Effects of four typical vegetations on soil active organic carbon and soil carbon in Loess Plateau

To explore the effect of vegetation restoration on soil carbon cycle and fractions of soil organic carbon pool on purple-soil hill slope in Hengyang City of Hunan Province, China was selected. The soil samples of 0 - 10 and 10 - 20 cm soil layers under three types of vegetation, i.e., grassland zone (GZ), grassland-forest zone (GFZ) and forest zone (FZ). The dynamics of soil active organic carbon (SAOC) fractions to provide theory basis for the influence of soil carbon cycle and different vegetation zones on the fractions of organic carbon pool and its stability. Results show: Microbial biomass carbon and easily oxidizable organic carbon exhibited a decreasing pattern: FZ, GZ, GFZ (p < 0.05); Dissolved organic carbon exhibited a decreasing pattern: FZ, GFZ, GZ (p < 0.05); Light fraction organic carbon was the highest in FZ (p < 0.05), and the second in GZ and GFZ; The availability of active organic carbon in 0 - 10 cm soil layer was higher than that of 10 - 20 cm soil layer (p < 0.05); In comparison with GFZ, the herb in GZ could increase the contents of active organic carbon.

Download Full-text

Total and dissolved soil organic and inorganic carbon and their relationships in typical loess cropland of Fenggu Basin

10.21203/rs.3.rs-55467/v2 ◽

2020 ◽

Author(s):

Tongping Lu ◽

Xiujun Wang ◽

Wenxi Zhang

Keyword(s):

Organic Carbon ◽

Soil Carbon ◽

Loess Plateau ◽

Soil Ph ◽

Negative Correlation ◽

Inorganic Carbon ◽

Yellow River ◽

The Yellow River ◽

Hydrological Process ◽

Complex Relationships

Abstract There is evidence of connections between soil organic carbon (SOC) and inorganic carbon (SIC) in dryland of north China. However, fractions of SOC and SIC and the relationship are not well understood in the Loess Plateau that undergoes profound erosion and redeposition. A study was conducted in low-elevation cropland of Loess Plateau across two distinctive basins: Linfen basin (LFB) with lower soil pH (<8.4) and subject to erosion-redeposition, and Yuncheng basin (YCB) with higher soil pH (>8.6) and under the influence of the Yellow River. Soil samples were collected from 30 sites over 100 cm. We determined SOC, SIC, dissolved organic carbon (DOC) and other properties. Above 100 cm, SOC stock is significantly higher in LFB (10.0±2.6 kg C m-2) than in YCB (6.9±1.5 kg C m-2), but SIC lower in LFB (14.0±2.5 kg C m-2) than in YCB (17.0±5.7 kg C m-2). We find a significantly negative correlation between SOC and SIC stocks in LFB, but no clear relationship in YCB. DOC:SOC ratio (an indicator for DOC desorption or SOC stability) is significantly higher below 40 cm in YCB (1.9%) than LFB (1.2%), indicating stronger DOC desorption in YCB that has stronger hydrological process due to the influence of the Yellow River. Overall, SOC has a negative correlation with SIC and soil pH, and DOC:SOC ratio has a significantly positive correlation with soil pH. Our analyses suggest that erosion/re-deposition of topsoil is partly responsible for the negative SIC-SOC relationship in LFB, and high soil pH and stronger hydrological processes are attributable to relatively lower levels of SOC in YCB. This study highlights that soil carbon fractions in the lowland of Loess Plateau are influenced by many drivers, which leads to complex relationships between major soil carbon pools.

Download Full-text

Fractions of soil organic and inorganic carbon and their relationships in typical loess cropland of Fenggu Basin

10.21203/rs.3.rs-55467/v1 ◽

2020 ◽

Author(s):

Tongping Lu ◽

Xiujun Wendy Wang ◽

Wenxi Zhang

Keyword(s):

