scholarly journals Earthworms act as biochemical reactors to convert labile plant compounds into stabilized soil microbial necromass

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Gerrit Angst ◽  
Carsten W. Mueller ◽  
Isabel Prater ◽  
Šárka Angst ◽  
Jan Frouz ◽  
...  
Keyword(s):  
Organic Matter ◽  
Carbon Sequestration ◽  
Soil Carbon ◽  
Conclusive Evidence ◽  
Total Carbon ◽  
Total Carbon Content ◽  
Soil Microbial ◽  
Biochemical Reactors ◽  
Stabilized Soil ◽  
Plant Compounds

AbstractEarthworms co-determine whether soil, as the largest terrestrial carbon reservoir, acts as source or sink for photosynthetically fixed CO2. However, conclusive evidence for their role in stabilising or destabilising soil carbon has not been fully established. Here, we demonstrate that earthworms function like biochemical reactors by converting labile plant compounds into microbial necromass in stabilised carbon pools without altering bulk measures, such as the total carbon content. We show that much of this microbial carbon is not associated with mineral surfaces and emphasise the functional importance of particulate organic matter for long-term carbon sequestration. Our findings suggest that while earthworms do not necessarily affect soil organic carbon stocks, they do increase the resilience of soil carbon to natural and anthropogenic disturbances. Our results have implications for climate change mitigation and challenge the assumption that mineral-associated organic matter is the only relevant pool for soil carbon sequestration.

The impact of porosity on organic matter cycling in a two-dimensional porous medium 

2021 ◽  
Author(s):  
Hanbang Zou ◽  
Pelle Ohlsson ◽  
Edith Hammer
Keyword(s):  
Porous Medium ◽  
Organic Matter ◽  
Carbon Sequestration ◽  
Soil Carbon ◽  
Pore Network ◽  
Pore Scale ◽  
Decomposition Of Organic Matter ◽  
Organic Matter Cycling ◽  
The Impact

<p>Carbon sequestration has been a popular research topic in recent years as the rapid elevation of carbon emission has significantly impacted our climate. Apart from carbon capture and storage in e.g. oil reservoirs, soil carbon sequestration offers a long term and safe solution for the environment and human beings. The net soil carbon budget is determined by the balance between terrestrial ecosystem sink and sources of respiration to atmospheric carbon dioxide. Carbon can be long term stored as organic matters in the soil whereas it can be released from the decomposition of organic matter. The complex pore networks in the soil are believed to be able to "protect" microbial-derived organic matter from decomposition. Therefore, it is important to understand how soil structure impacts organic matter cycling at the pore scale. However, there are limited experimental studies on understanding the mechanism of physical stabilization of organic matter. Hence, my project plan is to create a heterogeneous microfluidic porous microenvironment to mimic the complex soil pore network which allows us to investigate the ability of organisms to access spaces starting from an initial ecophysiological precondition to changes of spatial accessibility mediated by interactions with the microbial community.</p><p>Microfluidics is a powerful tool that enables studies of fundamental physics, rapid measurements and real-time visualisation in a complex spatial microstructure that can be designed and controlled. Many complex processes can now be visualized enabled by the development of microfluidics and photolithography, such as microbial dynamics in pore-scale soil systems and pore network modification mimicking different soil environments – earlier considered impossible to achieve experimentally. The microfluidic channel used in this project contains a random distribution of cylindrical pillars of different sizes so as to mimic the variations found in real soil. The randomness in the design creates various spatial availability for microbes (preferential flow paths with dead-end or continuous flow) as an invasion of liquids proceeds into the pore with the lowest capillary entry pressure. In order to study the impact of different porosity in isolation of varying heterogeneity of the porous medium, different pore size chips that use the same randomly generated pore network is created. Those chips have the same location of the pillars, but the relative size of each pillar is scaled. The experiments will be carried out using sterile cultures of fluorescent bacteria, fungi and protists, synthetic communities of combinations of these, or a whole soil community inoculum. We will quantify the consumption of organic matter from the different areas via fluorescent substrates, and the bio-/necromass produced. We hypothesise that lower porosity will reduce the net decomposition of organic matter as the narrower pore throat limits the access, and that net decomposition rate at the main preferential path will be higher than inside branches</p>

scholarly journals Soil Carbon Sequestration Due to Salt-Affected Soil Amelioration with Coal Bio-Briquette Ash: A Case Study in Northeast China

