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A practical procedure for determining soil parameters when analysing the deformation of peat by finite-element analysis (FEA) using the Cam Clay model is presented. FEA has not been frequently used to predict the deformation of peat soil, even though it can be a powerful prediction tool. The main reason for this is that a practical method for determining parameters has not been established. In this paper, the remarkable correlation between the soil parameters required for FEA using the Cam Clay model and the natural water content (wn) and ignition loss (Li) of peat and organic clay is presented. Then, based on this correlation, a flow chart for determining the soil parameters of peat and organic clay is proposed. Using this chart, it is possible to determine soil parameters directly from triaxial compression, oedometer and other detailed tests or to estimate them from wn, Li and other physical indexes. A trial embankment on peat soil in Hokkaido, Japan, was also created. FEA was performed on the trial embankment using the proposed procedure for determining the soil parameters. The results of the FEA corresponded to the measured settlement behaviour in the trial embankment with an accuracy in the range −4% to +8%. The FEA results also modelled the measured behaviour of pore water pressure and lateral and vertical displacements in the trial embankment very well. [ABSTRACT FROM AUTHOR]

A successful crop rotation choice is key to the profitability and sustainability of farm management and may simultaneously have an impact on soil organic carbon (SOC) content. In this study, we estimated how changes in crop rotations affected SOC balance in Finland between 2009 and 2018, using geospatial data and Bayesian modeling. The area designated for perennial-dominated and diverse cereal rotations increased over the study period. Perennial grassland rotation was found to have a positive impact on SOC balance, while rotations dominated by annual crops did not differ in their impacts on SOC content. At the national scale, changes in Finnish crop rotations resulted in an estimated annual mitigation of the loss of SOC content by 1336 Mg C year−1 in mineral soils and reduced the carbon dioxide emissions of organic soils by 10,475 Mg C year−1. The combined effect of these two contributions is 11,811 Mg C year−1, with an 80% probability interval of (−6600; 30,300) Mg C year−1. While the overall impact of changes in crop rotations on SOC is relatively small, a continued change to more diverse and perennial-dominated crop rotations may have other agronomic and environmental benefits, e.g. on resilience and biodiversity. [ABSTRACT FROM AUTHOR]

Changes in land usage, increasing climatic uncertainty, and dynamic development of the rate of natural population growth of the Eurasian beaver will lead to increasing benefits and disadvantages from beaver activity. During three growing seasons from 2020 to 2022, four cross-sections were marked on unused sub-irrigation systems with the periodic occurrence of beaver dams, located on organic soils in parts of the facility protected by the Habitats Directive (natural habitat 6510) in Central Poland. Periodic water table measurements in wells, the beds of adjacent ditches, and the riverbed were carried out. Identification of the states and structures of plant communities was done using the botanical-weight analysis of several samples with an area of 1 m2. Beaver dams increased water levels in the river, ditches, and groundwater depth in over 78% of events in 2020–2022 years. A large impact of precipitation on the hydraulic conditions in the meadow was observed. In the studied area, since a moderately moist habitat (6510) is protected within the Natura 2000 network, phenomena increasing soil moisture, in the absence of mowing of meadows and the occurrence of expansive herbaceous vegetation that tolerates increased moisture, may lead to the disappearance of these habitats, especially in the zone near the riverbed. [ABSTRACT FROM AUTHOR]

This study was conducted to verify the usefulness of the laser diffractometer method for determining the particle size distribution of selected organic soils from the Podkarpacie region in Poland. The soil selected for this research represented three main classification groups, namely, low-organic, medium-organic and high-organic soil, in accordance with the standard criterion. Particle size distribution was determined using two types of laser diffractometers: the Helos laser diffractometer manufactured by Sympatec GmbH (Clausthal-Zellerfeld, Germany) and the laser particle size analyzer Analysette 22 MicroTech plus manufactured by Fritsch GmbH (Idar-Oberstein, Germany). The standard mechanical and sedimentation methods, which are perfect for testing mineral soils, are not applicable to organic soils; therefore, a serious problem was found and examined. A reference method that could verify the test results obtained using the laser diffractometer methods was required. After analyzing the literature, the hydrometric (sedimentation) method was adopted as the reference method. Currently, there are no reliable and fully verified methods for testing soils with such a complex skeleton structure, and the resources, standards and guidelines concerning the issues discussed are extremely limited; therefore, new research methods are being sought to fill this gap, and this work is a step in this direction. The results of the conducted studies and analyses have shown that laser diffractometry methods can be useful for determining the particle size distribution of organic soils, but to a limited extent, depending mainly on the quantity of organic substances. The highest agreement was obtained by comparing the results of the sedimentation method with those obtained using the diffractometer analyzer Analysette 22 in the group of highly organic soils. [ABSTRACT FROM AUTHOR]

Soil classification methods currently rely on soil borings or cone/piezocone penetrometer tests (CPT/CPTu). Literature provides several methods that classify soils based on two parameters (typically tip resistance and friction sleeve/porewater pressure) obtained from CPTu data, defining a soil behavior type. However, these methods face challenges in reliably classifying certain soils, such as organic soils. Robust and complex analyses are required to classify organic soils accurately. In this study, a random forest (RF) based method is developed to predict the presence and depth of organic soils. The RF model utilized features from CPTu soundings including tip resistance, sleeve friction, and pore pressure. The true location of organic soils, derived from index properties obtained from soil borings, served as the model's outputs. Unseen CPTu data was used to predict organic soils throughout the entire project alignment, serving as validation for the model. The model achieved an F1 score of 0.89. Settlement analyses were conducted to evaluate the practical implications of the model's predictions on levee fill costs. The RF-based model yielded settlement predictions that closely matched those obtained through boring predictions. In contrast, traditional classification methods underestimated settlements, resulting in lower estimates for levee fill costs. [ABSTRACT FROM AUTHOR]

