Fire-fallow agriculture as a sustainable cropping system for maintaining organic carbon in Maré Loyalty Island (New Caledonia, southwest Pacific)

AbstractThe Loyalty Islands are part of the French archipelago of New Caledonia in the Southwest Pacific. In these islands, Gibbsic Ferralsols (Humic) are traditionally used for fire-fallow cultivation (FFC) by the Kanak people, but the planting of perennial orchards has been encouraged over the past two decades. The impacts of this policy on soil organic carbon (SOC) are nevertheless unknown, especially in these clay-free soils in which organic matter is the main contributor to soil fertility. SOC and permanganate oxidizable organic carbon (POXC) were studied in the soils of avocado orchards, FFC, and secondary and native forests. Mean SOC stocks are particularly high, ranging between 71.9 and 194.4 MgC ha−1 in an equivalent soil mass of 2000 Mg ha−1, but they are significantly impacted by land use. Avocado farming reduced SOC stocks by about 30% compared to forest soils, even if fields were established on secondary forests that had already experienced SOC losses. In contrast, FFC did not impact them. The POXC content decreased as the degree of soil anthropization increased; however, it was less sensitive than SOC in highlighting the impacts of land use. SOC storage can be achieved through changes in agricultural practices in avocado farming, with support for farmers in transitioning from family farming to perennial cultivation and the policy management of secondary forests designed to enhance the recovery of native forests.

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Soil Organic Carbon Depletion from Forests to Grasslands Conversion in Mexico: A Review

Agriculture ◽

10.3390/agriculture8110181 ◽

2018 ◽

Vol 8 (11) ◽

pp. 181 ◽

Cited By ~ 6

Author(s):

Deb Aryal ◽

Danilo Morales Ruiz ◽

César Tondopó Marroquín ◽

René Pinto Ruiz ◽

Francisco Guevara Hernández ◽

...

Keyword(s):

Land Use ◽

Organic Carbon ◽

Land Use Change ◽

Soil Organic Carbon ◽

Tropical Forests ◽

Soil Depth ◽

Carbon Stocks ◽

Soil Horizon ◽

Native Forests ◽

Soc Stocks

Land use change from forests to grazing lands is one of the important sources of greenhouse gas emissions in many parts of the tropics. The objective of this study was to analyze the extent of soil organic carbon (SOC) loss from the conversion of native forests to pasturelands in Mexico. We analyzed 66 sets of published research data with simultaneous measurements of soil organic carbon stocks between native forests and pasturelands in Mexico. We used a generalized linear mixed effect model to evaluate the effect of land use change (forest versus pasture), soil depth, and original native forest types. The model showed that there was a significant reduction in SOC stocks due to the conversion of native forests to pasturelands. The median loss of SOC ranged from 31.6% to 52.0% depending upon the soil depth. The highest loss was observed in tropical mangrove forests followed by highland tropical forests and humid tropical forests. Higher loss was detected in upper soil horizon (0–30 cm) compared to deeper horizons. The emissions of CO2 from SOC loss ranged from 46.7 to 165.5 Mg CO2 eq. ha−1 depending upon the type of original native forests. In this paper, we also discuss the effect that agroforestry practices such as silvopastoral arrangements and other management practices like rotational grazing, soil erosion control, and soil nutrient management can have in enhancing SOC stocks in tropical grasslands. The results on the degree of carbon loss can have strong implications in adopting appropriate management decisions that recover or retain carbon stocks in biomass and soils of tropical livestock production systems.