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1019
Author(s):  
Yuji Sakai ◽  
Masataka Nakamura ◽  
Chang Wang
Keyword(s):  
Carbon Sequestration ◽  
Carbon Content ◽  
Soil Carbon ◽  
Calcium Hydroxide ◽  
Northeast China ◽  
Control Plot ◽  
Total Carbon ◽  
Pig Manure ◽  
Soil Amelioration ◽  
Salt Affected Soil

Increasing soil carbon storage and biomass utilization is an effective process for mitigating global warming. Coal bio-briquettes (CBB) are made using two low-ranked coals with high sulfur content, corn stalks, and calcium hydroxide, and the combustion ash can ameliorate the physicochemical properties in salt-affected soil. CBB ash contains mainly calcium compounds, such as calcium sulfate, calcium hydroxide, and calcium carbonate, and coal fly ash and biomass ash. In this paper, changes in soil carbon and nitrogen content through salt-affected soil amelioration during 5 months using two CBB ashes and pig manure were examined in Northeast China. Application rates of CBB ash were 0 tha−1 (control), 11.6 tha−1, 23.2 tha−1, 46.4 tha−1, and 69.6 tha−1. Consequently, total carbon content in topsoil (0–0.15 m) after harvest of maize in all test fields indicated a range between 27.7 tCha−1 and 50.2 tCha−1, and showed increased levels compared to untreated salt-affected soil. In a 3.0% (69.6 tha−1) application plot of only CBB ash with higher carbon and higher exchangeable Ca2+, the carbon content increased by 51.5% compared to control plot, and changes in carbon sequestration compared to untreated soil was roughly twice that of the control plot. CBB ash contributed to carbon application and pig manure supply as a form of N fertilization in the case of all test plots. Changes in carbon content due to soil amelioration have a significant relationship with changes in corn production and soil chemical properties, such as pH, Na+, Cl−, sodium adsorption ratio (SAR), and exchangeable sodium percentage (ESP). Therefore, CBB production from low-ranked coal and waste biomass, and the use of CBB ash in agriculture is advocated as an effective means for sequestering carbon.

scholarly journals Soil Microbial Community Structure and Physicochemical Properties in Amomum tsaoko-based Agroforestry Systems in the Gaoligong Mountains, Southwest China

2019 ◽  
Vol 11 (2) ◽  
pp. 546 ◽  
Author(s):  
Guizhou Liu ◽  
Man Jin ◽  
Chuantao Cai ◽  
Chaonan Ma ◽  
Zhongsuzhi Chen ◽  
...  
Keyword(s):  
Organic Matter ◽  
Microbial Biomass ◽  
Physicochemical Properties ◽  
Phospholipid Fatty Acid ◽  
Soil Microbial Communities ◽  
Total Carbon ◽  
Native Forest ◽  
Soil Microbial Community Structure ◽  
Soil Microbial ◽  
The Impact

Amomum tsaoko is cultivated in forests of tropical and subtropical regions of China, and the planting area is expanding gradually. However, little attention has been paid to the impact of A. tsaoko cultivation on the soil characteristics of the regions. We analyzed the effects of the A. tsaoko-forest agroforestry system (AFs) on the composition of soil microbial communities with increasing stand ages. We also compared the soil physicochemical properties, microbial biomass, and phospholipid fatty acid (PLFA) composition between native forest (NF) and AFs. The results showed that the level of total carbon, nitrogen, and organic matter dramatically dropped in AFs with increasing stand ages. pH affected other soil properties and showed close correlation to total carbon (P = 0.0057), total nitrogen (P = 0.0146), organic matter (P = 0.0075), hydrolyzable nitrogen (P = 0.0085), available phosphorus (P < 0.0001), and available potassium (P = 0.0031). PLFAs of bacteria (F = 4.650, P = 0.037), gram-positive bacteria (F = 6.640, P = 0.015), anaerobe (F = 5.672, P = 0.022), and total PLFA (F = 4.349, P = 0.043) were significantly affected by different treatments, with the greatest value for NF treatment, and least value for AF5. However, the microbial biomass declined during the initial 5 years of cultivation, but it reached the previous level after more than 10 years of cultivation. Our research suggests that AFs is a profitable land-use practice in the Gaoligong Mountains and that AFs showed a recovering trend of the soil nutrient condition with increasing stand ages. However, the severe loss of nitrogen in the soil of AFs requires additional nitrogen during cultivation to restore it to pre-cultivation levels.

