scholarly journals Density, amount, and carbon content of organic matter in soils – some methodical reflections

1960 ◽  
Vol 32 (1) ◽  
pp. 125-127
Author(s):  
Reijo Heinonen

The density of soil organic matter has been derived from an equation representing the regression of soil density on the clay and organic matter contents. When the amount of organic matter was taken as equalling 1.9 times the total organic carbon, this resulted in the value 1.47 for the density of soil organic matter, which is believed to be an appropriate figure.

2014 ◽  
Vol 1073-1076 ◽  
pp. 696-699
Author(s):  
Baek Hoon Kim ◽  
Seung Kyun Son ◽  
Hee Jun Lim ◽  
Han Seung Kim

Soil organic matter (SOM) is derived from dead biomass of animals and plants, and its formation process in which the precursor materials of SOM are transformed into macro organic molecules through geo-chemical and geo-biological reactions in the subsurface environment is referred to as humification. Carbon content increases, but oxygen content decreases along with marked increased in molecular weight and degree of condensation of SOM during humification. It has been known that humus materials evolve in the order of biopolymer, fulvic acid, humic acid, and humin. Humification process takes place in a geological time scale, but it can be accelerated at extremely high temperatures, which can be achieved by microwave (MW) with hyperthermal catalysts (HTCs). Thus, MW was irradiated to the mixture of soil and HTCs to stimulate humification of SOM and to enhance its binding capacity for recalcitrant organic contaminants in this study. MW irradiation with HTCs was optimized, and the characteristic changes of SOMs before and after the irradiation were assessed to confirm humification. Soils were collected from 4 different forest regions in Seoul, Korea (Konkuk University, Yongma Mountain, Surak Mountain, and Bukhan Mountain), and they were screened by wet-sieving. Each component of SOM was isolated by acid-base extraction/selective exchange resin, which was proposed by the International Humic Substance Society. Total organic carbon (TOC) content, specific ultraviolet absorbance (SUVA), E4/E6 ratio, and Fourier transform-infrared spectroscopy (FT-IR) spectrum of SOM before and after MW irradiation were examined. Soil of Surak Mountain exhibited the highest organic carbon content, but Yongma Mountain contained the highest amount of fulvic acid. Soils of Yongma Mountain and Konkuk University were chosen due to their high fulvic acid content, which supported that these soils are relatively geologically-young soils. Powdered and granulated activated carbon (PAC and GAC), graphite, charcoal, and carbon nanotube (CNT) were selected and screened with regard to their hyperthermal activity under MW irradiation. The temperature changes by MW with HTCs were monitored at various MW irradiation intensity and time. Graphite-and CNT-soil mixtures exhibited the optimum heating capacity at 600 W, resulting in heating HTC-soil mixtures to approximately 1,000oC within 10 min. TOCs, SUVAs, E4/E6 ratios, and FT-IR spectra of SOM supported effective humification of SOM after MW irradiation with HTCs, and notable increase in binding capacity with hydrophobic organic contaminants. The results of this study are expected to provide the fundamental information for developing the performance-efficient and cost-effective treatment process for the removal of persistent organic contaminants based on MW and HTC.


2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
Carlos Eduardo Pacheco Lima ◽  
Mariana Rodrigues Fontenelle ◽  
Luciana Rodrigues Borba Silva ◽  
Daiane Costa Soares ◽  
Antônio Williams Moita ◽  
...  

The present work aimed to evaluate the behavior of ten fertility attributes of soil organic matter physical fractions and total organic carbon upon addition of three EM Bokashis to a Rhodic Ferralsol (FRr) and a Dystric Cambisol (CMd). An experiment was carried out in greenhouse in which the soils were placed into plastic trays and cultivated with tomato. A completely randomized design was used with four repetitions and factorial scheme of 2 × 3 + 2, consisting of two soils (FRr and CMd), three EM Bokashis (Poultry Manure Bokashi (BPM); CNPH Bokashi (BC); and Cattle Manure Bokashi (BCM)), and two controls (both soils without addition of Bokashi). The following fertility attributes were evaluated: pH, Ca2+, Mg2+, K+, Na+, P, SB, H + Al, CEC, andV. Particulate organic carbon (POC) and mineral-associated organic carbon (MOC) and total organic carbon (TOC) were also investigated. Finally, the Principal Component Analysis was conducted in order to identify possible patterns related to soils when fertilized with EM Bokashi. The addition of EM Bokashi increased the soil fertility and contents of POC. Different EM Bokashi presents distinguished effects on each soil. The PCA suggests that BPM presents higher capacity to modify the analyzed chemical attributes.


