scholarly journals Thresholds in aridity and soil carbon-to-nitrogen ratio govern the accumulation of soil microbial residues

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Zhiguo Hao ◽  
Yunfei Zhao ◽  
Xia Wang ◽  
Jinhong Wu ◽  
Silong Jiang ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Carbon ◽  
Aridity Index ◽  
Carbon Accumulation ◽  
Humid Climate ◽  
Carbon To Nitrogen Ratio ◽  
Fungal Abundance ◽  
Nitrogen Ratio ◽  
Microbial Residues

AbstractMicrobial moribunds after microbial biomass turnover (microbial residues) contribute to the formation and stabilization of soil carbon pools; however, the factors influencing their accumulation on a global scale remain unclear. Here, we synthesized data for 268 amino sugar concentrations (biomarkers of microbial residues) in grassland and forest ecosystems for meta-analysis. We found that soil organic carbon, soil carbon-to-nitrogen ratio, and aridity index were key factors that predicted microbial residual carbon accumulation. Threshold aridity index and soil carbon-to-nitrogen ratios were identified (~0.768 and ~9.583, respectively), above which microbial residues decreased sharply. The aridity index threshold was associated with the humid climate range. We suggest that the soil carbon-to-nitrogen ratio threshold may coincide with a sharp decrease in fungal abundance. Although dominant factors vary between ecosystem and climate zone, with soil organic carbon and aridity index being important throughout, our findings suggest that climate and soil environment may govern microbial residue accumulation.

scholarly journals Carbon Accumulation in Arable Soils: Mechanisms and the Effect of Cultivation Practices and Organic Fertilizers

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1079
Author(s):  
Jörg Gerke
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Carbon ◽  
Humic Substances ◽  
Saturation Index ◽  
Farmyard Manure ◽  
Carbon Accumulation ◽  
Organic Fertilizers ◽  
Organic Carbon Content ◽  
Arable Soils

The organic carbon content of soils is a key parameter of soil fertility. Moreover, carbon accumulation in soils may mitigate the increase in atmospheric CO2 concentration. The principles of carbon accumulation in arable soils are well known. The inclusion of clover/alfalfa/grass within the rotation is a central instrument to increase soil organic carbon. In addition, the regular application of rotted or composted farmyard manure within the rotation can increase soil organic carbon contents much more than the separate application of straw and cattle slurry. Humic substances, as a main stable part of soil organic carbon, play a central role in the accumulation of soil carbon. A major effect of compost application on soil carbon may be the introduction of stable humic substances which may bind and stabilize labile organic carbon compounds such as amino acids, peptides, or sugars. From this point of view, a definite soil carbon saturation index may be misleading. Besides stable composts, commercially available humic substances such as Leonardite may increase soil organic carbon contents by stabilization of labile C sources in soil.

scholarly journals Long-term Fertilization Enhances Soil Carbon Stability by Increase the Ratio of Passive Carbon: Evidence From Four Typical Croplands

2021 ◽  
Author(s):  
Wei Zhou ◽  
Shilin Wen ◽  
Yunlong Zhang ◽  
Andrew S. Gregory ◽  
Minggang Xu ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Carbon ◽  
Active Carbon ◽  
Large Scale ◽  
Carbon Accumulation ◽  
Response Ratio ◽  
Soil Carbon Accumulation ◽  
The Stability

Abstract Aims Soil organic carbon (SOC) plays an important role in improving soil quality, however how long-term fertilization influences SOC and contrasting active carbon (AC) and passive C (PC) pools at large scale remains unclear. The aim of this study was to examine the effect of long-term fertilization on SOC, including AC and PC, across four typical croplands in China and to explore the potential relationships and mechanism. Methods We assessed the effect of different fertilization (standard and 1.5 × standard of inorganic fertilizer (NPK) with or without manure (M), with a control for comparison) at soil depths (0-20 cm, 20-40 cm, 40-60 cm) on SOC, AC and PC. Results We found that SOC, AC and PC increased in the order Control < NPK < NPKM < 1.5NPKM. 1.5NPKM resulted in a significant increase in SOC, AC and PC, of 76.3%, 53.0% and 108.5% respectively across the soil profile (0-60 cm) compared with Control. The response ratio of PC to long-term fertilization was 2.1 times greater than that of AC across four sites on average. In addition, Clay was identified as the most important factor in explaining the response of AC and PC to different fertilization application, respectively. Conclusions Long-term fertilization enhanced both AC and PC, but the greater response of PC suggests that fertilization application could enhance the stability of carbon and thus the potential of cropland for soil carbon accumulation.

