Soil organic carbon dynamics from agricultural management practices under climate change

Abstract. Sequestration of soil organic carbon (SOC) on cropland has been proposed as a climate change mitigation strategy to reduce global greenhouse gas (GHG) concentrations in the atmosphere, which in particular is needed to achieve the targets proposed in the Paris Agreement to limit the increase in atmospheric temperature to well below 2 ∘C. We analyze the historical evolution and future development of cropland SOC using the global process-based biophysical model LPJmL, which was recently extended by a detailed representation of tillage practices and residue management (version 5.0-tillage2). We find that model results for historical global estimates for SOC stocks are at the upper end of available literature, with ∼2650 Pg C of SOC stored globally in the year 2018, ∼170 Pg C of which is stored in cropland soils. In future projections, assuming no further changes in current cropland patterns and under four different management assumptions with two different climate forcings, RCP2.6 and RCP8.5, results suggest that agricultural SOC stocks decline in all scenarios, as the decomposition of SOC outweighs the increase in carbon inputs into the soil from altered management practices. Different climate change scenarios, as well as assumptions on tillage management, play a minor role in explaining differences in SOC stocks. The choice of tillage practice explains between 0.2 % and 1.3 % of total cropland SOC stock change in the year 2100. Future dynamics in cropland SOC are most strongly controlled by residue management: whether residues are left on the field or harvested. We find that on current cropland, global cropland SOC stocks decline until the end of the century by only 1.0 % to 1.4 % if residue retention management systems are generally applied and by 26.7 % to 27.3 % in the case of residue harvest. For different climatic regions, increases in cropland SOC can only be found for tropical dry, warm temperate moist, and warm temperate dry regions in management systems that retain residues.

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SOC sequestration potentials for agricultural management practices under climate change

10.5194/esd-2021-35 ◽

2021 ◽

Author(s):

Tobias Herzfeld ◽

Jens Heinke ◽

Susanne Rolinski ◽

Christoph Müller

Keyword(s):

Climate Change ◽

Management Practices ◽

Atmospheric Temperature ◽

Residue Management ◽

Biophysical Model ◽

Management Systems ◽

Minor Role ◽

Climate Change Scenarios ◽

Warm Temperate ◽

Soc Stocks

Abstract. Sequestration of soil organic carbon (SOC) on cropland has been proposed as a climate change mitigation strategy to reduce global greenhouse gas (GHG) concentrations in the atmosphere, which is in particular needed to achieve the targets proposed in the Paris Agreement to limit the increase in atmospheric temperature to well below 2 °C. We here analyze the historical evolution and future development of cropland SOC using the global process-based biophysical model LPJmL, which was recently extended by a detailed representation of tillage practices and residues management (version 5.0–tillage2). We find that model results for historical global estimates for SOC stocks are at the upper end of available literature, with ~2650 Pg C of SOC stored globally in the year 2018, of which ~170 Pg C are stored in cropland soils. In future projections, assuming no further changes in current cropland patterns and under four different management assumptions with two different climate forcings, RCP2.6, and RCP8.5, results suggest that agricultural SOC stocks decline in all scenarios, as the decomposition of SOC outweighs the increase of carbon inputs into the soil from altered management practices. Different climate-change scenarios, as well as assumptions on tillage management, play a minor role in explaining differences in SOC stocks. The choice of tillage practice explains between 0.2 % and 1.3 % of total cropland SOC stock change in the year 2100. Future dynamics in cropland SOC are most strongly controlled by residue management, whether residues are left on the field or harvested. We find that on current cropland, global cropland SOC stocks decline until the end of the century by only 1.0 % to 1.4 % if residue-retention management systems are generally applied and by 26.7 % to 27.3 % in case of residues harvest. For different climatic regions, increases in cropland SOC can only be found for tropical dry, warm temperate moist, and warm temperate dry regions in management systems that retain residues.

