Peat Soil Samples Research Articles

Microbial DNA sample preservation and possible artifacts for field-based research in remote tropical peatlands

Surveying bacterial and archaeal microbial communities in host and environmental studies requires the collection and storage of samples. Many studies are conducted in distant locations challenging these prerequisites. The use of preserving buffers is an important alternative when lacking access to cryopreservation, however, its effectivity for samples with challenging chemistry or samples that provide opportunities for fast bacterial or archaeal growth upon exposure to an aerobic environment, like peat samples, requires methodological assessment. Here, in combination with an identified optimal DNA extraction kit for peat soil samples, we test the application of several commercial and a homemade preservation buffer and make recommendations on the method that can most effectively preserve a microbiome reflective of the original state. In treatments with a non-optimal buffer or in the absence, we observed notable community shifts beginning as early as three days post-preservation lowering diversity and community evenness, with growth-driven artifacts from a few specific phyla. However other buffers retain a very close composition relative to the original state, and we described several metrics to understand some variation across them. Due to the chemical effects of preservation buffers, it is critical to test their compatibility and reliability to preserve the original bacterial and archaeal community in different environments.

Human health and ecological risk assessment of heavy metals in topsoil of different peatland use types

Peatlands, known for their ability to retain and immobilize heavy metals due to unique waterlogged conditions and organic matter, face challenges when subjected to disturbances such as land use changes. These disruptions alter the organic matter, redox potential, and pH of the peatsoil, potentially influencing the migration, mobilization, and increased availability of stored heavy metals. Peatsoil samples from various peatland use types (improved and semi-natural grassland, forest, industrial cutaway bog) were collected to assess the human health and ecological risk associated with heavy metals (Cd, Cu, Hg, Pb, and Zn) in Co-Offaly, Ireland. Results reveal variations in heavy metal concentrations across peatland use types, with Cd, Hg, and Pb in improved and semi-natural grassland peatsoils exceeding the World Health Organization (WHO) permissible safety limits. Contamination factors (CF) were higher in improved grassland, especially for Cd and Pb, exceeding one. Hakanson potential ecological risk assessment indicates acceptable overall risk levels, though variations exist between improved grassland, unimproved grassland, forest, and industrial cutaway bog. Combined exposure routes (dermal, ingestion and inhalation routes) to all heavy metals do not exceed safe exposure levels (indicating low non-carcinogenic risks. However, the cancer risk (CR) exceeds acceptable thresholds across all use types, with higher CR in improved grassland, especially for children. Overall, the findings emphasize the need for careful consideration of heavy metal risks associated with land use changes in peatlands, particularly in the improved grassland areas.

Stabilization of Fibrous Peat Soils with Addition Palm Shell Ash Waste

South Sumatra Province has a peat area of 1.4 million Ha. The distribution of peat soil in Ogan Ilir is 23,687.91 Ha. Peat soil has a low bearing capacity. This research aims to explain the effect of stabilization on peat soil characteristics. Peat soil samples were taken using the Block Sampling method. The research locations are Parit Village and Lorok Village, Ogan Ilir Regency. Peat soil needs better properties and is unsuitable for foundation soil for civil construction. To overcome this, one method of soil improvement is required, namely the chemical stabilization method: changing the chemical properties of the soil by adding a mixture. The mixture used is palm shell ash waste with variations of 0%, 10%, 15%, 20%, 25%. Soil properties (physical and chemical), SEM, EDS, PTS, and CBR tests were carried out to determine the effect of this mixture. Soil properties test results: water content () in Parit Village 226.39%, and Lorok Village 252.39%. The fiber content (FC) test results for Parit Village were 25.18% and for Lorok Village 28.01%. Peat soil is classified as fibrous peat soil. The CBR value for Parit Village was 4.60%, and Lorok Village was 4.16%. The results of the immersion CBR test showed that Parit Village had a curing period of 7 days, a variation of 5%, namely 4.68%. Look Village obtained the most outstanding results: a curing period of 14 days, a variation of 25%, and 4.76%. The CBR value obtained in this study is 3%-5% (average) when used for subgrade strength with compaction conditions depending on the road category.

