scholarly journals Quantifying and isolating stable soil organic carbon using long-term bare fallow experiments

2010 ◽  
Vol 7 (11) ◽  
pp. 3839-3850 ◽  
Author(s):  
P. Barré ◽  
T. Eglin ◽  
B. T. Christensen ◽  
P. Ciais ◽  
S. Houot ◽  
...  
Keyword(s):  
Simulation Models ◽  
Co2 Concentration ◽  
Turnover Time ◽  
Soil C ◽  
Climate Conditions ◽  
Stable Pool ◽  
Pool Model ◽  
Bare Fallow ◽  
The Stability

Abstract. The stability of soil organic matter (SOM) is a major source of uncertainty in predicting atmospheric CO2 concentration during the 21st century. Isolating the stable soil carbon (C) from other, more labile, C fractions in soil is of prime importance for calibrating soil C simulation models, and gaining insights into the mechanisms that lead to soil C stability. Long-term experiments with continuous bare fallow (vegetation-free) treatments in which the decay of soil C is monitored for decades after all inputs of C have stopped, provide a unique opportunity to assess the quantity of stable soil C. We analyzed data from six bare fallow experiments of long-duration (>30 yrs), covering a range of soil types and climate conditions, and sited at Askov (Denmark), Grignon and Versailles (France), Kursk (Russia), Rothamsted (UK), and Ultuna (Sweden). A conceptual three pool model dividing soil C into a labile pool (turnover time of a several years), an intermediate pool (turnover time of a several decades) and a stable pool (turnover time of a several centuries or more) fits well with the long term C decline observed in the bare fallow soils. The estimate of stable C ranged from 2.7 g C kg−1 at Rothamsted to 6.8 g C kg−1 at Grignon. The uncertainty associated with estimates of the stable pool was large due to the short duration of the fallow treatments relative to the turnover time of stable soil C. At Versailles, where there is least uncertainty associated with the determination of a stable pool, the soil contains predominantly stable C after 80 years of continuous bare fallow. Such a site represents a unique research platform for characterization of the nature of stable SOM and its vulnerability to global change.

scholarly journals Long-term bare fallow experiments offer new opportunities for the quantification and the study of stable carbon in soil

2010 ◽  
Vol 7 (3) ◽  
pp. 4887-4917 ◽  
Author(s):  
P. Barré ◽  
T. Eglin ◽  
B. T. Christensen ◽  
P. Ciais ◽  
S. Houot ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Carbon ◽  
Co2 Concentration ◽  
Soil C ◽  
Climate Conditions ◽  
Stable Pool ◽  
Bare Fallow ◽  
The Stability ◽  
A Site

Abstract. The stability of soil carbon is a major source of uncertainty for the prediction of atmospheric CO2 concentration during the 21st century. Isolating experimentally the stable soil carbon from other, more vulnerable, pools is of prime importance for calibrating soil C models, and gaining insights on the mechanisms leading to soil organic carbon (SOC) stability. Long-term bare fallow experiments, in which the decay of SOC is monitored for decades after inputs from plant material have stopped, represent a unique opportunity to assess the stable organic carbon. We synthesized data from 6 bare fallow experiments of long-duration, covering a range of soil types and climate conditions, at Askov (Denmark), Grignon and Versailles (France), Kursk (Russia), Rothamsted (UK), and Ultuna (Sweden). The conceptual model of SOC being divided into three pools with increasing turnover times, a labile pool (~ years), an intermediate pool (~ decades) and a stable pool (~ several centuries or more) fits well with the long term SOC decays observed in bare fallow soils. The modeled stable pool estimates ranged from 2.7 gC kg−1 at Rothamsted to 6.8 gC kg−1 at Grignon. The uncertainty over the identification of the stable pool is large due to the short length of the fallow records relative to the time scales involved in the decay of soil C. At Versailles, where there is least uncertainty associated with the determination of a stable pool, the soil contains predominantly stable C after 80 years of continuous bare fallow. Such a site represents a unique research platform for future experimentation addressing the characteristics of stable SOC and its vulnerability to global change.

