scholarly journals Combined Use of Carbon and Nitrogen Isotopes for Assessment of Soil Organic Matter Sources and Decomposition in a Typical Karst Area of Yunnan–Guizhou Plateau, Southwestern China

2021 ◽  
Author(s):  
Howard Omar Beckford ◽  
Changshun SONG ◽  
Cheng CHANG ◽  
Hongbing JI
Keyword(s):  
Organic Matter ◽  
Carbon Sequestration ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Nitrogen Isotopes ◽  
Karst Area ◽  
Soil Profiles ◽  
Carbon And Nitrogen ◽  
Karst Soil ◽  
Guizhou Plateau

Abstract Soil organic matter (SOM) has substantial influence on geochemical cycle, soil stability and global climate change, however total organic carbon sequestration mechanisms in karst soil remain poorly understood. For this study we assess, total organic content (TOC), total nitrogen (TN), C/N ratio and isotopes of carbon and nitrogen in four soil profiles over critical karst area to investigate organic matter source, mechanisms that influence fractionation and factors affecting SOM in Yunnan–Guizhou Plateau, Southwestern China. The results revealed that SOM comprised of mixed sources derived from both exogenous and endogenous materials. The soil profiles indicate intense vertical variation in δ13C and δ15N with an increase in both isotopes in the upper layers, deceased in δ13C below 20 cm and irregular fluctuation in δ15N with depth. Mechanisms such as mineralization and selective preservation influence isotopic fractionation in the upper soil surface, while translocation, nitrification and denitrification dominated the subsoil layers. Variation in TOC, TN and stable carbon and nitrogen isotopes were influence by vegetation cover, topography, soil water and external contribution. Moreover, the decrease in TOC and TN with depth were due to downward translocation of dissolved organic carbon and nitrogen caused by monsoon climate. Our results revealed that combination of TOC, TN, C/N, δ13C and δ15N can be used as proxy to decipher SOM source, external influence and stability of karst soils. Furthermore, the intense change in δ13C and δ15N throughout the soil profiles suggest that this karst soil is unstable which have implications for land management and carbon sequestration.

scholarly journals Properties of Humic Acids in Meadow Soils Irrigated with the Slope-and-Flooding System

Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2553
Author(s):  
Magdalena Banach-Szott ◽  
Andrzej Dziamski ◽  
Maciej Markiewicz
Keyword(s):  
Organic Matter ◽  
Carbon Sequestration ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Humic Acids ◽  
Infrared Spectra ◽  
Soil Protection ◽  
Mean Values ◽  
Irrigation Ditch ◽  
The Mean

The still-advancing soil degradation and the related losses of soil organic carbon stocks due to the limited inflow of organic residues in agro-ecosystems encourage more and more soil protection. Establishing meadow ecosystems is one of the key methods of agricultural land use preventing losses of organic carbon in soils. Based on the research on the properties of humic acids, it is possible to determine the advancement of the processes of transformation and decomposition of soil organic matter. The obtained results may allow for the development of a soil protection strategy and more effective sequestration of organic carbon. Therefore, the aim of the research was to determine the properties of humic acids defining the quality of organic matter of meadow soils irrigated for 150 years with the slope-and-flooding system. The research was performed based on the soils (Albic Brunic Arenosol) sampled from Europe’s unique complex of permanent irrigated grasslands (the same irrigation management for 150 years), applying the slope-and-flooding system: the Czerskie Meadows. The soil samples were assayed for the content of total organic carbon (TOC) and the particle size distribution. HAs were extracted with the Schnitzer method and analysed for the elemental composition, spectrometric parameters in the UV-VIS (ultraviolet-visible) range, hydrophilic and hydrophobic properties and the infrared spectra. The research results showed that the HAs properties depend on the depth and the distance from the irrigation ditch. The HAs of soils sampled from the depth of 0–10 cm were identified with a lower “degree of maturity” as compared with the HAs of soils sampled from the depth of 20–30 cm, reflected by the values of atomic ratios (H/C, O/C, O/H), absorbance coefficients, and the FT-IR (Fourier transform infrared) spectra. The mean values of the H/C ratio in the HAs molecules of soils sampled from the depth of 20–30 cm were lower by 8.2% than those from the depth of 0–10 cm. The mean values of the absorbance coefficient A4/6 in the HAs molecules of soils sampled from the depth of 20–30 cm were lower by 9.6% than in the HAs molecules of soils sampled from the depth of 0–10 cm. The HAs molecules of the soils sampled 25 m from the irrigation ditch were identified with a higher degree of humification, as compared with the HAs of the soils sampled 5 m from the irrigation ditch. The results identified that humic acids produced in the many-year irrigated sandy soils were identified with a high degree of humification, which proves the relative stability of the soil’s organic matter. It confirms the importance of meadow soils for the carbon sequestration process. It should also be emphasized that the research area is interesting, although hardly described in terms of organic matter properties. Further and more detailed applicable research is planned, e.g., monitoring of total organic carbon content and comparing the properties of irrigated and non-irrigated meadow soils. Continuity of research is necessary to assess the direction of the soil organic matter transformation in such a unique ecosystem. The obtained results may allow for the development of, inter alia, models of agricultural practices that increase carbon sequestration in soils. In the long term, this will allow for greater environmental benefits and, thus, also increased financial benefits.

