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

Soil Research ◽  
2014 ◽  
Vol 52 (5) ◽  
pp. 463 ◽  
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.

scholarly journals On the rebound: soil organic carbon stocks can bounce back to near forest levels when agroforests replace agriculture in southern India

2015 ◽  
Vol 2 (2) ◽  
pp. 871-902 ◽  
Author(s):  
H. C. Hombegowda ◽  
O. van Straaten ◽  
M. Köhler ◽  
D. Hölscher
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Tree Species ◽  
Regional Scale ◽  
Clay Fraction ◽  
Carbon Stocks ◽  
Southern India ◽  
Reference Plot ◽  
Soc Stock ◽  
Soc Stocks

Abstract. Tropical agroforestry has an enormous potential to sequester carbon while simultaneously producing agricultural yields and tree products. The amount of soil organic carbon (SOC) sequestered is however influenced by the type of the agroforestry system established, the soil and climatic conditions and management. In this regional scale study, we utilized a chronosequence approach to investigate how SOC stocks changed when the original forests are converted to agriculture, and then subsequently to four different agroforestry systems (AFSs): homegarden, coffee, coconut and mango. In total we established 224 plots in 56 plot clusters across four climate zones in southern India. Each plot cluster consisted of four plots: a natural forest reference plot, an agriculture reference and two of the same AFS types of two ages (30–60 years and > 60 years). The conversion of forest to agriculture resulted in a large loss the original SOC stock (50–61 %) in the top meter of soil depending on the climate zone. The establishment of homegarden and coffee AFSs on agriculture land caused SOC stocks to rebound to near forest levels, while in mango and coconut AFSs the SOC stock increased only slightly above the agriculture stock. The most important variable regulating SOC stocks and its changes was tree basal area, possibly indicative of organic matter inputs. Furthermore, climatic variables such as temperature and precipitation, and soil variables such as clay fraction and soil pH were likewise all important regulators of SOC and SOC stock changes. Lastly, we found a strong correlation between tree species diversity in homegarden and coffee AFSs and SOC stocks, highlighting possibilities to increase carbon stocks by proper tree species assemblies.

Contrasting agricultural management effects on soil organic carbon dynamics between topsoil and subsoil

Soil Research ◽  
2021 ◽  
Vol 59 (1) ◽  
pp. 24
Author(s):  
Yui Osanai ◽  
Oliver Knox ◽  
Gunasekhar Nachimuthu ◽  
Brian Wilson
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Nitrogen Availability ◽  
Cropping Systems ◽  
Cropping System ◽  
Agricultural Management ◽  
Agricultural Practice ◽  
Organic Fraction ◽  
Soc Stock ◽  
The Impact

Agricultural practices (e.g. tillage, crop rotation and fertiliser application) have a strong influence on the balance between carbon (C) input and output by altering physicochemical and microbial properties that control decomposition processes in the soil. Recent studies suggest that the mechanisms by which agricultural practice impacts soil organic carbon (SOC) dynamics in the topsoil may not be the same as those in the subsoil. Here, we assessed SOC stock, soil organic fractions and nitrogen availability to 1.0 m in soils under a cotton (Gossypium hirsutum L.)-based cropping system, and assessed the impact of agricultural management (three historical cropping systems with or without maize (Zea mays L.) rotation) on SOC storage. We found that the maize rotation and changes in the particulate organic fraction influenced SOC stock in the topsoil, although the overall change in SOC stock was small. The large increase in subsoil SOC stock (by 31%) was dominated by changes in the mineral-associated organic fraction, which were influenced by historical cropping systems and recent maize rotation directly and indirectly via changes in soil nitrogen availability. The strong direct effect of maize rotation on SOC stock, particularly in the subsoil, suggests that the direct transfer of C into the subsoil SOC pool may dominate C dynamics in this cropping system. Therefore, agricultural management that affects the movement of C within the soil profile (e.g. changes in soil physical properties) could have a significant consequence for subsoil C storage.

