scholarly journals Microspectroscopic visualization of how biochar elevates the soil organic carbon ceiling

2021 ◽  
Author(s):  
Zhe (Han) Weng ◽  
Lukas Van Zwieten ◽  
Michael Rose ◽  
Bhupinder Pal Singh ◽  
Ehsan Tavakkoli ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Molecular Diversity ◽  
Three Dimensional ◽  
Specific Enzyme ◽  
Eucalyptus Saligna ◽  
Soil C ◽  
Decadal Scale ◽  
Use Efficiency ◽  
Microbial C

Abstract The soil carbon saturation concept suggests an upper limit to store soil organic carbon (SOC), set by the mechanisms that protect soil organic matter from decomposition. Biochar has the capacity to protect new C including rhizodeposits and microbial necromass. However, the decadal scale mechanisms by which biochar influences the molecular diversity, spatial heterogeneity, and temporal changes of SOC persistence remain unresolved. Here we show that the soil C saturation ceiling of a Ferralsol under subtropical pasture could be elevated by 2 Mg (new) C ha-1 by the application of Eucalyptus saligna biochar 8.2 years after the first application. Using one, two-, and three-dimensional analyses, significant increases were observed in the spatial distribution of root-derived 13C in microaggregates (53-250 µm, 11 %) and new C protected in mineral fractions (<53 µm, 5 %). Microbial C-use efficiency was concomitantly improved by lowering specific enzyme activities, contributing to the decreased mineralization of native SOC by 18 %. We provide evidence that the global SOC ceiling can be elevated using biochar in Ferralsols by 0.01-0.1 Pg new C yr-1.

scholarly journals Soil Organic Carbon Stocks in Terrestrial Ecosystems of China: Revised Estimation on Three-Dimensional Surfaces

2016 ◽  
Vol 8 (10) ◽  
pp. 1003 ◽  
Author(s):  
Rui Zhou ◽  
Xianzhang Pan ◽  
Hongxu Wei ◽  
Xianli Xie ◽  
Changkun Wang ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Three Dimensional ◽  
Terrestrial Ecosystems ◽  
Carbon Stocks ◽  
Soil Organic Carbon Stocks

scholarly journals Organic matter mineralisation in contrasting agricultural soils amended with sewage sludge .

2014 ◽  
Vol 4 ◽  
Author(s):  
Jose Navarro Pedreño ◽  
Ignacio Gómez Lucas ◽  
Jose Martín Soriano Disla
Keyword(s):  
Organic Matter ◽  
Single Dose ◽  
Sewage Sludge ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Agricultural Soils ◽  
Dry Weight ◽  
Soil C ◽  
Multiple Sensor ◽  
Sludge Application

The mineralisation of organic matter (OM) when sewage sludge was used as amendment in 70 contrasting agricultural soils from Spain was analysed. Soils received a single dose of sewage sludge (equivalent to 50t dry weight ha<sup>-1</sup>) and the O<sub>2</sub> consumption was continuously monitored for 30 days using a multiple sensor respirometer in a laboratory experiment. The cumulative O<sub>2</sub> consumption and rates after 8 and 30 days of incubation (O<sub>2 cum</sub> 8d, 30d and O<sub>2 rate</sub> 8d, 30d), the respiratory quotient (RQ), the maximum O<sub>2</sub> rates over the incubation period (O<sub>2 max</sub>) and time from the beginning of the incubation when O<sub>2 max</sub> occurred (T<sub>max</sub>), were determined in both amended and non-amended soils. Sewage sludge application resulted in increased values for O<sub>2 max</sub>, O<sub>2 rate</sub> 8d, and O<sub>2 cum</sub> 30d. Differences were minor for T<sub>max</sub>, RQ 8d and O<sub>2 rate</sub> 30d. A considerable amount of the initial OM applied was mineralised during the first 8 days. Organic matter decomposition (as expressed by O<sub>2 cum</sub> 30d) was favoured in soils with high values of pH, carbonates, soil organic carbon and low values of amorphous Mn. Soils with these characteristics may potentially lose soil C after sewage sludge application.

scholarly journals Coupled changes in soil organic carbon fractions and microbial community composition in urban and suburban forests

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Xueying Zhang ◽  
Xiaomei Chen ◽  
Muying Liu ◽  
Zhanying Xu ◽  
Hui Wei
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Community Composition ◽  
Microbial Community Structure ◽  
Soil Microorganisms ◽  
Microbial Community Composition ◽  
Soil C ◽  
Suburban Forests

Abstract Climate change and rapid urbanization have greatly impacted urban forest ecosystems and the carbon (C) cycle. To assess the effects of urbanization on forest soil C and soil microorganisms, six natural forests in a highly-urbanized region were selected as the research objects. Soil samples were collected to investigate the content and fractions of the soil organic carbon (SOC), as well as the soil microbial community composition. The results showed that the SOC content and fractions were substantially lower in the urban forests than in the suburban forests. Meanwhile, the total amount of phospholipid fatty acids (PLFAs) at suburban sites was twice more than that at urban sites, with shifts in microbial community structure. The potential differences in C inputs and nutrient limitation in urban forests may aggravate the low quantity and quality of SOC and consequently impact microbial community abundance and structure. Variation in microbial community structure was found to explain the loss of soil C pools by affecting the C inputs and promoting the decomposition of SOC. Therefore, the coupled changes in SOC and soil microorganisms induced by urbanization may adversely affect soil C sequestration in subtropical forests.