Modelling dynamic interactions between soil structure and soil organic matter

2020 ◽  
Author(s):  
Nicholas Jarvis ◽  
Elsa Coucheney ◽  
Claire Chenu ◽  
Anke Herrmann ◽  
Thomas Keller ◽  
...  
Keyword(s):  
Organic Matter ◽  
Carbon Sequestration ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Physical Properties ◽  
Management Practices ◽  
Animal Manure ◽  
Soil Bulk Density ◽  
Organic Carbon Content

<p>The aggregated structure of soil is known to reduce rates of soil organic matter (SOM) decomposition and therefore influence the potential for long-term carbon sequestration. In turn, the storage and turnover of SOM strongly determines soil aggregation and thus the physical properties of soil. The two-way nature of these interactions has not yet been explicitly considered in soil organic matter models. In this study, we present and describe a new model of these dynamic feedbacks between SOM storage, soil pore structure and soil physical properties. We show the results of a test of the model against measurements made during 61 years in a field trial located near Uppsala (Sweden) in two treatments with different OM inputs (bare fallow, animal manure). The model was able to successfully reproduce long-term trends in soil bulk density and organic carbon content (SOC), as well as match limited data on soil pore size distribution and surface elevation. The results suggest that the model approach presented here could prove useful in analyses of the effects of soil and crop management practices and climate change on the long-term potential for soil organic carbon sequestration.</p>

Organic Carbon and Nitrogen stocks in two soil types of Northwestern Tunisia: Temporal and spatial variation

2020 ◽  
Author(s):  
Ahlem Tlili ◽  
Imene Dridi ◽  
Moncef Gueddari
Keyword(s):  
Organic Matter ◽  
Global Warming ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Experimental Period ◽  
North West ◽  
Carbon And Nitrogen ◽  
Forest Region ◽  
Nitrogen Sequestration ◽  
Deep Horizon