scholarly journals On the rebound: soil organic carbon stocks can bounce back to near forest levels when agroforests replace agriculture in southern India

SOIL ◽  
2016 ◽  
Vol 2 (1) ◽  
pp. 13-23 ◽  
Author(s):  
H. C. Hombegowda ◽  
O. van Straaten ◽  
M. Köhler ◽  
D. Hölscher
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Tree Species ◽  
Regional Scale ◽  
Clay Fraction ◽  
Carbon Stocks ◽  
Southern India ◽  
Home Garden ◽  
Soc Stock ◽  
Soc Stocks

Abstract. Tropical agroforestry has an enormous potential to sequester carbon while simultaneously producing agricultural yields and tree products. The amount of soil organic carbon (SOC) sequestered is influenced by the type of the agroforestry system established, the soil and climatic conditions, and management. In this regional-scale study, we utilized a chronosequence approach to investigate how SOC stocks changed when the original forests are converted to agriculture, and then subsequently to four different agroforestry systems (AFSs): home garden, coffee, coconut and mango. In total we established 224 plots in 56 plot clusters across 4 climate zones in southern India. Each plot cluster consisted of four plots: a natural forest reference, an agriculture reference and two of the same AFS types of two ages (30–60 years and > 60 years). The conversion of forest to agriculture resulted in a large loss the original SOC stock (50–61 %) in the top meter of soil depending on the climate zone. The establishment of home garden and coffee AFSs on agriculture land caused SOC stocks to rebound to near forest levels, while in mango and coconut AFSs the SOC stock increased only slightly above the agriculture SOC stock. The most important variable regulating SOC stocks and its changes was tree basal area, possibly indicative of organic matter inputs. Furthermore, climatic variables such as temperature and precipitation, and soil variables such as clay fraction and soil pH were likewise all important regulators of SOC and SOC stock changes. Lastly, we found a strong correlation between tree species diversity in home garden and coffee AFSs and SOC stocks, highlighting possibilities to increase carbon stocks by proper tree species assemblies.

scholarly journals Potential and constraints for applying the “4 per 1000 Initiative” in the Caribbean: the case of Guadeloupe

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Pierre Chopin ◽  
Jorge Sierra
Keyword(s):  
Climate Change ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Cropping Systems ◽  
Agricultural Area ◽  
Local Market ◽  
Sequestration Potential ◽  
The Caribbean ◽  
The Impact ◽  
Soc Stocks

AbstractThis paper assesses the feasibility of the 4 per 1000 initiative for agricultural soils in the tropics more specifically in Guadeloupe, as a representative case study of the Caribbean and other tropical regions. We used a locally adapted and calibrated model describing soil organic carbon dynamics under the impact of climate change and a broad range of scenarios combining increased use of organic amendments, reduced soil tillage, and increased land area for the local market. We found that, in its current state, only 26% of agricultural area could achieve a 4‰ year−1 increase in soil organic carbon (SOC) stocks in the coming 30 years, due mainly to perennial cropping systems (sugarcane, banana, orchards) occupying soils with the lowest SOC stocks. Implementing reduced tillage with increased use of locally produced composts would increase the agricultural area reaching the 4 per 1000 target to 31%. However, at territory scale, all scenarios tested showed an annual decrease in SOC stocks varying from − 0.1 to − 3.2‰. The limited area on which the 4 per 1000 target is feasible and generalized SOC losses were mainly linked to the current high SOC stocks in volcanic and calcareous soils on the island and lack of practices capable of further increasing C inputs in current cropping systems. We concluded that C sequestration potential in the Caribbean is rather limited and that increasing SOC stocks, even lower than 4 per 1000, should be the primary target in adaptation to climate change, by increasing the resilience of cropping systems based mainly on SOC-poor soils.

