Wyniki wyszukiwania - AGRO

1

The effect of the content of organic carbon in the soil on the chemical composition of the soil solution

100%

Rutkowska B., Szulc W., Labetowicz J.

Polish Journal of Soil Science

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2004

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tom 37

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nr 2

On the basis of 136 soil samples collected from an area of Poland, the effect of the content of organic carbon in the soil on the chemical composition of soil solution was analyzed. With an increase of organic carbon content in the soil, a significant increase of calcium and to a lesser extent of magnesium, bicarbonates and phosphates in the soil solution was observed. No correlation was noted between the organic carbon soil content and the concentration of aluminium in the soil solution. The contents of organic matter in the soil influenced the concentrations of microelements in the soil solution more than the macroelements content in this soil. The concentrations of manganese, iron, zinc and copper were positively correlated, the concentration of molybdenum was negatively correlated and the concentration of boron did not show any relationship with the soils content of organic carbon.

2

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Sequestration of organic carbon influenced by the application of straw residue and farmyard manure in two different soils

86%

Mahmoodabadi M., Heydarpour E.

International Agrophysics

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2014

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tom 28

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nr 2

Soil organic carbon is one of the most important soil components, which acts as a sink for atmospheric CO2. This study focuses on the effect of different methods of organic matter application on the soil organic carbon sequestration in a 4-month experiment under controlled greenhouse conditions. Three rates of straw residue and farmyard manure were added to uncultivated and cropland soils. Two treatments of straw residue and farmyard manure incorporation were used into: a soil surface layer and 0-20 cm soil depth. The result showed that the application of organic matter, especially the farmyard manure incorporation led to a significant increase in the final soil organic carbon content. Higher amounts of soil organic carbon were stored in the cropland soil than in the uncultivated soil. On average, the soil surface layer treatment caused a higher sequestration of soil organic carbon compared to the whole soil depth treatment. If higher rates of organic matter were added to the soils, lower carbon sequestration was observed and vice versa. The result indicated that the carbon sequestration ranged farmyardmanure > strawresidue and cropland soil > uncultivated soil. The findings of this research revealed the necessity of paying more attention to the role of organic residue management in carbon sequestration and prevention of increasing global warming.

3

State-space estimation of soil organic carbon stock

86%

Timm L. C., Ogunwole J. O., Obidike-Ugwu E. O., Gabriels D. M.

International Agrophysics

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2014

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tom 28

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nr 2

Understanding soil spatial variability and identifying soil parameters most determinant to soil organic carbon stock is pivotal to precision in ecological modelling, prediction, estimation and management of soil within a landscape. This study investigates and describes field soil variability and its structural pattern for agricultural management decisions. The main aim was to relate variation in soil organic carbon stock to soil properties and to estimate soil organic carbon stock from the soil properties. A transect sampling of 100 points at 3 m intervals was carried out. Soils were sampled and analyzed for soil organic carbon and other selected soil properties along with determination of dry aggregate and water-stable aggregate fractions. Principal component analysis, geostatistics, and state-space analysis were conducted on the analyzed soil properties. The first three principal components explained 53.2% of the total variation; Principal Component 1 was dominated by soil exchange complex and dry sieved macroaggregates clusters. Exponential semivariogram model described the structure of soil organic carbon stock with a strong dependence indicating that soil organic carbon values were correlated up to 10.8m.Neighbouring values of soil organic carbon stock, all waterstable aggregate fractions, and dithionite and pyrophosphate iron gave reliable estimate of soil organic carbon stock by state-space.

4

Dissolvable organic carbon in groundwater as an indicator of its contamination as a result of many years of on-ground storage of manure

86%

Urbaniak M., Pietrzak S.

Polish Journal of Agronomy

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2011

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nr 04

5

Changes in soil organic carbon and its density fractions after shrub-planting for desertification control

86%

Liu J.-B., Zhang Y.-Q., Wu B., Qin S.-G., Lai Z.-R.