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Assessment on the rates and potentials of soil organic carbon sequestration in agricultural lands in Japan using a process-based model and spatially explicit land-use change inventories – Part 1: Historical trend and validation based on nation-wide soil monitoring

Biogeosciences ◽

10.5194/bg-11-4429-2014 ◽

2014 ◽

Vol 11 (16) ◽

pp. 4429-4442 ◽

Cited By ~ 15

Author(s):

Y. Yagasaki ◽

Y. Shirato

Keyword(s):

Land Use ◽

Organic Carbon ◽

Land Use Change ◽

Paddy Fields ◽

Spatially Explicit ◽

Crop Fields ◽

Upland Crop ◽

Soc Stock ◽

Stock Change ◽

Soc Stocks

Abstract. In order to estimate a country-scale soil organic carbon (SOC) stock change in agricultural lands in Japan, while taking into account the effect of land-use changes, climate, different agricultural activities and the nature of soils, a spatially explicit model simulation system was developed using Rothamsted Carbon Model (RothC) with an integration of spatial and temporal inventories. Simulation was run from 1970 to 2008 with historical inventories. Simulated SOC stock was compared with observations in a nation-wide stationary monitoring program conducted during 1979–1998. Historical land-use change, characterized by a large decline in the area of paddy fields as well as a small but continuous decline in the area of orchards, occurred along with a relatively large increase in upland crop fields, unmanaged grasslands, and settlements (i.e. conversion of agricultural fields due to urbanization or abandoning). Results of the simulation on SOC stock change under varying land-use change indicated that land-use conversion from agricultural fields to settlements or other lands, as well as that from paddy fields to croplands have likely been an increasing source of CO2 emission, due to the reduction of organic carbon input to soils and the enhancement of SOC decomposition through transition of soil environment from anaerobic to aerobic conditions. The area-weighted mean concentrations of the simulated SOC stocks calculated for major soil groups under paddy fields and upland crop fields were comparable to those observed in the monitoring. Whereas in orchards, the simulated SOC stocks were underestimated. As the results of simulation indicated that SOC stock change under managed grasslands and settlements has been likely a major sink and source of CO2 emission at country-scale, respectively, validation of SOC stock change under these land-use types, which could not have been accomplished due to limited availability or a lack of measurement, remains a forthcoming challenge.

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Potential soil organic carbon stock and its uncertainty under various cropping systems in Australian cropland

Soil Research ◽

10.1071/sr13294 ◽

2014 ◽

Vol 52 (5) ◽

pp. 463 ◽

Cited By ~ 18

Author(s):

Zhongkui Luo ◽

Enli Wang ◽

Jeff Baldock ◽

Hongtao Xing

Keyword(s):

Monte Carlo ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Cropping Systems ◽

Regional Scale ◽

Cropping System ◽

Soil Conditions ◽

Sequestration Potential ◽

Soc Stock ◽

Soc Stocks

The diversity of cropping systems and its variation could lead to great uncertainty in the estimation of soil organic carbon (SOC) stock across time and space. Using the pre-validated Agricultural Production Systems Simulator, we simulated the long-term (1022 years) SOC dynamics in the top 0.3 m of soil at 613 reference sites under 59 representative cropping systems across Australia’s cereal-growing regions. The point simulation results were upscaled to the entire cereal-growing region using a Monte Carlo approach to quantify the spatial pattern of SOC stock and its uncertainty caused by cropping system and environment. The predicted potential SOC stocks at equilibrium state ranged from 10 to 140 t ha–1, with the majority in a range 30–70 t ha–1, averaged across all the representative cropping systems. Cropping system accounted for ~10% of the total variance in predicted SOC stocks. The type of cropping system that determined the carbon input into soil had significant effects on SOC sequestration potential. On average, the potential SOC stock in the top 0.3 m of soil was 30, 50 and 60 t ha–1 under low-, medium- and high-input cropping systems in terms of carbon input, corresponding to –2, 18 and 26 t ha–1 of SOC change. Across the entire region, the Monte Carlo simulations showed that the potential SOC stock was 51 t ha–1, with a 95% confidence interval ranging from 38 to 64 t ha–1 under the identified representative cropping systems. Overall, predicted SOC stock could increase by 0.99 Pg in Australian cropland under the identified representative cropping systems with optimal management. Uncertainty varied depending on cropping system, climate and soil conditions. Detailed information on cropping system and soil and climate characteristics is needed to obtain reliable estimates of potential SOC stock at regional scale, particularly in cooler and/or wetter regions.

