scholarly journals Impact of grazing intensity on seasonal variations in soil organic carbon and soil CO 2 efflux in two semiarid grasslands in southern Botswana

2012 ◽  
Vol 367 (1606) ◽  
pp. 3076-3086 ◽  
Author(s):  
Andrew D. Thomas
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Seasonal Variations ◽  
Field Experiments ◽  
Grazing Intensity ◽  
C Sequestration ◽  
Ecosystem Functions ◽  
Semiarid Environments ◽  
The Impact ◽  
And Storage

Biological soil crusts (BSCs) are an important source of organic carbon, and affect a range of ecosystem functions in arid and semiarid environments. Yet the impact of grazing disturbance on crust properties and soil CO 2 efflux remain poorly studied, particularly in African ecosystems. The effects of burial under wind-blown sand, disaggregation and removal of BSCs on seasonal variations in soil CO 2 efflux, soil organic carbon, chlorophyll a and scytonemin were investigated at two sites in the Kalahari of southern Botswana. Field experiments were employed to isolate CO 2 efflux originating from BSCs in order to estimate the C exchange within the crust. Organic carbon was not evenly distributed through the soil profile but concentrated in the BSC. Soil CO 2 efflux was higher in Kalahari Sand than in calcrete soils, but rates varied significantly with seasonal changes in moisture and temperature. BSCs at both sites were a small net sink of C to the soil. Soil CO 2 efflux was significantly higher in sand soils where the BSC was removed, and on calcrete where the BSC was buried under sand. The BSC removal and burial under sand also significantly reduced chlorophyll a , organic carbon and scytonemin . Disaggregation of the soil crust, however, led to increases in chlorophyll a and organic carbon. The data confirm the importance of BSCs for C cycling in drylands and indicate intensive grazing, which destroys BSCs through trampling and burial, will adversely affect C sequestration and storage. Managed grazing, where soil surfaces are only lightly disturbed, would help maintain a positive carbon balance in African drylands.

Impacts of tillage practices on total, loose- and occluded-particulate, and humified organic carbon fractions in soils within a field in southern Ontario

2001 ◽  
Vol 81 (2) ◽  
pp. 149-156 ◽  
Author(s):  
X M Yang ◽  
B D Kay
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
C Sequestration ◽  
Southern Ontario ◽  
Tillage Practices ◽  
Equivalent Mass ◽  
Organic Carbon Fractions ◽  
And Storage ◽  
Mass Basis ◽  
Private Farm

The effects of no-tillage (NT) and moldboard plowing (MP) on the distribution and storage of soil organic carbon (SOC) and different C fractions were determined along a transect on a private farm in southern Ontario, Canada, where a paired NT and MP strip traversing three soil series had been in existence for 19 yr. Soil samples were collected to a depth of 60 cm in seven increments. SOC was determined in each sample and for the top 30 cm, the organic carbon was fractionated into loose-, occluded-particulate organic matter (loose-POM and occluded-POM) and humified fraction (HF). After 19 yr, soils under NT contained significantly (P < 0.05) more SOC than soils under MP on both an equivalent depth basis and an equivalent mass basis. Greater concentrations of loose- and occluded-POM were found in NT than MP surface soils (0-10 cm). MP favored higher loose-POM contents than NT practices at a depth of 10-20 cm. The HF fraction accounted for most of the increase in SOC in the Huron and Brady soils, whereas the occluded POM accounted for more of the increase in the Fox soil. Our results indicate that the extent of SOC sequestration under NT is strongly dependent on soil type and cropping history. Key words: Tillage practices, soil organic carbon, C fraction, C sequestration

scholarly journals Soil Organic Carbon Sequestration after Biochar Application: A Global Meta-Analysis

Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2474
Author(s):  
Arthur Gross ◽  
Tobias Bromm ◽  
Bruno Glaser
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Field Experiments ◽  
Meta Analysis ◽  
C Sequestration ◽  
Scale Production ◽  
Fecal Matter ◽  
Incubation Experiments ◽  
Sequestration Potential

