scholarly journals QUALITATIVE ASSESSMENT OF ROADSIDE POLLUTED SOILS / KOKYBINIS UŽTERŠTŲ PAKELĖS DIRVOŽEMIŲ VERTINIMAS

2013 ◽  
Vol 5 (4) ◽  
pp. 363-368
Author(s):  
Eglė Kiaunytė ◽  
Mantas Pranskevičius

Soil as an ecosystem is actively involved in the climate formation process. Therefore, it is important to assess soil quality indicators such as total carbon and CO2 emissions. Soil respiration shows carbon emission from soil into the atmosphere. This is a great indicator illustrating the biological activity of soil. The most effective CO2 emission can be noticed in the afternoon and may reach 0,201 g CO2 m-2h-1. Soil organic matter is considered to be its indicator of quality, which is one of the most important components of biosphere consistency and stability. Following the conducted study, a significant trend towards the content of total carbon in the layer of the surface (0–10 cm) soil was observed. Article in Lithuanian. Santrauka Dirvožemis, kaip ekosistema, aktyviai dalyvauja klimato formavimosi procesuose, todėl svarbu vertinti tokius dirvožemio kokybės rodiklius kaip bendroji anglis ir CO2 emisija. Dirvožemio kvėpavimas rodo anglies emisiją iš dirvožemio į atmosferą. Tai rodiklis, gerai iliustruojantis dirvožemio biologinį aktyvumą. Aktyviausia CO2 emisija – iki 0,201 g CO2 m–2h–1 esti popiečio valandomis. Dirvožemio organinių medžiagų kiekis laikomas dirvožemio kokybės rodikliu, vienu svarbiausių biosferos pastovumo ir stabilumo veiksnių. Atliekant tyrimą pastebėta ryški bendrosios anglies kiekių dominavimo paviršiniame (0–10 cm) dirvožemio sluoksnyje tendencija.

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.


2021 ◽  
Author(s):  
Gerardo Ojeda ◽  
Hernando García ◽  
Susanne Woche ◽  
Jorg Bachmann ◽  
Georg Guggenberger ◽  
...  

<p><strong>Contextualization</strong>: In 2011, it was published a curious conundrum, which forms the basis of the present study: why, when organic matter is thermodynamically unstable, does it persist in soils, sometimes for thousands of years? The question challenges the idea that the recalcitrant or labile character of soil organic matter (SOM) is a sufficient argument to ensure SOM persistence. Temperature could play an important role in SOM decomposition, especially in tropics. Particularly, tropical dry forest (TDF) represents an important ecosystem with unique biodiversity and fertile soils in Colombia. At present, the increase in population density and consequently, in the demands of energy and arable land, have led to its degradation.</p><p> </p><p><strong>Knowledge gap</strong>: Although the mentioned question was formulated several years ago, it has still to be answered, hence limiting the development of new soil organic carbon (SOC) models or the quantification of its ecosystem services. A key point, in terms of soil carbon storage, is to determine the maximum rate of CO<sub>2</sub> emissions from soils (Rmax). Traditionally, it is considered that Rmax occurs at the 50% of field capacity. Unfortunately, information about the environmental conditions under which this maximum occurs is scarce.</p><p><strong> </strong></p><p><strong>Purpose</strong>: The main objectives of this study were: (a) determine the maximum rate of soil respiration or CO<sub>2</sub> emissions from soil in TDF soils and (b) to estimate the main environmental drivers of maximum SOM decomposition along a temperature gradient (20°, 30°, 40°C) in incubated soils.</p><p><strong> </strong></p><p><strong>Methodology</strong>: Soils pertained to permanent plots were sampled in six different TDF of Colombia. The evolution of CO<sub>2</sub> emissions (monitored by an infrared gas analyser), relative humidity and soil temperature were recorded in time on incubated soils samples. Temperature was maintained constant at 20°C, 30°C and 40°C during soil incubations under soil drying conditions. Additionally, elemental composition (Fe, Ca, O, Al, Si, K, Mg, Na) of SOM and chemical composition of soil organic carbon (SOC: aromatic-C, O-alkyl-C, Aliphatic-C, Phenolic and Ketonic-C) were determined by X-ray photoelectron spectroscopy (XPS).</p><p><strong> </strong></p><p><strong>Results and conclusions</strong>: The majority of TDF soil samples (90.7%) presented that its peak of CO<sub>2</sub> emissions occurs at soil-water contents higher than saturation (0 MPa), at 20°, 30° and 40°C. Clearly, to consider that the maximum soil respiration rate could be observed at the 50% of field capacity, underestimated the real maximum value of carbon mineralization (48-68%.) Globally, increases in the Rmax values corresponded to increases in electrical conductivity, soil desorption rates, total carbon and nitrogen contents, and decreases in bulk density (BD) and aggregate stability. Taking into account the temperature gradient, increments in calcium and aromatic carbon contents corresponded to decrements in Rmax values but only at 30°C and 40°C, respectively. Some authors indicated that at high soil moisture contents, iron reduction could be release protected carbon. However, no significant relation between Fe and Rmax was observed. Consequently, physical and chemical properties related to SOM accessibility and decomposability by microbial activity, were the main drivers and controls of maximum SOM decomposition rates.</p>