scholarly journals Increasing soil organic carbon sequestration and yield stability simultaneously through combined no-tillage and straw return in wheat-maize rotation

2021 ◽  
Author(s):  
Jianglan Shi ◽  
Shuo Li ◽  
Xiushuang Li ◽  
Xiaohong Tian
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Cropping Systems ◽  
Yield Stability ◽  
No Tillage ◽  
Grain Yields ◽  
Rotation System ◽  
Straw Return ◽  
Soc Stock ◽  
Soc Stocks

Knowledge about the changes in soil organic carbon (SOC) stocks and grain yields under different tillage and straw management is necessary to assess the feasibility and sustainability of conservation agriculture. An 8-year experiment was conducted in an intensive wheat (Triticum aestivum L.)–maize (Zea mays L.) rotation system in the southern Loess Plateau of China. Three tillage methods [control with no-tillage and straw removal (CK), no-tillage with straw stubbles 30–40 cm in height (NT), and rotary tillage with straw incorporation (RT)] were applied before maize planting, and two straw treatments [straw return (SR) and no straw return (SR0)] were applied after maize harvest. Thus, the treatments included CK-SR, CK-SR0, NT-SR, NT-SR0, RT-SR, and RT-SR0. Over 8 years, the SOC stock exhibited similar dynamic trends in all treatments, but was higher in NT, RT, and SR plots than in CK-SR0 plots. Compared with the initial soil, the SOC stock increased largest (34.1%) in NT-SR. Compared with the CK-SR0, the NT-SR, RT-SR, CK-SR, NT-SR0 and RT-SR0 increased the wheat grain yield by 47.2%, 36.8%, 24.9%, 25.1%, and 20.0%, respectively. The NT, RT and SR increased crop yield stability with the highest sustainable yield index in NT-SR for both wheat (0.67) and maize (0.70). This study showed the NT-SR was the best strategy for improving SOC stocks, grain yields and agricultural sustainability for the wheat-maize rotation system in northwestern China and other areas with similar climates and cropping systems.

scholarly journals Estimating soil organic carbon stocks of Swiss forest soils by robust external-drift kriging

2014 ◽  
Vol 7 (3) ◽  
pp. 1197-1210 ◽  
Author(s):  
M. Nussbaum ◽  
A. Papritz ◽  
A. Baltensweiler ◽  
L. Walthert
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Near Infrared ◽  
Likelihood Method ◽  
Standard Errors ◽  
Soil Profiles ◽  
Near Infrared Reflectance ◽  
Soc Stock ◽  
Soc Stocks ◽  
External Drift

Abstract. Accurate estimates of soil organic carbon (SOC) stocks are required to quantify carbon sources and sinks caused by land use change at national scale. This study presents a novel robust kriging method to precisely estimate regional and national mean SOC stocks, along with truthful standard errors. We used this new approach to estimate mean forest SOC stock for Switzerland and for its five main ecoregions. Using data of 1033 forest soil profiles, we modelled stocks of two compartments (0–30, 0–100 cm depth) of mineral soils. Log-normal regression models that accounted for correlation between SOC stocks and environmental covariates and residual (spatial) auto-correlation were fitted by a newly developed robust restricted maximum likelihood method, which is insensitive to outliers in the data. Precipitation, near-infrared reflectance, topographic and aggregated information of a soil and a geotechnical map were retained in the models. Both models showed weak but significant residual autocorrelation. The predictive power of the fitted models, evaluated by comparing predictions with independent data of 175 soil profiles, was moderate (robust R2 = 0.34 for SOC stock in 0–30 cm and R2 = 0.40 in 0–100 cm). Prediction standard errors (SE), validated by comparing point prediction intervals with data, proved to be conservative. Using the fitted models, we mapped forest SOC stock by robust external-drift point kriging at high resolution across Switzerland. Predicted mean stocks in 0–30 and 0–100 cm depth were equal to 7.99 kg m−2 (SE 0.15 kg m−2) and 12.58 kg m−2 (SE 0.24 kg m−2), respectively. Hence, topsoils store about 64% of SOC stocks down to 100 cm depth. Previous studies underestimated SOC stocks of topsoil slightly and those of subsoils strongly. The comparison further revealed that our estimates have substantially smaller SE than previous estimates.