Soil Organic Carbon Accumulation under Different Forms of Organo-Mineral Fertilizers and Methods of Their Application on Ukrainian Black Soil

2020 ◽  
Author(s):  
Viktoriia Hetmanenko ◽  
Ievgen Skrylnyk ◽  
Anzhela Kutova
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Black Soil ◽  
Carbon Accumulation ◽  
Mineral Fertilizers ◽  
Fertilizer Treatment ◽  
Soil C ◽  
Significant Difference ◽  
Humus Composition

&lt;p&gt;Soil organic carbon management is a key element in solving such urgent global-scale challenges as overcoming degradation of soils and mitigating climate change. Organic fertilizers application has a significant potential for sequestering C in soils, but their efficiency depends on decomposition characteristics. Firstly, it noted the dependence of resynthesis of humic compounds in a soil on a quality of organic inputs, secondly - a need for zonal approach to fertilizers production based on amphiphile properties of macromolecules.&lt;/p&gt;&lt;p&gt;The present study was conducted in long-term field experiment on black soil in Forrest-Steppe zone of Ukraine. The technology of production of organo-mineral fertilizers (OMFs) was based on the regulated processing of livestock waste with mineral components to stabilize it with hydrophobic bonds. OMFs in amorphous and granular form were compared in case of broadcast and band method of incorporation. The dose of OMF input was equivalent 350 C kg ha&lt;sup&gt;-1&lt;/sup&gt; and 80 N, 80 P, 80 K kg ha&lt;sup&gt;-1&lt;/sup&gt;. Organic carbon content in soil was determined by Turin method. Different organic matter fractions were isolated: humic acids (HA), fulvic acids (FA), and humin.&lt;/p&gt;&lt;p&gt;The soil C accumulation rates in OMF treatment was by 15 % higher than in manure treatment and up to 70 % higher than in chemical fertilizer treatment, respectively. The soil C accumulation was strongly influenced by the form of OMF and method of their application. The highest TOC level was found over band application of amorphous OMF, accumulating 6.2 t C ha&lt;sup&gt;&amp;#8211;1&lt;/sup&gt; yr&lt;sup&gt;&amp;#8211;1 &lt;/sup&gt;in 0-20 cm soil layer. Lower efficiency of broadcast incorporation OMFs could be explained by more intensive mineralization due to higher aeration. Taking into account the effect of OMFs on C stock an advantage of amorphous form versus granulated OMF with similar composition was proven. Black soil on control plot (without fertilization) had almost equal ratio between HA, FA and humin in humus composition. The content of humic compound increased in all treatments. Applying OMF significantly increased HA content in black soil compared to applying mineral fertilizer. OMFs application promoted the increase of the degree of condensation of organic matter. The highest HA/FA was found under the effect of broadcast incorporation OMF. That means that low molecular weight compounds were rapidly degraded while more resistant to mineralization HA were formed in soil. There was no significant difference in humus composition between amorphous and granulated OMF.&lt;/p&gt;

Volumetric soil quality modelling with machine learning in a diverse agricultural landscape in Andalusia, Spain

2020 ◽  
Author(s):  
Tobias Rentschler ◽  
Martin Bartelheim ◽  
Marta Díaz-Zorita Bonilla ◽  
Philipp Gries ◽  
Thomas Scholten ◽  
...  
Keyword(s):  
Machine Learning ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Properties ◽  
Soil Quality ◽  
Three Dimensional ◽  
Soil Mapping ◽  
Soil Profiles ◽  
Soil Functions ◽  
Depth Functions

&lt;p&gt;Soils and soil functions are recognized as a key resource for human well-being throughout time. In an agricultural and forestry perspective, soil functions contribute to food and timber production. Other soil functions are related to freshwater security and energy provisioning. In general, the capacity of a soil to function within specific boundaries is summarised as soil quality. Knowledge about the spatial distribution of soil quality is crucial for sustainable land use and the protection of soils and their functions. This spatial knowledge can be obtained with accurate and efficient machine-learning-based soil mapping approaches, which allow the estimation of the soil quality at distinct locations. However, the vertical distribution of soil properties is usually neglected when assessing soil quality at distinct locations. To overcome such limitations, the depth function of soil properties needs to be incorporated in the modelling. This is not only important to get a better estimation of the overall soil quality throughout the rooting zone, but also to identify factors that limit plant growth, such as strong acidity or alkalinity, and the water holding capacity. Thus, the objective of this study was to model and map the soil quality indicators pH, soil organic carbon, sand, silt and clay content as a volumetric entity. The study area is located in southern Spain in the Province of Seville at the Guadalquivir river. It covers 1,000&amp;#160;km&lt;sup&gt;2&lt;/sup&gt; of farmland, citrus and olive plantations, pastures and wood pasture (Dehesa) in the Sierra Morena mountain range, at the Guadalquivir flood plain and tertiary terraces. Soil samples were taken at 130 soil profiles in five depths (or less at shallow soils). The profiles were randomly stratified depending on slope position and land cover. We used a subset of 99 samples from representative soil profiles to assess the overall 513 samples with FT-IR spectroscopy and machine learning methods to model equal-area spline, polynomial and exponential depth functions for each soil quality indicator at each of the 130 profiles. These depth functions were modelled and predicted spatially with a comprehensive set of environmental covariates from remote sensing data, multi-scale terrain analysis and geological maps. By solving the spatially predicted depth functions with a vertical resolution of 5&amp;#160;cm, we obtained a volumetric, i.e. three-dimensional, map of pH, soil organic carbon content and soil texture. Preliminary results are promising for volumetric soil mapping and the estimation of soil quality and limiting factors in three-dimensional space.&lt;/p&gt;