scholarly journals Modern Landfills as Potential Feed Back Processes to Counteract Global Warming

2017 ◽  
pp. 780-787
Author(s):  
Torleif Bramryd ◽  
Michael Johansson
Keyword(s):  
Carbon Dioxide ◽  
Organic Matter ◽  
Organic Carbon ◽  
Carbon Dioxide Emissions ◽  
Landfill Gas ◽  
Mineral Soil ◽  
Motor Fuel ◽  
Total Carbon ◽  
Water Evaporation ◽  
Total Carbon Content

Provided that produced biogas is effectively collected, landfills are important sinks for organic carbon compensating for emissions of CO2 from burning of fossil fuels. Sequestrating of long-lived organic carbon in the landfill itself is the most pronounced factor, but also other processes during landfill management will increase the capture and binding of CO2.. Compost produced in connection to the landfills and applied as soil improvement, is another important sink for organic carbon.The landfills in the World have been estimated to accumulate around 100 x 106 metric tons of C. Normally about 25-40 percent of the total carbon content in the waste can be converted into biogas in traditional landfills. During landfilling most of the organic carbon in fossil derived products, like plastics, synthetic rubber, textiles and other synthetic materials, As these products take part in the methane gas production, the landfill gas (biogas) can be regarded as a true biofuel. In contrast to incineration, high moisture content in the waste will not decrease the yield of energy per ton of waste. In a reactor landfill treating approximately 100 000 tons of waste per year, a longlived organic fraction corresponding to about 45 000 metric tons of carbon dioxide is longterm accumulated each year. This compensates for the annual carbon dioxide emissions from about 15 000 – 20 000 cars, provided that each one runs 15 000 km per year with fossil fuel. The technique for effective collection of landfill gas, and new techniques to upgrade and liquefy the biogas, have decreased the risk for emissions to the atmosphere. Modern bioreactor landfills have been estimated to have less than 10% diffuse biogas emissions to the atmosphere. Also in Sweden (Helsingborg), plants are built to convert landfill gas to upgraded, liquefied motor fuel. This will lead to strongly reduced diffuse emissions of landfill gas to the atmosphere. The utilization of leachates as forest fertilizer results in an improved biomass production and increased accumulation of soil organic matter. Increased tree and field layer productivity also means that the potential for water evaporation (eg. evapotranspiration) increase, reducing the costs for waste-water treatment or the risk for diffuse ground water pollution. Also in the mineral soil, increased long-lived fractions of humus normally are found. This should be added to the carbon accumulating effect of the landfill itself, where long-lived organic matter, mainly derived from lignin and from fossil fractions as plastics and synthetic textiles is long-term accumulated. In this respect the landfill system has similar effects compared to natural peatlands and lake and sea sediments, Ifproduced biogas is collected effectively, the landfill thus can be an important factor to counteract the “green-house effect” and climate change.

scholarly journals Geomorphological controls over carbon distribution in permafrost soils: the case of the Narsajuaq river valley, Nunavik (Canada)

2020 ◽  
Vol 6 (4) ◽  
pp. 509-528
Author(s):  
Samuel Gagnon ◽  
Michel Allard
Keyword(s):  
Carbon Content ◽  
Soil Carbon ◽  
Weighted Average ◽  
Field Measurements ◽  
River Valley ◽  
Total Carbon ◽  
Total Carbon Content ◽  
Geomorphological Mapping ◽  
Soil Carbon Content ◽  
Spatial Coverage