Agromet ◽  
2013 ◽  
Vol 25 (1) ◽  
pp. 1
Author(s):  
Ade Irawan ◽  
Tania June

<em>Soil respiration and rate of CO2 emission is determined by its temperature and its organic matter. Canopy opening of a pristine forest affect the amount of radiation energy that are able to go down the canopy and determine the microclimate variability at the forest floor and rate of CO2 emission. This resesarch was conducted at  Babahaleka Forest Lore Lindu National Park, Central Sulawesi  and supported under the  cooperation of IPB-STORMA (Stability of Rainforest Margin) project, with an objective to determine the effect of soil temperature as a consequence of different level of canopy opening (and incoming radiation) on CO2 emission from soil respiration process.  Soil CO2 emission was measured through CO2 gas sampling using a closed chamber method and analyzed using  CO2 gas analyzer.  Measurement of soil temperature, air temperature,  relative humidity and soil organic matter were conducted at each CO2 gas sampling sites for further analysis of correlation between them. It was shown that soil temperature and soil surface temperature, soil moisture and air temperature affected soil respiration and CO2 emission from the soil surface.  Average soil surface CO2 fluxes was 299.15 mgCO<sub>2</sub>m<sup>-2</sup>h<sup>-1</sup>, with fluxes from more open canopy cover was higher than that from a closed canopy cover, 329.33-375.77 mgCO<sub>2</sub>m<sup>-2</sup>h<sup>-1</sup> and 209.24-304.18 mgCO<sub>2</sub>m<sup>-2</sup>h<sup>-1</sup> respectively.</em>


Soil Research ◽  
2002 ◽  
Vol 40 (5) ◽  
pp. 859 ◽  
Author(s):  
D. S. Mendham ◽  
A. M. O'Connell ◽  
T. S. Grove

The influence of land-use management on Walkley-Black soil carbon (C) concentration, 3 concentrations of permanganate oxidisable C (33, 167, and 333 mm), microbial biomass, and soil respiration in a laboratory incubation was tested in surface soil from 10 sites in south-western Australia. The sites ranged in total C concentration from 1.9 to 8.3%, and represented a broad climatic and soil-type distribution across south-western Australia. At each of the sites, 0-10 cm soil was collected from plots in pasture (20-71 years old), Eucalyptus globulus plantation (7-10 years old, established on ex-pasture), and native vegetation. Soil profiles and position in the landscape for each of the land-use types were matched as closely as possible at each site to minimise influences other than land use. Total C was highly correlated with clay content. Land use caused no significant change in the relationship between total C and soil texture, and land use had little effect on total C concentration. Permanganate-oxidisable C was highly correlated with Walkley-Black organic C (R2�&gt;�0.90) for all 3 concentrations that were investigated. Only the most dilute concentration of permanganate-oxidisable C (33 mm) was sensitive enough to detect small changes in soil organic matter with land use (P = 0.045). Microbial biomass and respiration at 25 kPa matric potential moisture content and 35°C temperature were used as biological indicators of soil organic matter lability. Cumulative respired C was more sensitive to land use than Walkley-Black organic C, with lower respiration in native soils compared with managed soils with low C concentrations, but higher than the managed soils at sites with high C concentrations. Microbial biomass was not significantly affected by land use. Microbial biomass and cumulative respired C were strongly influenced by soil texture, with the microbial quotient (proportion of microbial biomass in total carbon) and the proportion of total C respired significantly lower in soils with higher silt and clay contents. Land use had no significant effect on these relationships. Overall, land use caused only minor differences in the biological and chemical indicators of organic matter quality across a broad range of sites in south-western Australia.


