Storage of Soil Organic Carbon and Its Spatial Variability in an Agro-Pastoral Ecotone of Northern China

Spatial distribution of soil organic carbon (SOC) is important for the development of ecosystem carbon cycle models and assessment of soil quality. In this study, a total of 732 soil samples from 122 soil profiles (0–10, 10–20, 20–40, 40–60, 60–80, and 80–100 cm) were collected by a combination of fixed-point sampling and route surveys in an agro-pastoral ecotone of northern China and the spatial variation of the SOC in the samples was analyzed through classical statistical and geostatistical approaches. The results showed that the SOC contents decreased from 4.31 g/kg in the 0–10 cm to 1.57 g/kg in the 80–100 cm soil layer. The spatial heterogeneity of the SOC exhibited moderate and strong dependence for all the soil layers owing to random and structural factors including soil texture, topography, and human activities. The spatial distributions of the SOC increased gradually from northeast to southwest in the 0–40 cm soil layers, but there was no general trend in deep soil layers and different interpolation methods resulted in the inconsistent spatial distribution of SOC. The storage of SOC was expected to be 25 Tg in the 0–100 cm soil depths for the whole area of 7692 km2. The SOC stocks estimated by two interpolation approaches were very close (25.65 vs. 25.86 Tg), but the inverse distance weighting (IDW) interpolation generated a more detailed map of SOC and with higher determination coefficient (R2); therefore, the IDW was recognized as an appropriate method to investigate the spatial variability of SOC in this region.

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Spatial variability of soil organic carbon in the West Liao River Basin

Israel Journal of Ecology and Evolution ◽

10.1163/22244662-20181020 ◽

2018 ◽

Vol 64 (1-4) ◽

pp. 25-34

Author(s):

Yong-hua Zhu ◽

Sheng Zhang ◽

Biao Sun ◽

Xiao-kang Xi ◽

Yu Liu ◽

...

Keyword(s):

Spatial Distribution ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Spatial Variability ◽

Soil Depth ◽

Soil Layer ◽

Kriging Interpolation ◽

Spherical Models ◽

Basin Edge ◽

Depth Increase

Quantification of the pattern and spatial distribution of soil organic carbon (SOC) is essential to comprehending many eco-hydrological processes. To obtain a better understanding of the spatial variability of SOC in a typical farming-pastoral zone, 270 soil samples were collected at 45 sampling sites from every 20 cm soil layer. Semi-variance function theory and ordinary Kriging interpolation were applied to identify the spatial variability of SOC. The results showed that SOC in the area was relatively low and decreased with depth and from the basin edge to the centre with a measured mean content of 0.07–0.65 g/kg. The strongest variability in the zone in the top soil layer (0–40 cm) was in the centre part of the zone, which was supposed to be the most concentrated area of human activities in the zone. As soil depth increase, the degree of variation of SOC decreased. Gaussian, exponential, and spherical models were suggested to successfully simulate SOC in different soil depth zones. The spatial distribution of SOC showed strong variability in the same soil depth zone, with a nugget to sill ratio of less than 14% and a range of 30–160 km.

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The Vertical Differences in the Change Rates and Controlling Factors of Soil Organic Carbon and Total Nitrogen along Vegetation Restoration in a Subtropical Area of China

Sustainability ◽

10.3390/su12166443 ◽

2020 ◽

Vol 12 (16) ◽

pp. 6443

Author(s):

Zhiwei Cao ◽

Xi Fang ◽

Wenhua Xiang ◽

Pifeng Lei ◽

Changhui Peng

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Total Nitrogen ◽

Surface Soil ◽

Lower Layer ◽

Soil Layer ◽

Vegetation Restoration ◽

Soil Factors ◽

Deep Soil ◽

Soil Layers

The study was to investigate the change patterns of soil organic carbon (SOC), total nitrogen (TN), and soil C/N (C/N) in each soil sublayer along vegetation restoration in subtropical China. We collected soil samples in four typical plant communities along a restoration chronosequence. The soil physicochemical properties, fine root, and litter biomass were measured. Our results showed the proportion of SOC stocks (Cs) and TN stocks (Ns) in 20–30 and 30–40 cm soil layers increased, whereas that in 0–10 and 10–20 cm soil layers decreased. Different but well-constrained C/N was found among four restoration stages in each soil sublayer. The effect of soil factors was greater on the deep soil than the surface soil, while the effect of vegetation factors was just the opposite. Our study indicated that vegetation restoration promoted the uniform distribution of SOC and TN on the soil profile. The C/N was relatively stable along vegetation restoration in each soil layer. The accumulation of SOC and TN in the surface soil layer was controlled more by vegetation factors, while that in the lower layer was controlled by both vegetation factors and soil factors.