The Global Long-Term Agricultural Experiment Network

2020 ◽  
Author(s):  
Carolina Cardoso Lisboa ◽  
Jonathan Storkey ◽  
Carlos Eduardo Pellegrino Cerri ◽  
Christian Thierfelder ◽  
Juan Andres Quincke ◽  
...  
Keyword(s):  
Food Production ◽  
Deep Understanding ◽  
Agricultural Science ◽  
Modeling Tools ◽  
Soil C ◽  
Climate Conditions ◽  
C Stocks ◽  
Agricultural Experiment ◽  
The Impact

<p>Balancing food production with environmentally sustainable land management can have important climate change mitigation co-benefits. Recent reports, including the IPCC latest Special Report, launched at the COP 25 in December 2019, have highlighted the significant role of soil carbon (C) stocks in agricultural soils in achieving CO<sub>2</sub> zero emissons and contributing to CO<sub>2</sub> removal. However, to measure the soil C balance (C-gains and C-losses), a deep understanding of the processes governing the changes in soil C stocks in agricultural systems is required as well as knowledge on the impact of management over long and short time scales under distinct climate conditions. An understanding of the mechanisms underpinning these processes depends on robust evidence-based datasets that can be applied to several different models to model soil C-dynamics over time and make predictions upon future scenarios.  The datasets from long-term experiments (LTEs) can be extremely valuable to facilitate the evaluation of alternative food production systems impact/effect on soil health, as such soil C stocks. Employing modeling tools to analyse these data, would lead to better evaluation of land use and management practices and its environmental impacts around the globe. With the aim of supporting the agricultural science community in meeting this and related objetives, the Global Long-Term Agricultural Experiment Network (GLTEN) was launched in October 2019. The main goal of the network is to assemble and harmonize, following FAIR Data Principle (findable, accessible, interoperable and reusable), metadata from LTEs through the online GLTEN-Metadata Portal (https://glten.org/). This initial scientific investigation of the data shared between the experiments focusses on soil C data analyzed using free available tools to exploit and compare the trade-offs between several agricultural practices and C-offset given the distinct soil type and climate conditions. With the support of the GLTEN-members, we will start these joint analyses applying the Carbon Benefits Tools (https://banr.nrel.colostate.edu/CBP/) and the RothC Model (https://www.rothamsted.ac.uk/rothamsted-carbon-model-rothc). The progress of this collaborative work relies on the commitment and expertise of the GLTEN-members and we expect that the outcome from this investigation will support the knowledge refining and advancing the development of existing modeling tools. Furthermore, we will demonstrate the potential for the GLTEN to provide a platform that supports and facilitates collaborative research among the community.</p>

scholarly journals ANALYSIS OF ECOLOGICAL AND BIOLOGICAL FEATURES OF CASTANEA SATIVA MILL. IN NATURAL AND CLIMATE CONDITIONS OF THE CENTRAL BLACK EARTH REGION (ON THE EXAMPLE OF THE VORONEZH REGION)

2021 ◽  
Vol 11 (1) ◽  
pp. 24-35
Author(s):  
Svetlana Degtyareva ◽  
Valentina Dorofeeva ◽  
Valentina Shipilova
Keyword(s):  
Castanea Sativa ◽  
Cold Weather ◽  
Climate Conditions ◽  
Biological Features ◽  
Factors Influencing ◽  
Voronezh Region ◽  
Castanea Sativa Mill ◽  
The Stability ◽  
Species Ecology

Knowledge of species ecology and biology in general and characteristics of its acclimatization in a particular region are the basis for its successful selection. In this work, the authors present the results of long-term phenological observations of Castanea sativa Mill. since its planting (1967). Ecological and biological analysis has showed some discrepancies in the passage of phenophases. If the growth processes were not completed before the onset of the autumn-winter cold weather, then in recent years the leaf fall ends at the end of October, annual shoots lignify, growth and generative buds are formed. But, in general, it allows us to draw conclusions about the correspondence of the seasonal rhythms of development of the studied sowing chestnut as an introduced species to their local ecological-phytocenotic analogues. It was experimentally established that the fruits of the chestnut do not need pre-sowing treatment, because seed germination is high (70%). The groups of leading factors influencing the stability and development of the species as a whole (in the study area) have been identified. These are: lack of heat in summer, which affects the formation of fruits; short autumn period with high temperature drops, which limits the ripening of the shoots; different spring periods, contributing to the loss of hardening; unstable winter with sharp cold snaps and thaws, intensifying the nature of winter damage