Globally, annual emissions from managed organic soils accounts for up to 5% of all anthropogenic greenhouse gas (GHG) emissions. Climate-wise management and restoration of degraded organic soils could reduce GHG emissions quickly and at relatively low costs. The European Union (EU) Member States that have large areas of organic soils with high GHG emissions are Sweden, Finland, Germany, Ireland, Poland, Netherlands, and the Baltic countries. To meet the climate targets and objectives of the Paris Agreement the land-use sector is indispensable and mitigation policies targeting organic soils will be needed. The international regulatory framework is broad and quite unspecific. In contrast, the European Union has initiated binding regulation for the land-use sector through the EU Climate Law, the EU LULUCF regulation, and the proposed EU Nature Restoration Law. However, even this regulatory approach is not on track to deliver on its binding ambitions, indicating the need for more effective implementation measures also on organic soils in the EU and its member states. Furthermore, we argue that appropriate policy selection should consider current knowledge regarding the climate impacts of management options of organic soils. Lastly, we need more studies on GHG emissions, and standardized methods for GHG inventories, to resolve uncertainties surrounding the impacts of management to GHG emissions. Successful policy implementation requires more efforts but also improved scientific justification through continuous consideration of climate policy integrity and strengthening of the reliability of GHG inventories. [ABSTRACT FROM AUTHOR]

This article reviews nine soil carbon interventions to reduce soil carbon losses or increase stocks in grazing management systems, using their potential application in Aotearoa New Zealand (A‐NZ) as a case study. The interventions are classified into three strategies: (1) increasing carbon inputs through deep‐rooting and diverse species grasslands, reducing forage cropping and deferred grazing management; (2) increasing protection of carbon stocks by water table management on organic soils, reducing cropping on organic soils, full inversion tillage grassland renewal, the addition of clay minerals and enhanced rock weathering and (3) the adoption of integrated systems including establishing tree clusters into grasslands and agroforestry. We estimated the land area where these interventions could realistically be implemented in A‐NZ and assessed their potential impact on mitigating national overall agricultural greenhouse gas emissions. The potential impact of each intervention ranged from <1% to 2.5% of national agricultural greenhouse gas emissions over 20 years. However, confidence in these approaches is hindered by a lack of research data where these approaches have been tested for different soil types and conditions. Notably, water table management, which reduces carbon loss from organic soils, was the only intervention that could achieve moderate, short‐ and long‐term impacts with a confidence level assessed as 'likely'. We conclude that reducing further soil carbon losses and achieving modest increases in soil carbon stocks are possible but will require economic and political incentives that encourage the integration of multiple interventions at the farm scale. [ABSTRACT FROM AUTHOR]

Background: Flammable vegetation in Tasmania, Australia often grows on organic soils that can burn if sufficiently dry. Aims: To develop an approach to identify a safe window for prescribed burning of vegetation on Tasmanian organic soils, when vegetation is dry enough to be combustible, yet organic soils are unlikely to burn. Methods: We compiled a dataset of when organic soils did and did not burn when exposed to vegetation fires. Focussing on moorland, we used binomial modelling to estimate the probability of organic soil burning in relation to soil dryness index (SDI) computed from climate data. Vegetation combustibility was inferred from fuel moisture content estimated from climate data and records of area burnt. Key results: Risk of soil fire varied with vegetation. In moorland, modelling predicted a 17% risk when SDI was 10, a conservative estimate because our dataset was biased towards positive records of soil fire. Using an SDI threshold of 10, the average annual number of 'safe combustible' days varied across Tasmania from 26 to 53. Conclusions: This approach can be used to refine safe burning guidelines on organic soil. Implications: This approach, when applied to an improved dataset, will assist fire management on organic soils. We propose a method to identify the climate window when prescribed burning in Tasmania, Australia is unlikely to lead to organic soil combustion, using observations of when organic soil fires occurred, and vegetation is dry enough to burn. [ABSTRACT FROM AUTHOR]

Peatlands play a crucial role in carbon storage, but drainage and climate change-induced hydrological changes drivers degrade peat soils, followed by negative vertical displacement of the soil surface, referred to in the literature as peat subsidence. Assessing peatland subsidence is an important indicator of peatland status that allows the development of peatlands to be revealed over a given period. However, traditional methods are limited in their applicability to large and inaccessible peatlands. In this study, we introduce a remote sensing framework for easily indicating peat subsidence at a large scale. Our framework utilizes the Alaska Satellite Facility (ASF) Interferometry Synthetic Aperture Radar (InSAR) with on-demand cloud computing, employing an optimization process including a Small Baseline Set technique and seasonal-annual search approach. By implementing this approach in the Biebrza Valley, Poland, covering the period from April 2015 to April 2022, we unveiled a tragedy, an annual subsidence rate of 1.44 cm. It means a peat loss between 58.1 and 89.6 million cubic meters over seven years, an annual loss of 86.4 to 132.5 (average 109) m3, approximately 46 tons, of dry matter peat per hectare. This finding was verified through field surveys, with high accuracy. An R2 value of 0.7, and an RMSE value of 0.23 cm determine the reliability of this approach in estimating the vertical displacement. The potential of this tool as a robust method to assess large-scale peatlands would allow for the assessment of average water levels as well as greenhouse gas emissions over large areas of peatlands, even at the continental scale.

The paper presents the methods of determining the characteristic value on the basis of the standards: PN-B-03020:1981, PN-EN 1997-1:2008, prEN 1997-1:2022-09 and Schneider formula. Determination of the characteristic value of the undrained shear strength τfu was carried out using statistical method on the basis of the prEN 1997-1:2022-09 standard and Schneider formula. The statistical calculations were based on the results of field vane tests carried out in organic subsoil of test embankment in Antoniny test site before loading and after the 2nd embankment stage. In order to determine the undrained shear strength τfu of organic soils from field vane tests, the measured values of shear strength τf v were corrected using the average values of correction factors μ = μ(lab) determined on the basis of triaxial compression, simple shear and triaxial extension tests. The analysis of the calculation results shows that with relatively numerous data sets, large values of the coefficient of variation Vx result in significantly lower characteristic values of τfu obtained according to prEN 1997-1:2022-09, compared to the values obtained according to the Schneider formula. In the case of few data sets, for which high values of the coefficient kn are obtained, with high values of the coefficient of variation Vx , the comparison of the values according to prEN 1997-1:2022-09 with the values obtained according to the Schneider formula shows the greatest differences.