2020 ◽  
Vol 21 (2) ◽  
pp. 160-168
Author(s):  
N. A. Kodochilova ◽  
T. S. Buzynina ◽  
L. D. Varlamova ◽  
E. A. Katerova

The studies on assessment of changes in the content and composition of soil organic matter under the influence of the systematic use of mineral fertilizers (NPK)1, (NPK)2, (NPK)3 against the background of the aftereffect of single liming in doses of 1.0 and 2.0 h. a. (control – variants without fertilizers and lime) were conducted in the conditions of the Nizhny Novgorod region in a long – term stationary experiment on light-grey forest soil. The research was carried out upon comple-tion of the fifth rotation of the eight-field crop rotation. The results of the study showed that for 40 years (from 1978 to 2018) the humus content in the soil (0-20 cm) decreased by 0.19-0.52 abs. % in variants as compared to the original (1.60 %); though, humus mineralization was less evident against the background of long-term use of mineral fertilizers compared to non-fertilized control. The higher humus content in the topsoil was noted in the variants with minimal (NPK)1 and increased (NPK)2 doses of fertilizer – 1.41 and 1.25 %, respectively. The humus content in non-fertilized soil and when applying high (NPK)3 doses of mineral fertilizers was almost identical – 1.08-1.09 %. The predominant group in the composition of humus were humic acids, the content of which in the experiment on average was 37.8 % of the total carbon with an evident decrease from 42.6 % in the control to 31.8% when applying increased doses of mineral fertilizers. The aftereffect of liming, carried out in 1978, was unstable and did not significantly affect the content and composition of soil organic matter.


Radiocarbon ◽  
1992 ◽  
Vol 34 (3) ◽  
pp. 541-549 ◽  
Author(s):  
H. W. Scharpenseel ◽  
Peter Becker-Heidmann

Soil organic matter sequesters close to three times the carbon existing totally in the living biomass and nearly the same for the total carbon in the atmosphere. Models, such as Jenkinson's or Parton's Century model, help to define soil organic matter fractions of different functions, based on residence time/14C age. Rejuvenation of soil carbon was felt to be the principal impediment to absolute soil dating, in addition to the ambiguity of the initiation point of soil formation and soil age. Recent studies, for example, of Becker-Heidmann (1989), indicate that a soil 14C age of >1000 yr cannot have >0.1% rejuvenation in the total soil organic matter compartments/fractions to be possible and sustainable. Always problematic in earlier observations were age vs. depth increases, in 14C profile curves showing an inflection of reduced age in the deepest samples, i.e., from the rim of the organic matter containing epipedon. We attribute this phenomenon, in mollic horizons, to earthworm casts in the terminal part of the escape tube. Becker-Heidmann (1989) has shown, in thin layer soil profile dating, a highly significant correlation between the highest 14C ages and the highest clay content. Thus, optimization of soil dating is, to a lesser degree, related to the applied extracting solvent system than to soil texture fractions. Such observations allow us to mitigate error ranges inherent in dating dynamic soil systems.


Soil Research ◽  
1999 ◽  
Vol 37 (2) ◽  
pp. 279 ◽  
Author(s):  
M. J. Bell ◽  
P. W. Moody ◽  
S. A. Yo ◽  
R. D. Connolly