Organic Carbon ◽

Soil Carbon ◽

Loess Plateau ◽

Soil Ph ◽

Negative Correlation ◽

Inorganic Carbon ◽

Yellow River ◽

The Yellow River ◽

Hydrological Process ◽

Complex Relationships

Abstract There is evidence of connections between soil organic carbon (SOC) and inorganic carbon (SIC) in dryland of north China. However, fractions of SOC and SIC and the relationship are not well understood in the Loess Plateau that undergoes profound erosion and redeposition. A study was conducted in low-elevation cropland of Loess Plateau across two distinctive basins: Lingfeng basin (LFB) with lower soil pH (< 8.4) and subject to erosion-redeposition, and Yuncheng basin (YCB) with higher soil pH (> 8.6) and under the influence of the Yellow River. Soil samples were collected from 30 sites over 100 cm. We determined SOC, SIC, dissolved organic carbon (DOC) and other properties. Above 100 cm, SOC stock is significantly higher in LFB (10.0 ± 2.6 kg C m− 2) than in YCB (6.9 ± 1.5 kg C m− 2), but SIC lower in LFB (14.0 ± 2.5 kg C m− 2) than in YCB (17.0 ± 5.7 kg C m− 2). We find a significantly negative correlation between SOC and SIC stocks in LFB, but no clear relationship in YCB. On average, DOC:SOC ratio is significantly higher below 40 cm in YCB (1.9%) than LFB (1.2%), indicating stronger DOC desorption in YCB that has stronger hydrological process due to the influence of the Yellow River. Overall, SOC has a negative correlation with SIC and soil pH, and DOC:SOC ratio has a significantly positive correlation with soil pH. Our analyses suggest that erosion/re-deposition of topsoil is partly responsible for the negative SIC-SOC relationship in LFB, and high soil pH and stronger hydrological processes are attributable to relatively lower levels of SOC in YCB. This study highlights that soil carbon fractions in the lowland of Loess Plateau are influenced by many drivers, which leads to complex relationships between major soil carbon pools.

Download Full-text

Impacts of Rice Field Winter Planting on Soil Organic Carbon and Carbon Management Index

Research in Ecology ◽

10.30564/re.v3i4.4161 ◽

2021 ◽

Vol 3 (4) ◽

Author(s):

Haocheng Wang ◽

Guoqin Huang

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Total Organic Carbon ◽

Soil Carbon ◽

Rice Field ◽

Carbon Pool ◽

Cropping Patterns ◽

Soil Carbon Pool ◽

Double Cropping ◽

Active Organic Carbon

To tackle with the problem of prevailing farmland abandonment in winter, 5 treatments includes Chinese milk vetch-double cropping rice (CRR), rape-double cropping rice (RRR), garlic-double cropping rice (GRR), winter crop multiple cropping rotation (ROT), winter fallow control (WRR) were set up. By measuring soil total organic carbon, active organic carbon and its components and calculating the soil carbon pool management index in 0~15 cm and 15~30 cm soil layers in the early and late rice ripening stage. The effects of different winter planting patterns on the changes of soil organic carbon and carbon pool management index were discussed. In order to provide theoretical basis for the optimization and adjustment of winter planting pattern of double cropping rice field in the middle reaches of Yangtze River. The results showed that soil total organic carbon, active organic carbon and its components in different winter cropping patterns were increased, and ROT and CRR treatments were more beneficial to the accumulation of soil total organic carbon, active organic carbon and its components as well as the improvement of soil carbon pool management index, which should be preferred in the adjustment of cropping patterns.

Download Full-text

Total and dissolved soil organic and inorganic carbon and their relationships in typical loess cropland of Fengu Basin

Geoscience Letters ◽

10.1186/s40562-020-00167-3 ◽

2020 ◽

Vol 7 (1) ◽

Author(s):

Tongping Lu ◽

Xiujun Wang ◽

Wenxi Zhang

Keyword(s):

Organic Carbon ◽

Soil Carbon ◽

Loess Plateau ◽

Soil Ph ◽

Negative Correlation ◽

Inorganic Carbon ◽

Yellow River ◽

The Yellow River ◽

Hydrological Process ◽

Complex Relationships

Abstract There is evidence of connections between soil organic carbon (SOC) and inorganic carbon (SIC) in dryland of north China. However, fractions of SOC and SIC and the relationship are not well understood in the Loess Plateau that undergoes profound erosion and redeposition. A study was conducted in low-elevation cropland of Loess Plateau across two distinctive basins: Linfen basin (LFB) with lower soil pH (< 8.4) and subject to erosion–redeposition, and Yuncheng basin (YCB) with higher soil pH (> 8.6) and under the influence of the Yellow River. Soil samples were collected from 30 sites over 100 cm. We determined SOC, SIC, dissolved organic carbon (DOC) and other properties. Above 100 cm, SOC stock is significantly higher in LFB (10.0 ± 2.6 kg C m−2) than in YCB (6.9 ± 1.5 kg C m−2), but SIC lower in LFB (14.0 ± 2.5 kg C m−2) than in YCB (17.0 ± 5.7 kg C m−2). We find a significantly negative correlation between SOC and SIC stocks in LFB, but no clear relationship in YCB. DOC:SOC ratio (an indicator for DOC desorption or SOC stability) is significantly higher below 40 cm in YCB (1.9%) than LFB (1.2%), indicating stronger DOC desorption in YCB that has stronger hydrological process due to the influence of the Yellow River. Overall, SOC has a negative correlation with SIC and soil pH, and DOC:SOC ratio has a significantly positive correlation with soil pH. Our analyses suggest that erosion/re-deposition of topsoil is partly responsible for the negative SIC-SOC relationship in LFB, and high soil pH and stronger hydrological processes are attributable to relatively lower levels of SOC in YCB. This study highlights that soil carbon fractions in the lowland of Loess Plateau are influenced by many drivers, which leads to complex relationships between major soil carbon pools.