Soils in the northern circumpolar region play a central role in the global carbon cycle because the release of carbon through permafrost thaw and geomorphological disturbances can potentially cause a feedback on climate. However, large uncertainties in estimates of permafrost carbon stocks remain, mainly because of wide gaps in the spatial coverage of soil carbon sampling sites and the large mapping polygons used to upscale data. By combining mapping of landforms and knowledge of surficial geology to upscale soil carbon content measurements, we provide an assessment of soil total carbon content in the region of the Narsajuaq river valley (Nunavik, Canada) to generate the first high-resolution soil carbon estimate confirmed by field measurements in Nunavik. We estimate that the Narsajuaq river valley and the surrounding uplands have a weighted average of 3.4 kg C m−2 (0–100 cm), with 73% of the total carbon content stored in the top 30 cm. The results also indicate that the valley is a carbon hotspot in the region, containing 76% of the total carbon content (0–100 cm) of the study area. Although soil carbon estimates will always require field sampling, the geomorphological mapping approach can significantly improve carbon content estimates and provide better inputs for models.

scholarly journals Carbon sequestration potential of Alnus nepalensis in the mid hill of Nepal: A case study from Kaski district

1970 ◽  
Vol 18 (2) ◽  
pp. 3-9 ◽  
Author(s):  
S Ranabhat ◽  
KD Awasthi ◽  
R Malla
Keyword(s):  
Carbon Sequestration ◽  
Carbon Content ◽  
Soil Carbon ◽  
Total Carbon ◽  
Total Biomass ◽  
Carbon Sequestration Potential ◽  
Alnus Nepalensis ◽  
Sequestration Potential ◽  
Shallow Soils ◽  
Different Parts

This study was carried out to analyze the carbon content in different parts of Alnus nepalensis, and to assess the effect of aspect and altitude in the carbon storage in Alnus nepalensis as well as to quantify the total carbon sequestration (stock) in Alnus nepalensis forest in the mid-hills of Kaski District. The inventory for estimating above and below ground biomass of forest was carried out using stratified random sampling technique. The carbon content in different parts of Alnus nepalensis was quantified using combustion method in the laboratory. For determining the soil carbon content, six soil profiles from each aspect were excavated and soil samples were taken from soil profile up to 1 m depth for deep soil and up to bedrock for shallow soils at the interval of 20 cm. Mean carbon content in stem, branches, leaves and bark of Alnus nepalensis were found to be 40.52%, 33%, 9.56% and 16.4%, respectively. Total biomass carbon sequestered in northern aspect was 30.20 t/ha while for southern aspect it was 39.00 t/ha. In both the aspects higher carbon sequestration was observed at an elevation range of 1200-1300m i.e. 34.8 t/ha and 45.6 t/ha in northern and southern aspects, respectively. Soil carbon sequestration in northern and southern aspects was found to be 113.4 t/ha and 169.30 t/ ha, respectively. The total carbon sequestration potential of Alnus nepalensis forest was estimated to be 186.05 t/ha. Key words: Alnus nepalensis, altitude, aspect, carbon sequestration, mid hills   doi: 10.3126/banko.v18i2.2167 Banko Janakari, Vol. 18, No. 2, 3-9

Land-use change and climate change mitigation potential of agricultural soils in Finland

2020 ◽  
Author(s):  
Boris Tupek ◽  
Aleksi Lehtonen ◽  
Raisa Mäkipää ◽  
Pirjo Peltonen-Sainio ◽  
Saija Huuskonen ◽  
...  
Keyword(s):  
Land Use ◽  
Carbon Sequestration ◽  
Land Use Change ◽  
Soil Carbon ◽  
Carbon Balance ◽  
Carbon Stock ◽  
Total Carbon ◽  
Litter Input ◽  
Spruce Stands ◽  
Woody Litter

&lt;p&gt;We aimed to estimate a nation-wide potential to improve the carbon balance of the land use sector by removing part of the current croplands on mineral soil from food and feed production to extensive grasslands or afforestation in Finland. &amp;#160;We combined the existing data on forest and agricultural production, and climate with predictive capacity of YASSO07 soil carbon model to estimate changes of soil carbon stock (SOC) in Finland over the past land use change (LUC) from forest to agriculture in comparison with alternative LUC or continuous agriculture in future.&lt;/p&gt;&lt;p&gt;The model analysis revealed that SOC loss after deforestation during the cultivation period originated mainly from the absence of woody litter input. The non-woody litter input of the forest was comparable to that of the agricultural residues thus the SOC originating from non-woody litter has not changed much during cultivation. The model estimated approximately a 30 year delay in positive soil carbon balance after the afforestation. Longer for Norway spruce than for the Pubescent birch. The comparison of two dominant tree species used for afforestation highlighted a difference in soil versus biomass carbon sequestration. The total forest biomass production and total carbon stock was larger for spruce stands than for birch stands. However, due to larger foliar and fineroot litter input birch stands sequestered more carbon into the soil than spruce stands. The analysis further revealed that extensification of cropland to grassland would not meet 4 per mill soil carbon sequestration criterion needed for achieving Paris climate CO2 reduction target and due to the spatial limitation of afforestation other management measures need to be considered e.g. adding biochar to soils for successful and more permanent CO2 offsetting.&lt;/p&gt;