Polish Journal of Ecology

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2014

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tom 62

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nr 2

Planting shrubs on sand land and degraded pasture are two main measures for desertification control particularly in northwest China. However, their effects on soil organic carbon (SOC) and its fractions remain uncertain. We assessed the changes in stocks of SOC, light fraction of SOC (LF–SOC) and heavy fraction of SOC (HF–SOC) after planting Artemisia ordosica (AO, 17 years), Astragalus mongolicum (AM, 5 years) and Salix psammophila (SP, 16 years) in sand land and planting Caragana microphylla (CM, 24 years) on degraded pasture. Results show that: 1) after planting AO, AM and SP on sand land, SOC stocks increased by 162.5%, 45.2% and 70.8%, respectively, and LF–SOC accounted for a large proportion in the increased SOC. Dry weights of LF–SOC, rather than carbon concentrations, were higher in shrublands than that in sand land; 2) after planting CM on degraded pasture, SOC stock decreased by 9.3% and all the loss was HF–SOC in 60–100 cm soil layer where both herbaceous fine root biomass (HFRB) and soil water content (SWC) also decreased. The results indicate that planting shrubs can result in an increase of SOC in sand land, whereas that can lead to a decrease of SOC in degraded pasture. The increase of SOC in sand land mainly bases on the accumulation of dry weight of LF–SOC. The loss of SOC in degraded pasture is caused by the decrease of carbon concentrations of HF–SOC, which can be related to the reduction of HFRB and SWC in deep soil layer. Therefore, shrub-planting for desertification control not always improve the quantity and stability of SOC in northwest China.

6

Recent alterations of aerosol concentration, mercury distribution and organic matter deposition in the Arctic

86%

Pempkowiak J., Zielinski T., Petelski T., Zaborska A., Beldowski J.

Papers on Global Change

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2011

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nr 18

Material fluxes in the Arctic and Antarctic have been, in several respects, strongly affected recently. For example, atmospheric turbidity conditions are frequently subject to strong changes due to haze and dust transport episodes, which can cause considerable perturbations in the radiation balance of the atmosphere beyond regional scale. This, directly or indirectly, contributes to the increased mercury deposition and organic matter fluxes to sediments. The results show that local emissions are not always the most important factors influencing the composition of aerosol in the atmosphere of the west Spitsbergen region. The direct radiative impact of polar aerosols on the surface and at the top of the atmosphere (TOA) need to be studied more closely through both theoretical studies on the aerosol radiative properties and measurements of the surface reflectance characteristics. Mercury dissolved/solid partitioning, both in the unconsolidated, fluffy layer of suspended matter covering the sediments, and the uppermost sediment layer, indicate that the influence of the athmospheric mercury deposition event (AMDE) can prolong well into summer (July/August), and can provide a pathway to the food chain for mercury contained in sediments. Since terrigenous supplies of organic carbon to the Barents Sea are minor (∼5%) compared to the marine supply, modern sediment deposits in this region sequester on average 6.0 g/m2year organic carbon, or 5.8% of the annual integrated pelagic primary production. This burial fraction exceeds, by a factor of 3, the burial fraction derived for the Holocene.

7

Preliminary results on low molecular weight organic substances dissolved in the waters of the Gulf of Gdańsk

86%

Grzybowski W., Pempkowiak J.

Oceanologia

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2003

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tom 45

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nr 4

The content of low molecular weight LMW (<1000 Da) dissolved organic substances was determined by ultrafiltration (concentration factor of 2) in different water samples collected in the Gulf of Gdańsk. The proportion of this fraction (based on organic carbon concentration) ranged from 24 to 57%. The lowest percentage was detected in riverine samples. The DOC concentrations in ultrafiltrates was similar in all the samples analysed. The absorbance proportion (at 250 nm) due to the low molecular fraction in the overall absorbance ranged from 14 to 45% and in all but one sample was lower than the DOC percentage. There was no relationship between DOC and absorbance in the LMW fractions (r2 = 0.08), in contrast to the characteristics of the ‘bulk’ samples (r2 = 0.88).

8

Monosaccharides in the water of the Gulf of Gdańsk

86%

Grzybowski W., Maksymiuk A.