Tritium behavior in soil and mineral rock components used for plant cultivation

Immersion, percolation and tritium release experiments in peat and vermiculite soil samples were performed to analyze their behavior in this widely used medium for plant cultivation. Samples were immersed in tritiated water for 696 h and the isotope exchange capacity evaluated. A vertical flow regime was also considered with analysis for hydraulic conductivity to understand tritium mobility and therefore its availability. Peat soil showed a high tritium retention after percolation, but vermiculite seem to suppress its retention ability. The high moisture and organic content of peat enhanced its isotope exchange capacity. The falling head method was used to numerically evaluate the saturated hydraulic conductivity and outflow flux. Calculated isotope exchange capacity was 4.95×10-2 mol-T2O/g for peat and 3.38×10-2 mol-T2O/g for vermiculite. The tritium release experiment showed significant release of tritiated carbons in peat.

Effect of Beneficial Microbes on Macronutrient Uptake and Oil Palm Seedling Growth in Peat Soil

Peat soil has low fertility due to low content of macronutrients, such as N, P, K, Ca, & Mg. Efforts that can be made to increase nutrient availability and nutrient uptake for plants on peatlands are the utilization of beneficial microbes such as endophytic bacteria and arbuscular mycorrhizae. This study aims to identify the role of endophytic bacteria and arbuscular mycorrhizae applied to peat soil media to help increase macronutrient uptake and the growth of oil palm seedlings (main nursery). This study was conducted in June – December 2022. The peat soil sample was collected from oil palm plantations located in Siak Regency, Riau, with coordinates 0°45′22″ N, 101°44′27″ E. The experimental design used in this study was a completely randomized design (CRD) with 8 treatments and 5 replicates. The treatment given in this study was a variation of beneficial microbes with zeolite as the carrier. Beneficial microbes used in this study were arbuscular mycorrhizae, namely Glomus sp, and endophytic bacteria, i.e. Burkholderia cenocepacia and Pseudomonas fluorescens. Parameters observed in this study were plant growth (every 1 month) and leaf nutrient (6 months after planted). The results of this study indicated that the consortium application of endophytic bacteria and arbuscular mycorrhizae was the best treatment which was shown to have the best growth of oil palm seedlings compared to all treatments with plant height increment of 55.5 cm; stem diameter increment of 34.3 mm; and the number of fronds addition as many as 11 fronds. This is also supported by macronutrients content in the leaves of oil palm seedlings such as N, P, and K.

MEASUREMENT OF WATER RETENTION OF PEAT SOIL IN CANAL BLOCKING USING PRESSURE PLATE CHAMBER

Measuring air retention in constructed canal blockage is critical for determining changes in air content after canal blocking. The purpose of this study is to assess the influence of changes in levels on air retention values measured at three depths, namely 0-20 cm, 20-40 cm, and 40-60 cm, at four transect sampling stations created at a distance of 10 m to 260 m from the canal block. Changes in bulk density, porosity, and peat volume affect groundwater. Peat soil samples were collected from burned peatlands, and canal blocks were constructed. A pressure plate chamber was used to assess air retention. The findings of the investigation revealed that the air retention pattern of peat soil at 16 test sample locations was at maximum at PF 0.2 at each depth. At higher pressures (pF 2-4.2), peat groundwater is strongly bonded by peat soil particles. The average bulk density of peat is 0.2 2 and the porosity value is 86.79%. The higher the air content at each pF value has no influence on the porosity and bulk density values. Changes in air content between pF 2.0 and 4.2 lower average peat volume by 7.4%. The size of this value is assumed to be determined by the peat's type, maturity, and decomposition value

Investigation on the Engineering Properties of Peat Soil Stabilised Using Lime Stabilisation and Alkaline Activation

Peat soil is typically classified as a problematic soil due to its expansive behaviour that possesses geotechnical drawbacks. Thus, the condition of peat soil must be improved prior to any construction works. Stabilisation of peat soil can be done via chemical stabilisation and alkaline activation while incorporating industrial by-products or wastes as addictive. This study aims to investigate the effect of press mud as an additive in lime-stabilized and alkaline activator-stabilized peat soils. Press mud is a by-product of sugarcane juice filtering. The lime adopted is at 3 % and 5.5 % while the alkaline activator is used in cold and warm condition. A total of 5 percentages of press mud have been employed, namely 0%, 0.25%, 0.5%, 1% and 2%. The investigations revealed that regardless of the percentage of lime adopted, the optimum moisture content increases while the maximum dry density decreases when the percentage of press mud incorporated is increased. However, when the lime content is increased, the optimum moisture content increases significantly. The UCS of lime-stabilised peat soil sample achieved the greatest strength improvement when the lime and press mud is used at 5.5% and 0.25%, respectively. In contrast, the unconfined compressive strength (UCS) of 3% lime-stabilised peat soil samples with or without press mud shows comparable 28-day strength. On the other hand, the UCS of peat soil stabilised with alkaline activator shows significant improvement, while addition of press mud further improves the strength. Nonetheless, using warm alkaline activator improves the early strength development but cold alkaline activator results in higher 28-day UCS.