Areas excluded from agricultural production are susceptible to the presence of beaver families. The most significant changes occur during the initial period, when agricultural utilization is abandoned and beavers establish their presence on the land. During this period, some parcels remain uncultivated, while agricultural activities persist in neighboring areas. This situation is accompanied by the destruction of beaver dams, especially during periods of abundant water resources, and notably during intensive fieldwork. The article presents field studies aimed at determining the extent to which constructed and operational beaver dams contribute to changes in groundwater levels in drained peatland areas. In order to protect and sustainably use peat soils, it is necessary to maintain their high moisture content by ensuring a high groundwater level elevation. This can be achieved through the use of existing damming structures in the area (levees, weirs). Beaver dams can also serve a similar function, blocking the outflow of water from peat lands by raising the water level and consequently retaining it naturally. The specific objective was to develop principles for verifying factors influencing the effects of beaver dam construction on groundwater levels in fields within their range of influence. The water table levels within the study area during rainless periods were influenced by water levels in ditches, dependent on beaver activity in the nearby river. Beaver activities, manifested through dam construction, were influenced by periodic water resources in the river, defined by the cumulative monthly precipitation. Factors affecting groundwater levels in rainless periods on the plots also included the distance from the river cross-section and the permeability of soils expressed by the filtration coefficient of the active layer. Beaver dams had the greatest impact on stabilizing the water table in the soil profile closest to the river. [ABSTRACT FROM AUTHOR]

Disappearance of lakes is one of the most dangerous processes affecting the entire natural environment, including soil. This phenomenon is considered natural, resulting from climate change, however in recent decades, a significant acceleration of this process has been observed due to the direct impact of human activity. In areas directly adjacent to lakes, organic soils usually predominate. Unfortunately, wetlands are increasingly being drained and used for agricultural purposes. Under such circumstances, changes in the physical and chemical properties of these soils are often irreversible, causing their degradation. As an effect of increased mineralization, a number of typical modifications occur in soils, such as carbon loss, increased degree of peat decomposition, and changes in soil structure. Long-term dehydration has led to muck formation. Additionally, lowering of lake water uncovers previously flooded areas and increases the intensity of soil-forming processes. However, the presence of the Subaquatic qualifier in the World Reference Base for Soil Resources (WRB) suggests that sediments in shallow water bodies no more than 200 cm deep can also be classified as soils. The progressive disappearance of lakes observed all over the world is therefore a process affecting not only the reduction of water bodies, but also changes in the properties and typology of soils and vegetation cover. [ABSTRACT FROM AUTHOR]

Tree establishment on peatlands has various adverse effects on the environment, with one of the most significant being their transformation from carbon sinks to carbon sources. This transformation has largely been instigated by economic-driven ditching initiatives. In this study, 80 peat-rooted pine seedlings were subjected to hydrological scenarios corresponding to natural, ditched, and rewetted conditions to investigate how different management strategies affect tree growth and survival. The study was conducted in a greenhouse where all plants were exposed to identical conditions except for the water level, and focused on factors like stomatal conductance, plant survival, length, biomass, and radial tree growth. Wet conditions, specifically treatments rewetted and natural, resulted in consistently lower stomatal conductance compared to drier treatments. Plant survival was affected, with 15 deaths in the rewetted and 2 in natural groups. Moreover, length, biomass, radial growth, and cell formation were significantly lower for the groups exposed to wet conditions. Rewetting can therefore effectively control tree colonisations, and thereby preventing water consumption, litter fertilisation, and other positive feedback effects for the trees that might be negative for the carbon uptake and biodiversity in peatlands. This study thereby offers valuable insights for rewetting initiatives in tree colonised peatland ecosystems. [ABSTRACT FROM AUTHOR]

In Germany, emissions from drained organic soils contributed approximately 53.7 Mio. t of carbon dioxide equivalents (CO2-eq) to the total national greenhouse gas (GHG) emissions in 2021. In addition to restoration measures, shifting management practices, rewetting, or using peatlands for paludiculture is expected to significantly reduce GHG emissions. The effects of climate change on these mitigation measures remains to be tested. In a 2017 experimental field study on agriculturally used grassland on organic soil, we assessed the effects of rewetting and of predicted climate warming on intensive grassland and on extensively managed sedge grassland (transplanted Carex acutiformis monoliths). The testing conditions of the two grassland types included drained versus rewetted conditions (annual mean water table of − 0.13 m below soil surface), ambient versus warming conditions (annual mean air temperature increase of + 0.8 to 1.3 °C; use of open top chambers), and the combination of rewetting and warming. We measured net ecosystem exchange of CO2, methane and nitrous oxide using the closed dynamic and static chamber method. Here, we report the results on the initial year of GHG measurements after transplanting adult Carex soil monoliths, including the controlled increase in water level and temperature. We observed higher N2O emissions than anticipated in all treatments. This was especially unexpected for the rewetted intensive grasslands and the Carex treatments, but largely attributable to the onset of rewetting coinciding with freeze–thaw cycles. However, this does not affect the overall outcomes on mitigation and adaptation trends. We found that warmer conditions increased total GHG emissions of the drained intensive grassland system from 48.4 to 66.9 t CO2-eq ha−1 year−1. The shift in grassland management towards Carex paludiculture resulted in the largest GHG reduction, producing a net cooling effect with an uptake of 11.1 t CO2-eq ha−1 year−1. Surprisingly, we found that this strong sink could be maintained under the simulated warming conditions ensuing an emission reduction potential of − 80 t CO2-eq ha−1 year−1. We emphasize that the results reflect a single initial measurement year and do not imply the permanence of the observed GHG sink function over time. Our findings affirm that rewetted peatlands with adapted plant species could sustain GHG mitigation and potentially promote ecosystem resilience, even under climate warming. In a warmer world, adaptation measures for organic soils should therefore include a change in management towards paludiculture. Multi-year studies are needed to support the findings of our one-year experiment. In general, the timing of rewetting should be considered carefully in mitigation measures. [ABSTRACT FROM AUTHOR]