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Effect of cropping practices on soil organic carbon: evidence from long-term field experiments in Victoria, Australia

Soil Research ◽

10.1071/sr14227 ◽

2015 ◽

Vol 53 (6) ◽

pp. 636 ◽

Cited By ~ 16

Author(s):

Fiona Robertson ◽

Roger Armstrong ◽

Debra Partington ◽

Roger Perris ◽

Ivanah Oliver ◽

...

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Management Practices ◽

Field Experiments ◽

Residue Management ◽

Continuous Cropping ◽

Zero Tillage ◽

Stubble Retention ◽

Soc Stocks

Despite considerable research, predicting how soil organic carbon (SOC) in grain production systems will respond to conservation management practices, such as reduced tillage, residue retention and alternative rotations, remains difficult because of the slowness of change and apparent site specificity of the effects. We compared SOC stocks (equivalent soil mass to ~0–0.3 m depth) under various tillage, residue management and rotation treatments in three long-term (12-, 28- and 94-year-old) field experiments in two contrasting environments (Mallee and Wimmera regions). Our hypotheses were that SOC stocks are increased by: (1) minimum tillage rather than traditional tillage; (2) continuous cropping, rather than crop–fallow rotations; and (3) phases of crop or pasture legumes in rotations, relative to continuous cropping with cereals. We found that zero tillage and stubble retention increased SOC in some circumstances (by up to 1.5 Mg C ha–1, or 8%) but not in others. Inclusion of bare fallow in rotations reduced SOC (by 1.4–2.4 Mg C ha–1, or 8–12%) compared with continuous cropping. Including a pulse crop (field pea, where the grain was harvested) in rotations also increased SOC in some instances (by ~6–8 Mg C ha–1, or 29–35%) but not in others. Similarly, leguminous pasture (medic or lucerne) phases in rotations either increased SOC (by 3.5 Mg C ha–1, or 21%) or had no significant effect compared with continuous wheat. Inclusion of a vetch green manure or unfertilised oat pasture in the rotation did not significantly increase SOC compared with continuous wheat. The responses in SOC to these management treatments were likely to be due, in part, to differences in nitrogen and water availability (and their effects on carbon inputs and decomposition) and, in part, to other, unidentified, interactions. We conclude that the management practices examined in the present study may not reliably increase SOC on their own, but that significant increases in SOC are possible under some circumstances through the long-term use of multiple practices, such as stubble retention + zero tillage + legume N input + elimination of fallow. The circumstances under which increases in SOC can be achieved require further investigation.

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Differential long-term effects of climate change and management on stocks and distribution of soil organic carbon in productive grasslands

Biogeosciences Discussions ◽

10.5194/bgd-9-1055-2012 ◽

2012 ◽

Vol 9 (1) ◽

pp. 1055-1096 ◽

Cited By ~ 1

Author(s):

A. M. G. De Bruijn ◽

P. Calanca ◽

C. Ammann ◽

J. Fuhrer

Keyword(s):

Climate Change ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Climate Change Scenarios ◽

Long Term Effects ◽

Organic C ◽

Soil C ◽

The Impact ◽

Soc Stocks

Abstract. We studied the impact of climate change on the dynamics of soil organic carbon (SOC) stocks in productive grassland systems undergoing two types of management, an intensive type with frequent harvests and fertilizer applications and an extensive system where fertilization is omitted and harvests are fewer. The Oensingen Grassland Model was explicitly developed for this study. It was calibrated using measurements taken in a recently established permanent sward in Central Switzerland, and run to simulate SOC dynamics over 2001–2100 under three climate change scenarios assuming different elements of IPCC A2 emission scenarios. We found that: (1) management intensity dominates SOC until approximately 20 yr after grassland establishment. Differences in SOC between climate scenarios become significant after 20 yr and climate effects dominate SOC dynamics from approximately 50 yr after establishment, (2) carbon supplied through manure contributes about 60% to measured organic C increase in fertilized grassland. (3) Soil C accumulates particularly in the top 10 cm soil until 5 yr after establishment. In the long-term, C accumulation takes place in the top 15 cm of the soil profile, while C content decreases below this depth. The transitional depth between gains and losses of C mainly depends on the vertical distribution of root senescence and root biomass. We discuss the importance of previous land use on carbon sequestration potentials that are much lower at the Oensingen site under ley-arable rotation and with much higher SOC stocks than most soils under arable crops. We further discuss the importance of biomass senescence rates, because C balance estimations indicate that these may differ considerably between the two management systems.