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How will organic carbon stocks in mineral soils evolve under future climate? Global projections using RothC for a range of climate change scenarios

Biogeosciences ◽

10.5194/bg-9-3151-2012 ◽

2012 ◽

Vol 9 (8) ◽

pp. 3151-3171 ◽

Cited By ~ 57

Author(s):

P. Gottschalk ◽

J.U. Smith ◽

M. Wattenbach ◽

J. Bellarby ◽

E. Stehfest ◽

...

Keyword(s):

Land Use ◽

Organic Carbon ◽

Management Practices ◽

Climate Models ◽

Climate Model ◽

Net Primary Production ◽

Future Climate ◽

Climate Change Scenarios ◽

Soc Stocks ◽

Soc Decomposition

Abstract. We use a soil carbon (C) model (RothC), driven by a range of climate models for a range of climate scenarios to examine the impacts of future climate on global soil organic carbon (SOC) stocks. The results suggest an overall global increase in SOC stocks by 2100 under all scenarios, but with a different extent of increase among the climate model and emissions scenarios. The impacts of projected land use changes are also simulated, but have relatively minor impacts at the global scale. Whether soils gain or lose SOC depends upon the balance between C inputs and decomposition. Changes in net primary production (NPP) change C inputs to the soil, whilst decomposition usually increases under warmer temperatures, but can also be slowed by decreased soil moisture. Underlying the global trend of increasing SOC under future climate is a complex pattern of regional SOC change. SOC losses are projected to occur in northern latitudes where higher SOC decomposition rates due to higher temperatures are not balanced by increased NPP, whereas in tropical regions, NPP increases override losses due to higher SOC decomposition. The spatial heterogeneity in the response of SOC to changing climate shows how delicately balanced the competing gain and loss processes are, with subtle changes in temperature, moisture, soil type and land use, interacting to determine whether SOC increases or decreases in the future. Our results suggest that we should stop looking for a single answer regarding whether SOC stocks will increase or decrease under future climate, since there is no single answer. Instead, we should focus on improving our prediction of the factors that determine the size and direction of change, and the land management practices that can be implemented to protect and enhance SOC stocks.

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Insights into modelling of soil organic carbon from Irish grassland sites using ECOSSE model

10.5194/egusphere-egu2020-18940 ◽

2020 ◽

Author(s):

Alina Premrov ◽

Jesko Zimmermann ◽

Stuart Green ◽

Reamonn Fealy ◽

Matthew Saunders

Keyword(s):

Land Use ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Grassland Management ◽