Peatlands cover only 3–4% of the Earth's surface, but they store nearly 30% of global soil carbon stock. This significant carbon store is under threat as peatlands continue to be degraded at alarming rates around the world. It has prompted countries worldwide to establish regulations to conserve and reduce emissions from this carbon rich ecosystem. For example, the EU has implemented new rules that mandate sustainable management of peatlands, critical to reaching the goal of carbon neutrality by 2050. However, a lack of information on the extent and condition of peatlands has hindered the development of national policies and restoration efforts. This paper reviews the current state of knowledge on mapping and monitoring peatlands from field sites to the globe and identifies areas where further research is needed. It presents an overview of the different methodologies used to map peatlands in nine countries, which vary in definition of peat soil and peatland, mapping coverage, and mapping detail. Whereas mapping peatlands across the world with only one approach is hardly possible, the paper highlights the need for more consistent approaches within regions having comparable peatland types and climates to inform their protection and urgent restoration. The review further summarises various approaches used for monitoring peatland conditions and functions. These include monitoring at the plot scale for degree of humification and stoichiometric ratio, and proximal sensing such as gamma radiometrics and electromagnetic induction at the field to landscape scale for mapping peat thickness and identifying hotspots for greenhouse gas (GHG) emissions. Remote sensing techniques with passive and active sensors at regional to national scale can help in monitoring subsidence rate, water table, peat moisture, landslides, and GHG emissions. Although the use of water table depth as a proxy for interannual GHG emissions from peatlands has been well established, there is no single remote sensing method or data product yet that has been verified beyond local or regional scales. Broader land-use change and fire monitoring at a global scale may further assist national GHG inventory reporting. Monitoring of peatland conditions to evaluate the success of individual restoration schemes still requires field work to assess local proxies combined with remote sensing and modeling. Long-term monitoring is necessary to draw valid conclusions on revegetation outcomes and associated GHG emissions in rewetted peatlands, as their dynamics are not fully understood at the site level. Monitoring vegetation development and hydrology of restored peatlands is needed as a proxy to assess the return of water and changes in nutrient cycling and biodiversity. [ABSTRACT FROM AUTHOR]

Numerous studies focus on investigating organic soils with high organic content. However, only a limited amount of literature discusses the properties and behaviour of low organic content soils. Sri Lankan organic soil is an excellent example of a low organic content soil, demonstrating different behaviour from highly organic fibrous soil. Scanning electron microscope (SEM) images of Sri Lankan organic soil were studied to determine the reasons for these observed variations. Sri Lankan organic soils were observed to consist of highly decomposed organic matter in an amorphous state with higher proportions of mineral matter. The microstructure characteristics observed through SEM images mostly explained the variation of properties and behaviour of the Sri Lankan organic soil in contrast to highly organic fibrous soil. Correlations were also derived between properties of Sri Lankan organic soil and compared with similar relationships derived from other geological conditions. While some correlations derived in this study closely follow the relationships for other organic soils with similar microstructure characteristics, the acidity of the deposit resulted in different behaviour of a few correlations. This study improves the current knowledge of the effect of microstructure characteristics on the properties and behaviour of Sri Lankan low-organic clayey soils, which otherwise primarily depend on theories for highly organic peaty soils. Furthermore, the correlations derived and validated for low organic soils can be utilized in any organic clay deposit with similar microstructure characteristics. [ABSTRACT FROM AUTHOR]

Globally, annual emissions from managed organic soils accounts for up to 5% of all anthropogenic greenhouse gas (GHG) emissions. Climate-wise management and restoration of degraded organic soils could reduce GHG emissions quickly and at relatively low costs. The European Union (EU) Member States that have large areas of organic soils with high GHG emissions are Sweden, Finland, Germany, Ireland, Poland, Netherlands, and the Baltic countries. To meet the climate targets and objectives of the Paris Agreement the land-use sector is indispensable and mitigation policies targeting organic soils will be needed. The international regulatory framework is broad and quite unspecific. In contrast, the European Union has initiated binding regulation for the land-use sector through the EU Climate Law, the EU LULUCF regulation, and the proposed EU Nature Restoration Law. However, even this regulatory approach is not on track to deliver on its binding ambitions, indicating the need for more effective implementation measures also on organic soils in the EU and its member states. Furthermore, we argue that appropriate policy selection should consider current knowledge regarding the climate impacts of management options of organic soils. Lastly, we need more studies on GHG emissions, and standardized methods for GHG inventories, to resolve uncertainties surrounding the impacts of management to GHG emissions. Successful policy implementation requires more efforts but also improved scientific justification through continuous consideration of climate policy integrity and strengthening of the reliability of GHG inventories.

Peatland degradation might affect peatland functions. Sustainable agriculture practice, i.e., nutrient management, is one of the efforts that could be made to delay the degradation. Therefore, this research aimed to identify the best nutrient management practice for shallot production in degraded peatlands. A split-plot experimental design was performed in a greenhouse environment, with cultivars (Sembrani and Trisula) as the main plot and eleven combinations of NPK fertilizer as the subplot. All treatments received 4.4 t ha-1 dolomite to increase the soil pH. Results showed that Sembrani produced a higher bulb yield than Trisula. Trisula was sensitive to acidic soils and failed to yield a high bulb. The NPK recommended dose for Sembrani was 150 kg N ha-1, 100 kg P2O5 ha-1, and 100 kg K2O ha-1, producing 57.50 g plant-1 equal to 14.4 t ha-1 or 53% higher than the control (without NPK). Meanwhile, growing Trisula was not recommended for peatlands.

The paper presents the course of variability of the moisture content of the top layers in shallow (45 cm) and medium-deep (90 cm) peat-moorsh soil profiles in the years 2015–2019 against the background of the same meteorological conditions and a similar level of the groundwater table. The relative precipitation index ( RPI) classifies the years 2015 and 2016 as dry, 2017 as wet, and 2018 and 2019 as average. For periods of atmospheric droughts, the average daily climatic water balance ( CWB) ranged from –5.30 to –1.35 mm∙d –1. The water table did not fall below 90 cm b.g.l. during the entire study period, and the range of its fluctuations was 8 cm greater in the shallow than in the medium-deep profile. The range of moisture at different depths varied significantly and ranged from approx. 6% in periods of drought to about 80% in wet periods. Soil moisture throughout the measurement period was above the plant available water range (p F > 4.2). The occurrence of soil drought in the shallow peat-moorsh soil profile had a range of up to 40 cm, and in the medium-deep profile of up to 30 cm. The sequence of no-precipitation days and the maximum amount of daily evapotranspiration during them determine the possible timing of drought; however, it is the precipitation distribution in individual months, considered in the current CWB values, that ultimately determine the formation of soil water resources at the research site.

