Soil Carbon Investigation in Three Pedoclimatic and Agronomic Settings of Northern Italy

Sustainable agricultural management is needed to promote carbon (C) sequestration in soil, prevent loss of soil fertility, and reduce the release of greenhouse gases. However, the influence of agronomic practices on soil C sequestration depends on the existing pedoclimatic features. We characterized the soils of three farms far away each other in the Emilia-Romagna region (Northern Italy): an organic farm in the Northern Apennines, a biodynamic farm, and a conventional farm on the Po Plain. The total, inorganic, and organic carbon in soil, as well as the distinct humic fractions were investigated, analyzing both the elemental and isotopic (13C/12C) composition. In soils, organic matter appears to be variously affected by mineralization processes induced by microorganisms that consume organic carbon. In particular, organic carbon declined in farms located in the plain (e.g., organic carbon down to 0.75 wt%; carbon stock0-30 cm down to 33 Mg/ha), because of the warmer climate and moderately alkaline environment that enhance soil microbial activity. On the other hand, at the mountain farm, the minimum soil disturbance, the cold climate, and the neutral conditions favored soil C sequestration (organic carbon up to 4.42 wt%; carbon stock0-30 cm up to 160 Mg/ha) in humified organic compounds with long turnover, which can limit greenhouse gas emissions into the atmosphere. This work shows the need for thorough soil investigations, to propose tailored best-practices that can reconcile productivity and soil sustainability.

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Potential soil carbon sequestration of agricultural land around the world

10.5194/egusphere-egu21-3083 ◽

2021 ◽

Author(s):

Sylvia Vetter ◽

Michael Martin ◽

Pete Smith

Keyword(s):

Organic Carbon ◽

Management Practices ◽

Agricultural Land ◽

Ghg Emissions ◽

C Sequestration ◽

Organic Soils ◽

Soil C ◽

Sequestration Potential ◽

The World ◽

Soil C Sequestration

Reducing greenhouse gas (GHG) emissions in to the atmosphere to limit global warming is the big challenge of the coming decades. The focus lies on negative emission technologies to remove GHGs from the atmosphere from different sectors. Agriculture produces around a quarter of all the anthropogenic GHGs globally (including land use change and afforestation). Reducing these net emissions can be achieved through techniques that increase the soil organic carbon (SOC) stocks. These techniques include improved management practices in agriculture and grassland systems, which increase the organic carbon (C) input or reduce soil disturbances. The C sequestration potential differs among soils depending on climate, soil properties and management, with the highest potential for poor soils (SOC stock farthest from saturation).Modelling can be used to estimate the technical potential to sequester C of agricultural land under different mitigation practices for the next decades under different climate scenarios. The ECOSSE model was developed to simulate soil C dynamics and GHG emissions in mineral and organic soils. A spatial version of the model (GlobalECOSSE) was adapted to simulate agricultural soils around the world to calculate the SOC change under changing management and climate.Practices like different tillage management, crop rotations and residue incorporation showed regional differences and the importance of adapting mitigation practices under an increased changing climate. A fast adoption of practices that increase SOC has its own challenges, as the potential to sequester C is high until the soil reached a new C equilibrium. Therefore, the potential to use soil C sequestration to reduce overall GHG emissions is limited. The results showed a high potential to sequester C until 2050 but much lower rates in the second half of the century, highlighting the importance of using soil C sequestration in the coming decades to reach net zero by 2050.

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Modeling soil organic carbon dynamics and their driving factors in the main global cereal cropping systems

Atmospheric Chemistry and Physics ◽

10.5194/acp-17-11849-2017 ◽

2017 ◽

Vol 17 (19) ◽

pp. 11849-11859 ◽

Cited By ~ 7

Author(s):

Guocheng Wang ◽

Wen Zhang ◽

Wenjuan Sun ◽

Tingting Li ◽

Pengfei Han

Keyword(s):

Climate Change ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Crop Residue ◽