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Projected soil organic carbon stocks in German croplands under different climate change scenarios

10.5194/egusphere-egu2020-8004 ◽

2020 ◽

Author(s):

Catharina Riggers ◽

Christopher Poeplau ◽

Axel Don ◽

Cathleen Frühauf ◽

René Dechow

Keyword(s):

Climate Change ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Arable Land ◽

Future Climate Change ◽

Climate Projections ◽

Climate Change Scenarios ◽

Model Ensemble ◽

C Input ◽

Soc Stocks

Mineralization of soil organic carbon (SOC) is driven by temperature and soil moisture. Thus, climate change might affect future SOC stocks with implications for greenhouse gas fluxes from soils and soil fertility of arable land. We used a model ensemble of different SOC models and climate projections to project SOC stocks in German croplands up to 2099 under different climate change scenarios of the Intergovernmental Panel of Climate Change. Current SOC stocks and management data were derived from the German Agricultural Soil Inventory. We estimated the increase in carbon (C) input required to preserve or increase recent SOC stocks. The model ensemble projected declining SOC stocks in German croplands under current management and yield levels. This was true for a scenario with no future climate change (-0.065 Mg ha-1 a-1) as well as for the climate change scenarios (-0.070 Mg ha-1 a-1 to -0.120 Mg ha-1 a-1). Thereby, preserving current SOC stocks would require an increase in current C input to the soil of between 51 % (+1.3 Mg ha-1) and 93 % (+2.3 Mg ha-1). We further estimated that a C input increase of between 221 % and 283 % would be required to increase SOC stocks by 34.4 % in 2099 (4 &#8240; a-1). The results of this study indicate that increasing SOC stocks under climate change by a noticeable amount will be challenging since SOC losses need to be overcompensated.

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Differential long-term effects of climate change and management on stocks and distribution of soil organic carbon in productive grasslands

Biogeosciences ◽

10.5194/bg-9-1997-2012 ◽

2012 ◽

Vol 9 (6) ◽

pp. 1997-2012 ◽

Cited By ~ 11

Author(s):

A. M. G. De Bruijn ◽

P. Calanca ◽

C. Ammann ◽

J. Fuhrer

Keyword(s):

Climate Change ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Climate Change Scenarios ◽

Long Term Effects ◽

Organic C ◽

Soil C ◽

The Impact ◽

Soc Stocks

Abstract. We studied the impact of climate change on the dynamics of soil organic carbon (SOC) stocks in productive grassland systems undergoing two types of management, an intensive type with frequent harvests and fertilizer applications and an extensive system without fertilization and fewer harvests. Simulations were conducted with a dedicated newly developed model, the Oensingen Grassland Model. It was calibrated using measurements taken in a recently established permanent sward in Central Switzerland, and run to simulate SOC dynamics over 2001–2100 under various climate change scenarios assuming different elements of IPCC A2 emission scenarios. We found that: (1) management intensity dominates SOC until approximately 20 years after grassland establishment. Differences in SOC between climate scenarios become significant after 20 years and climate effects dominate SOC dynamics from approximately 50 years after establishment. (2) Carbon supplied through manure contributes about 60 % to measured organic C increase in fertilized grassland. (3) Soil C accumulates particularly in the top 10 cm of the soil until 5 years after establishment. In the long-term, C accumulation takes place in the top 15 cm of the soil profile, while C content decreases below this depth. The transitional depth between gains and losses of C mainly depends on the vertical distribution of root senescence and root biomass. We discuss the importance of previous land use on carbon sequestration potentials that are much lower at the Oensingen site under ley-arable rotation with much higher SOC stocks than most soils under arable crops. We further discuss the importance of biomass senescence rates, because C balance estimations indicate that these may differ considerably between the two management systems.