Biochar application to soil has the potential to sequester carbon in the long term because of its high stability and large-scale production potential. However, biochar technologies are still relatively new, and the global factors affecting the long-term fate of biochar in the environment are still poorly understood. To fill this important research gap, a global meta-analysis was conducted including 64 studies with 736 individual treatments. Field experiments covered experimental durations between 1 and 10 years with biochar application amounts between 1 and 100 Mg ha−1. They showed a mean increase in soil organic carbon (SOC) stocks by 13.0 Mg ha−1 on average, corresponding to 29%. Pot and incubation experiments ranged between 1 and 1278 days and biochar amounts between 5 g kg−1 and 200 g kg−1. They raised SOC by 6.3 g kg−1 on average, corresponding to 75%. More SOC was accumulated in long experimental durations of >500 days in pot and incubation experiments and 6–10 years in field experiments than in shorter experimental durations. Organic fertilizer co-applications significantly further increased SOC. Biochar from plant material showed higher C sequestration potential than biochar from fecal matter, due to higher C/N ratio. SOC increases after biochar application were higher in medium to fine grain textured soils than in soils with coarse grain sizes. Our study clearly demonstrated the high C sequestration potential of biochar application to agricultural soils of varying site and soil characteristics.

scholarly journals From the Ground Up: Prairies on Reclaimed Mine Land—Impacts on Soil and Vegetation

Land ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 455
Author(s):  
Rebecca M. Swab ◽  
Nicola Lorenz ◽  
Nathan R. Lee ◽  
Steven W. Culman ◽  
Richard P. Dick
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Properties ◽  
Plant Community ◽  
Prairie Restoration ◽  
Native Plant ◽  
Soil Microbial ◽  
Prairie Restorations ◽  
Mine Lands ◽  
The Impact

After strip mining, soils typically suffer from compaction, low nutrient availability, loss of soil organic carbon, and a compromised soil microbial community. Prairie restorations can improve ecosystem services on former agricultural lands, but prairie restorations on mine lands are relatively under-studied. This study investigated the impact of prairie restoration on mine lands, focusing on the plant community and soil properties. In southeast Ohio, 305 ha within a ~2000 ha area of former mine land was converted to native prairie through herbicide and planting between 1999–2016. Soil and vegetation sampling occurred from 2016–2018. Plant community composition shifted with prairie age, with highest native cover in the oldest prairie areas. Prairie plants were more abundant in older prairies. The oldest prairies had significantly more soil fungal biomass and higher soil microbial biomass. However, many soil properties (e.g., soil nutrients, β-glucosoidase activity, and soil organic carbon), as well as plant species diversity and richness trended higher in prairies, but were not significantly different from baseline cool-season grasslands. Overall, restoration with prairie plant communities slowly shifted soil properties, but mining disturbance was still the most significant driver in controlling soil properties. Prairie restoration on reclaimed mine land was effective in establishing a native plant community, with the associated ecosystem benefits.

scholarly journals Organic mulching promotes soil organic carbon accumulation to deep soil layer in an urban plantation forest

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Xiaodan Sun ◽  
Gang Wang ◽  
Qingxu Ma ◽  
Jiahui Liao ◽  
Dong Wang ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Carbon Content ◽  
Fine Roots ◽  
Soil Layer ◽  
Carbon Accumulation ◽  
Bulk Soil ◽  
Organic Mulch ◽  
The Impact ◽  
Soc Fractions

Abstract Background Soil organic carbon (SOC) is important for soil quality and fertility in forest ecosystems. Labile SOC fractions are sensitive to environmental changes, which reflect the impact of short-term internal and external management measures on the soil carbon pool. Organic mulching (OM) alters the soil environment and promotes plant growth. However, little is known about the responses of SOC fractions in rhizosphere or bulk soil to OM in urban forests and its correlation with carbon composition in plants. Methods A one-year field experiment with four treatments (OM at 0, 5, 10, and 20 cm thicknesses) was conducted in a 15-year-old Ligustrum lucidum plantation. Changes in the SOC fractions in the rhizosphere and bulk soil; the carbon content in the plant fine roots, leaves, and organic mulch; and several soil physicochemical properties were measured. The relationships between SOC fractions and the measured variables were analysed. Results The OM treatments had no significant effect on the SOC fractions, except for the dissolved organic carbon (DOC). OM promoted the movement of SOC to deeper soil because of the increased carbon content in fine roots of subsoil. There were significant correlations between DOC and microbial biomass carbon and SOC and easily oxidised organic carbon. The OM had a greater effect on organic carbon fractions in the bulk soil than in the rhizosphere. The thinnest (5 cm) mulching layers showed the most rapid carbon decomposition over time. The time after OM had the greatest effect on the SOC fractions, followed by soil layer. Conclusions The frequent addition of small amounts of organic mulch increased SOC accumulation in the present study. OM is a potential management model to enhance soil organic matter storage for maintaining urban forest productivity.