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Spatial Distribution of Glomalin-related Soil Proteins in Coniferous and Broadleaf mixed Temperate Forest

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha47411621 ◽

2019 ◽

Vol 47 (4) ◽

pp. 1087-1093

Author(s):

Yongming WANG ◽

Chunhua JI ◽

Zhaoyong SHI ◽

Xubin YIN ◽

Chenzhou LIU

Keyword(s):

Spatial Distribution ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Temperate Forest ◽

Soil Depth ◽

Soil Layer ◽

Moran’S I ◽

Digital Object Identifier ◽

Moran's I ◽

Soil Layers

Glomalin-related soil protein (GRSP), as an important component of soil organic carbon (SOC) pool, is a glycoprotein produced by the hyphae of arbuscular mycorrhizal fungi (AMF), which play a vital role in carbon and nutrient cycling in forest ecosystem. Here we investigated the spatial distribution of GRSP in plant community of the dominated species not associated with AMF based on a typical coniferous and broad-leaved temperate forest in Mt. Changbai, Northeastern China. Spatial distribution of GRSP including easily extractable GRSP (EEG) and total GRSP (TG) is represented by Moran’s I on different soil depth among seven soil layers of 0-5 cm, 5-10 cm, 10-20 cm, 20-30 cm, 30-50 cm, 50-70 cm and 70-100 cm. The concentrations of EEG and TG decreased with the increase of soil depth according to a logarithmic function. The Moran’s I coefficient of GRSP was negative in all soil layers except TG in 20-30 cm and 50-70 cm soil layers. When EEG and TG were considered, the Moran’s I coefficient was positive in majority of soil layers within the separation distance of less than 4 m but in soil layers of 10-20 cm and 20-30 cm for EEG and in 30-50 cm for TG. The largest Moran’s I coefficient including EEG and TG was observed in the soil layer of 5-10 cm. The spatial distribution of GRSP was discrete in typical coniferous and broad-leaved temperate forest, and was affected by mycorrhizal colonization rate, soil organic carbon and total nitrogen. ********* In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 4, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue. *********

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Spatial variability of soil organic carbon in a typical watershed in the source area of the middle Dan River, China

Soil Research ◽

10.1071/sr12327 ◽

2013 ◽

Vol 51 (1) ◽

pp. 41 ◽

Cited By ~ 13

Author(s):

Guo-Ce Xu ◽

Zhan-Bin Li ◽

Peng Li ◽

Ke-Xin Lu ◽

Yun Wang

Keyword(s):

Land Use ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Spatial Variability ◽

Spatial Heterogeneity ◽

Spatial Variation ◽

Soil Depth ◽

Source Area ◽

Soil Layers ◽

Land Use Types

Soil organic carbon (SOC) plays an important role in maintaining and improving soil fertility and quality, in addition to mitigating climate change. Understanding SOC spatial variability is fundamental for describing soil resources and predicting SOC. In this study, SOC content and SOC mass were estimated based on a soil survey of a small watershed in the Dan River, China. The spatial heterogeneity of SOC distribution and the impacts of land-use types, elevation, slope, and aspect on SOC were also assessed. Field sampling was carried out based on a 100 m by 100 m grid system overlaid on the topographic map of the study area, and samples were collected in three soil layers to a depth of 40 cm. In total, 222 sites were sampled and 629 soil samples were collected. The results showed that classical kriging could successfully interpolate SOC content in the watershed. Contents of SOC showed strong spatial heterogeneity based on the values of the coefficient of variation and the nugget ratio, and this was attributed largely to the type of land use. The range of the semi-variograms increased with increasing soil depth. The SOC content in the soil profile decreased as soil depth increased, and there were significant (P < 0.01) differences among the three soil layers. Land use had a great impact on the SOC content. ANOVA indicated that the spatial variation of SOC contents under different land use types was significant (P < 0.05). The SOC mass of different land-use types followed the order grassland > forestland > cropland. Mean SOC masses of grassland, forestland, and cropland at a depth of 0–40 cm were 5.87, 5.61, and 5.07 kg m–2, respectively. The spatial variation of SOC masses under different land-use types was significant (P < 0.05). ANOVA also showed significant (P < 0.05) impact of aspect on SOC mass in soil at 0–40 cm. Soil bulk density played an important role in the assessment of SOC mass. In conclusion, carbon in soils in the source area of the middle Dan River would increase with conversion from agricultural land to forest or grassland.

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Stoichiometric characteristics of different agroecosystems under the same climatic conditions in the agropastoral ecotone of northern China

Soil Research ◽

10.1071/sr18355 ◽

2019 ◽

Vol 57 (8) ◽

pp. 875

Author(s):

Xiajie Zhai ◽

Kesi Liu ◽

Deborah M. Finch ◽

Ding Huang ◽

Shiming Tang ◽

...