<p>Soil organic matter has generated international interest in carbon and nitrogen sequestration. In reality, small fluctuations of soil organic stock could have large impacts on global warming. Therefore, quantification of Soil Organic Carbon (SOCs) and Total Nitrogen (TNs) stocks in surface and deep horizons are important to control the release of greenhouse gases. The present research was undertaken in order to determine SOCs and TNs evolution over 50 years. For this aim, we selected two soils (P1 and P2) developed under contrasted pedogenetic conditions in North-West of Tunisia (Beja governorate). P1 is a Luvisol located in a forest region. However, P2 is a Cambisol situated in an agriculture zone. Soil samples were gathered from surface (0-30 cm) and deep (50-100 cm) horizons in 1971, 2005, 2012 and 2019. SOCs declined in surface and deep horizons during the experimental period in both studied soils. In the case of Luvisol, the values declined from 91.01 t/ha to 75.54 t/ha and from 53.00 t/ha to 24.51 t/ha, respectively in surface horizons and deep horizons. Likewise, the SOCs values decreased from 84.24 t/ha to 25.52 t/ha in surface horizons and from 24.45 t/ha to 14.20 t/ha in deep horizons of the Cambisol. The TNs recorded lower values than SOCs. Nevertheless, they showed the same behavior. Our results showed that the highest values of SOCs and TNs were recorded in the Luvisol. This soil exhibited the greatest amount of organic matter since it was developed under forest vegetation. In addition, the results showed an enrichment in SOCs and TNs of superficial horizons to the detriment of the deep horizons. Nevertheless, this decrease in organic stocks with depth occurred following different patterns according to soil type. In fact, the Cambisol reported an important depletion of soil organic stocks as compared to the Luvisol. The loss of SOCs and TNs were estimated to be 69.71% and 54.17% in surface horizon, and 41.94 % and 28.28 % in deep horizon, respectively. Indeed, the land-use change increases the decomposition of soil organic matter principal source of SOCs and TNs. Such a reduction has wider implications on global warming and soil fertility.  </p>

Studies on soil organic matter: Part III. The extraction of organic carbon and nitrogen from soil

1949 ◽  
Vol 39 (3) ◽  
pp. 280-282 ◽  
Author(s):  
J. M. Bremner
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Organic Nitrogen ◽  
Carbon And Nitrogen

A study has been made of the extraction of organic carbon and nitrogen from soil by various inorganic reagents. The results show that the organic carbon and nitrogen of soil are so intimately associated that, under the influence of any one of the reagents tested, the organic carbon is dissolved only along with, and in proportion to, the organic nitrogen. The relative proportions of carbon and nitrogen extracted vary, however, with both the soil and the extractant.

The Carbon-Nitrogen Ratio of Soil Organic Matter

1930 ◽  
Vol 20 (3) ◽  
pp. 348-354 ◽  
Author(s):  
W. McLean
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Arable Soils ◽  
Grassland Soils ◽  
Carbon And Nitrogen ◽  
Carbon Nitrogen Ratio ◽  
Nitrogen Ratio ◽  
Soil Climate ◽  
Range Of Variation

1. The average carbon-nitrogen ratio for fifty British soils from widely distributed areas approximates to the figure 10: 1 given by other investigators. The range of variation is from 6·5 to 13·5: 1. Sixteen foreign samples gave C/N ratios varying from 2·0 to 23·0: 1.2. Soils from limited areas, whether high or low in organic carbon, give approximately constant ratios, but these ratios vary from place to place according to soil, climate, etc. It is suggested that the C/N ratios may be specific.3. The C/N ratios of arable soils do not differ appreciably from those of grassland soils. The percentages of carbon and nitrogen are somewhat higher in the grassland samples than in the arable samples.

scholarly journals Tracing the source of soil organic matter eroded from temperate forest catchments using carbon and nitrogen isotopes

2016 ◽  
Vol 445 ◽  
pp. 172-184 ◽  
Author(s):  
Emma P. McCorkle ◽  
Asmeret Asefaw Berhe ◽  
Carolyn T. Hunsaker ◽  
Dale W. Johnson ◽  
Karis J. McFarlane ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Temperate Forest ◽  
Nitrogen Isotopes ◽  
Carbon And Nitrogen Isotopes ◽  
Carbon And Nitrogen

scholarly journals Impact of deadwood decomposition on soil organic carbon sequestration in Estonian and Polish forests

2019 ◽  
Vol 76 (4) ◽  
Author(s):  
Ewa Błońska ◽  
Jarosław Lasota ◽  
Arvo Tullus ◽  
Reimo Lutter ◽  
Ivika Ostonen
Keyword(s):  
Organic Matter ◽  
Carbon Sequestration ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Carbon Content ◽  
Tree Species ◽  
Decomposition Rates ◽  
Soil Organic Carbon Sequestration ◽  
Organic Carbon Sequestration