Carbon stability in a texture contrast soil in response to depth and long-term phosphorus fertilisation of grazed pasture

Soil Research ◽  
2020 ◽  
Vol 58 (1) ◽  
pp. 21 ◽  
Author(s):  
Elizabeth C. Coonan ◽  
Alan E. Richardson ◽  
Clive A. Kirkby ◽  
Lynne M. Macdonald ◽  
Martin R. Amidy ◽  
...  
Keyword(s):  
Plant Material ◽  
Fine Fraction ◽  
Coarse Fraction ◽  
Metabolic Quotient ◽  
Microbial Decomposition ◽  
Soil C ◽  
Soil Fractions ◽  
The Stability ◽  
Phosphorus Fertilisation

It is important to understand the stability of soil organic matter (SOM) sequestered through land management changes. In this study we assessed differences in carbon (C) stability of pasture soils that had high and low C content (2.35% vs 1.73% whole soil C in the 0–10 cm layer) resulting from long-term phosphorus fertilisation. We used soil size fractionation (fine fraction, coarse fraction and winnowing) to assess the amount of stable C and indicators of microbial decomposition capacity (catabolic profiles, metabolic quotient) to assess C stability. As a main effect throughout the 60-cm profile, C concentrations were higher in the fine fraction soil in the high (excess P fertiliser; P2) than low (no P fertiliser; P0) treatments, demonstrating a larger stable C fraction. For both P2 and P0, there was a strong correlation between C measured in the fine fraction and winnowed fraction in the 0–30 cm layer (R = 0.985, P < 0.001), but no correlation was observed for the 30–60 cm layer (R = 0.121, P > 0.05). In addition, we conducted two incubation experiments to assess C stability in the treatments with depth and to assess C stability in the physical soil fractions. For the surface soils (0–10 cm), the highest respiration occurred in fractions containing plant material, including roots (coarse fraction, 0.65 g CO2-C kg–1 soil; whole soil, 1.48 g CO2-C kg–1 soil), which shows that the plant material was less stable than the fine and winnowed soil fractions (0.43 and 0.40 g CO2-C kg–1 soil respectively). Soil respiration, microbial metabolic quotient and substrate utilisation were similar in P0 and P2. Collectively, the data show that the increased C in P2 was associated with increased C concentrations in the more stable fine soil fraction, but with no change in the stability of the C within the fractions.

scholarly journals Stability of Woodchips Biochar and Impact on Soil Carbon Stocks: Results from a Two-Year Field Experiment

Forests ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1350
Author(s):  
Irene Criscuoli ◽  
Maurizio Ventura ◽  
Katja Wiedner ◽  
Bruno Glaser ◽  
Pietro Panzacchi ◽  
...  
Keyword(s):  
Climate Change ◽  
Field Experiment ◽  
Priming Effect ◽  
Soil Organic C ◽  
Organic C ◽  
Soil C ◽  
Total Soil ◽  
C Stock ◽  
The Stability

Biochar has been shown to improve soil quality and crop yields. Furthermore, thanks to its high carbon content (C) and stable chemical structure, biochar can sequester C in the soil for a long time, mitigating climate change. However, the variability in published biochar stability in the soil makes verifying this trait under different environmental and agricultural conditions necessary. Moreover, most of the published literature refers to short-term incubation experiments, which are considered to not adequately represent long-term dynamics under field conditions. This article reports the results of a field experiment carried out in a vineyard near Merano, northern Italy, where the stability of woodchips biochar in soil, its impact on the total soil C stocks as well as on the original soil organic C (priming effect) were studied over two years. Vineyard soil (Dystric Eutrochrept) was amended with biochar (25 and 50 t ha−1) alone or together with compost (45 t ha−1) and compared with unamended control soil. Two methods assessed the stability of biochar in soil: the isotopic mass balance approach and the quantification of Benzene PolyCarboxylic Acids (BPCAs), molecular markers of biochar. The amount of C in the soil organic matter (SOM-C) was determined in the amended plots by subtracting the amount of biochar-C from the total soil organic C stock, and the occurrence of priming effect was verified by comparing SOM-C values at the beginning and at the end of the experiment. Results did not show any significant biochar degradation for both application rates, but results were characterized by a high variation. The application of 50 t ha−1 of biochar significantly increased soil C stock while no effect of biochar on the degradation of SOM-C was observed. Results were confirmed in the case of biochar application together with compost. It can be concluded that the use of woodchips biochar as a soil amendment can increase soil C content in the medium term. However, further analyses are recommended to evaluate the impact of biochar on climate change mitigation in the long term.