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Soil Layer ◽

Soil Nutrient ◽

Northern China ◽

Climatic Conditions ◽

N:P Ratios ◽

C:P Ratio ◽

The Mean ◽

Natural Grassland

Ecological stoichiometry affects the processes and functions of ecosystems, but the similarities and differences of stoichiometric characteristics among diverse agropastoral ecosystems under the same climatic conditions remain unclear. In this study, plant and soil stoichiometric characteristics of different agroecosystems, namely natural grassland (free-grazing and mowed grassland), artificial grassland (oat, Chinese leymus and corn silage), field crops (naked oats, flax and wheat) and commercial crops (cabbage and potatoes), were investigated in Guyuan County, China. Results showed total nitrogen (TN), total phosphorus (TP) and N:P ratios in plant tissue varied significantly among ecosystem types (P < 0.05). In general, the mean soil organic carbon, TN and TP content in the 0–0.3 m soil layer in potatoes (8.01, 1.05 and 0.33 g kg–1 respectively) were significantly lower than in other agroecosystems (P < 0.05). The mean C:N ratios of the 0–0.3 m soil layer did not differ significantly among the agroecosystems (P > 0.05). However, the C:P ratio was lower in potato than cabbage sites (24.64 vs 33.17), and was lower at both these sites than in other agroecosystems (P < 0.05). With regard to N:P ratios, only the potato ecosystem had lower values than in other ecosystems (P < 0.05), which did not differ significantly (P > 0.05). Above all, N is more likely to be limiting than P for biomass production in local agroecosystems. Soil C:P and N:P ratios decreased significantly with an increase in the utilisation intensity (from natural grassland to commercial crop). The findings of this study suggest that restoring, preserving and increasing soil organic carbon (especially for cabbage and potatoes), scientifically adjusting the application of N and P fertiliser and enhancing subsidies for low-loss soil nutrient systems, such as grassland, rather than commercial crops will help improve and sustain agroecosystems.

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Spatial variability and dynamics of soil pH, soil organic carbon and matter content: The case of the Wonji Shoa sugarcane plantation

Journal of Water and Land Development ◽

10.2478/jwld-2019-0045 ◽

2019 ◽

Vol 42 (1) ◽

pp. 59-66

Author(s):

Megersa Olumana Dinka ◽

Meseret Dawit

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Spatial Variability ◽

Soil Ph ◽

Ph Value ◽

Bottom Layer ◽

Matter Content ◽

Soil Layers ◽

Emission Effect ◽

Greenhouse Emission

Abstract This study presents the spatial variability and dynamics of soil organic carbon (SOC), soil organic matter (SOM) and soil pH contents at the Wonji Shoa Sugar Estate (WSSE), Ethiopia. Soil samples were collected immediately after the sugarcane was harvested and then analysed for SOC, SOM and pH content using standard procedures. The analysis results showed that the pH value varied between 6.7–8.4 (neutral to moderately alkaline) and 7.3–8.5 (neutral to strongly alkaline) for the top and bottom soil profiles, respectively. The SOM content is in the range of 1.1–6.7% and 0.74–3.3% for the upper and lower soil layers, respectively. Nearly 45% of the samples demonstrated a SOM content below the desirable threshold (<2.1%) in the bottom layer and, hence, inadequate. Moreover, most of the topsoil layer (95%) has an SOM content exceeding the desirable limit and hence is categorized within the normal range. Interestingly, the SOC content showed a spatial variability in both the surface and sub-surface soil layers. A lower SOC and SOM content was found for the sub-soil in the south and southwestern part of the plantation. A further decline in the SOC and SOM content may face the estate if the current waterlogging condition continues in the future for a long period. Overall, the study result emphasizes the need to minimize the pre-harvest burning of sugarcane and action is needed to change the irrigation method to green harvesting to facilitate the SOC retention in the soil and minimize the greenhouse emission effect on the environment, hence improving soil quality in the long-term.

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The Spatial Distribution Characteristics of Soil Organic Carbon and Its Effects on Topsoil under Different Karst Landforms

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17082889 ◽

2020 ◽

Vol 17 (8) ◽

pp. 2889 ◽

Cited By ~ 2

Author(s):

Xingfu Wang ◽

Xianfei Huang ◽

Jiwei Hu ◽

Zhenming Zhang

Keyword(s):

Spatial Distribution ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Soil Depth ◽