Subsurface Characterization of Malaysian Hemic Peat and Soft Clays Using CPTu and MASW

Geotechnical engineers practice a variety of in-situ investigation techniques to comprehensively characterize peat soil properties. Peat soil is a challenging soil characterized by its high water content, organic content, and low strength, making its geotechnical properties difficult to assess accurately. High water saturation and the presence of fresh fibres in peat also risk sample disturbance in collecting undisturbed peat soil samples which causes underestimation. An In-situ test known as the Cone penetration test with pore pressure measurement (CPTu) was investigated to measure the cone resistance (qc), sleeve friction (fs), and pore water pressure (u2) at various depths. In parallel, multichannel analysis of surface waves (MASW) was employed to determine the shear wave velocity (Vs) profile of the peat soil. The findings revealed that CPTu and MASW data were able to delineate the soil stratigraphy and estimate the peat thickness. However, the presence of fresh fibres in peat causes overestimation of the qc and fs values, causing difficulties in accurately determining the peat strength. Overall, the combination of CPTu and MASW data offered a comprehensive understanding of the peat’s geotechnical and dynamic characteristics. The findings have significant implications for engineering practices and ultimately contribute to safer and more resilient construction projects in challenging peat soil environments.

Effect of Curing Time on Compressive Strength Performance of Coconut Shell Charcoal Ash (CSCA) and Fly Ash Stabilized Peat Soil

Peat soils are considered problematic soils and unstable for engineering projects due to geotechnical problems such as high compressibility and poor shear strength. Peatland could be an alternative to future development due to a lack of suitable and pricey land. Stabilization of the peat soil should be done before construction to improve its engineering features. The influence of curing time on the compressive strength performance of Coconut Shell Charcoal Ash (CSCA) with fly ash to stabilized peat is presented in this research. Some engineering variables including physical and mechanical properties were examined. The modified stabilized peat soils were made by adding various amounts of CSCA to the dry weight of the peat soil, ranging from 3%, 6%, 9%, and 12%, while fly ash constant 10%. The treated samples were cured for 0, 7, 14, and 28 days to see how curing affected the results. The results show that when the amount of CSCA with fly ash applied to the peat soil samples increased, the compressive strength also increased. On the other hand, showed that as the amount of CSCA with a constant fly ash content and the curing duration increased, so did the unconfined compressive strength test. The result shows that the addition of CSCA with fly ash into the mixture helps to stabilize and improve the strength of the soil.

Peat Formation in Rewetted Fens as Reflected by Saturated n-Alkyl Acid Concentrations and Patterns

The conversion of cultivated fen peat soils into rewetted soils can mitigate global climate change. Specifically, carbon in newly formed peat can store atmospheric CO2 for a long time in soil, but alterations in the quality of soil organic matter are not well known. To shed light on the complex processes of peat degradation or new formation under dry or rewetting conditions, we investigated and quantified saturated n-alkyl acids as an indicator compound class of peatlands response to the contrasting management practices. The concentrations of saturated n-alkyl acids from two soil layers of the drained and rewetted were determined in two soil layers of drained and rewetted fenland types such as Alder Carr forest, coastal peatland, and percolation mire. The analytical methods were solvent extraction, methylation with tetramethylammonium hydroxide, and gas chromatography/mass spectrometry. The saturated n-alkyl acid distribution pattern showed that the concentrations of long C-chain lengths were larger by factors of up to 28 relative to the short C-chain lengths. The effect of rewetting was reflected by the ratios of the summed concentrations of long (n-C21:0 to n-C34:0) to short (n-C10:0 to n-C20:0) C-chain saturated n-alkyl acids for drained and rewetted peat soil samples. These ratios were consistently lower in samples from the rewetted sites, indicating a higher input of microbial bio- and necromass to soil organic matter, likely from algae and anaerobic bacteria, under rewetting. The results suggest that the enrichment of microbial biomass and necromass in rewetted soils may be an important contributor to the formation of new peat in fenlands, irrespective of fenland type.