Download Full-text

Soil organic carbon dynamics jointly controlled by climate, carbon inputs, soil properties and soil carbon fractions

Global Change Biology ◽

10.1111/gcb.13767 ◽

2017 ◽

Vol 23 (10) ◽

pp. 4430-4439 ◽

Cited By ~ 86

Author(s):

Zhongkui Luo ◽

Wenting Feng ◽

Yiqi Luo ◽

Jeff Baldock ◽

Enli Wang

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Soil Properties ◽

Soil Carbon ◽

Carbon Dynamics ◽

Carbon Fractions ◽

Soil Organic Carbon Dynamics ◽

Soil Carbon Fractions

Download Full-text

Long-Term Nitrogen Addition Decreases Soil Carbon Mineralization in an N-Rich Primary Tropical Forest

Forests ◽

10.3390/f12060734 ◽

2021 ◽

Vol 12 (6) ◽

pp. 734

Author(s):

Xiankai Lu ◽

Qinggong Mao ◽

Zhuohang Wang ◽

Taiki Mori ◽

Jiangming Mo ◽

...

Keyword(s):

Microbial Biomass ◽

Organic Carbon ◽

Tropical Forest ◽

Soil Carbon ◽

Tropical Forests ◽

Carbon Mineralization ◽

N Deposition ◽

Soil Carbon Mineralization ◽

N Additions

Anthropogenic elevated nitrogen (N) deposition has an accelerated terrestrial N cycle, shaping soil carbon dynamics and storage through altering soil organic carbon mineralization processes. However, it remains unclear how long-term high N deposition affects soil carbon mineralization in tropical forests. To address this question, we established a long-term N deposition experiment in an N-rich lowland tropical forest of Southern China with N additions such as NH4NO3 of 0 (Control), 50 (Low-N), 100 (Medium-N) and 150 (High-N) kg N ha−1 yr−1, and laboratory incubation experiment, used to explore the response of soil carbon mineralization to the N additions therein. The results showed that 15 years of N additions significantly decreased soil carbon mineralization rates. During the incubation period from the 14th day to 56th day, the average decreases in soil CO2 emission rates were 18%, 33% and 47% in the low-N, medium-N and high-N treatments, respectively, compared with the Control. These negative effects were primarily aroused by the reduced soil microbial biomass and modified microbial functions (e.g., a decrease in bacteria relative abundance), which could be attributed to N-addition-induced soil acidification and potential phosphorus limitation in this forest. We further found that N additions greatly increased soil-dissolved organic carbon (DOC), and there were significantly negative relationships between microbial biomass and soil DOC, indicating that microbial consumption on soil-soluble carbon pool may decrease. These results suggests that long-term N deposition can increase soil carbon stability and benefit carbon sequestration through decreased carbon mineralization in N-rich tropical forests. This study can help us understand how microbes control soil carbon cycling and carbon sink in the tropics under both elevated N deposition and carbon dioxide in the future.

Download Full-text

Can Agricultural Management Induced Changes in Soil Organic Carbon Be Detected Using Mid-Infrared Spectroscopy?

Remote Sensing ◽

10.3390/rs13122265 ◽

2021 ◽

Vol 13 (12) ◽

pp. 2265

Author(s):

Jonathan Sanderman ◽

Kathleen Savage ◽

Shree Dangal ◽

Gabriel Duran ◽

Charlotte Rivard ◽

...

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Soil Carbon ◽

Diffuse Reflectance Spectroscopy ◽

Low Cost ◽

Soil Survey ◽

Mid Infrared ◽

Mir Spectroscopy ◽

Induced Changes ◽

Carbon Change

A major limitation to building credible soil carbon sequestration programs is the cost of measuring soil carbon change. Diffuse reflectance spectroscopy (DRS) is considered a viable low-cost alternative to traditional laboratory analysis of soil organic carbon (SOC). While numerous studies have shown that DRS can produce accurate and precise estimates of SOC across landscapes, whether DRS can detect subtle management induced changes in SOC at a given site has not been resolved. Here, we leverage archived soil samples from seven long-term research trials in the U.S. to test this question using mid infrared (MIR) spectroscopy coupled with the USDA-NRCS Kellogg Soil Survey Laboratory MIR spectral library. Overall, MIR-based estimates of SOC%, with samples scanned on a secondary instrument, were excellent with the root mean square error ranging from 0.10 to 0.33% across the seven sites. In all but two instances, the same statistically significant (p < 0.10) management effect was found using both the lab-based SOC% and MIR estimated SOC% data. Despite some additional uncertainty, primarily in the form of bias, these results suggest that large existing MIR spectral libraries can be operationalized in other laboratories for successful carbon monitoring.

Download Full-text