scholarly journals Threshold conditions for the accumulation of microbial residues in terrestrial ecosystems

2021 ◽  
Author(s):  
Zhiguo Hao ◽  
Yunfei Zhao ◽  
Xia Wang ◽  
Silong Jiang ◽  
Jinjin Xiao ◽  
...  
Keyword(s):  
Large Scale ◽  
C:N Ratio ◽  
Aridity Index ◽  
Sharp Decrease ◽  
Terrestrial Ecosystems ◽  
Humid Climate ◽  
Climate Type ◽  
Fungal Abundance ◽  
Microbial Residue ◽  
Microbial Residues

Abstract Microbial residues play important roles in the formation and stability of soil carbon pools; however, the factors affecting large-scale accumulation of microbial residues remain unclear. Here, we collected data of 268 amino sugar levels (biomarkers of microbial residues) from previous field studies and found that soil organic carbon (SOC), soil C:N ratio, and aridity index mainly determine the accumulation of microbial residual carbon. Moreover, we found that the threshold of the aridity index where microbial residue starts decreasing is in the range of humid climate type, while the threshold of soil C:N ratio represents a point of sharp decrease in fungal abundance. Although SOC and aridity index were important in all cases, the dominant factors for predicting microbial residues varied across different ecosystems and climate zones, with pH being particularly important. Hence, climate and soil environment play important roles in the process of microbial residue accumulation.

scholarly journals 317 Cattle and carbon on pastures – hearsay or evidence?

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 52-52
Author(s):  
Alan J Franzluebbers
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Carbon ◽  
Weather Conditions ◽  
Relevant Information ◽  
Carbon Accumulation ◽  
Ongoing Research ◽  
Southeastern Us ◽  
Soil Carbon Accumulation ◽  
Type Of Management

Abstract Does soil organic carbon accumulate in high density stocking of pastures? Should the detail of grazing management matter in answering this question? Would wishing that soil carbon increase with a particular type of management mean that it would actually increase? Does a practice that stores soil carbon in one region mean that it will store soil carbon in another region? How would we know the answer to any of these questions if we didn’t collect some relevant information? Soil carbon accumulation might be viewed as limited in potential in the southeastern US with the combination of highly weathered soils and favorable weather conditions for decomposition of organic matter inputs. However, these same environmental conditions could also be viewed as ideal for promoting soil carbon accumulation from a highly degraded state. In fact, there are plenty of soils in the region that have undergone severe degradation from decades of historical degradation. This presentation will explore some approaches taken to answer the question of whether soil carbon can be sequestered in managed pastures of the southeastern US. It will also probe into the question of type of management and its role in potential soil organic carbon sequestration. A combination of published and ongoing research will form the basis of this presentation.

scholarly journals Evaluation of Properties and Elements in the Surface of Acidic Soil in the Central Region of Thailand

2021 ◽  
Vol 44 (3) ◽  
Author(s):  
Patarapong Kroeksakul ◽  
Arin Ngamniyom ◽  
Kun Silprasit ◽  
Sakawjai Tepamongkol ◽  
Punnada Teerapanaprinya ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Ph ◽  
Soil Acidity ◽  
Acidic Soil ◽  
Carbon To Nitrogen Ratio ◽  
Nitrogen Ratio ◽  
Central Thailand

The study aimed to evaluate and correlate acidic soil components to understand the phenomena of this type of soil. The soil samples were collected from 64 locations in 3 provinces of central Thailand and were tested for soil pH, element content, soil organic matter (SOM), and soil organic carbon (SOC). The results show that soil acidity in central Thailand has an average pH of 4.71 ± 0.87. The soil acidity level ranges from very strongly acidic in Phatum Thani and Nakhon Nayok provinces to strongly acidic in Chachoengsao province. Soil bulk density is about 0.34 g/cm3, and the correlation of soil pH to lead (Pb), nickel (Ni), nitrogen (N), carbon-to-nitrogen ratio (C/N ratio), and zinc (Zn) is as follows: principle component 1 (PC1) is carbon-to-nitrogen ratio > pH > zinc (C/N ratio > pH > Zn), and principle component 2 (PC2) is soil organic carbon > bulk density > soil organic matter (SOC > BD > SOM). Soil pH, SOM, and SOC are in similar groups. The soil abundance at the study site was compared with the ideal soil for plants, and heavy metal contamination in the acidic soil of the central region did not exceed the standard limit. The study found a correlation between SOM and SOM (r = 0.715; p < 0.01), indicating soil quality and microbial activity.

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

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.

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