◽  
pp. 425-425 ◽  
Author(s):  
Ingrid Kögel-Knabner ◽  
Claire Chenu ◽  
Ellen Kandeler ◽  
Alessandro Piccolo
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Physicochemical Processes ◽  
Organic Matter Stabilization ◽  
And Control

Soil organic matter in soils of the Russian Arctic: insights from 13C-NMR spectroscopy

2020 ◽  
Author(s):  
Ivan Alekseev ◽  
Evgeny Abakumov
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Humic Acids ◽  
13C Nmr ◽  
Cold Climate ◽  
Molecular Organization ◽  
Cold Temperatures ◽  
Organic Matter Stabilization ◽  
Global Carbon

<p>Polar soils play a key role in global carbon circulation and stabilization as they contain maximum stocks of soil organic matter (SOM) within the whole pedosphere. Cold climate and active layer dynamics result in the stabilization of essential amounts of organic matter in soils, biosediments, and grounds of the polar biome. Chemical composition of soil organic carbon (SOC) determines its decomposability and may affect soil organic matter stabilization (SOM) rate (Beyer, 1995). This is quite important for understanding variability in SOC pools and stabilization rate in context of changes in plant cover or climate (Rossi et al. 2016). <sup>13</sup>C nuclear magnetic resonance spectroscopy, which provides detailed information on diversity of structural composition of humic acids and SOM, may also be used to study the SOM dynamics under decomposition and humification proceses (Kogel-Knabner, 1997; Zech et al., 1997). This study aims to characterize molecular organization of the humic acids, isolated from various permafrost-affected soils of Yamal region and to assess the potential vulnerability of soils organic matter in context of possible mineralization processes. Organic carbon stocks for studied area were 7.85 ± 2.24 kg m-2 (for 0-10 cm layer), 14.97 ± 5.53 kg m-2 (for 0-30 cm), 23.99 ± 8.00 kg m-2 (for 0-100 cm). Results of solid-state 13C-NMR spectrometry showed low amounts of aromatic components in studied soils. All studied humic powders are characterized by predominance of aliphatic structures, and also carbohydrates, polysaccharides, ethers and amino acids. High content of aliphatic fragments in studied humic acids shows their similarity fulvic acids. Low level of aromaticity reflects the accumulation in soil of lowly decomposed organic matter due to cold temperatures. Our results provide further evidence of high vulnerability and sensitivity of permafrost-affected soils organic matter to Arctic warming. Consequently, these soils may play a crucial role in global carbon balance under effects of climate warming.</p>

Carbon saturation drives spatial patterns of soil organic matter losses under long-term bare fallow

Geoderma ◽  
2017 ◽  
Vol 306 ◽  
pp. 89-98 ◽  
Author(s):  
N. Meyer ◽  
L. Bornemann ◽  
G. Welp ◽  
H. Schiedung ◽  
M. Herbst ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Spatial Patterns ◽  
Carbon Saturation ◽  
Bare Fallow

NMR spectroscopy approach to study soil organic matter formation under different plant composition during 50 years

2021 ◽  
Author(s):  
Karin Kauer ◽  
Sandra Pärnpuu
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Nmr Spectroscopy ◽  
Soil Organic Matter ◽  
Soil Mineral ◽  
Plant Composition ◽  
Density Fractions ◽  
Soil Organic Matter Decomposition ◽  
Mineral Fraction ◽  
Bare Fallow

<p>The aim of this research was to study the effect of different plants on soil organic matter (SOM) composition. The composition of SOM was studied in a field experiment established in 1964 on a carbonaceous glacial till soil with very low initial SOC concentration (1.28 g kg<sup>-1</sup>). The effects on SOM composition of bare fallow, barley, grasses, and clover-grasses mixture, were studied using 13C nuclear magnetic resonance (NMR) spectroscopy which is a common tool to characterize SOM. In 2014 the soil samples were collected from 0-5 cm soil layer, air-dried samples sieved through a 2-mm sieve and pretreated with 10% HF solution before NMR spectroscopy analysis. Samples of bulk soil and density fractionated mineral fraction (John et al., 2005) were analyzed. Also, a sample from barley treatment collected in 1966 was analyzed.</p><p>O/N-alkyl C was the most abundant C type at the start of the experiment and also in all treatments after 50 years. During 50 years the proportions of O/N-alkyl C and alkyl C increased but contributions of carboxyl C and aromatic C decreased. The ratio of alkyl C/O-alkyl C, which describes the degree of soil organic matter decomposition, decreased from 0.47 (in 1966) to 0.40-0.44 in treatments with plants. In bare fallow treatment, the SOM decomposition stage did not change a lot during the time. In soil mineral fraction the differences between treatments appeared more clearly and the degree of decomposition decreased in line: bare fallow>barley>clover-grasses>grasses (0.49>0.40>0.36>0.34) and this was due to higher O/N-alkyl-C content in treatments with plants. The higher O/N-alkyl C contribution in soil heavy fraction can be attributed to microbially synthesized carbohydrates (Yeasmin et al., 2020) and depended on the amount and properties of C input into the soil in different treatments.</p><p>In conclusion, the SOM composition was influenced by plant composition and the effect was more pronounced in soil mineral fraction. The SOM degree of decomposition was higher in treatment with annual crop (barley during 50 years). Under perennial grasses and clover-grasses mixture, the soil organic matter decomposition degree was lower.</p><p>This work was supported by the Estonian Research Council grant PSG147.</p><p>References</p><p>John, B., Yamashita, T., Ludwig, B., & Flessa, H. (2005). Storage of organic carbon in aggregate and density fractions of silty soils under different types of land use. Geoderma, 128(1–2), 63–79. https://doi.org/10.1016/j.geoderma.2004.12.013</p><p>Yeasmin, S., Singh, B., Smernik, R. J., & Johnston, C. T. (2020). Effect of land use on organic matter composition in density fractions of contrasting soils: A comparative study using 13C NMR and DRIFT spectroscopy. Science of the Total Environment, 726, 138395. https://doi.org/10.1016/j.scitotenv.2020.138395</p>

scholarly journals Role of Earthworms in Soil Fertility Maintenance through the Production of Biogenic Structures

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Tunira Bhadauria ◽  
Krishan Gopal Saxena
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Management Practices ◽  
Soil Productivity ◽  
Published Data ◽  
Critical Function ◽  
Water Excretion ◽  
Organic C ◽  
Organic Matter Stabilization ◽  
Biogenic Structures

The soil biota benefits soil productivity and contributes to the sustainable function of all ecosystems. The cycling of nutrients is a critical function that is essential to life on earth. Earthworms (EWs) are a major component of soil fauna communities in most ecosystems and comprise a large proportion of macrofauna biomass. Their activity is beneficial because it can enhance soil nutrient cycling through the rapid incorporation of detritus into mineral soils. In addition to this mixing effect, mucus production associated with water excretion in earthworm guts also enhances the activity of other beneficial soil microorganisms. This is followed by the production of organic matter. So, in the short term, a more significant effect is the concentration of large quantities of nutrients (N, P, K, and Ca) that are easily assimilable by plants in fresh cast depositions. In addition, earthworms seem to accelerate the mineralization as well as the turnover of soil organic matter. Earthworms are known also to increase nitrogen mineralization, through direct and indirect effects on the microbial community. The increased transfer of organic C and N into soil aggregates indicates the potential for earthworms to facilitate soil organic matter stabilization and accumulation in agricultural systems, and that their influence depends greatly on differences in land management practices. This paper summarises information on published data on the described subjects.

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