2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Lanlan Zhang ◽  
Zhen Li ◽  
Shiwen Zhang ◽  
Shasha Xia ◽  
Hongguang Zou ◽  
...  

Soil organic matter (SOM), as a kind of natural polymers, affects the migration and transport of ions and particles in soil system due to its surface characteristics and interaction and then causes significant changes in soil quality such as soil fertility loss and pollutant transfer. It is of great importance to study the temporal and spatial evolution of soil organic matter and its driving mechanism for soil health management. This study aims to fully reveal the evolution characteristics and driving mechanism of soil organic carbon (SOC) in farmland of the Beijing plain based on a six-year site monitoring. According to the research results, there is a significant difference in the overall soil organic content during the 6-year period. The temporal stability of SOC is moderate, and it is inversely proportional to SOC content in terms of spatial distribution. SOC content increases as organic fertilizer input rises, and an extra unit (15 kg·ha−1) of organic fertilizer input leads to an increase of 0.057 g·kg−1 in SOC content. The soil with higher clay content exhibits higher SOC content. The organic carbon content in different soil texture types increases with time, and there is a significant difference between the increases in medium loam and light loam. The grain field plantation system exhibited declining SOC content, while the protected vegetable fields, open vegetable fields, and orchards all showed an increase in SOC content. According to our results, the SOC content of farmland in the plain areas of Beijing is largely dependent on the input of organic carbon if other conditions remain unchanged or exhibit insignificant changes.


2019 ◽  
Vol 64 (2) ◽  
pp. 230-237
Author(s):  
Renata Rauch ◽  
Rita Foldenyi

It is not only Total Organic Carbon content (TOC) but also the type of Organic Matter (OM) that the sorption of organic pollutants by soils or other natural absorbents is correlated with. Therefore, the characterization of organic components in the adsorbents is very important to elucidate sorption mechanisms.Oil shale samples were collected in Pula, Hungary. The TOC content of the investigated samples was approximately 6.8-40.1 m/m %. The characterization of the organic matter in samples was carried out by using Scanning Electron Microscopy (SEM), elemental analysis, thermal analysis, and GC-MS technics. The results predominantly indicated the presence of a low degree of the branching of aliphatic chain components in the samples. The Humic Substances (HS) content of the samples was only 1-6 m/m %, which could be determined after the treatment of oil shale with hydrogen peroxide.The influence of the amount and type of organic material in oil shale samples was studied on the adsorption of 2,4-dichlorophenol (2,4-DCP) as a model contaminant. For this aim a series of batch equilibration experiments was carried out. The results show that the total organic carbon content of samples is a strong indicator of 2,4-DCP adsorption, while the HS content is an important feature controlling sorption capacity. The study suggests that the special organic matter (kerogen) content of the oil shale plays a major role in its high adsorption capacity and in the nonlinearity of the isotherms. The HS covering the surface could decrease the sorption capacities despite the fact that though the amount of this organic material is quite low.


2021 ◽  
Vol 54 (2A) ◽  
pp. 60-74
Author(s):  
Arwa M. S. Al-Dolaimy

A total of 56 cuttings samples of Sargelu and Kurrachine formations from different wells (Ain Zalah, Baiji, and Jabal Kand) in northern Iraq have been investigated in this study. Both the Sargelu and Kurrachine formations were examined using Rock-Eval pyrolysis to assess the richness of organic matter and thermal maturity level. The Sargelu Formation Have Total Organic Carbon wt.% ranged from 0.22–2.52 wt.%, average 1.26 wt.% in Ain Zalah Well, and between 0.57–8.90 wt.%, average 2.95 wt.% in Baiji Well, and between 0.81–11.80 wt.%, average 5.01wt.% in for Kand Well. It is considered a potential source rock based on total organic carbon content. total organic carbon wt. % in Ain Zalah and Kand in the Kurrachine Formation is considered poor source rock with a total organic carbon content of 0.17, 0.39 wt. %, respectively, while in Baiji Well is considered moderate source rock with total organic carbon content 0.53 wt. %. The Rock-Eval data are not always sufficient to define the kind of organic matter through the use of the van Krevelen diagram because HI and OI are affected by both matrix mineralogy and the kerogen mixture. For accurate assessments of the source rocks, gas chromatography has been relied on, which provides a direct indication of the kerogen type as well as the type of hydrocarbons that kerogen can generate during maturity. Gas chromatography analysis indicates that all selected samples contained type II kerogen. The highest value of the TAS/ (MAS+TAS) ratio was found in Ain Zalah samples (Sargelu Formation), and this result indicates the occurrence of an aromatization process with increasing thermal maturation.