Changes in land usage, increasing climatic uncertainty, and dynamic development of the rate of natural population growth of the Eurasian beaver will lead to increasing benefits and disadvantages from beaver activity. During three growing seasons from 2020 to 2022, four cross-sections were marked on unused sub-irrigation systems with the periodic occurrence of beaver dams, located on organic soils in parts of the facility protected by the Habitats Directive (natural habitat 6510) in Central Poland. Periodic water table measurements in wells, the beds of adjacent ditches, and the riverbed were carried out. Identification of the states and structures of plant communities was done using the botanical-weight analysis of several samples with an area of 1 m2. Beaver dams increased water levels in the river, ditches, and groundwater depth in over 78% of events in 2020–2022 years. A large impact of precipitation on the hydraulic conditions in the meadow was observed. In the studied area, since a moderately moist habitat (6510) is protected within the Natura 2000 network, phenomena increasing soil moisture, in the absence of mowing of meadows and the occurrence of expansive herbaceous vegetation that tolerates increased moisture, may lead to the disappearance of these habitats, especially in the zone near the riverbed.

This study was conducted to verify the usefulness of the laser diffractometer method for determining the particle size distribution of selected organic soils from the Podkarpacie region in Poland. The soil selected for this research represented three main classification groups, namely, low-organic, medium-organic and high-organic soil, in accordance with the standard criterion. Particle size distribution was determined using two types of laser diffractometers: the Helos laser diffractometer manufactured by Sympatec GmbH (Clausthal-Zellerfeld, Germany) and the laser particle size analyzer Analysette 22 MicroTech plus manufactured by Fritsch GmbH (Idar-Oberstein, Germany). The standard mechanical and sedimentation methods, which are perfect for testing mineral soils, are not applicable to organic soils; therefore, a serious problem was found and examined. A reference method that could verify the test results obtained using the laser diffractometer methods was required. After analyzing the literature, the hydrometric (sedimentation) method was adopted as the reference method. Currently, there are no reliable and fully verified methods for testing soils with such a complex skeleton structure, and the resources, standards and guidelines concerning the issues discussed are extremely limited; therefore, new research methods are being sought to fill this gap, and this work is a step in this direction. The results of the conducted studies and analyses have shown that laser diffractometry methods can be useful for determining the particle size distribution of organic soils, but to a limited extent, depending mainly on the quantity of organic substances. The highest agreement was obtained by comparing the results of the sedimentation method with those obtained using the diffractometer analyzer Analysette 22 in the group of highly organic soils.

Changes in soil use have detrimental effects on its properties. This research was conducted to evaluate the physical degradation of histosol soils in the Putumayo department, Colombia. To do so, two types of areas were assessed: those without intervention (T0) and areas affected by mound structures caused by combined actions of livestock and high humidity, commonly known as "tatucos." These areas were categorized based on the percentage of deformation incidence: low degradation (T1); moderate (T2); and high (T3). Sampling was done at a depth of 15 cm, both in the tatucos-affected zone and its surrounding area. The height and diameter of the mound were measured, along with physical properties: apparent and bulk density, porosity, volumetric moisture, penetration resistance, and degree of organic material decomposition. The primary soil use in the area is extensive livestock farming. It was established that in areas with high degradation (T3), there was an average mound diameter of 151.9 ± 4.46 cm and a height of 22.7 ± 2.59 cm. Regarding physical properties, there was an apparent density of 0.24 g.cm-3, a bulk density of 1.62 g.cm-3, and a penetration resistance of 0.71 MPa. These values were significantly higher than those observed in the areas without intervention. Therefore, it is inferred that the alteration of land use causes a change in physical properties, which are vital for agro ecosystems in the southern regions of Colombia.

Copyright of Irrigation & Drainage is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Peatland degradation might affect peatland functions. Sustainable agriculture practice, i.e., nutrient management, is one of the efforts that could be made to delay the degradation. Therefore, this research aimed to identify the best nutrient management practice for shallot production in degraded peatlands. A split-plot experimental design was performed in a greenhouse environment, with cultivars (Sembrani and Trisula) as the main plot and eleven combinations of NPK fertilizer as the subplot. All treatments received 4.4 t ha-1 dolomite to increase the soil pH. Results showed that Sembrani produced a higher bulb yield than Trisula. Trisula was sensitive to acidic soils and failed to yield a high bulb. The NPK recommended dose for Sembrani was 150 kg N ha-1, 100 kg P2O5 ha-1, and 100 kg K2O ha-1, producing 57.50 g plant-1 equal to 14.4 t ha-1 or 53% higher than the control (without NPK). Meanwhile, growing Trisula was not recommended for peatlands. [ABSTRACT FROM AUTHOR]

Copyright of Revista de Ciencias Agricolas is the property of University of Narino, Faculty of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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Drained tropical peat soils for agriculture emit more carbon dioxide (CO2) into the atmosphere from their stored carbon compared with their pristine state. Field and laboratory experiments were conducted to assess whether the natural zeolite of the clinoptilolite (ZeoC) species could be included in the pineapple fertilization program to decrease the CO2 emissions from tropical sapric soils. The static closed-chamber and laboratory incubation methods were used to determine the effects of ZeoC on the CO2 emitted from a drained sapric soil planted with Moris pineapple. The treatments assessed were as follows: (a) suggested ratio of ZeoC (5 g, 10 g, 14 g, and 20 g of ZeoC) and 20 g compound NPK 30:1:32 fertilizer, enumerated based on the pineapple plant requirement; (b) 20 g of compound NPK 30:1:32 fertilizer only; and (c) unfertilized sapric soils. The drained sapric soils amended with ZeoC (rate of 5 g to 20 g/plant) minimized the CO2 emissions compared with those without the ZeoC, because of the physical and chemical sorption of organic compounds and polar CO2 onto the lattices of ZeoC, which inhibited organic matter decomposition. ZeoC fertilization reduces sapric soil acidity and improves Moris pineapple fruit quality attributes and yield. Monthly pineapple fertilization with ZeoC at the vegetative and flowering phases is an alternative agronomic strategy to reduce CO2 emissions. This approach does not reduce pineapple yield on drained tropical sapric soils. [ABSTRACT FROM AUTHOR]