scholarly journals Soil Organic Carbon Stocks in Afforested Agricultural Land in Lithuanian Hemiboreal Forest Zone

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1562
Author(s):  
Iveta Varnagirytė-Kabašinskienė ◽  
Povilas Žemaitis ◽  
Kęstutis Armolaitis ◽  
Vidas Stakėnas ◽  
Gintautas Urbaitis
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Forest Floor ◽  
Agricultural Land ◽  
Forest Stand ◽  
Stand Age ◽  
Soc Stock ◽  
The Mean ◽  
Soc Stocks ◽  
Topsoil Layer

In the context of the specificity of soil organic carbon (SOC) storage in afforested land, nutrient-poor Arenosols and nutrient-rich Luvisols after afforestation with coniferous and deciduous tree species were studied in comparison to the same soils of croplands and grasslands. This study analysed the changes in SOC stock up to 30 years after afforestation of agricultural land in Lithuania, representing the cool temperate moist climate region of Europe. The SOC stocks were evaluated by applying the paired-site design. The mean mass and SOC stocks of the forest floor in afforested Arenosols increased more than in Luvisols. Almost twice as much forest floor mass was observed in coniferous than in deciduous stands 2–3 decades after afforestation. The mean bulk density of fine (<2 mm) soil in the 0–30 cm mineral topsoil layer of croplands was higher than in afforested sites and grasslands. The clear decreasing trend in mean bulk density due to forest stand age with the lowest values in the 21–30-year-old stands was found in afforested Luvisols. In contrast, the SOC concentrations in the 0–30 cm mineral topsoil layer, especially in Luvisols afforested with coniferous species, showed an increasing trend due to the influence of stand age. The mean SOC values in the 0–30 cm mineral topsoil layer of Arenosols and Luvisols during the 30 years after afforestation did not significantly differ from the adjacent croplands or grasslands. The mean SOC stock slightly increased with the forest stand age in Luvisols; however, the highest mean SOC stock was detected in the grasslands. In the Arenosols, there was higher SOC accumulation in the forest floor with increasing stand age than in the Luvisols, while the proportion of SOC stocks in mineral topsoil layers was similar and more comparable to grasslands. These findings suggest encouragement of afforestation of former agricultural land under the current climate and soil characteristics in the region, but the conversion of perennial grasslands to forest land should be done with caution.

scholarly journals Regional simulation of soil organic carbon dynamics for dry farmland in Northeast China using the CENTURY model

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245040
Author(s):  
Feng Zhang ◽  
Shihang Wang ◽  
Mingsong Zhao ◽  
Falv Qin ◽  
Xiaoyu Liu
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Carbon Content ◽  
Regional Scale ◽  
Organic Carbon Content ◽  
Century Model ◽  
Carbon Sequestration Potential ◽  
Soil Organic Carbon Content ◽  
Sequestration Potential ◽  
Temporal And Spatial