Investigation on Dielectric Properties of Sludge Waste from Water Treatment Using Microwave Non-Destructive Testing (MNDT)

The demand for water cleanup rises in tandem with a country's requirements and development. Recovery of purified water containing nutrients and other beneficial materials is a critical opportunity that must be taken advantage of. A challenge that needs to be tackled is the necessity for large capacity and high-value management of sludge waste following the water treatment process. The pH level and microwave frequencies influence were used as a starting point for assessing the content of the sludge waste. Microwavenon-destructive testing (MNDT) is a microwave measurement that can be used to determine the dielectric characteristics of materials without destroying or modifying the sample's content. The methodology employs a free-space measurement technique with a frequency range of 8 to 12 GHz (X-band). Through S-parameters acquired, a correlation analysis was done to analyze the effect of frequencies with the sludge waste. A comparative investigation with peat soil samples in establishing if the sludge has similar attributes to normal soil is used to ensure the accuracy of the sludge waste data. It can be determined that the sludge waste has a high signal correlation towards the frequency band 8 GHz to 12 GHz, which is compatible with the MNDT approach. All of the sludge samples had a pH range that is appropriate for agricultural use.

Impact of Sugarcane Bagasse Ash (SCBA) and Cement to the Strength Improvement of Hemic Peat

Peat soils are derived from organic deposition consisting of dead trees. Peat soils have low shear strength and cannot afford large loads. Various treatment methods are used to stabilize peat soils and most of them use cement as a main binder to increase the strength of peat soils. However, the use of large quantities of cement is not environment friendly due to the release of carbon dioxide (CO2) and wastage of energy consumption by the cement production industry. Therefore, the introduction of SCBA as a substitution binder for some cement dosage is good as well as reducing the degradation of dumping waste which is increasingly uncontrollable. The objective of this study is to identify the basic and physical properties of peat soil from Pontian, Johor. In addition, this study was also conducted to identify the impact of SCBA on peat soil stabilization with cement. There are 5 different mixtures for cement and SCBA which are C100, C95S5, C90S10, C85S15 and C80S20 used in this study. Sample C95S5 with mixtures 95% cement and 5% SCBA were the optimum samples for this study based on unconfined compression strength (UCS) tests. The C95S5 sample successfully achieved the maximum strength of the whole sample with a strength of 190 kN/m2, 209 kN/m2, and 219 kN/m2 recorded for wet curing periods of 7,14 and 28 days. Therefore, the use of SCBA materials in the stabilization of peat soils with cement and calcium chloride (CaCl2) is seen to have a positive effect in increasing the shear strength of Hemic peat soil samples.

Experimental Study Of Improving The Physical Properties Of Peat Soil Using Sand And Bio-Grouting Techniques With The Assistance Of Bacillus Subtilis Bacteria

Peat soil was categorized as soft soil, which means that the soil is in bad condition and problematic when construction was built on it. It was necessary to increase the carrying capacity of peat soils, one of which is chemical stabilization of the soil, by adding additives that can react with the soil and using new environmentally friendly methods.
 In this study, samples of peat soil were taken from Buana Makmur Village km55, Dayun District, Siak Regency. The stabilizing agent used was sand as much as 5% by weight of dry soil, Bacillus Subtilis bacteria obtained from the Agriculture Laboratory of the Islamic University of Riau, and also CaCL₂ and Urea. The method for stabilizing the physical properties of peat soil in this study is the Bio-Grouting method, testing the physical properties of peat soil follows the procedures of ASTM (American Society For Testing And Materials) and SNI 1965-2008 for testing methods for determining water content for soil and rock in the laboratory. SNI 1964-2008 test method for soil specific gravity, SNI 8460-2017 geotechnical design requirements, SK SNI -04-05-1989-F fine sand used for construction, SNI-02-2801-1998 urea standard. To test the physical properties was carried out by providing variations in the mixing of bacterial cementation solutions with levels of 0% (without treatment), 5%, 10%, 15%, 20%, and 25% and then allowed to stand for 14 days using a tightly closed plastic container.
 The results of testing the physical properties of peat soil found that the peat soil was included in the original soil type with water content = 407.45% and specific gravity (Gs) = 1.30gr, while from the physical properties tests carried out the highest water content occurred in the addition of bacterial cementation solution 10% = 177.2% and the lowest specific gravity occurs when the bacterial cementation solution is added 10% = 1.27gr.