Abstract Key message The deadwood of different tree species with different decomposition rates affects soil organic carbon sequestration in Estonian and Polish forests. In warmer conditions (Poland), the deadwood decomposition process had a higher rate than in cooler Estonian forests. Soil organic matter fractions analysis can be used to assess the stability and turnover of organic carbon between deadwood and soil in different experimental localities. Context Deadwood is an important element of properly functioning forest ecosystem and plays a very important role in the maintenance of biodiversity, soil fertility, and carbon sequestration. Aims The main aim was to estimate how decomposition of deadwood of different tree species with different decomposition rates affects soil organic carbon sequestration in Estonian and Polish forests. Methods The investigation was carried out in six forests in Poland (51° N) and Estonia (58° N). The study localities differ in their mean annual air temperature (of 2 °C) and the length of the growing season (of 1 month). The deadwood logs of Norway spruce (Picea abies (L.) Karst.), common aspen (Populus tremula L.), and silver birch (Betula pendula Roth) were included in the research. Logs in three stages of decomposition (III–V) were selected for the analysis. Results There were differences in the stock of soil organic carbon in two experimental localities. There was a higher soil carbon content under logs and in their direct vicinity in Polish forests compared to those in the cooler climate of Estonia. Considerable differences in the amount of soil organic matter were found. The light fraction constituted the greatest quantitative component of organic matter of soils associated with deadwood. Conclusion A higher carbon content in surface soil horizons as an effect of deadwood decomposition was determined for the Polish (temperate) forests. More decomposed deadwood affected soil organic matter stabilization more strongly than less decayed deadwood. This relationship was clearer in Polish forests. Higher temperatures and longer growing periods primarily influenced the increase of soil organic matter free light fraction concentrations directly under and in close proximity to logs of the studied species. The slower release of deadwood decomposition products was noted in Estonian (hemiboreal) forests. The soil organic matter mineral fraction increased under aspen and spruce logs at advanced decomposition in Poland.

scholarly journals A CENTURY 5 model using for estimation of soil organic matter behaviour at predicted climate change

2008 ◽  
Vol 2 (No. 1) ◽  
pp. 25-34 ◽  
Author(s):  
J. Sobocká ◽  
J. Balkovič ◽  
M. Lapin
Keyword(s):  
Climate Change ◽  
Organic Matter ◽  
Carbon Sequestration ◽  
Soil Organic Matter ◽  
Crop Rotation ◽  
Soil Type ◽  
Cropping System ◽  
Total Carbon ◽  
Soil Conditions ◽  
Carbon And Nitrogen

The trends of carbon sequestration behaviour have been estimated for the most fertile soil type of Slovakia based on the prognosticated regional climate change scenario. The processes were modelled and simulated by CENTURY 5 model to provide these inputs: predicted information about quantification of carbon and nitrogen fluxes, and primary net of organic matter production. Soil conditions were represented by the soil type calcareous Haplic Chernozem (Danubian lowland), and the climatic scenario was related to the meteorological station Hurbanovo modelled for the period of 2005&minus;2090. The dynamics of soil carbon and nitrogen was assessed using a conventional cropping system, concretely for 5-years crop rotation winter wheat-maize-oats (feed)-alfalfa-alfalfa modified into two alternatives: with fertilisation and without irrigation (ALT1), and excluding fertilisation and irrigation (ALT2). The model CENTURY 5 provides the simulation of three soil organic matter pools: the active (labile) pool (C<sub>L</sub>), the slow (sequestration) pool (C<sub>S</sub>), and the passive (resistant) pool (C<sub>P</sub>). The results of the model simulation for the conventional crop rotation predict that the supplies of active and slow SOM pools (C<sub>L</sub>, C<sub>S</sub>) do not show any statistically significant decreasing tendency in relation to the expected climate scenario. A moderately linear decreasing trend is expected with the passive SOM pool (C<sub>P</sub>), however, this decreasing tendency is not recognised during total carbon running (C<sub>TOT</sub>). I.e., in the future conventional crop-rotation farming no significant climate change impacts on total carbon sequestration will be presumed. In the case of ALT1, the model shows a gradual but very moderate decrease mainly with CS pool, and in that of ALT2 a significant decreasing trend is recognised with all SOM pools, mainly with CS pool. Amazing is the finding that in the case of non-irrigated but fertilised cropping system (in dry weather), the anticipated significant decrease in carbon sequestration was not observed, however, more drastic changes can be predicted in the non-fertilised and non-irrigated alternative. The average aboveground live carbon and belowground live carbon in both alternative cropping systems in relation to the conventional one have been compared. It was, estimated: in ATL1, that the primary net of organic matter decreased by almost 38% (aboveground live C) and by 43% (belowground live C), and in ALT2 by 43% (aboveground live C) and 45% (belowground live C), respectively. All these findings can be considered as the modelling outputs at the given input data, not as a firmly confirmed prognosis. Nevertheless, the achieved results of CENTURY 5 modelling assume that in the case of sufficient fertilisation and irrigation with well-managed cropping rotation practice under fertile soil conditions of Slovakia, no serious changes in carbon supplies in all SOM pools can be expected.