Oceanologia

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2001

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tom 43

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nr 2

The concentration of monosaccharides in samples collected in the Gulf of Gdańsk area was determined in water filtered through ∼0.8 μm pore size filters. Seawater concentrations ranged from about 0.2 to 1.1 mg C dm−3, the highest values being detected at the mouth of the river Vistula. Seasonality was detectable in the data distribution; the majority of autumn values lay within the 0.2–0.4 range while concentrations in the spring samples were higher and the values more widely scattered. Measurements of monosaccharide concentrations at selected points during the whole observation period showed that values increased from spring to autumn as much as 5-fold. Concomitant analyses in Vistula river water yielded concentrations from 0.4 to 1.2 mg C dm−3. These latter values were all higher than those recorded in seawater in the corresponding months.

9

The content of DOC, POC, and TOC in lobelian lakes

86%

Baralkiewicz D., Kraska M., Siepak J.

Polish Journal of Environmental Studies

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1996

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tom 05

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nr 6

The material for our study came from 44 lobelian lakes located near Bytów. The lakes differed in size, depth, and drainage area development. The objective of the study was to determine the content of TOC, DOC, and POC in these lakes using a high temperature method. COD was also measured using a dichromate method, and after that the results were expressed by the TOC values. Then the TOC values obtained via the two methods were compared. The lakes under investigation proved to contain different amounts of dissolved organic carbon (1.8-19.0 mg/1), with POC falling within the range 0-33% of TOC.

10

Seasonal distribution of dissolved and particulate organic carbon in the water column of a meromictic lake

86%

Dunalska J., Gorniak D., Teodorowicz M., Gasecka K.

Polish Journal of Environmental Studies

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2004

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tom 13

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nr 4

This study investigated concentration changes of dissolved and particulate organic carbon in a meromictic lake to determine the lake’s productivity. It was revealed that the dominant form of organic carbon was the dissolved form (DOC). Maximum production activity was observed in summer (with the peak in June). At the same time, the factors restricting that process were determined, such as: strong pressure of the bacteria competing with the phytoplankton for mineral nutrients, and simultaneous precipitation of phosphates on HS-Fe complexes. The generated organic matter was settling intensively, and one of the transport methods of the dissolved organic matter was adsorption on calcium carbonate and bacterial transformation of the part of DOC into POC.

11

Content of carbon, nitrogen and selected heavy metals in composts

86%

Gondek K.

Journal of Elementology

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2007

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tom 12

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nr 1

Chemical composition of composts depends on a number of factors, including a type of composted waste and composting technology. This study was conducted to determine concentrations of carbon, nitrogen and selected heavy metals in composts manufactured from various waste substances and using different technologies. Organic carbon content in the composts depended on a type of composted waste - the smallest quantities were found in the compost of municipal waste. Organic matter transformations occurring during composting probably led to a systematic decline of the soluble organic compound amounts. The share of soluble carbon in the total concentration did not exceed 35% of the analysed composts. The composts based on plant waste were more abundant in nitrogen and the share of nitrogen extracted with sodium pyrophosphate and sodium base did not exceed 40%. Analysis of fractional composition of humus compounds of the composts revealed higher content of humic acid carbon in relation to fulvic acid carbon. The proportion of non-hydrolysing carbon in these materials was on average over 70%. The content of the most mobile heavy metal forms in the composts was low and implied that these elements occurred in a form less available to plants.

12

The effect of dissolved organic carbon on pelagial and near-sediment water traits in lakes

86%

Banas K.

Acta Societatis Botanicorum Poloniae

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2005

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tom 74

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nr 2

The effect of dissolved organic carbon (DOC) on the environmental conditions of macrophytes has been studied in 35 lakes divided into soft- and hardwater: oligohumic (<4.0 mg C dm-3), α-mesohumic (4.0-8.0 mg C dm-3), β-mesohumic (8.1-16.0 mg C dm-3) and polihumic (>16.0 mg C dm-3). The optimum environmental conditions for macrophytes have been found in oligohumic lakes, characterised by low water colour and its good transparency. In soft- and hardwater lakes increasing concentration of DOC is accompanied with an increase in the colour (r=0.95), while the visibility decreases. With increasing DOC in the near-sediment layer the pH values decrease while the concentration of nitrogen increases and the concentration of phosphorus slightly increases. In hardwater lakes with increasing DOC concentration, the redox potential, conductivity, total hardness and calcium concentration in the near-sediment water decrease, whereas the content of CO2 remains at a very low level.

13

Organic carbon contents in bottom sediments from the upper River Narew and its tributaries

86%

Skorbilowicz E., Skorbilowicz M.