scholarly journals Temperature sensitivity of SOM decomposition governed by aggregate protection and microbial communities

2019 ◽  
Vol 5 (7) ◽  
pp. eaau1218 ◽  
Author(s):  
Shuqi Qin ◽  
Leiyi Chen ◽  
Kai Fang ◽  
Qiwen Zhang ◽  
Jun Wang ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Temperature Sensitivity ◽  
Temperature Response ◽  
Climate Feedback ◽  
Soil C ◽  
Active Pool ◽  
Pool Model ◽  
Som Decomposition

Temperature sensitivity (Q10) of soil organic matter (SOM) decomposition is a crucial parameter for predicting the fate of soil carbon (C) under global warming. However, our understanding of its regulatory mechanisms remains inadequate, which constrains its accurate parameterization in Earth system models and induces large uncertainties in predicting terrestrial C-climate feedback. Here, we conducted a long-term laboratory incubation combined with a two-pool model and manipulative experiments to examine potential mechanisms underlying the depth-associated Q10 variations in active and slow soil C pools. We found that lower microbial abundance and stronger aggregate protection were coexisting mechanisms underlying the lower Q10 in the subsoil. Of them, microbial communities were the main determinant of Q10 in the active pool, whereas aggregate protection exerted more important control in the slow pool. These results highlight the crucial role of soil C stabilization mechanisms in regulating temperature response of SOM decomposition, potentially attenuating the terrestrial C-climate feedback.

Technological Analysis of the Orientation of the Pitched Icelandic Turf Roof to the Cardinal Points and their Effect on the Stability of the Vegetative Layers

2014 ◽  
Vol 1041 ◽  
pp. 19-22 ◽  
Author(s):  
Petr Selnik ◽  
Klara Necadova ◽  
Martin Mohapl
Keyword(s):  
Functional Condition ◽  
Local Climate ◽  
Climate Conditions ◽  
Long Term Stability ◽  
The Stability ◽  
The Right ◽  
Weather Impacts ◽  
Technological Analysis ◽  
Made In

This article is focused on the assessment of the pitched turf green roof to the cardinal points, its permanent sustainable functional condition and investigation of a possible damage caused by local climate. The solution of these problems is the crucial factor in next development, use and expansion of this type of roofing in European broader range. This study of the roof construction that was made in Iceland offers conclusion based on quick changes of the local climate conditions and demanding extreme weather impacts. The main aim of this research is proposed the right possible solution and design of this construction including dealing with the details, select the convenient orientation to the cardinal points and surroundings to provide long-term stability of this construction.

scholarly journals Reviews and syntheses: The mechanisms underlying carbon storage in soil

2020 ◽  
Vol 17 (21) ◽  
pp. 5223-5242 ◽  
Author(s):  
Isabelle Basile-Doelsch ◽  
Jérôme Balesdent ◽  
Sylvain Pellerin
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Abiotic Factors ◽  
Agricultural Practices ◽  
Turnover Time ◽  
Carbon Turnover ◽  
Soil C ◽  
C Dynamics ◽  
C Stocks