2019 ◽  
Vol 76 (4) ◽  
Author(s):  
Ewa Błońska ◽  
Jarosław Lasota ◽  
Arvo Tullus ◽  
Reimo Lutter ◽  
Ivika Ostonen

Abstract Key message The deadwood of different tree species with different decomposition rates affects soil organic carbon sequestration in Estonian and Polish forests. In warmer conditions (Poland), the deadwood decomposition process had a higher rate than in cooler Estonian forests. Soil organic matter fractions analysis can be used to assess the stability and turnover of organic carbon between deadwood and soil in different experimental localities. Context Deadwood is an important element of properly functioning forest ecosystem and plays a very important role in the maintenance of biodiversity, soil fertility, and carbon sequestration. Aims The main aim was to estimate how decomposition of deadwood of different tree species with different decomposition rates affects soil organic carbon sequestration in Estonian and Polish forests. Methods The investigation was carried out in six forests in Poland (51° N) and Estonia (58° N). The study localities differ in their mean annual air temperature (of 2 °C) and the length of the growing season (of 1 month). The deadwood logs of Norway spruce (Picea abies (L.) Karst.), common aspen (Populus tremula L.), and silver birch (Betula pendula Roth) were included in the research. Logs in three stages of decomposition (III–V) were selected for the analysis. Results There were differences in the stock of soil organic carbon in two experimental localities. There was a higher soil carbon content under logs and in their direct vicinity in Polish forests compared to those in the cooler climate of Estonia. Considerable differences in the amount of soil organic matter were found. The light fraction constituted the greatest quantitative component of organic matter of soils associated with deadwood. Conclusion A higher carbon content in surface soil horizons as an effect of deadwood decomposition was determined for the Polish (temperate) forests. More decomposed deadwood affected soil organic matter stabilization more strongly than less decayed deadwood. This relationship was clearer in Polish forests. Higher temperatures and longer growing periods primarily influenced the increase of soil organic matter free light fraction concentrations directly under and in close proximity to logs of the studied species. The slower release of deadwood decomposition products was noted in Estonian (hemiboreal) forests. The soil organic matter mineral fraction increased under aspen and spruce logs at advanced decomposition in Poland.


2021 ◽  
Vol 28 (3) ◽  
pp. 399-410
Author(s):  
Mantas Pranskevicius ◽  
Dainius Paliulis

Abstract Soil as an ecosystem is actively involved into climate formation process. Therefore, it is important to assess such soil quality indicators as total organic carbon (TOC) and CO2 emissions. Soil organic matter is considered to be its indicator of quality, which is one of the most important components of biosphere consistency and stability. Soil respiration shows carbon emission from soil into the atmosphere. This is a great indicator, illustrating soil biological activity. Impact of soil temperature, air humidity, time of day was evaluated on CO2 emission from the soil. The highest CO2 emission is observed in afternoon hours, up to 0.201 g CO2∙m–2·h–1.


2017 ◽  
Vol 9 (12) ◽  
pp. 152
Author(s):  
Carlos Augusto Rocha de Moraes Rego ◽  
Jonas Francisco Egewarth ◽  
Marcio André Francziskowski ◽  
Felipe Eliazar Cremonez ◽  
Paulo Sérgio Rabello de Oliveira ◽  
...  

Soil organic matter is degraded and easily altered by the type of management. The objective of this work is to determine the total organic carbon and humic substance fractions in the organic matter of the soil with different management types and depths in the western region of Paraná, Brazil. The work was carried out in the Experimental Farm “Professor Antônio Carlos dos Santos Pessoa”, belonging to the State University of the West of Paraná. Five soil management systems were evaluated: one area with corn cultivation for silage (CS); other area with succession of crops, with soybean in summer and corn in winter (SC); the next area also with succession of crops, with soy in the summer and oat in the winter (SO); the following area with permanent pasture with Tifton (PP); and the last area with crop-livestock integration (ILC). For each management system, four plots were randomly selected, in each plot three simple samples were collected in a diagonal direction to form a composite sample for the depth of 0.00-0.05 m, 0.05-0.10 m and 0.10-0.15 m. Total organic carbon, fractionation of the humic substances and the AH/AF and EA/HUM ratios were calculated. For most of the analyzed variables, it was verified that there were significant differences (P < 0.05) between the systems evaluated in the studied depths. In the evaluated areas, the PP, SO and ILC systems presented the highest carbon content for all attributes analyzed.


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