Global climate change impact has increased in recent decades and put urgency on implementing effective climate change mitigation (CCM) activities. Rewetting of drained peatlands is an acknowledged measure to reduce GHG emissions from organic soils in the agriculture and land use sectors. Under waterlogged conditions, decomposition of organic matter in peat decreases, and emissions of CO2 are reduced. Thus, the soil carbon stock is saved, and wet management of the site reactivates carbon sequestration. To reach CCM targets, the first rewetting and paludiculture trials have been implemented in Latvia. In this article, we review the current status of paludiculture in Latvia and evaluate the pros and cons of their wider implementation. The majority of paludiculture projects and pilot studies in Latvia have not been published so far and are reported here for the first time. Our assessment of paludiculture shows that trails on Alnus, Phalaris, Phragmites, Sphagnum, and Typha installed by the private enterprises have promising results for upcoming large-scale implementation. There are available areas for paludiculture in Latvia, but the current legislation and national framework policies (environment, agriculture, forest, and climate) do not fully support such activities yet and must be adapted. [ABSTRACT FROM AUTHOR]

The paper presents the course of variability of the moisture content of the top layers in shallow (45 cm) and medium-deep (90 cm) peat-moorsh soil profiles in the years 2015-2019 against the background of the same meteorological conditions and a similar level of the groundwater table. The relative precipitation index (RPI) classifies the years 2015 and 2016 as dry, 2017 as wet, and 2018 and 2019 as average. For periods of atmospheric droughts, the average daily climatic water balance (CWB) ranged from -5.30 to -1.35 mm·d-1. The water table did not fall below 90 cm b.g.l. during the entire study period, and the range of its fluctuations was 8 cm greater in the shallow than in the medium-deep profile. The range of moisture at different depths varied significantly and ranged from approx. 6% in periods of drought to about 80% in wet periods. Soil moisture throughout the measurement period was above the plant available water range (pF > 4.2). The occurrence of soil drought in the shallow peat-moorsh soil profile had a range of up to 40 cm, and in the medium-deep profile of up to 30 cm. The sequence of no-precipitation days and the maximum amount of daily evapotranspiration during them determine the possible timing of drought; however, it is the precipitation distribution in individual months, considered in the current CWB values, that ultimately determine the formation of soil water resources at the research site. [ABSTRACT FROM AUTHOR]

The purpose of the study was to determine the geotechnical properties of peat and relate them to the fibre content. Peat soil tested in this study was collected from the peatland in the north-eastern Poland, 250 km north-east of Warsaw. Peat samples were taken from eight different depths below the ground surface over an area of approximately 2500 m2. The research programme consisted of laboratory tests of the physical properties of peat and compressibility tests conducted in oedometers. Tests were performed in accordance with the current international and European standards using specialised research equipment. Based on the degree of decomposition, peat was divided into fibric (with more than 66% of fibres), hemic (fibre content from 33% to 66%) and sapric (less than 33% of plant fibres). The bulk and particle densities, natural water content, organic content, initial void ratio and the degree of decomposition were investigated as the physical properties of peat. Based on the oedometer tests, the constrained modulus, compression and secondary compression indexes were determined. It was concluded that the fibric peat is characterised by the lowest bulk and particle densities, the highest water and organic contents, void ratio and compressibility in comparison to hemic and sapric peat. The characteristics of peat have been related to the results presented in the literature.

The Marchetti Dilatometer test is a non-destructive in situ test that can be used to determine the geotechnical properties of soils. This paper presents the results of a study that investigated the correlations between the parameters obtained from the Marchetti Dilatometer test and geomechanical parameters for soft soils, mainly organic soils, obtained in the laboratory. The study was conducted in the El Garrochal sector in Southern Quito, Ecuador. The results of the study showed that there are significant correlations between the Marchetti Dilatometer test and the undrained shear strength, modulus of elasticity, and density of soil. The equations that were developed in this study can be used to estimate these geomechanical parameters from the results of the Marchetti Dilatometer test for the South Quito sector, which are valuable for geotechnical engineers to design structures in these types of soils. The equations that were developed in this study can be used to improve the accuracy of the design of these structures. [ABSTRACT FROM AUTHOR]

This paper deals with the problem of determining the particle size distribution of selected organic soils from the vicinity of Rzeszów (Poland), using a laser diffractometer method, the knowledge of which will allow to determine the degree of differentiation or similarity of the tested organic soils in this aspect. The HELOS Laser Diffractometer manufactured by Sympatec GmbH was used for the tests. For proper analysis, the researches results in the form of graphs were grouped according to the content of organic substances in accordance with the standard classification. The conducted research was primarily aimed at presenting the grain differentiation and particle size distribution in terms of the applied method and comparing the test results of samples of selected, different organic soils, prepared using the same dispersion procedure and carried out in exactly the same test conditions, generated using capabilities of a diffractometer. Summing up, the laser diffractometer method presented in the article, although not fully verified in the case of organic soils, seems to be a the perspective method with capabilities allowing it to be nominated as an exceptionally useful method for the investigations of soft soils, including organic soils. [ABSTRACT FROM AUTHOR]

Meadows on organic soils perform an essential role as a source of fodder and biomass for energy purposes. In the case of intensive meadows, it is crucial to use grass mixtures that enable obtaining high yields of good quality; however, on organic soils, the grass species composition changes dynamically. We carried out the full cultivation (ploughing) for grassland restoration. The floristic composition of meadow sward in the first year of full use (2013) was similar to the composition of mixtures used for sowing (2012) individual plots. Festuca arundinacea and Phleum pratense showed greater resistance to low temperatures in winter and excess water in spring compared to Lolium perenne. In comparison, we obtained the highest yield (fresh and dry mass) from mixtures with Festuca arundinacea and Lolium perenne. We obtained the best quality forage from the first swath and the object with the highest share of Lolium perenne. For grassland restoration in the analysed habitat, it is reasonable to use grass mixtures with varied compositions, in which the share of Lolium perenne is between 25–50%. [ABSTRACT FROM AUTHOR]

