Impacts of Mineral Colloids on the Transformation of Biomolecules and Physical and Chemical Protection of Soil Organic Carbon

2010 ◽  
pp. 13-16
Author(s):  
Pan Ming Huang
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Chemical Protection ◽  
Physical And Chemical

scholarly journals Soil organic carbon (SOC) accumulation in rice paddies under long-term agro-ecosystem experiments in southern China – VI. Changes in microbial community structure and respiratory activity

2011 ◽  
Vol 8 (1) ◽  
pp. 1529-1554 ◽  
Author(s):  
D. Liu ◽  
X. Liu ◽  
Y. Liu ◽  
L. Li ◽  
G. Pan ◽  
...  
Keyword(s):  
Microbial Community ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Respiratory Activity ◽  
Microbial Biomass Carbon ◽  
Southern China ◽  
Biomass Carbon ◽  
Rice Paddies ◽  
Physical And Chemical

Abstract. Biological stabilization within accumulated soil organic carbon (SOC) has not been well understood, while its role in physical and chemical protection as well as of chemical recalcitrance had been addressed in Chinese rice paddies. In this study, topsoil samples were collected and respiratory activity measured in situ following rice harvest under different fertilization treatments of three long-term experimental sites across southern China in 2009. The SOC contents, microbial biomass carbon (SMBC) and nitrogen (SMBN) were analysed using chemical digestion and microbial community structure assessment via clony dilute plate counting methods. While SOC contents were consistently higher under compound chemical fertilization (Comp-Fert) or combined organic and inorganic fertilization (Comb-Fert) compared to N fertilization only (N-Fert), there was significantly higher fungal-bacterial ratio under Comb-Fert than under N-Fert and Comp-Fert. When subtracting the background effect under no fertilization treatment (Non-Fert), the increase both in SMBC and SMBN under fertilization treatment was found very significantly correlated to the increase in SOC over controls across the sites. Also, the ratio of culturable fungal to bacterial population numbers (F/B ratio) was well correlated with soil organic carbon contents in all samples across the sites studied. SOC accumulation favoured a build-up the microbial community with increasing fungal dominance in the rice paddies under fertilization treatments. While soil respiration rates were high under Comb-Fert as a result of enhanced microbial community build-up, the specific soil respiratory activity based on microbial biomass carbon was found in a significantly negatively correlation with the SOC contents for overall samples. Thus, a fungal-dominated microbial community seemed to slow SOC turnover, thereby favouring SOC accumulation under Comp-Fert or under Comb-Fert in the rice paddies. Therefore, the biological stabilization process is of importance in SOC sequestration in the rice paddies, operating with physical and chemical protection and chemical recalcitrance. However, sufficient understanding and prediction of SOM dynamics needs further quantitative characterization of the simultaneous operation of several mechanisms.

scholarly journals Estimation of carbon stocks under different soil uses in the central highlands of Mexico

2016 ◽  
Vol 66 (1) ◽  
Author(s):  
Gustavo Alvarez Arteaga ◽  
Belina García Fajardo ◽  
María Estela Orozco Hernández ◽  
Patricia Mireles Lezama ◽  
Julieta Contreras Martínez
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Management Practices ◽  
Anthropogenic Activities ◽  
Abiotic Factors ◽  
Chemical Properties ◽  
Biological Properties ◽  
Carbon Stocks ◽  
Soil Organic Carbon Stocks ◽  
Physical And Chemical

The loss of organic carbon stocks from the soil and their expulsion into the atmosphere due to the effect of anthropogenic activities must be understood as a problem that goes beyond the environmental to the social and economic context, with the soil degradation being just one of its many impacts. While the accumulation of carbon in the soil depends naturally on the interaction among a series of biotic and abiotic factors, management practices often cause the deterioration of its physical, chemical and biological properties, and, thus, increase the levels of mineralization and a reduction in carbon stocks. This research was undertaken in the municipality of San José del Rincón, State of Mexico, in volcanic soils under different conditions of soil use and disturbation time periods. Samples were obtained at 11 plots, on which physical and chemical analyses were undertaken, obtaining soil organic carbon stocks at 20 cm top soil. The results indicated that, for the soils used for agriculture and induced pasture, there were significant increases in the bulk density, greater acidity and a decrease in carbon concentration compared to forest soils. The organic carbon stocks taken from soils used in forestry, agriculture and induced pasture at a depth of 20 cm were 131, 53 and 63 Mg C ha-1 respectively, results which suggest the timing and intensity of management are determinants in the loss of soil organic carbon stocks from the soil, as well as the alteration of some of their physical and chemical properties.