scholarly journals Dynamics of soil organic carbon in the steppes of Russia and Kazakhstan under past and future climate and land use

2021 ◽  
Vol 21 (3) ◽  
Author(s):  
Susanne Rolinski ◽  
Alexander V. Prishchepov ◽  
Georg Guggenberger ◽  
Norbert Bischoff ◽  
Irina Kurganova ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Organic Carbon ◽  
Land Use Change ◽  
Soil Organic Carbon ◽  
Arable Land ◽  
Future Climate ◽  
Future Climate Change ◽  
Climate Scenarios ◽  
The Impact

AbstractChanges in land use and climate are the main drivers of change in soil organic matter contents. We investigated the impact of the largest policy-induced land conversion to arable land, the Virgin Lands Campaign (VLC), from 1954 to 1963, of the massive cropland abandonment after 1990 and of climate change on soil organic carbon (SOC) stocks in steppes of Russia and Kazakhstan. We simulated carbon budgets from the pre-VLC period (1900) until 2100 using a dynamic vegetation model to assess the impacts of observed land-use change as well as future climate and land-use change scenarios. The simulations suggest for the entire VLC region (266 million hectares) that the historic cropland expansion resulted in emissions of 1.6⋅ 1015 g (= 1.6 Pg) carbon between 1950 and 1965 compared to 0.6 Pg in a scenario without the expansion. From 1990 to 2100, climate change alone is projected to cause emissions of about 1.8 (± 1.1) Pg carbon. Hypothetical recultivation of the cropland that has been abandoned after the fall of the Soviet Union until 2050 may cause emissions of 3.5 (± 0.9) Pg carbon until 2100, whereas the abandonment of all cropland until 2050 would lead to sequestration of 1.8 (± 1.2) Pg carbon. For the climate scenarios based on SRES (Special Report on Emission Scenarios) emission pathways, SOC declined only moderately for constant land use but substantially with further cropland expansion. The variation of SOC in response to the climate scenarios was smaller than that in response to the land-use scenarios. This suggests that the effects of land-use change on SOC dynamics may become as relevant as those of future climate change in the Eurasian steppes.

Soil organic carbon storage by shaded and unshaded coffee systems and its implications for climate change mitigation in China

2021 ◽  
pp. 1-8
Author(s):  
Ziwei Xiao ◽  
Xuehui Bai ◽  
Mingzhu Zhao ◽  
Kai Luo ◽  
Hua Zhou ◽  
...  
Keyword(s):  
Climate Change ◽  
Linear Regression ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Multiple Linear Regression ◽  
Carbon Storage ◽  
Soil Ph ◽  
Soil Bulk Density ◽  
Soil N ◽  
And Storage

Abstract Shaded coffee systems can mitigate climate change by fixation of atmospheric carbon dioxide (CO2) in soil. Understanding soil organic carbon (SOC) storage and the factors influencing SOC in coffee plantations are necessary for the development of sound land management practices to prevent land degradation and minimize SOC losses. This study was conducted in the main coffee-growing regions of Yunnan; SOC concentrations and storage of shaded and unshaded coffee systems were assessed in the top 40 cm of soil. Relationships between SOC concentration and factors affecting SOC were analysed using multiple linear regression based on the forward and backward stepwise regression method. Factors analysed were soil bulk density (ρb), soil pH, total nitrogen of soil (N), mean annual temperature (MAT), mean annual moisture (MAM), mean annual precipitation (MAP) and elevations (E). Akaike's information criterion (AIC), coefficient of determination (R2), root mean square error (RMSE) and residual sum of squares (RSS) were used to describe the accuracy of multiple linear regression models. Results showed that mean SOC concentration and storage decreased significantly with depth under unshaded coffee systems. Mean SOC concentration and storage were higher in shaded than unshaded coffee systems at 20–40 cm depth. The correlations between SOC concentration and ρb, pH and N were significant. Evidence from the multiple linear regression model showed that soil bulk density (ρb), soil pH, total nitrogen of soil (N) and climatic variables had the greatest impact on soil carbon storage in the coffee system.