The aim of this paper is to study the effect of the organic matter (OM) content on the effectiveness of the soil stabilization process using the biopolymer xanthan gum. Five different artificial soils with an organic matter content in the range of 1.5 to 7.7% are subjected to unconfined compressive strength (UCS) and oedometer tests to evaluate their strength, stiffness and compressibility, respectively. These results are complemented by an analysis of SEM images. The results from the UCS tests show a positive effect of the stabilization process in terms of strength and stiffness in a range of an OM content of 1.5 to 5.5%, but a detrimental effect for a higher OM content (7.7%) is observed. Due to the hydration of the biopolymer's hydrogels, the compressibility tends to increase in specimens stabilized with xanthan gum. This effect is amplified for higher OM contents. The results of oedometer tests also show that the stabilization with xanthan gum brings about a significant decrease in the coefficient of consolidation, inducing an increase in the primary consolidation time. [ABSTRACT FROM AUTHOR]

Influence of humic substances on the strength of binder‐improved organic soils Organogenic and organic soils are often classified as having a low bearing capacity and therefore mostly do not meet the requirements on civil engineering use for common geotechnical structures. Soil stabilization methods make it possible to increase the strength and stiffness of soft soils, e.g. by mixing binders into the soil matrix and thus, achieve the important societal goals of resource conservation and waste avoidance. However, the processes involved in cement hydration under the presence of organic components are very complex and multivariate. In particular, the soluble fraction of humic substances in the organic material can lead to the target design strength not being achieved. In order to investigate the influence of humic substances, in particular humic acids, on the strength‐determining cement hydration, the objective of the present study was to quantify the humic fractions of different organic soils in order to asses processes involved in the setting process during subsequent strength testing. In addition, a color scale was developed for the qualitative determination of humic acids, which is proposed for use in practice. The analysis of the humic fractions is based on their extraction and subsequent determination by UV/VIS spectroscopy using calibration standards. The subsequent testing of the unconfined compressive strength is based on binder‐improved sand samples, to which organic material was added in different proportions. It is shown that not only the choice of the binder nor the proportion of the organic admixtures, but in particular the composition of the organic material has an influence on the stabilization potential of organogenic and organic soils. [ABSTRACT FROM AUTHOR]

Stored carbon varies among wetlands, yet they rank among the highest carbon accumulating ecosystems. Leaf litter production and aboveground carbon storage are frequently used as proxies for estimating primary productivity, which can be affected by flooding, salinity and other environmental factors. The objective of this study was to quantify leaf litter production and soil carbon density in two coastal tropical wetland types, namely mangrove swamps and forested freshwater wetlands. Water and soil physicochemical properties, together with leaf litter production, were measured bimonthly between 2007 and 2009 in wetlands of both types, located on the coast of the Gulf of Mexico. The soils ranged from entirely mineral to entirely organic in the top metre. Mangrove sites had relatively uniform hydroperiods and moderately reductive soils, whereas forested freshwater wetlands had reducing conditions. Electrical conductivity was lower and pH less acidic in forested freshwater wetland soils. Litterfall was around 1000 g m-2 yr-1 and annual production did not differ significantly between wetlands, despite the presence of acidic soils with prolonged flooding and high salinity in the mangrove swamps. Also, there were no consistent differences in soil carbon density between the two wetland types. Some forested freshwater wetlands had low litter production and high soil carbon density, whereas some mangrove swamps had high litter production and low soil carbon density. We present information regarding aboveground biomass turnover and belowground carbon storage in coastal tropical forested wetlands which is greatly needed to support us in understanding, valuing and conserving these neglected ecosystems.

This paper discusses the use of the Casagrande Cup and Cone Penetrometer Methods for determining the liquid limit of selected organic soils in in the south-eastern region of Poland in laboratory conditions in accordance with the latest standard guidelines. 10 methods established on the basis of literature materials were used to interpret the test results: 4 for test in the Casagrande Cup and 6 for the Cone Penetrometer. The results were compared and used to determine the parameters necessary to assessment of consistency of all type of soils, e.g.: plasticity index ���� (%), consistency index ���� (–) or liquidity index ���� (–). The knowledge of these parameters makes it possible to determine the degree of plasticity of the tested soils using the Cassagrande chart. The conducted research and analyses have shown that the results of determining the liquid limit using the selected methods are not always comparable. The application of calculation methods based on the results of laboratory tests organic soils carried out in accordance with the procedures of the one standard (PN-B-04481: 1988), in the case of interpretation with Method No. 5 and Method No. 7, generated results with the widest range and the highest values in relation to the reference values (Method No. 1). In terms of the suitability of a given method, the type of tested soil, extremely complicated, diverse and heterogeneous structure turned out to be important, and most importantly, the content of organic parts, as evidenced by the results of consistency determination.

ABSTRACT In the Cerrado, the palm swamps ( veredas ) are characterized by being humid and stable environments that lead to the formation of Histosols ( Organossolos ). and soils with surface horizons of organic constitution, which are fragile and sensitive to anthropic action. This study aimed to evaluate the impact of anthropization (recurrent forest fires and livestock farming) on the chemical, physical and morphological properties of soils in two palm swamps in the Environmental Preservation Area (EPA) of Pandeiros River, Minas Gerais, namely: Água Doce, in preserved condition, and Taboa, in anthropized condition. Four soil profiles were morphologically described, two profiles in each palm swamp, with subsequent chemical and physical analyses, calculations of organic carbon stock and identification of the origin of organic matter. The results were analyzed using descriptive statistics and Pearson’s correlation coefficient. Soil morphological properties were influenced by vegetation cover, drainage and anthropization conditions. As for the physical and chemical properties, adequate values were observed in the preserved palm swamp, including lower bulk density values and higher cation contents. Anthropic actions in the anthropized palm swamp caused degradation of soils, revealed by subsidence, reduction in organic carbon content, increase in bulk density and decrease in fertility. Changes promoted in the soils of the palm swamps compromise ecosystem services, indicating that actions at either local or governmental level should be stimulated for the preservation and conservation of these environments.