Abstract. Soil organic matter (OM) represents a key C pool for climate regulation but also an essential component for soil functions and services. Scientific research in the 21st century has considerably improved our knowledge of soil organic matter and its dynamics, particularly under the pressure of the global disruption of the carbon cycle. This paper reviews the processes that control C dynamics in soil, the representation of these processes over time, and their dependence on variations in major biotic and abiotic factors. The most recent advanced knowledge gained on soil organic matter includes the following. (1) Most organic matter is composed of small molecules, derived from living organisms, without transformation via additional abiotic organic polymerization; (2) microbial compounds are predominant in the long term; (3) primary belowground production contributes more to organic matter than aboveground inputs; (4) the contribution of less biodegradable compounds to soil organic matter is low in the long term; (5) two major factors determine the soil organic carbon production “yield” from the initial substrates: the yield of carbon used by microorganisms and the association with minerals, particularly poorly crystalline minerals, which stabilize microbial compounds; (6) interactions between plants and microorganisms also regulate the carbon turnover time and therefore carbon stocks; (7) among abiotic and biotic factors that regulate the carbon turnover time, only a few are considered in current modeling approaches (i.e., temperature, soil water content, pH, particle size, and sometimes C and N interactions); and (8) although most models of soil C dynamics assume that the processes involved are linear, there are now many indications of nonlinear soil C dynamics processes linked to soil OM dynamics (e.g., priming). Farming practices, therefore, affect soil C stocks not only through carbon inputs but also via their effect on microbial and organomineral interactions, yet it has still not been possible to properly identify the main mechanisms involved in C loss (or gain). Greater insight into these mechanisms and their interdependencies, hierarchy and sensitivity to agricultural practices could provide future levers of action for C sequestration in soil.

The Stability of the WHO Reference Thromboplastin NIBS & C 67/40

1979 ◽  
Vol 42 (04) ◽  
pp. 1135-1140 ◽  
Author(s):  
G I C Ingram
Keyword(s):  
Human Brain ◽  
Collaborative Study ◽  
Calibration Constant ◽  
Long Term Stability ◽  
Freeze Dried ◽  
Show Evidence ◽  
Human Material ◽  
Reference Preparation ◽  
The Stability

SummaryThe International Reference Preparation of human brain thromboplastin coded 67/40 has been thought to show evidence of instability. The evidence is discussed and is not thought to be strong; but it is suggested that it would be wise to replace 67/40 with a new preparation of human brain, both for this reason and because 67/40 is in a form (like Thrombotest) in which few workers seem to use human brain. A �plain� preparation would be more appropriate; and a freeze-dried sample of BCT is recommended as the successor preparation. The opportunity should be taken also to replace the corresponding ox and rabbit preparations. In the collaborative study which would be required it would then be desirable to test in parallel the three old and the three new preparations. The relative sensitivities of the old preparations could be compared with those found in earlier studies to obtain further evidence on the stability of 67/40; if stability were confirmed, the new preparations should be calibrated against it, but if not, the new human material should receive a calibration constant of 1.0 and the new ox and rabbit materials calibrated against that.The types of evidence available for monitoring the long-term stability of a thromboplastin are discussed.

Application of the method of mathematical modeling for forecasting channel deformations at the underwater crossing of the main pipeline

2020 ◽  
Vol 10 (6) ◽  
pp. 599-609
Author(s):  
Valery А. Gruzdev ◽  
◽  
Georgy V. Mosolov ◽  
Ekaterina A. Sabayda ◽  
◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Roughness Coefficient ◽  
Computational Domain ◽  
Channel Deformations ◽  
Geological Surveys ◽  
Kuban River ◽  
The Stability ◽  
Protective Structures

In order to determine the possibility of using the method of mathematical modeling for making long-term forecasts of channel deformations of trunk line underwater crossing (TLUC) through water obstacles, a methodology for performing and analyzing the results of mathematical modeling of channel deformations in the TLUC zone across the Kuban River is considered. Within the framework of the work, the following tasks were solved: 1) the format and composition of the initial data necessary for mathematical modeling were determined; 2) the procedure for assigning the boundaries of the computational domain of the model was considered, the computational domain was broken down into the computational grid, the zoning of the computational domain was performed by the value of the roughness coefficient; 3) the analysis of the results of modeling the water flow was carried out without taking the bottom deformations into account, as well as modeling the bottom deformations, the specifics of the verification and calibration calculations were determined to build a reliable mathematical model; 4) considered the possibility of using the method of mathematical modeling to check the stability of the bottom in the area of TLUC in the presence of man-made dumping or protective structure. It has been established that modeling the flow hydraulics and structure of currents, making short-term forecasts of local high-altitude reshaping of the bottom, determining the tendencies of erosion and accumulation of sediments upstream and downstream of protective structures are applicable for predicting channel deformations in the zone of the TLUC. In all these cases, it is mandatory to have materials from engineering-hydro-meteorological and engineering-geological surveys in an amount sufficient to compile a reliable mathematical model.

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