Journal of Elementology

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2008

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tom 13

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nr 1

The study dealt with the bottom sediments from the Narew River in the section Bondary-Tykocin 18 tributaries in the catchment of the upper Narew. Samples were collected in summer (August) and autumn (October) 2005 from the surface layer of bottom sediments in the shore zone. Determinations of organic carbon were performed on a TOC 1200 analyzer (Thermo Euroglas). The bottom sediments collected from the upper Narew contained less organic carbon, which resulted from intensive mineralization. Sediments from the small rivers were most abundant in organic carbon. These rivers are characterized by a low flow rate and, in most cases, they are overgrown by water plants. The organic carbon contents were highly varied between the sampling points. Positive linear correlation was found between combustion loss and organic carbon content.

14

Alexandrium minutum cysts in sediment cores from the Eastern Harbour of Alexandria, Egypt

86%

Ismael A. A., Khadr A. M.

Oceanologia

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2003

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tom 45

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nr 4

Alexandrium minutum cysts were studied in sediment cores from its type locality, the Eastern Harbour of Alexandria, following the disappearance of the species from the plankton since 1994. Three cores were sampled in the summer of 1999 along the north-south axis of the harbour. The sediments were subjected to grain size analysis and their organic carbon content was determined. The sediments consisted of medium, coarse and very coarse sand. Grain size and organic carbon content were negatively and significantly correlated in core 1 but followed a parallel trend in cores 2 and 3. Seven dinoflagellate cysts, representing 6 genera were identified from the cores. Their relative abundance showed a remarkable difference. A. minutum cysts contributed a maximum of 17.4% to the total cysts. The distribution profile of A. minutum cysts in the cores reflects the bloom duration but not its productivity. The cyst distribution in the cores is the resultant of two opposite processes, the sedimentation rate and the continuous erosion of the bottom sediments, which is not related to sediment texture.

15

Accumulation of organic carbon in reclaimed soils. Dumping grounds: Belchatow, Machow, Turow

72%

Gruszczynski S.

Infrastruktura i Ekologia Terenów Wiejskich

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2015

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nr IV/4

16

Effects of the conversion of a degraded alpine Kobresia meadow on the organic carbon and nitrogen of soil and plants

72%

Qiao Y., Duan Z., Li X., Quan X., Liang H.

Polish Journal of Ecology

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2015

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tom 63

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nr 4

Three sites with both degraded alpine Kobresia meadow (DM) and adjacent mix-seeded perennial grasses pastures (MSP) in the headwater region of the Yellow River, Qinghai-Tibetan Plateau, were selected to investigate plant and soil organic carbon (SOC), total nitrogen (TN) and their isotope composition. The SOC and TN in the top soil layer to a depth of 10 cm were significantly affected by ploughing and planting mix-seeded perennial grasses. The SOC content in 0–10 cm soil layer of MSPs was 25.6%, 5.5% and 12.9% lower than those of DMs at the I-III sites, respectively, and the rate of OC density loss was 23.8, 14.5 and 18.2%, respectively. The soil TN content in 0–10 cm soil layer of MSPs was 16.6%, 2.2% and 9.4% lower than those of the DMs at three sites, respectively, and the TN density was 15.6, 10.6 and 15.3% lower than those of DMs, respectively. The plant and soil ¹³C values (-27.03‰, -25.16‰, respectively) suggest that the vegetation of both DMs and MSPs are C₃ plant communities. The 15 N value in the soil (>4‰) was significantly greater than in plants (<2‰). No differences of either ¹³C or ¹⁵N abundance between MSPs and DMs at Site I and II, but were found at Site III, indicating that the effects were site specific. The rehabilitation of a degraded Kobresia meadow has a significant influence on the soil properties, SOC and TN. Caution should be taken in site selection before performing conversion.

17

Lumbricidae communities in soil monitoring sites differently managed and polluted with heavy metals

72%

Tischer S.