Integrating peatland restoration measures with climate policy is critical for meeting climate targets, but the current policies often fall short of utilizing the large potential that exists. Despite growing private sector interest, few regional voluntary carbon markets for peatlands have emerged worldwide. In this study, we explore three pioneering examples from Europe. From the perspective of social innovation, we aim to provide clarity on how these innovations emerged and developed, which actors drove the innovation process by assuming which roles, and which factors fostered or hindered the development. We do so by mapping the innovation process using Process Net-Map. The results show that all three cases have followed remarkably similar patterns in their innovation processes. Four phases, i.e. preparation, definition, refinement, and up-scaling were identified, as were actors' roles as innovators, promoters, intermediaries, implementers, and knowledge providers. However, the case studies are very different with regard to which actor constellation drove the innovation process: MoorFutures is driven by public and scientific actors, Valuta vor Veen is promoted by civil society actors in consultation with practitioners, and Hiilipörssi shifted from civil society to private actors. The governance modes, that is, actor constellation and their goals, have led to differences in concept, robustness of methodology, mitigation measure, and possibly potential for up-scaling. Our study indicates that the timing of interventions when actors with certain roles stepped in can accelerate the innovation process. Important political, economic, technical, and social factors influencing the innovation process, especially knowledge and trust accumulated between some key actors, are outlined. Private funding for regional voluntary carbon markets (VCMs) can tap the climate mitigation potential from peatlands, which is not currently adequately addressed by governments. Actor constellation drove the innovation process, leading to different concepts, methodologies, and mitigation measures. The timing of interventions by actors, notably providing seed funding, network, expertise and visibility, was critical for success. Building trust for regional VCMs requires not only a robust methodology to calculate emission reductions but also partnership and endorsement. The future development of climate policy on peatlands could be a decisive factor in regional VCMs. [ABSTRACT FROM AUTHOR]

In engineering practice, due to the high compressibility and very low shear strength of organic soils, it is difficult to construct an embankment on organic subsoil. High variability and significant change in geotechnical parameters cause difficulties in predicting the behavior of organic soils under embankment loading. The aim of the paper was to develop empirical relationships used in the preliminary design for evaluating the settlement and undrained shear strength of organic subsoil loaded by embankment based on data obtained from four test sites. Statistical multiple regression models were developed for evaluating the settlement in time and undrained shear strength in time individually for peat and gyttja. Neural networks to predict the settlement and undrained shear strength in time for peat and gyttja simultaneously as double-layer subsoils as well as a separate neural network for peat and a separate neural network for gyttja as single-layer subsoils were also developed. The vertical stress, thickness, water content, initial undrained shear strength of peat and gyttja, and time were used as the independent variables. Artificial neural networks are characterized by greater prediction accuracy than statistical multiple regression models. Multiple regression models predict dependent variables with maximum relative errors of about 35% to about 60%, and neural networks predict output variables with maximum relative errors of about 25% to about 30%. [ABSTRACT FROM AUTHOR]

Crop productivity on tropical peat soils is poor partly because of their nutrient deficiency and the acidic nature of tropical peat soils. Ammonium (NH4+) and nitrate (NO3– ) ions are commonly leached from tropical peat soils principally because of high rainfall and lack of clay to retain these nutrients. Leaching of these ions into water bodies causes water pollution through eutrophication which has been implicated in disrupting productive aquatic life. To reverse this act of environmental quality degradation, clinoptilolite zeolite (CZ) could be used to retain nutrients including NH4+ and NO3– in tropical peat soils for crop use because of the alkalinity and high affinity of CZ for retention of macronutrients. Moreover, this approach could be used as an innovative and sustainable alternative for high use of lime (CaCO3 ) because of the liming effect of CZ. However, information on using CZ on tropical peat soils is scarcely explored. Thus, CZ was tested in a leaching study to determine its effects on soil total nitrogen (N), exchangeable ammonium, and nitrate retention in a tropical peat soil. Treatments evaluated were: (i) soil only, (ii) nitrogen, phosphorus, potassium (NPK) fertilizer alone, and (iii) combination of different amounts of clinoptilolite zeolite (25%, 50%, 75%, and 100%) and different amounts of NPK fertilizer (50%, 75%, and 100%). The peat soils with CZ improved soil pH, exchangeable NH4+, and available NO3– . The mixture of CZ and NPK fertilizer reduced NH4+ and NO3– loss because CZ has high affinity for NH4+ whereas NO3– was absorbed into the channels of CZ. Co-application of 100% CZ with 100%, 75%, and 50% NPK fertilizer, together with 75%, 50%, and 25% CZ with 100% fertilizer increased total N of the peat soil. Ability of CZ to buffer the soil pH reduces the need for liming. This alternative way of retaining N in tropical peat soils is practical and a sustainable approach for improving peat soil productivity. [ABSTRACT FROM AUTHOR]

Global climate change impact has increased in recent decades and put urgency on implementing effective climate change mitigation (CCM) activities. Rewetting of drained peatlands is an acknowledged measure to reduce GHG emissions from organic soils in the agriculture and land use sectors. Under waterlogged conditions, decomposition of organic matter in peat decreases, and emissions of CO2 are reduced. Thus, the soil carbon stock is saved, and wet management of the site reactivates carbon sequestration. To reach CCM targets, the first rewetting and paludiculture trials have been implemented in Latvia. In this article, we review the current status of paludiculture in Latvia and evaluate the pros and cons of their wider implementation. The majority of paludiculture projects and pilot studies in Latvia have not been published so far and are reported here for the first time. Our assessment of paludiculture shows that trails on Alnus, Phalaris, Phragmites, Sphagnum, and Typha installed by the private enterprises have promising results for upcoming large-scale implementation. There are available areas for paludiculture in Latvia, but the current legislation and national framework policies (environment, agriculture, forest, and climate) do not fully support such activities yet and must be adapted.