Environmental Research ◽

Research Centre ◽

Identification System ◽

Site Specific ◽

Stocking Rates ◽

Soc Stocks

AbstractGrassland represents the dominant land use in Ireland, and the estimation of soil organic carbon (SOC) stocks and changes for Irish grasslands requires further improvements. This study uses the ECOSSE 6.2b process-based model in site-specific mode (Smith et al., 2010) to predict SOC stocks and changes associated with different grassland management practices. The work presented here aims to provide preliminary insights into SOC modelling procedures. Five Irish sites under different grassland management were selected from the 2009 LUCAS SOC database (JRC, 2018). Due to the lack of repeated SOC measurements over time, the initial SOC input values (required for the simulation initialisation) were assigned from the Irish NSDB database (EPA, 2007). This was done based on the site-specific information from both databases such as distance and matching land-use. The initial SOC values from the NSDB were assigned to 2002 (i.e. the start of simulation). Information on management was obtained from the Irish Integrated Administration and Control System database,LPIS (Zimmermann et al., 2016b), climate data were obtained from M&#201;RA (Met &#201;ireann, 2018) and atmospheric N deposition from http://www.emep.int (Premrov et al. 2019). Fertilisation inputs were adapted from the literature and categorised based on stocking rates derived from Green et al. (2016). The 2009 yearly averaged SOC predicted values were compared to LUCAS measured SOC across five sites (r2 = 0.06), showing over- and under-estimation of simulated SOC, which could be due to potential poor matching NSDB and LUCAS data. This result indicates that the repeated SOC field-measurements over the time are needed for proper model-parameterisation. This was further supported by the observed strong relationship between initial SOC inputs and ECOSSE predicted SOC (r2 = 0.85) indicating the high sensitivity of model SOC predictions to the initial SOC inputs.&#160;AcknowledgementsSOLUM project is funded under the Irish EPA Research programme 2014-2020. Thanks go to Dr Marta Dondini (U. Aberdeen) and Dr Rowan Fealy (Maynooth U.) for their support.&#160;LiteratureEPA, 2007. National Soils Database (NSDB). Environmental Protection Agency (EPA), Ireland.Green, S., et.al., 2016. Cattle stocking rates estimated in temperate intensive grasslands with a spring growth model derived from MODIS NDVI time-series. Int. J. Appl. Earth Obs. & Geoinfo. 52, 166-174.JRC, 2018. LUCAS 2009 TOPSOIL data, European Soil data Centre. Joint Research Centre. European Commission.Met &#201;ireann, 2018. M&#201;RA: Met &#201;ireann Re-Analysis &#8211; Climate Re-analysis.Premrov, A., et al., 2019. Biogeochemical modelling of soil organic carbon-insights into the processing procedures of selected atmospheric input data: Part II. IGRM2019.UCD. Dublin.Smith, J., et al., 2010. ECOSSE. User Manual.Zimmermann, J., et al., 2016. The Irish Land-Parcels Identification System (LPIS). Experiences in ongoing and recent environmental research and land cover mapping. Biol. & Environm. Proceedings RIA 116B, 53-62.

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Forest conversion to poplar plantation in a Lombardy floodplain (Italy): effects on soil organic carbon stock

Biogeosciences ◽

10.5194/bg-11-6483-2014 ◽

2014 ◽

Vol 11 (22) ◽

pp. 6483-6493 ◽

Cited By ~ 14

Author(s):

C. Ferré ◽

R. Comolli ◽

A. Leip ◽

G. Seufert

Keyword(s):

Land Use ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Management Practices ◽

Natural Forest ◽

Aerial Photographs ◽

Forest Conversion ◽

Poplar Plantation ◽

C Stocks ◽

Soc Stocks

Abstract. Effects of forest conversion to poplar plantation on soil organic carbon (SOC) stocks were investigated by sampling paired plots in an alluvial area of the Ticino River in Northern Italy. According to land registers and historical aerial photographs, the two sites were part of a larger area of a 200 yr old natural forest that was partly converted to poplar plantation in 1973. The soil sampling of three layers down to a depth of 100 cm was performed at 90 and 70 points in the natural forest (NF) and in the nearby poplar plantation (PP) respectively. The substitution of the natural forest with the poplar plantation strongly modified soil C stock down to a depth of 55 cm, although the management practices at PP were not intensive. After calculation of equivalent soil masses and of SOC stocks in individual texture classes, the comparison of C stocks showed an overall decrease in SOC of 5.7 kg m−2 or 40% in consequence of 37 years of poplar cultivation. Our case study provides further evidence that (i) spatial heterogeneity of SOC is an important feature in paired plot studies requiring a careful sampling strategy and high enough number of samples; (ii) land use changes through tillage are creating a more homogeneous spatial structure of soil properties and may require the application of dedicated spatial statistics to tackle eventual problems of pseudo-replicates and auto-correlation; (iii) short rotation forests are not properly represented in current reporting schemes for changes of SOC after land use change and may better be considered as cropland.