scholarly journals Soil Organic Carbon Dynamics in Semi-Arid Irrigated Cropping Systems

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 484
Author(s):  
Andrew M. Bierer ◽  
April B. Leytem ◽  
Robert S. Dungan ◽  
Amber D. Moore ◽  
David L. Bjorneberg
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Empirical Data ◽  
Cropping Systems ◽  
C Sequestration ◽  
Conventional Tillage ◽  
Dndc Model ◽  
Application Timing ◽  
Winter Triticale ◽  
Semi Arid

Insufficient characterization of soil organic carbon (SOC) dynamics in semi-arid climates contributes uncertainty to SOC sequestration estimates. This study estimated changes in SOC (0–30 cm depth) due to variations in manure management, tillage regime, winter cover crop, and crop rotation in southern Idaho (USA). Empirical data were used to drive the Denitrification Decomposition (DNDC) model in a “default” and calibrated capacity and forecast SOC levels until 2050. Empirical data indicates: (i) no effect (p = 0.51) of winter triticale on SOC after 3 years; (ii) SOC accumulation (0.6 ± 0.5 Mg ha–1 year–1) under a rotation of corn-barley-alfalfax3 and no change (p = 0.905) in a rotation of wheat-potato-barley-sugarbeet; (iii) manure applied annually at rate 1X is not significantly different (p = 0.75) from biennial application at rate 2X; and (iv) no significant effect of manure application timing (p = 0.41, fall vs. spring). The DNDC model simulated empirical SOC and biomass C measurements adequately in a default capacity, yet specific issues were encountered. By 2050, model forecasting suggested: (i) triticale cover resulted in SOC accrual (0.05–0.27 Mg ha–1 year–1); (ii) when manure is applied, conventional tillage regimes are favored; and (iii) manure applied treatments accrue SOC suggesting a quadratic relationship (all R2 > 0.85 and all p < 0.0001), yet saturation behavior was not realized when extending the simulation to 2100. It is possible that under very large C inputs that C sequestration is favored by DNDC which may influence “NetZero” C initiatives.

Modelling long-term soil organic carbon dynamics under the impact of land cover change and soil redistribution

CATENA ◽  
2017 ◽  
Vol 151 ◽  
pp. 63-73 ◽  
Author(s):  
Samuel Bouchoms ◽  
Zhengang Wang ◽  
Veerle Vanacker ◽  
Sebastian Doetterl ◽  
Kristof Van Oost
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Land Cover ◽  
Land Cover Change ◽  
Carbon Dynamics ◽  
Soil Redistribution ◽  
The Impact ◽  
Soil Organic Carbon Dynamics

scholarly journals The Effect of Anaerobic Digestate on the Soil Organic Carbon and Humified Carbon Fractions in Different Land-Use Systems in Lithuania

Land ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 133
Author(s):  
Alvyra Slepetiene ◽  
Mykola Kochiieru ◽  
Linas Jurgutis ◽  
Audrone Mankeviciene ◽  
Aida Skersiene ◽  
...  
Keyword(s):  
Land Use ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Field Experiments ◽  
Soil Layer ◽  
Fertilization Rate ◽  
Agricultural System ◽  
Main Task ◽  
Carbon Fractions ◽  
Fertilization Effects

The most important component of agricultural system are soils as the basis for the growth of plants, accumulation of water, plant nutrients and organic matter. The main task of our research was to ascertain changes in soil organic carbon (SOC) and mobile humified carbon fractions in digestate-treated soils. We have performed three field experiments using the same design on two soil types in 2019–2020. We studied the fertilization effects of different phases of digestate on Retisol and Fluvisol. Fertilization treatments: control; separated liquid digestate 85 kg ha−1 N; and 170 kg ha−1 170 N; separated solid digestate 85 kg ha−1 N; and 170 kg ha−1 N. We have found a greater positive effect on the increase in SOC because of the use of the maximum recommended fertilization rate of the solid digestate. The content of mobile humic substances (MHS) tended to increase in grassland and crop rotation field in digestate-treated soil. In our experiment, maximum concentration of SOC was found in 0–10 cm soil layer, while in the deeper layers the amount of SOC, MHS and mobile humic acids proportionally decreased. We concluded, that long-term factors as soil type and land use strongly affected the humification level expressed as HD (%) in the soil and the highest HD was determined in the grassland soil in Fluvisol.

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