Polish Journal of Ecology

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2008

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tom 56

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nr 4

635-646

Species composition, density and biomass of earthworms were studied on 84 differently managed and polluted sites (field, grassland, deciduous forest, coniferous forest, alluvial sites and mine spoil). All these sites are constantly monitored since a decade. In 13 sites amounts of heavy metals increased from: Cd – 3 to 6 mg kg⁻¹, Zn – 303 to 606 mg kg⁻¹, Pb – 95 to 317 mg kg⁻¹, Ni – 31 to 55 mg kg⁻¹, Cr – 58 to 80 mg kg⁻¹, and Cu – 59 to 114 mg kg⁻¹ soil, that is up to 2000, 880, 1090, 295, 320, and 520% higher, respectively, than in unpolluted field sites. Results show that metal pollution is not a dominating factor determining the species diversity and densities of earthworms. Remarkable differences in the distribution of ecological groups were found between biotope types. The endogeic species (Aporrectodea caliginosa Savigny, Aporrectodea rosea Savigny, Allolobophora chlorotica Savigny, Octolasion cyaneum Savigny) dominate in field and grassland habitats. The anecic species (Lumbricus terrestris L., Aporrectodea longa Ude), however, appear mostly in grassland. Epigeic species (Lumbricus rubellus Hoffmeister, Lumbricus castaneus Savigny, Dendrobaena octaedra Savigny) are found exclusively (in addition to the other two life forms) in grassland and the forest habitats. Differences in earthworm biomass between monitoring sites are not related to ecological risk assessment. These differences may be largely dependant on soil properties e.g. pH and organic matter. A matrix with the ecological requirements of earthworm species was developed.

18

Modelling flow in the porous bottom of the Barents Sea shelf

72%

Massel S. R.

Oceanologia

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2013

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tom 55

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nr 1

19

Ocena zmienności przestrzennej uziarnienia gleby i zawartości węgla organicznego w krajobrazie lessowym

72%

Rejman J., Iglik I., Brodowski R., Turski M., Smarz M.

Acta Agrophysica

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2011

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tom 18

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nr 2[193]

Zmienność przestrzenną zawartości frakcji piasku, pyłu i iłu oraz C organicznego gleby badano w obrębie pola położonego w wierzchowinowej części krajobrazu lessowego. Parametry gleby oznaczono w warstwie ornej (0-25 cm), a próby pobrano w układzie siatki regularnej 10×10 m (72 punkty). Stwierdzono, że zmienność przestrzenna badanych cech gleby dobrze opisywana była izotropowymi modelami semiwariancji typu sferycznego. Zasięg zmienności przestrzennej poszczególnych frakcji uziarnienia był uzależniony od wielkości cząstek, będąc najmniejszym dla zawartości iłu (28,4 m), a największym dla piasku (121,8 m). Wartość najmniejsza oznacza, że przyjęty krok próbkowania był wystarczający do oceny zmienności przestrzennej frakcji uziarnienia w wierzchowinowej części zlewni lessowej. Zmienność przestrzenną zawartości C organicznego charakteryzował izotropowy model sferyczny o zasięgu autokorelacji 50,2 m.

20

Comparison of two methods of soil organic carbon determination

72%

Barancikova G., Makovnikova J.

Polish Journal of Soil Science

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2015

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tom 48

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nr 1

Soil organic carbon (SOC) is one of the basic soil parameters which takes part in many biological, chemical and physical soil processes and the SOC is currently considered as a key indicator of soil quality. For this reason determination of the SOC is a part of soil complex monitoring which has been performed in Slovakia since 1993. From 1993 until 2007 the “wet” method of determination of the SOC was used. Since 2008 the “dry” method for determination of the SOC has been applied. The goal of this work has been to evaluate and compare two methods of the SOC determination; the “wet”(Ťiurin method in modification of Nikitin (TN)) and the “dry” determination of the SOC by means of the CN analyser (EA), which was performed on 95 soil samples of topsoil coming from 17 sampling sites with a wide range of the SOC (1–15%). Sampling sites include arable lands and grasslands and represent main soil types and subtypes of Slovakia. On the basis of statistical processing it has been found that in soils with the SOC content up to 3%, differences between two methods are minimal. However, in the case of a higher content of the SOC, the EA method reaches a higher value than the TN method. Obtained data shows that in the case of soil samples with a higher content of the SOC, when changing an analytical method, the PTF function that reduces differences and allows to use all time series monitoring data should be used for the purpose of the tracking trends of the SOC monitoring.

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