Estimates of soil organic carbon stocks in central Canada using three different approaches

2002 ◽  
Vol 32 (5) ◽  
pp. 805-812 ◽  
Author(s):  
J S Bhatti ◽  
M J Apps ◽  
C Tarnocai
Keyword(s):  
Surface Layer ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Carbon ◽  
Soil Depth ◽  
Peat Soil ◽  
Regression Line ◽  
Organic C ◽  
Soil C ◽  
Total Soil

This study compared three estimates of carbon (C) contained both in the surface layer (0–30 cm) and the total soil pools at polygon and regional scales and the spatial distribution in the three prairie provinces of western Canada (Alberta, Saskatchewan, and Manitoba). The soil C estimates were based on data from (i) analysis of pedon data from both the Boreal Forest Transect Case Study (BFTCS) area and from a national-scale soil profile database; (ii) the Canadian Soil Organic Carbon Database (CSOCD), which uses expert estimation based on soil characteristics; and (iii) model simulations with the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS2). At the polygon scale, good agreement was found between the CSOCD and pedon (the first method) total soil carbon values. Slightly higher total soil carbon values obtained from BFTCS averaged pedon data (the first method), as indicated by the slope of the regression line, may be related to micro- and meso-scale geomorphic and microclimate influences that are not accounted for in the CSOCD. Regional estimates of organic C from these three approaches for upland forest soils ranged from 1.4 to 7.7 kg C·m–2 for the surface layer and 6.2 to 27.4 kg C·m–2 for the total soil. In general, the CBM-CFS2 simulated higher soil C content compared with the field observed and CSOCD soil C estimates, but showed similar patterns in the total soil C content for the different regions. The higher soil C content simulated with CBM-CFS2 arises in part because the modelled results include forest floor detritus pool components (such as coarse woody debris, which account for 4–12% of the total soil pool in the region) that are not included in the other estimates. The comparison between the simulated values (the third method) and the values obtained from the two empirical approaches (the first two methods) provided an independent test of CBM-CFS2 soil simulations for upland forests soils. The CSOCD yielded significantly higher C content for peatland soils than for upland soils, ranging from 14.6 to 28 kg C·m–2 for the surface layer and 60 to 181 kg C·m–2 for the total peat soil depth. All three approaches indicated higher soil carbon content in the boreal zone than in other regions (subarctic, grassland).

scholarly journals Effects of species-dominated patches on soil organic carbon and total nitrogen storage in a degraded grassland in China

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6897 ◽  
Author(s):  
Yujuan Zhang ◽  
Shiming Tang ◽  
Shu Xie ◽  
Kesi Liu ◽  
Jinsheng Li ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Total Nitrogen ◽  
Microbial Biomass Nitrogen ◽  
Soil C ◽  
Artemisia Frigida ◽  
C Stocks ◽  
Soil C And N ◽  
C And N

Background Patchy vegetation is a very common phenomenon due to long-term overgrazing in degraded steppe grasslands, which results in substantial uncertainty associated with soil carbon (C) and nitrogen (N) dynamics because of changes in the amount of litter accumulation and nutrition input into soil. Methods We investigated soil C and N stocks beneath three types of monodominant species patches according to community dominance. Stipa krylovii patches, Artemisia frigida patches, and Potentilla acaulis patches represent better to worse vegetation conditions in a grassland in northern China. Results The results revealed that the soil C stock (0–40 cm) changed significantly, from 84.7 to 95.7 Mg ha−1, and that the soil organic carbon content (0–10 cm) and microbial biomass carbon (0–10 and 10–20 cm) varied remarkably among the different monodominant species communities (P < 0.05). However, soil total nitrogen and microbial biomass nitrogen showed no significant differences among different plant patches in the top 0–20 cm of topsoil. The soil C stocks under the P. acaulis and S. krylovii patches were greater than that under the A. frigida patch. Our study implies that accurate estimates of soil C and N storage in degenerated grassland require integrated analyses of the concurrent effects of differences in plant community composition.

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