Soil organic carbon content has a significant impact on soil fertility and grain yield, making it an important factor affecting agricultural production and food security. Dry farmland, the main type of cropland in China, has a lower soil organic carbon content than that of paddy soil, and it may have a significant carbon sequestration potential. Therefore, in this study we applied the CENTURY model to explore the temporal and spatial changes of soil organic carbon (SOC) in Jilin Province from 1985 to 2015. Dry farmland soil polygons were extracted from soil and land use layers (at the 1:1,000,000 scale). Spatial overlay analysis was also used to extract 1282 soil polygons from dry farmland. Modelled results for SOC dynamics in the dry farmland, in conjunction with those from the Yushu field-validation site, indicated a good level of performance. From 1985 to 2015, soil organic carbon density (SOCD) of dry farmland decreased from 34.36 Mg C ha−1 to 33.50 Mg C ha−1 in general, having a rate of deterioration of 0.03 Mg C ha−1 per year. Also, SOC loss was 4.89 Tg from dry farmland soils in the province, with a deterioration rate of 0.16 Tg C per year. 35.96% of the dry farmland its SOCD increased but 64.04% of the area released carbon. Moreover, SOC dynamics recorded significant differences between different soil groups. The method of coupling the CENTURY model with a detailed soil database can simulate temporal and spatial variations of SOC at a regional scale, and it can be used as a precise simulation method for dry farmland SOC dynamics.

scholarly journals Soil organic carbon stocks are systematically overestimated by misuse of the parameters bulk density and stone content

2016 ◽  
Author(s):  
Christopher Poeplau ◽  
Cora Vos ◽  
Axel Don
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Bulk Density ◽  
Agricultural Soils ◽  
Soil Layer ◽  
Future Studies ◽  
Soil Organic Carbon Stocks ◽  
Soc Stock ◽  
The Mean ◽  
Soc Stocks

Abstract. Estimation of soil organic carbon (SOC) stocks requires estimates of the carbon content, bulk density, stone content and depth of a respective soil layer. However, different application of these parameters could introduce a considerable bias. Here, we explain why three out of four frequently applied methods overestimate SOC stocks. In stone rich soils (> 30 Vol. %), SOC stocks could be overestimated by more than 100 %, as revealed by using German Agricultural Soil Inventory data. Due to relatively low stone content, the mean systematic overestimation for German agricultural soils was 2.1–10.1 % for three different commonly used equations. The equation ensemble as re-formulated here might help to unify SOC stock determination and avoid overestimation in future studies.

scholarly journals Quantification of Soil Organic Carbon in Biochar-Amended Soil Using Ground Penetrating Radar (GPR)

2019 ◽  
Vol 11 (23) ◽  
pp. 2874
Author(s):  
Xiaoqing Shen ◽  
Tyler Foster ◽  
Heather Baldi ◽  
Iliyana Dobreva ◽  
Byron Burson ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Ground Penetrating Radar ◽  
Predictive Models ◽  
Naive Bayes ◽  
Cropping Systems ◽  
Naïve Bayes ◽  
Soil Conditions ◽  
Tree Roots ◽  
Ground Penetrating

The application of biochar amendments to soil has been proposed as a strategy for mitigating global carbon (C) emissions and soil organic carbon (SOC) loss. Biochar can provide additional agronomic benefits to cropping systems, including improved crop yield, soil water holding capacity, seed germination, cation exchange capacity (CEC), and soil pH. To maximize the beneficial effects of biochar amendments towards the inventory, increase, and management of SOC pools, nondestructive analytical methods such as ground penetrating radar (GPR) are needed to identify and quantify belowground C. The use of GPR has been well characterized across geological, archaeological, engineering, and military applications. While GPR has been predominantly utilized to detect relatively large objects such as rocks, tree roots, land mines, and peat soils, the objective of this study was to quantify comparatively smaller, particulate sources of SOC. This research used three materials as C sources: biochar, graphite, and activated C. The C sources were mixed with sand—12 treatments in total—and scanned under three moisture levels: 0%, 10%, and 20% to simulate different soil conditions. GPR attribute analyses and Naïve Bayes predictive models were utilized in lieu of visualization methods because of the minute size of the C particles. Significant correlations between GPR attributes and both C content and moisture levels were detected. The accuracy of two predictive models using a Naïve Bayes classifier for C content was trivial but the accuracy for C structure was 56%. The analyses confirmed the ability of GPR to identify differences in both C content and C structure. Beneficial future applications could focus on applying GPR across more diverse soil conditions.

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