scholarly journals The chemical nature of nitrogen in native soil organic matter

1993 ◽  
Vol 80 (5) ◽  
pp. 219-221 ◽  
Author(s):  
H. Knicker ◽  
R. Fr�nd ◽  
H. -D. L�demann
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Chemical Nature ◽  
Native Soil

scholarly journals Using Bulk Soil Radiocarbon Measurements to Estimate Soil Organic Matter Turnover Times: Implications for Atmospheric CO2 Levels

Radiocarbon ◽  
1996 ◽  
Vol 38 (2) ◽  
pp. 181-190 ◽  
Author(s):  
Kevin G. Harrison
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Carbon ◽  
Carbon Storage ◽  
Organic Matter Turnover ◽  
Native Soil ◽  
Soil Organic Matter Turnover ◽  
Anthropogenic Nitrogen ◽  
Derivatives Of ◽  
Anthropogenic Nitrogen Deposition

Although soil contains about three times the amount of carbon present in the preindustrial atmosphere, determining how perturbations (e.g., changing land use, CO2 fertilization, changing climate and anthropogenic nitrogen deposition) alter soil carbon storage and influence atmospheric CO2 levels has proved elusive. Not knowing the soil carbon turnover times causes part of this uncertainty. I outline a strategy for using radiocarbon measurements to estimate soil organic matter turnover times and inventories in native soil. The resulting estimates of carbon exchange produce reasonable agreement with measurements of CO2 fluxes from soil. Furthermore, derivatives of the model are used to explore soil carbon dynamics of cultivated and recovering soil. Because the models can reproduce observed soil 14C measurements in native, cultivated, and recovering ecosystems (i.e., the underlying assumptions appear reasonable), the native model was modified to estimate the potential rate of additional carbon storage because of CO2 fertilization. This process may account for 45–65% of the “missing CO2 sink.”

scholarly journals Experimental evidence for sequestering C with biochar by avoidance of CO2emissions from original feedstock and protection of native soil organic matter

GCB Bioenergy ◽  
2014 ◽  
Vol 7 (3) ◽  
pp. 512-526 ◽  
Author(s):  
H. M. S. K. Herath ◽  
M. Camps-Arbestain ◽  
M.J. Hedley ◽  
M.U.F. Kirschbaum ◽  
T. Wang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Experimental Evidence ◽  
Native Soil

scholarly journals Organic Carbon Decomposition in Soil Amended With Organic Compost From Slaughterhouse Residues

2018 ◽  
Vol 10 (8) ◽  
pp. 7
Author(s):  
Magnum de Sousa Pereira ◽  
Julius Blum ◽  
Henrique Antunes de Souza ◽  
Carlos Kenji Taniguchi
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Nonlinear Models ◽  
Soil Protection ◽  
K Value ◽  
Carbon Decomposition ◽  
Native Soil ◽  
Compost Application ◽  
Organic Compost ◽  
Native Organic Matter

Decomposition kinetic of applied compost in soil depends on the decomposition rate coefficient (k), environmental conditions and the interactions with soil. However, studies with the aim of determining k values for different materials rarely consider interactions with soil. The objective of the current study was to estimate k value of an organic compost, considering the interactions with the soil. Samples of soil mixed with compost were incubated in hermetic recipients for 126 days and evolved C-CO2 was quantified. Nonlinear models proposed in the present study were fitted to evolved C-CO2 data. Better fitting was found in a model that divided the soil organic matter in four pools (labile and recalcitrant native soil organic matter; protected and unprotected added organic matter), values of k on both native organic matter pools were multiplied by a constant denominated priming (pr) only in the cases where the compost was added to the soil and the amount of C in the protected pool is limited to the soil protection capacity. Organic compost produced using carcasses, sheepfold residues and slaughterhouse residues presented k value equal to 0.01179 day-1 at 31 oC without water stress. Compost application increased in 9.8% the decomposition of the native soil organic matter.

The long-term effect of biochar on composition of soil organic matter 

2021 ◽  
Author(s):  
Sandra Pärnpuu ◽  
Karin Kauer ◽  
Henn Raave
Keyword(s):  
Organic Matter ◽  
Nmr Spectroscopy ◽  
Soil Organic Matter ◽  
Soil Samples ◽  
Bulk Soil ◽  
Organic C ◽  
Native Soil ◽  
Soil Hydrophobicity ◽  
Som Decomposition

<p>Biochar has been described as relatively stable form of C with long mean residence time due to its predominantly aromatic structure. Addition of biochar can sequester C in the soil, albeit the effect of biochar on native soil organic C decomposition, whether it stimulates or reduces the decomposition of native soil organic matter, requires further understanding. The aim of this research was to study the long-term impact of biochar (BC) on the composition of soil organic matter (SOM) in Fragi-Stagnic Albeluvisol. The work was compiled on the basis of field experiment, set up on a production field in 2011. The experiment was drawn up of two treatments and four replicates, where on half of the replicates slow-pyrolysis hardwood BC (51.8% C, 0.43% N) produced at 500-600 °C was applied 50 Mg ha<sup>-1</sup>. The soil samples were collected from 0-10 cm soil layer in autumn 2020. The air-dried samples were sieved through a 2-mm sieve and divided into two fractions: the particulate organic matter (POM) fraction (soil particles larger than 0.063 mm) and the mineral-associated organic matter (MAOM) (<0.063 mm) by density fractionation method. The soil organic carbon (SOC) and total nitrogen (Ntot) concentrations of bulk soil and fractions were measured. The chemical composition of SOM was studied using <sup>13</sup>C nuclear magnetic resonance (NMR) spectroscopy. Bulk soil samples and fractions were pretreated with 10% HF solution before NMR spectroscopy analysis. Two indices were calculated: the ratio of alkyl C/O-alkyl C, which describes the degree of SOM decomposition and soil hydrophobicity (HI): (aromatic-C+alkyl-C)/O/N-Alkyl-C.</p><p>The addition of BC to the soil increased the SOC concentration but did not influence the Ntot concentration and the soil C/N ratio increased from 11.6 to 16.7. The distribution of POM and MAOM was not affected by the BC and POM proportion accounted for an average of 57–58%. The SOC concentrations of POM and MAOM fractions were higher in the BC variant. The BC increased the proportion of aromatic-C in the SOM, as the proportion of aromatic-C in initial BC was high (almost 92%). Initially the BC is inherently highly hydrophobic and increased the HI of bulk soil, POM, and MAOM fractions. The HI increased in line: MAOM<bulk<POM (1.51<1.67<1.97). An increase in HI inhibits the decomposition of SOM and it was also confirmed by a decreased ratio of alkyl-C/O-alkyl-C after the BC addition. The decomposition degree was lowest in POM fraction where SOC concentration was more than doubled due to BC. The suppressed decomposition was caused by the limitation of soil Ntot concentration and increased C/N ratio.</p><p>In conclusion, the effect of BC on the composition of SOM was still evident after 10 years of increasing SOC concentration and soil hydrophobicity and decreasing SOM decomposition degree promoting C sequestration to the soil.</p><p>This work was supported by the Estonian Research Council grant PSG147.</p>

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