scholarly journals Carbon Sequestration in Broad Leaved Forests of Mid-Hills of Nepal: A Case Study from Palpa District

1970 ◽  
Vol 3 ◽  
pp. 20-29
Author(s):  
Bishnu P Shrestha
Keyword(s):  
Carbon Sequestration ◽  
Soil Carbon ◽  
Forest Biomass ◽  
Total Carbon ◽  
Total Biomass ◽  
Biomass Carbon ◽  
Deep Soil ◽  
Below Ground ◽  
Shallow Soils

This study was carried out to quantify total carbon sequestration in two broad leaved forests (Shorea and Schima-Castanopsis forests) of Palpa district. The inventory for estimating above and below ground biomass of forest was carried out using stratified random sampling. Biomass was calculated using allometric models. Soil samples were taken from soil profile upto 1 m depth for deep soil and up to bed rock for shallow soils at the interval of 20 cm. Walkey and Black method were applied for measuring soil organic carbon. Total biomass carbon in Shorea and Schima-Castanopsis forest was found 101.66 and 44.43 t ha-1 respectively. Soil carbon sequestration in Schima-Castanopsis and Shorea forest was found 130.76 and 126.07 t ha-1 respectively. Total carbon sequestration in Shorea forest was found 1.29 times higher than Schima-Castanopsis forest. The study found that forest types play an important role on total carbon sequestration. Key Words: Carbon sequestration, Shorea forest, Schima-Castanopsis forest, Biomass carbon, Soil carbon DOI: 10.3126/init.v3i0.2424 The Initiation Vol.3 2009 p.20-29

scholarly journals Stability and biodegradability of organic matter from Arctic soils of Western Siberia: insights from <sup>13</sup>C-NMR spectroscopy and elemental analysis

Solid Earth ◽  
2016 ◽  
Vol 7 (1) ◽  
pp. 153-165 ◽  
Author(s):  
E. Ejarque ◽  
E. Abakumov
Keyword(s):  
Organic Matter ◽  
Nmr Spectroscopy ◽  
Climate Warming ◽  
Western Siberia ◽  
Total Carbon ◽  
The Arctic ◽  
Total Carbon Content ◽  
Ambient Temperatures ◽  
Arctic Soils ◽  
Spatial Coverage

Abstract. Arctic soils contain large amounts of organic matter which, globally, exceed the amount of carbon stored in vegetation biomass and in the atmosphere. Recent studies emphasise the potential sensitivity for this soil organic matter (SOM) to be mineralised when faced with increasing ambient temperatures. In order to better refine the predictions about the response of SOM to climate warming, there is a need to increase the spatial coverage of empirical data on SOM quantity and quality in the Arctic area. This study provides, for the first time, a characterisation of SOM from the Gydan Peninsula in the Yamal Region, Western Siberia, Russia. On the one hand, soil humic acids and their humification state were characterised by measuring the elemental composition and diversity of functional groups using solid-state 13C-nuclear magnetic resonance (NMR) spectroscopy. Also, the total mineralisable carbon was measured. Our results indicate that there is a predominance of aliphatic carbon structures, with a minimal variation of their functional-group composition both regionally and within soil depth. This vertical homogeneity and low level of aromaticity reflects the accumulation in soil of lowly decomposed organic matter due to cold temperatures. Mineralisation rates were found to be independent of SOM quality, and to be mainly explained solely by the total carbon content. Overall, our results provide further evidence on the sensitivity that the soils of Western Siberia may have to increasing ambient temperatures and highlight the important role that this region can play in the global carbon balance under the effects of climate warming.

Sign in / Sign up

Export Citation Format

Share Document