Retention Rate ◽

C Sequestration ◽

Soil C ◽

C Input ◽

Soil C Sequestration ◽

Residue Retention

Abstract. Changes in the soil organic carbon (SOC) stock are determined by the balance between the carbon input from organic materials and the output from the decomposition of soil C. The fate of SOC in cropland soils plays a significant role in both sustainable agricultural production and climate change mitigation. The spatiotemporal changes of soil organic carbon in croplands in response to different carbon (C) input management and environmental conditions across the main global cereal systems were studied using a modeling approach. We also identified the key variables that drive SOC changes at a high spatial resolution (0.1°  ×  0.1°) and over a long timescale (54 years from 1961 to 2014). A widely used soil C turnover model (RothC) and state-of-the-art databases of soil and climate variables were used in the present study. The model simulations suggested that, on a global average, the cropland SOC density increased at annual rates of 0.22, 0.45 and 0.69 Mg C ha−1 yr−1 under crop residue retention rates of 30, 60 and 90 %, respectively. Increasing the quantity of C input could enhance soil C sequestration or reduce the rate of soil C loss, depending largely on the local soil and climate conditions. Spatially, under a specific crop residue retention rate, relatively higher soil C sinks were found across the central parts of the USA, western Europe, and the northern regions of China. Relatively smaller soil C sinks occurred in the high-latitude regions of both the Northern and Southern hemispheres, and SOC decreased across the equatorial zones of Asia, Africa and America. We found that SOC change was significantly influenced by the crop residue retention rate (linearly positive) and the edaphic variable of initial SOC content (linearly negative). Temperature had weak negative effects, and precipitation had significantly negative impacts on SOC changes. The results can help guide carbon input management practices to effectively mitigate climate change through soil C sequestration in croplands on a global scale.

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Modeling soil organic carbon dynamics and its driving factors in global main cereal cropping systems

10.5194/acp-2017-430 ◽

2017 ◽

Author(s):

Guocheng Wang ◽

Wen Zhang ◽

Wenjuan Sun ◽

Tingting Li ◽

Pengfei Han

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Crop Residue ◽

Retention Rate ◽

C Sequestration ◽

The United States ◽

Soil C ◽

C Input ◽

Soil C Sequestration ◽

Residue Retention

Abstract. The net fluxes of carbon dioxide (CO2) between the atmosphere and agricultural systems are mainly characterized by the changes in soil carbon stock, which is determined by the balance between carbon input from organic materials and output through soil C decomposition. The spatiotemporal changes of cropland soil organic carbon (SOC) in response to different carbon (C) input management and environmental conditions across the global main cereal systems were studied using a modeling approach. We also identified the key variables driving SOC changes at a high spatial resolution (0.1° × 0.1°) and long time scale (54 years from 1961 to 2014). The widely used soil C turnover model (RothC) and the state-of-the-art databases of soil and climate were used in the present study. The model simulations suggested that, on a global average, the cropland SOC density increased at an annual rate of 0.22, 0.45 and 0.69 MgC ha−1 yr−1 under a crop residue retention rate of 30 %, 60 % and 90 %, respectively. Increased quantity of C input could enhance the soil C sequestration or reduce the soil C loss rate, depending largely on the local soil and climate conditions. Spatially, under a certain crop residue retention rate, a relatively higher soil C sink were generally found across the central parts of the United States, western Europe, northern regions of China, while a relatively smaller soil C sink generally occurred in regions at high latitudes of both northern and southern hemisphere, and SOC decreased across the equatorial zones of Asia, Africa and America. We found that SOC change was significantly influenced by the crop residue retention rate (linearly positive), and the edaphic variable of initial SOC content (linearly negative). Temperature had weakly negative effects, and precipitation had significantly negative impacts on SOC changes. The results can help target carbon input management for effectively mitigating climate change through cropland soil C sequestration on a global scale.

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High organic carbon input can accelerate global warming in rice paddy soil: increase unprotected soil organic carbon and CH4 emission

10.5194/egusphere-egu21-9438 ◽

2021 ◽

Author(s):

Hyeonji Song ◽

Snowie Galgo ◽

Ronley Canatoy ◽

Hogyeong Chae ◽

Pil Joo Kim

Keyword(s):