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Drivers of Organic Carbon Stocks in Different LULC History and Along Soil Depth for a 30 Years Image Time Series

Remote Sensing ◽

10.3390/rs13112223 ◽

2021 ◽

Vol 13 (11) ◽

pp. 2223

Author(s):

Mahboobeh Tayebi ◽

Jorge Tadeu Fim Rosas ◽

Wanderson de Sousa Mendes ◽

Raul Roberto Poppiel ◽

Yaser Ostovari ◽

...

Keyword(s):

Remote Sensing ◽

Land Use ◽

Random Forest ◽

Organic Carbon ◽

Soil Properties ◽

Soil Depth ◽

Controlling Factors ◽

Land Use History ◽

The Impact ◽

Soc Stocks

Soil organic carbon (SOC) stocks are a remarkable property for soil and environmental monitoring. The understanding of their dynamics in crop soils must go forward. The objective of this study was to determine the impact of temporal environmental controlling factors obtained by satellite images over the SOC stocks along soil depth, using machine learning algorithms. The work was carried out in São Paulo state (Brazil) in an area of 2577 km2. We obtained a dataset of boreholes with soil analyses from topsoil to subsoil (0–100 cm). Additionally, remote sensing covariates (30 years of land use history, vegetation indexes), soil properties (i.e., clay, sand, mineralogy), soil types (classification), geology, climate and relief information were used. All covariates were confronted with SOC stocks contents, to identify their impact. Afterwards, the abilities of the predictive models were tested by splitting soil samples into two random groups (70 for training and 30% for model testing). We observed that the mean values of SOC stocks decreased by increasing the depth in all land use and land cover (LULC) historical classes. The results indicated that the random forest with recursive features elimination (RFE) was an accurate technique for predicting SOC stocks and finding controlling factors. We also found that the soil properties (especially clay and CEC), terrain attributes, geology, bioclimatic parameters and land use history were the most critical factors in controlling the SOC stocks in all LULC history and soil depths. We concluded that random forest coupled with RFE could be a functional approach to detect, map and monitor SOC stocks using environmental and remote sensing data.

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Isotope Analysis Reveals Differential Impacts of Artificial and Natural Afforestation On Soil Organic Carbon Dynamics in Abandoned Farmland

10.21203/rs.3.rs-238894/v2 ◽

2021 ◽

Author(s):

Dongrui Di ◽

Guangwei Huang

Keyword(s):

Land Use ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Soil Aggregates ◽

Aggregate Size ◽

Plant Residues ◽

Significant Difference ◽

Land Use System ◽

Time Substitution ◽

Soc Stocks

Abstract Backgrounds A multitude of studies have applied different methods to study the dynamics of soil organic carbon (SOC), but the differential impact of artificial and natural afforestation on SOC dynamic are still poorly understood. Methods and aims We investigated the SOC dynamics following artificial and natural afforestation in Loess Plateau of China, characterizing soil structure and stoichiometry using stable isotope carbon and radiocarbon models. We aim to compare SOC dynamics, clarify SOC source under different afforestation, examine comparability of the study areas and find how soil aggregate size classes control SOC dynamics, finally to evaluate effect of reforestation project.Results The 0-10cm and 10-20 cm SOC stocks were significant higher than other two land-use system. At other depths, there is no significant difference among the three land-use system. Total top soil SOC stocks, C:N and C:P of differently sized soil aggregates significantly increased following afforestation. 13C results and Radiocarbon models indicated that the SOC decomposition rate and new SOC input rate were lower under natural afforestation than artificial afforestation. Conclusions Afforestation can accumulate SOC in top soils mainly resulting from in topsoil changing. SOC resource is mainly from macroaggregate formation provided by fresh plant residues. SOC loss from soil respiration was derived from microaggregates during afforestation. The“space-for-time substitution” method is suitable for comparability of the study areas.