scholarly journals Soil organic carbon

2020 ◽  
Vol 119 (2) ◽  
pp. 053
Author(s):  
María Paz Salazar ◽  
Rafael Villarreal ◽  
Luis Alberto Lozano ◽  
María Florencia Otero ◽  
Nicolás Guillermo Polich ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Management Practices ◽  
Fulvic Acids ◽  
Chemical Fractionation ◽  
Vertical Variation ◽  
Fine Particulate ◽  
Different Depths ◽  
Physical And Chemical ◽  
Quality Diagnosis

Soil organic carbon (SOC) is an important factor for soil quality diagnosis. Physical and chemical fractionation of SOC are useful to characterize SOC, because some fractions are more sensitive indicators of the effects of different management practices. The aims of this study were (i) to determine values of SOC and different fractions of SOC at different depths and positions in an Argiudoll of the Argentinian Pampas under NT, and (ii) to determine the relation between physical and chemical fractions of SOC. In an experimental plot located in Chascomús, we determined SOC content, humic acids (HA), fulvic acids (FA), humins, coarse and fine particulate organic carbon (POCc and POCf) and mineral associated organic carbon (MOC), at different depths and in the row and inter-row. The content of SOC and different SOC fractions, as well as the contribution of each fraction to SOC showed a vertical variation. The contribution of HA and POCc (newer and more labile fractions) to SOC was larger in the surface than in deeper layers, while humins’ (older and more recalcitrant fraction) contribution to SOC increased with depth, and the contribution of FA, POCf and MOC to SOC remained relatively constant. There was no effect of row and inter-row in SOC content and composition. FA content was correlated to POCc, HA content to POCc and POCf and humins to MOC.

Effects of management on soil organic carbon and structural stability in olive grove toposequences in Mediterranean areas.

2020 ◽  
Author(s):  
Manuel González-Rosado ◽  
Jesús Aguilera Huertas ◽  
Beatriz Lozano-García ◽  
Luis Parras-Alcántara
Keyword(s):  
Climate Change ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Management Practices ◽  
Agricultural Soils ◽  
Conventional Tillage ◽  
Tillage Practices ◽  
Climate Change Effects ◽  
Combat Climate Change ◽  
Physical And Chemical

<p>Carbon sequestration in agricultural soils has been defined as a positive strategy to mitigate the climate change effects. To implement this strategy, it is necessary to reduce the soil physical disturbances that encourage its degradation. It is therefore essential to analyze the consequences that conventional tillage practices have on agrosystems as a first step towards developing sustainable management practices that are in line with strategies to combat climate change. In order to evaluate the conventional tillage impact in olive groves, a toposequence was carried out where three profiles of 50 cm depth each were opened in three topographical positions: summit, backslope and toeslope. The physical and chemical soil properties were analyzed, including soil organic carbon (SOC) and mean weight diameter (MWD) of the aggregates, which showed a plot scale low SOC levels and low MWD being subject to erosive processes which negatively impacts on its SOC storage capacity.</p>

scholarly journals Soil organic carbon in a toposequence in the semiarid of Paraíba, Brazil

2020 ◽  
Vol 9 (5) ◽  
pp. e164953365
Author(s):  
Cheila Deisy Ferreira ◽  
Francisco Tibério de Alencar Moreira ◽  
Patrícia Carneiro Souto ◽  
Lyanne dos Santos Alencar ◽  
César Henrique Alves Borges
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Carbon Content ◽  
Soil Analysis ◽  
Superficial Layer ◽  
The Other ◽  
Organic Carbon Content ◽  
Physical And Chemical ◽  
Upper Third

Organic carbon is a sensible indicator to evaluate the environmental quality of the soil. The objective of this study was to evaluate the organic carbon content of the soil in a toposequence in Serra do Teixeira, municipality of Teixeira, PB. Soil samples were collected in the upper third (UT), upper middle third (UMT), lower middle third (LMT) and lower third (LT) on three depths (0-5, 5-10 and 10-20 cm), with five replicates for each depth, resulting in a total of 60 samples. The organic carbon was evaluated using the methodology of Walkey-Black. Physical and chemical soil analysis were also carried out. The highest mean of carbon content was found in the first 5 cm (19.83 g dm-3), significantly differing from the other depths. It was also observed that the mean content of soil organic carbon on LMT was significantly higher than the other thirds, with 19.39 g dm-3. It is concluded that the highest contents of organic carbon are found on the most superficial layer of the soil. The organic carbon content variations found along the toposequence indicates influence of the relief and the anthropic action.

scholarly journals Spatial Distribution of Soil Organic Carbon in Amazonia

2018 ◽  
Vol 10 (9) ◽  
pp. 153
Author(s):  
G. F. Franco ◽  
J. J. L. L. de Souza ◽  
A. L. L. de Faria ◽  
M. C. C. Campos ◽  
L. M. Da Costa
Keyword(s):  
Spatial Distribution ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Pearson Correlation ◽  
C:N Ratio ◽  
Reduction Process ◽  
Exchange Capacity ◽  
Parent Material ◽  
Organic Carbon Content ◽  
Physical And Chemical