Soil Layer ◽

Guizhou Province ◽

Impact Factors ◽

Distribution Characteristics ◽

Spatial Distribution Characteristics ◽

Karst Landforms

Karst landforms are widely distributed in Guizhou Province, and the karst terrain is complex. To investigate the spatial distribution characteristics of soil organic carbon (SOC) in topsoil in different karst landforms, a total of 920 samples were taken from different karst landforms. The study areas, Puding, Xingyi, Guanling, Libo and Yinjiang in Guizhou Province, represent the karst plateau (KP), karst peak-cluster depression (KPCD), karst canyon (KC), karst virgin forest (KVF) and karst trough valley (KTV) landforms, respectively. The characteristics of the SOC contents in areas with different vegetation, land use and soil types under different karst landforms were analyzed. The dimensionality of the factors was reduced via principal component analysis, the relationships among SOC content and different factors were subjected to redundancy analysis, and the effects of the main impact factors on SOC were discussed. The results showed that there was a large discrepancy in the SOC contents in the topsoil layers among different types of karst landforms, the changes in the SOC content in the topsoil layer were highly variable, and the discrepancy in the upper soil layer was higher than that in the lower soil layer. The SOC contents in the 0–50 cm topsoil layers in different karst landforms were between 7.76 and 38.29 g·kg−1, the SOC content gradually decreased with increasing soil depth, and the descending order of the SOC contents in different karst landforms was KTV > KVF > KC > KPCD > KP.

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A review of the impacts of land use change, climate zone, forest type and age on soil organic carbon and other soil quality indicators following afforestation

10.5194/egusphere-egu2020-7370 ◽

2020 ◽

Author(s):

Yang Guo ◽

Mohamed Abdalla ◽

Mikk Espenberg ◽

Astley Hastings ◽

Paul Hallett ◽

...

Keyword(s):

Land Use ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Forest Type ◽

Soil Depth ◽

Soil Layer ◽

Limiting Factor ◽

Barren Land ◽

Soil Layers ◽

Climate Zone

<p>The main aim of this global review and systematic analysis was to investigate the impacts of previous land use system, climate zone and forest type and age on soil organic carbon (SOC), total nitrogen (TN) and total phosphorus (TP), in the different soil layers (0-20, 20-60 and 60-100 cm), following afforestation. We collected 85 publications on SOC, TN and TP stock changes, covering di&#64256;erent countries and climate zones. The data were classified into groups depending on these investigated parameters and analyzed using R version 3.6.1. We found that afforestation significantly increased SOC and TN stocks in the 0-20 and 20-60 soil layers, with values of 45% and 44% for SOC, 30% and 22% for TN, respectively, but had no impact on TP stock. Previous land use systems had the largest influence on SOC, TN and TP stocks, with greater accumulations on barren land compared to cropland and grassland. Climate zone influenced SOC, TN and TP stocks, with significant accumulations in the moist than in the dry climate zone. Afforestation with broadleaf deciduous and broadleaf evergreen forests led to greater SOC, TN and TP accumulations in each soil layer throughout the investigated profile (0-100 cm), compared to coniferous forests. Afforestation for <20 years had significantly increased SOC and TN stocks only at the soil surface (0-20 cm) whilst afforestation for &#8805; 20 years had significantly accumulated them up to 100 cm soil depth. TP stock did not change with the forest age, suggesting that it may become a limiting factor for carbon sequestration under the older-age forest. Following afforestation, the change of soil bulk density had inverse relationships with SOC or TN stocks changes but had no effect on TP stock change.</p>

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Effect of Reclamation on the Vertical Distribution of SOC in Three Types of Wetland Soils

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.962-965.1386 ◽

2014 ◽

Vol 962-965 ◽

pp. 1386-1391

Author(s):

Li Li Huo ◽

Xian Guo Lv ◽

Da Song Lin

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Vertical Distribution ◽

Paddy Field ◽

Soil Layer ◽

Soil Profiles ◽

Wetland Soils ◽

Soil Layers ◽

Soc Density ◽

The Vertical Distribution

To investigate how reclamation of wetlands in three different soil types impacts the vertical distribution of soil organic carbon (SOC) content in soil profiles, contents and density of soil organic carbon (SOC) in soil profiles of three types of wetland soils in wetland, soybean and paddy field in Sanjiang Plain were determined. Both soybean and paddy field were reclaimed from wetland. We observed that reclamation significantly reduced SOC content in 0-10,10-20 and 20-30 cm soil layers in meadow albic soil and meadow marsh soil, and 0-10,10-20,20-30 and 30-40 cm soil layers in peat bog soil, there were no significant difference in SOC contents in soil layers under 0-30 or 0-40 cm before and after reclamation. After reclamation, SOC density in three types of wetland soils decreased, and SOC density in soybean field were higher than that in paddy field. Either in wetlands or farm lands in the three types of wetland soils, most of the SOC storage in 0-100 cm soil layer was stored in 0-50 cm soil layer. Though wetland reclamation reduced the SOC content, it hasn’t changed the regularity of SOC vertical distribution. The relationships between SOC content and soil depth in wetlands and farm lands all could be described by exponential functions in three types of soils. The specific functions are useful to estimate and predict the regional SOC pool by models.

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