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How will organic carbon stocks in mineral soils evolve under future climate? Global projections using RothC for a range of climate change scenarios

Biogeosciences Discussions ◽

10.5194/bgd-9-411-2012 ◽

2012 ◽

Vol 9 (1) ◽

pp. 411-451 ◽

Cited By ~ 7

Author(s):

P. Gottschalk ◽

J. U. Smith ◽

M. Wattenbach ◽

J. Bellarby ◽

E. Stehfest ◽

...

Keyword(s):

Land Use ◽

Organic Carbon ◽

Management Practices ◽

Climate Model ◽

Net Primary Production ◽

Future Climate ◽

General Question ◽

Climate Change Scenarios ◽

Soc Stocks ◽

Soc Decomposition

Abstract. We use a soil carbon (C) model (RothC), driven by a range of climate models for a range of climate scenarios to examine the impacts of future climate on global soil organic carbon (SOC) stocks. The results suggest an overall global increase in global SOC stocks by 2100 under all scenarios, but with a different extent of increase among the climate model and emissions scenarios. Projected land use changes are also simulated, but have relatively small impacts at the global scale. Whether soils gain or lose SOC depends upon the balance between C inputs and decomposition. Changes in net primary production (NPP) change C inputs to the soil, whilst decomposition usually increases under warmer temperatures, but can also be slowed by decreased soil moisture. Underlying the global trend of increasing SOC under future climate is a complex pattern of regional SOC change. SOC losses are projected to occur in northern latitudes where higher SOC decomposition rates due to higher temperatures are not balanced by increased NPP, whereas in tropical regions, NPP increases override losses due to higher SOC decomposition. The spatial heterogeneity in the response of SOC to changing climate shows how delicately balanced the competing gain and loss processes are, with subtle changes in temperature, moisture, soil type and land use, interacting to determine whether SOC increases or decreases in the future. Our results suggest that we should stop asking the general question of whether SOC stocks will increase or decrease under future climate since there is no single answer. Instead, we should focus on improving our prediction of the factors that determine the size and direction of change, and the land management practices that can be implemented to protect and enhance SOC stocks.

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Carbon Stocks in Miombo Woodlands: Evidence from over 50 Years

Forests ◽

10.3390/f12070862 ◽

2021 ◽

Vol 12 (7) ◽

pp. 862

Author(s):

Medha Bulusu ◽

Christopher Martius ◽

Jessica Clendenning

Keyword(s):

Land Use ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Carbon Stocks ◽

Dry Forest ◽

Miombo Woodlands ◽

Old Growth ◽

Aboveground Carbon ◽

Wide Range ◽

Soc Stocks

Miombo woodlands are extensive dry forest ecosystems in central and southern Africa covering ≈2.7 million km2. Despite their vast expanse and global importance for carbon storage, the long-term carbon stocks and dynamics have been poorly researched. The objective of this paper was to present and summarize the evidence gathered on aboveground carbon (AGC) and soil organic carbon (SOC) stocks of miombo woodlands from the 1960s to mid-2018 through a literature review. We reviewed the data to find out to what extent aboveground carbon and soil organic carbon stocks are found in miombo woodlands and further investigated if are there differences in carbon stocks based on woodland categories (old-growth, disturbed and re-growth). A review protocol was used to identify 56 publications from which quantitative data on AGC and SOC stocks were extracted. We found that the mean AGC in old-growth miombo (45.8 ± 17.8 Mg C ha−1), disturbed miombo (26.7 ± 15 Mg C ha−1), and regrowth miombo (18.8 ± 16.8 Mg C ha−1) differed significantly. Data on rainfall, stand age, and land-use suggested that the variability in aboveground carbon is site-specific, relating to climatic and geographic conditions as well as land-use history. SOC stocks in both old-growth and re-growth miombo were found to vary widely. It must be noted these soil data are provided only for information; they inconsistently refer to varying soil depths and are thus difficult to interpret. The wide range reported suggests a need for further studies which are much more systematic in method and reporting. Other limitations of the dataset include the lack of systematic sampling and lack of data in some countries, viz. Angola and Democratic Republic of the Congo.

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