Chemical and physical degradation of Red Ferrosols in eastern Australia is a major issue necessitating the development of more sustainable cropping systems. This paper derives critical concentrations of the active (permanganate-oxidisable) fraction of soil organic matter (C1) which maximise soil water recharge and minimise the likelihood of surface runoff in these soils. Ferrosol soils were collected from commercial properties in both north and south Queensland, while additional data were made available from a similar collection of Tasmanian Ferrosols. Sites represented a range of management histories, from grazed and ungrazed grass pastures to continuously cropped soil under various tillage systems. The concentration of both total carbon (C) and C1 varied among regions and farming systems. C1 was the primary factor controlling aggregate breakdown, measured by the percentage of aggregates <0·125 mm (P125) in the surface crust after simulated rainfall. The rates of change in P125 per unit change in C1 were not significantly different (P < 0·05) for soils from the different localities. However, soils from the coastal Burnett (south-east Queensland) always produced lower P125 (i.e. less aggregate breakdown) than did soils from the inland Burnett and north Queensland locations given the same concentration of C1. This difference was not associated with a particular land use. The ‘critical’ concentrations of C1 for each region were taken as the C1 concentrations that would allow an infiltration rate greater than or equal to the intensity of a 1 in 1 or 1 in 10 year frequency rainfall event of 30 min duration. This analysis also provided an indication of the risk associated with the concentrations of C1 currently characterising each farming system in each rainfall environment. None of the conventionally tilled Queensland Ferrosols contained sufficient C1 to cope with rainfall events expected to occur with a 1 in 10 frequency, while in many situations the C1 concentration was sufficiently low that runoff events would be expected on an annual basis. Our data suggest that management practices designed both to maximise C inputs and to maintain a high proportion of active C should be seen as essential steps towards developing a more sustainable cropping system.


Soil Research ◽  
1998 ◽  
Vol 36 (4) ◽  
pp. 655 ◽  
Author(s):  
A. Conteh ◽  
G. J. Blair ◽  
I. J. Rochester

The contribution of cotton stubble to the soil organic matter content of Vertisols under cotton production is not well understood. A 3-year experiment was conducted at the Australian Cotton Research Institute to study the effects of burning and incorporating cotton stubble on the recovery of fertiliser nitrogen (N), lint yield, and organic matter levels. This study reports on the changes in soil organic matter fractions as affected by burning and incorporating cotton stubble into the soil. Soil samples collected at the start and end of the 3-year experiment were analysed for total carbon (CT), total N (NT), and δ13C (a measure of 13C/12C isotopic ratios). Labile carbon (CL) was determined by ease of oxidation and non-labile carbon (CNL) was calculated as the difference between CT and CL. Based on the changes in CT, CL, and CNL, a carbon management index (CMI) was calculated. Further analyses were made for total polysaccharides (PT), labile polysaccharides (PL), and light fraction C (LF-C). Stubble management did not significantly affect the NT content of the soil. After 3 years, the stubble-incorporated plots had a significantly higher content of CT, CL, and polysaccharides. Incorporation of stubble into the soil increased the CMI by 41%, whereas burning decreased the CMI by 6%. The amount of LF-C obtained after 3 years in the stubble-incorporated soil was almost double that obtained in the stubble-burnt soil. It was concluded that for sustainable management of soil organic matter in the Vertisols used for cotton production, stubble produced in the system should be incorporated instead of burnt.


2008 ◽  
Vol 54 (No. 5) ◽  
pp. 204-211 ◽  
Author(s):  
M. Růžková ◽  
L. Růžek ◽  
K. Voříšek

Formerly arable luvic chernozem set aside for ten years (1997–2006) with different herbaceous cover (grass, legumes and their mixtures) and agronomical practices (mulching and cut/harvesting) was studied. The experimental plot was maintained as black, spontaneous and controlled fallows from 1997 until July 2003 (BD period). In July 2003 the plots were desiccated by glyphosate herbicide and were run as a black fallow until August 2004 (AD). The last period (AG) was characterized by monoculture of Italian ryegrass cut/harvested twice a year until October 2006. The experimental soils were characterized with 18 parameters. Mulched plots in all periods (BD, AD and AG) were evaluated as highly microbial active plots. The black fallow (BD) permanently maintained by glyphosate herbicide was the lowest in biological parameters. The desiccation caused a highly significant increase (<I>P</I> < 0.01) of nitrates in topsoil, but in following period (AG) their significant decrease was detected. Desiccation enhanced carbon immobilization into microbial cells especially on mulched and cut/harvested sites (BD, AD). Due to mulching accumulation of soil organic matter highly significantly increased (<I>P</I> < 0.01). This induced a highly significant (<I>P</I> < 0.01) increase in the basal respiration (AD, AG) as the soil organic matter accumulated in the period BD was intensively mineralized.


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