Global Warming ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Rice Paddy ◽

C Sequestration ◽

Soil C ◽

Saturation Degree ◽

Soil Saturation ◽

Soc Stock ◽

Soil C Sequestration

Soil C sequestration is widely regarded as the most reasonable way to mitigate global warming. Traditionally, a high amount of organic carbon (OC) input is strongly recommended to increase soil organic carbon (SOC) stocks in croplands. However, according to the whole-soil saturation theory, stable SOC (mineral-associated SOC) accumulation can be limited at a certain point, relying on silt and clay contents. Most studies based on the theory were conducted in aerobic soil condition. This relationship is still uncertain in a rice paddy that makes up 10.8% of total arable land and has an anaerobic soil environment. In this study, we investigated high OC addition can enhance soil C sequestration in a rice paddy. We added different OC levels (0.5, 2.0, 2.9, and 4.6 Mg C ha-1 yr-1) in rice paddy by incorporating cover crop biomass for nine years. SOC stock and soil saturation degree were determined. Unprotected, sand-associated, silt-associated, and clay-associated SOC were separated via density and size fractionation. Respired C losses (CO2-C and CH4-C) were monitored using the static closed chamber method. SOC stock did not linearly increase with higher amount of OC input. The carbon sequestration efficiency (i.e. the increase of SOC per unit of OC input) decreases with the amount OC added. Higher OM input significantly increased unprotected labile SOC content. Unprotected SOC (<1.85 g cm-3) exponentially increased as the SOC saturation degree was higher. On the other hand, stable SOC content did not exhibit a linear relationship with the SOC saturation degree. The higher OC addition level exponentially increased respired C loss. In particular, C loss via CH4 was more sensitive to high OC addition. We conclude that higher OC addition in rice paddy without consideration in terms of SOC stock saturation point can accelerate global warming by increasing labile SOC accumulation and CH4 emission.

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Impact of pasture establishment on CO2 emissions from a Vertisol: Consequences for soil C sequestration (Martinique, West Indies)

Canadian Journal of Soil Science ◽

10.4141/s05-022 ◽

2006 ◽

Vol 86 (5) ◽

pp. 779-782 ◽

Cited By ~ 3

Author(s):

T. Chevallier ◽

E. Blanchart ◽

A. Albrecht ◽

C. Feller ◽

M. Bernoux

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

West Indies ◽

C Sequestration ◽

Soil C ◽

C Storage ◽

Digitaria Decumbens ◽

Market Gardening ◽

Soil C Sequestration ◽

Soc Mineralization

Establishing pasture on cultivated tropical Vertisols can increase soil organic carbon (SOC), but it is not known whether this increase results solely from enhanced inputs or also from suppressed mineralization. We measured CO2 emissions from a Vertisol under market gardening, and under “young” and “old” Digitaria decumbens pastures. Emissions of CO2-C increased in pastures, compared to market gardening, but relative SOC mineralization (CO2-C/SOC) decreased, implying the protection of SOC against mineralization with pasture establishment. Key words: Tropical pasture, carbon fluxes, soil organic carbon, physical protection, C storage

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Soil C sequestration and CO2 fluxes under maize-based conservation agriculture systems in the Eastern Cape, South Africa

South African Journal of Plant and Soil ◽

10.1080/02571862.2020.1836274 ◽

2021 ◽

pp. 1-8

Author(s):

Lindah Muzangwa ◽

Pearson Nyari Stephano Mnkeni ◽

Cornelius Chiduza

Keyword(s):

South Africa ◽

Conservation Agriculture ◽

C Sequestration ◽

Co2 Fluxes ◽

Eastern Cape ◽

Soil C ◽

Agriculture Systems ◽

Soil C Sequestration

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Higher stand densities can promote soil carbon storage after conversion of temperate mixed natural forests to larch plantations

European Journal of Forest Research ◽

10.1007/s10342-020-01346-9 ◽

2020 ◽

Author(s):

Meng Na ◽

Xiaoyang Sun ◽

Yandong Zhang ◽

Zhihu Sun ◽

Johannes Rousk

Keyword(s):

Forest Management ◽

Soil Carbon ◽

Stand Density ◽

C Sequestration ◽

Tree Density ◽

Natural Forests ◽

Soil C ◽

C Storage ◽

Soil C Storage ◽

Soil C Sequestration

AbstractSoil carbon (C) reservoirs held in forests play a significant role in the global C cycle. However, harvesting natural forests tend to lead to soil C loss, which can be countered by the establishment of plantations after clear cutting. Therefore, there is a need to determine how forest management can affect soil C sequestration. The management of stand density could provide an effective tool to control soil C sequestration, yet how stand density influences soil C remains an open question. To address this question, we investigated soil C storage in 8-year pure hybrid larch (Larix spp.) plantations with three densities (2000 trees ha−1, 3300 trees ha−1 and 4400 trees ha−1), established following the harvesting of secondary mixed natural forest. We found that soil C storage increased with higher tree density, which mainly correlated with increases of dissolved organic C as well as litter and root C input. In addition, soil respiration decreased with higher tree density during the most productive periods of warm and moist conditions. The reduced SOM decomposition suggested by lowered respiration was also corroborated with reduced levels of plant litter decomposition. The stimulated inputs and reduced exports of C from the forest floor resulted in a 40% higher soil C stock in high- compared to low-density forests within 8 years after plantation, providing effective advice for forest management to promote soil C sequestration in ecosystems.

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