The Amazon rainforest is considered the most important ecosystem in the world for the global carbon balance due to its high carbon storage in soil and in the vegetation. Unfortunately, there are few studies about organic fraction of its soils. Thus, the present research aimed to quantify the soil organic carbon content (OC) and to analyze its spatial distribution using 701 soil samples from minimally anthropic areas compiled from previous studies. Descriptive statistics, Pearson correlation and spatial variability analyses of OC and other physical and chemical soil data were performed. The high variability of OC between soil groups were attributed to the preservation and protection of carbon by oxides, reduction process and organic-rich parent material. OC was strongly positively correlated with total nitrogen (N) content, C:N ratio and cation exchange capacity at pH 7.0. The maps produced showing the spatial distribution of CO and that based on C:N ratio would be support for the creation of priority areas in the conservation of ecosystem.

scholarly journals Effect of Land Use Change on Soil Carbon Stock and Selected Soil Properties in Gobu Sayyo, Western Ethiopia

2021 ◽  
Author(s):  
mengistu welemariam ◽  
Deginet Wako ◽  
Getahun Kitila
Keyword(s):  
Land Use ◽  
Organic Carbon ◽  
Land Use Change ◽  
Soil Organic Carbon ◽  
Soil Properties ◽  
Chemical Properties ◽  
Cultivated Land ◽  
Forest Land ◽  
Soc Stock ◽  
Physical And Chemical

Abstract Background: Land-use change is one of the major factors affecting soil degradation. The pressures of the human population on land resources have increased land-use change with more negative effects on soil carbon storage and soil properties. The objective of this study was to assess the effect of land-use changes on soil organic carbon (SOC) stock and selected soil physicochemical properties in Gobu Sayyo, Western Ethiopia. Soil samples were collected from three adjacent land uses i.e., forest land, grazing land, and cultivated lands at 0-20cm and 20cm-40cm soil depths. A total of 36 composite soil samples were collected and the major soil properties and SOC storage of the area were analyzed and computed based on their standard procedures.Results: Soil organic carbon stock was significantly (p<0.05) higher (43.09-81.86 tone ha-1) in forest land and was significantly lower (38.08-43.09 tone ha-1) in cultivated land at the of depth of 0-20cm. SOC stock decreased with dept in all land uses. Changes in land use and soil depth affected the physical and chemical properties of soil. The physical soil property such as bulk density (BD) was higher (1.62 gcm-3) in the cultivated land whereas, the lowest (1.08 gcm-3) was recorded in the forest at 0-20cm depth. Comparatively the moisture content was higher (25.89%) under forest land at the depth of 20-40cm and was lower (11.22%) under cultivated lands. The chemical soil properties like exchangeable Ca2+, Mg2+, and K+ were higher in forest lands. Organic carbon, avP, TN, ex.Ca2+, ex.Mg2+, ex.K+, and CEC were lower under cultivated lands. pH increased with depth and was higher under forest land and lower under cultivated land. Soils of the study area are in general acidic to slightly acid with pH value ranging from 4-6-6.02. The pH, SOC, TN, av. Phosphorus and CEC were higher under forest land as compared to cultivated and grazing lands. Conclusion: It can be concluded that soil organic carbon stocks, the physical and chemical properties were affected by land-use change and depth. Therefore, reducing the intensity of cultivation, adopting integrated soil fertility management, and maintaining forest land must be practiced to save the soil of the area from degradation.

scholarly journals Soil organic carbon under different landscape attributes in croplands of Northeast China

2008 ◽  
Vol 54 (No. 10) ◽  
pp. 420-427 ◽  
Author(s):  
Z.M. Wang ◽  
B. Zhang ◽  
K.S. Song ◽  
D.W. Liu ◽  
F. Li ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Type ◽  
Northeast China ◽  
Agricultural Soils ◽  
Geometric Mean ◽  
Chemical Properties ◽  
Exponential Model ◽  
Dry Farming ◽  
Physical And Chemical

Soil organic carbon (SOC) was measured in topsoil samples of agricultural soils from 311 locations of Jiutai County, Northeast China. The spatial characteristics of SOC were studied using the Geographic Information Systems and geostatistics. Effects of other soil physical and chemical properties, elevation, slope, soil type and land use type were explored. SOC concentrations followed a lognormal distribution, with a geometric mean of 1.50%. The experimental variogram of SOC has been fitted with an exponential model. Our results highlighted total nitrogen and pH as the soil properties that have the greatest influence on SOC levels. Upland eroding areas have significantly less SOC than soils in deposition areas. Results showed that, soil type had a significant relationship with SOC, reflecting the effect of soil parent materials. Soil samples from paddy fields and vegetable fields had higher SOC concentrations than those from dry farming land.

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