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Greek National Map of Soil Organic Carbon

10.5194/egusphere-egu21-13211 ◽

2021 ◽

Author(s):

Dimitris Triantakonstantis ◽

Spyros Detsikas

Keyword(s):

Climate Change ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Management Practices ◽

Agricultural Soils ◽

Meteorological Data ◽

Soil Management ◽

Support Vector ◽

Soc Stocks ◽

Map Accuracy

Soil organic carbon (SOC) is the carbon that remains in the soil after the partial decomposition of any material produced by living organisms. It is an essential parameter for agricultural production, the potential sequestration of CO&#8322; in soil and a vital soil function for global carbon cycle. However, a vast potential of soil carbon is removed from agricultural soils due to non-sustainable soil management practices. Mapping SOC and its changes over time and space is highly valuable for estimating the CO&#8322; emissions and effects of climate change to the environment. In the present work, the Greek National Map of SOC is presented calculating the SOC stock in 30 arc-seconds spatial resolution using the Global Soil Partnership and Food and Agriculture Organization of the United Nations (FAO) guidelines for SOC mapping. The presented methodology considers the reference framework of the SCORPAN model for digital soil mapping, which can predict SOC stocks in correspondence with soil forming factors. Among the key variables used for estimating SOC stocks are environmental covariates such as climate and meteorological data, thematic maps, digital terrain data, geomorphometry and soil data. Data mining and geostatistical techniques (random forests, support vector machines, regression-kriging) are used to estimate the SOC stocks. Internal and external map accuracy is used to evaluate the performance of the Greek National SOC map. Accuracy of FAO&#8217;s methodology was examined herein using different modelling approaches. As indicated in the results, the most accurate map was produced by the random forest technique and an accuracy of FAC2=0.968, RMSE=0.322 and r=0.756. The main findings are also discussed herein covering aspects relevant to the method implementation, validation and feasibility of operational implementation.Keywords: soil organic carbon, climate change, soil management practices, Greek National Map

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How much carbon input is required to preserve or increase projected soil organic carbon stocks in German croplands under climate change?

Plant and Soil ◽

10.1007/s11104-020-04806-8 ◽

2021 ◽

Author(s):

Catharina Riggers ◽

Christopher Poeplau ◽

Axel Don ◽

Cathleen Frühauf ◽

René Dechow

Keyword(s):

Climate Change ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Climate Scenario ◽

Climate Projections ◽

Climate Change Scenarios ◽

Soil Organic Carbon Stocks ◽

Soc Stock ◽

Soc Stocks ◽

Negative Emission Technology

Abstract Aims Increasing soil organic carbon (SOC) stocks is discussed as negative emission technology with the potential to remove relevant amounts of carbon from the atmosphere. At the same time, climate change-driven losses of SOC to the atmosphere might impede such goals. Methods In this study, we used an ensemble of different SOC models and climate projections to project SOC stocks in German croplands up to 2099 under different climate change scenarios. We then estimated the required increase in organic carbon (OC) input to preserve or increase SOC stocks. Results Projected SOC stocks of German croplands are estimated to decline under current OC input levels and management, both with and without climate change. Depending on the climate scenario, we estimated that the OC input to the soil in 2099 needs to be between 51% (+ 1.3 Mg ha− 1) and 93% (+ 2.3 Mg ha− 1) higher than today to preserve current SOC stock levels. A SOC stock increase of 34.4% (4‰ a− 1) would even require an OC input increase of between 221% (+ 5.5 Mg ha− 1) and 283% (+ 7.1 Mg ha− 1). Conclusions Our study highlights that under climate change increasing SOC stocks is considerable challenging since projected SOC losses have to be compensated first before SOC built up is possible. This would require unrealistically high OC input increases with drastic changes in agricultural management.