Linking soil organic matter thermal stability with contents of clay, bound water, organic carbon and nitrogen

Geoderma ◽  
2018 ◽  
Vol 316 ◽  
pp. 38-46 ◽  
Author(s):  
Jiří Kučerík ◽  
David Tokarski ◽  
Michael Scott Demyan ◽  
Ines Merbach ◽  
Christian Siewert
Keyword(s):  
Thermal Stability ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Bound Water ◽  
Carbon And Nitrogen

scholarly journals Which are important soil parameters influencing the spatial heterogeneity of <sup>14</sup>C in soil organic matter?

2016 ◽  
Author(s):  
Stephan John ◽  
Gerrit Angst ◽  
Kristina Kirfel ◽  
Sebastian Preusser ◽  
Carsten W. Mueller ◽  
...  
Keyword(s):  
Organic Matter ◽  
Spatial Distribution ◽  
Soil Organic Matter ◽  
Microbial Biomass ◽  
Organic Carbon ◽  
Soil Texture ◽  
Soil Parameters ◽  
Soil Profiles ◽  
Fine Silt ◽  
Distribution Of Roots

Abstract. Radiocarbon (14C) analysis is an important tool that can provide information on the dynamics of organic matter in soils. Radiocarbon concentrations of soil organic matter (SOM) however, reflect the heterogeneous mixture of various organic compounds and are affected by different chemical, biological, and physical soil parameters. These parameters can vary strongly in soil profiles and thus affect the spatial distribution of the apparent 14C age of SOM considerably. The heterogeneity of SOM and its 14C signature may be even larger in subsoil horizons, which are thought to receive organic carbon inputs following preferential pathways. This will bias conclusions drawn from 14C analyses of individual soil profiles considerably. We thus investigated important soil parameters, which may influence the 14C distribution of SOM as well as the spatial heterogeneity of 14C distributions in soil profiles. The suspected strong heterogeneity and spatial variability, respectively of bulk SOM is confirmed by the variable 14C distribution in three 185 cm deep profiles in a Dystric Cambisol. The 14C contents are most variable in the C horizons because of large differences in the abundance of roots there. The distribution of root biomass and necromass and its organic carbon input is the most important factor affecting the 14C distribution of bulk SOM. The distance of the soil profiles to a beech did not influence the horizontal and vertical distribution of roots and 14C concentrations. Other parameters were found to be of minor importance including microbial biomass-derived carbon and soil texture. The microbial biomass however, may promote a faster turnover of SOM at hot spots resulting in lower 14C concentration there. Soil texture had no statistically significant influence on the spatial 14C distribution of bulk SOM. However, SOM in fine silt and clay sized particles (< 6.3 µm) yields slightly higher 14C concentrations than bulk SOM particularly at greater soil depth, which is in contrast to previous studies where silt and clay fractions contained older SOM stabilized by organo-mineral interaction. 14C contents of fine silt and clay correlate with the microbial biomass-derived carbon suggesting a considerable contribution of microbial-derived organic carbon. In conclusion, 14C analyses of bulk SOM mainly reflect the spatial distribution of roots, which is strongly variable even on a small spatial scale of few meters. This finding should be considered when using 14C analysis to determine SOM.

Sign in / Sign up

Export Citation Format

Share Document