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Influence of agricultural management on soil organic carbon: A compendium and assessment of Canadian studies

Canadian Journal of Soil Science ◽

10.4141/s03-009 ◽

2003 ◽

Vol 83 (4) ◽

pp. 363-380 ◽

Cited By ~ 194

Author(s):

A. J. VandenBygaart ◽

E. G. Gregorich ◽

D. A. Angers

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Management Practices ◽

Agricultural Management ◽

Organic Fertilizers ◽

Published Data ◽

Native Land ◽

Soc Stocks ◽

Long Term Studies

To fulfill commitments under the Kyoto Protocol, Canada is required to provide verifiable estimates and uncertainties for soil organic carbon (SOC) stocks, and for changes in those stocks over time. Estimates and uncertainties for agricultural soils can be derived from long-term studies that have measured differences in SOC between different management practices. We compiled published data from long-term studies in Canada to assess the effect of agricultural management on SOC. A total of 62 studies were compiled, in which the difference in SOC was determined for conversion from native land to cropland, and for different tillage, crop rotation and fertilizer management practices. There was a loss of 24 ± 6% of the SOC after native land was converted to agricultural land. No-till (NT) increased the storage of SOC in western Canada by 2.9 ± 1.3 Mg ha-1; however, in eastern Canada conversion to NT did not increase SOC. In general, the potential to store SOC when NT was adopted decreased with increasing background levels of SOC. Using no-tillage, reducing summer fallow, including hay in rotation with wheat (Triticum aestivum L.), plowing green manures into the soil, and applying N and organic fertilizers were the practices that tended to show the most consistent in creases in SOC storage. By relating treatment SOC levels to those in the control treatments, SOC stock change factors and their levels of uncertainty were derived for use in empirical models, such as the United Nations Intergovernmental Panel on Climate Change (IPCC). Guidelines model for C stock changes. However, we must be careful when attempting to extrapolate research plot data to farmers’ fields since the history of soil and crop management has a significant influence on existing and future SOC stocks. Key words: C sequestration, tillage, crop rotations, fertilizer, cropping intensity, Canada

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The resilience of soil organic carbon stocks under contrasting hill country pasture management practices

NZGA: Research and Practice Series ◽

10.33584/rps.17.2021.3449 ◽

2021 ◽

Vol 17 ◽

Author(s):

Alec Mackay ◽

Ronaldo Eduardo Vibart ◽

Catherine McKenzie ◽

Brian Devantier ◽

Emma Noakes

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Management Practices ◽

Pasture Management ◽

Single Superphosphate ◽

Hill Country ◽

Soil Organic Carbon Stocks ◽

Environmental Goals ◽

The Stability ◽

Soc Stocks

In 2020 we measured the stability of soil organic carbon (SOC) concentrations and stocks under contrasting hill country pasture regimes, by sampling three slope classes and three aspect locations on each of three farmlets of a long-term phosphorus fertiliser and sheep grazing experiment. The farmlets included no annual phosphorus (NF), 125 kg of single superphosphate/ha (LF), or 375 kg superphosphate/ha (HF) that has been applied on an annual basis since 1980. Results from the 2020 sampling event were added to previous results reported from soil samples collected in 2003 and 2014. The SOC concentrations in the topsoil (0-75 mm depth), ranging from 4.23 to 5.99% across all slopes and aspects of the farmlets, fell within the normal range (≥3.5 and <7.0%) required for sustaining production and environmental goals. A trend was shown for greater SOC stocks in the topsoil in the HF farmlet (34.0 Mg/ ha) compared with the other two farmlets (31.6 Mg/ha), but this trend was not evident in the deeper soil layers (75-150, 150-300, 0-300 mm). Under the current conditions, topographical features such as slope and aspect had a more profound influence on SOC stocks than management history.

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