Estimation of Carbon pool in various agricultural crops in peatlands of West and Central Kalimantan, Indonesia

Tropical peat is an important natural ecosystem, and its natural state plays an important role in climate regulation. These peatlands globally provide vital environmental benefits, especially in case of their enormous carbon storage potential. Peat land also functions as a source of livelihood for the community, especially for agricultural activities, and this will lead to the potential loss of carbon stock in peatlands. This study examines plants' potential to create Carbon to offset carbon dioxide emissions and different land use types. The study focused on Central and West Kalimantan, Indonesia. Peat soil samples were collected from various types of land from 0-15, 15-45, and 45-100 cm depth and analyzed for physical and chemical parameters. The cylinder chamber method with infrared gas analysis model EGM-4 was used to measure CO2 emissions. Plant carbon sequestration was measured in a 6.25 m2 plot in the study sites of Central Kalimantan. The study showed that type of commodity and period of management affect the carbon content in peat with different land uses, and it is affected by soil bulk density, organic matter content, and CO2 emission. In the case of study crops, oil palm, rubber, corn, and mustard emit the highest CO2. Further, corn crop has the highest potential to fix carbon dioxide and produces more Carbon per hectare than the Carbon emitted from corn-planted under peatland conditions. The study indicated that the type of commodity and the time of its management affected the carbon content in peat with different land uses, and carbon content got the change with soil bulk density and soil organic matter content.

Dynamics of the heavy metals content (Zn, Cd, Pb, Cu) during the decomposition of sphagnum moss at the drained and post-pyrogenic sites of oligotrophic bogs

The aim of the study. Assessment of heavy metals (Zn, Cd, Pb, Cu) dynamic during the decomposition of Sphagnum fuscum L. in native, drained and post-pyrogenic oligotrophic peatlands. Location and time of the study. The study was carried out in 2019–2021 in two oligotrophic bogs: “Bakcharskoye” (field station “Vasyuganye” (IMCES SB RAS)) and “Iksinskoye”, which are the north-eastern spurs of the Great Vasyugan mire and located in the Bakcharsky district of the Tomsk region. Methods. Decomposition rate of Sph. fuscum L. was determined by the method of partially isolated samples, which is widely used to study the processes of transformation of plant material and peat. In the original and decomposed samples of sphagnum moss and peat soil (in layers 0-10, 10-20, 20-30), the ash content of peat was determined according to GOST-11306-83. The percentage of total carbon and nitrogen in samples of peat (up to 30 cm from the surface) and plant residues was determined together with the determination of isotopic composition using EA-IRMS (Elemental Analyzer/Isotope Ratio Mass Spectrometry). The concentrations of heavy metals (Zn, Cd, Pb, Cu) in samples of peat and plant residues were determined by stripping voltammetry. Results. Three-year experiment on decomposition of Sph. fuscum in four ecosystems (natural – VASnat, drained – VASdry, post-pyrogenic – Iksa 1 and Iksa2) showed that fire affected the decomposition rate: on average, mass loss in post-pyrogenic bogs was 1.4–1.6 times lower compared to the natural site. For almost all sites, a relationship was found between the mass loss and the concentration of heavy metals, with the exception of Cd during the first year of the experiment. The concentration of all elements in moss residues decreased during the decomposition process at all study sites. During moss decomposition the similarity in the release of biogenic elements Cu and Zn was recorded in the drained and post-pyrogenic sites (VASdry, Iksa1, Iksa2), while for Cd and Pb, which are not biogenic elements, such similarity was not revealed. Conclusions. Peat fires affect plant residue decomposition by decreasing its rate of decomposition. The study revealed incremental dynamics of HMs content in plant residues: at the initial stage, HMs are released, whereas during the second and third years, in some cases, the accumulation of HMs is observed. However, by the end of the experiment, the release of heavy metals during decomposition was observed for all elements.

Variations in peat soil properties at the west coast of Sumatra Island

Peat in coastal areas has different characteristics compared to peat in inland areas because coastal peat usually has high DHL, pyrite, marine sandy substratum, and maturity which is generally classified as hemic to sapric. These variants in soil characteristics drive peculiarity in its management. For this reason, a more detailed information about the characteristics is needed to allow sustainable management and utilization. A total of 78 peat soil samples from 20 peat soil profiles taken over west coast of Sumatra was studied and analyzed for their physical and chemical properties. Field observations were made using a peat auger to determine thickness and maturity, substratum, presence of pyrite, and others. Results showed that peat thickness varied from shallow (50-100 cm), medium (100-200 cm), to very deep (>700 cm); peat situated closer to the coast generally has shallow peat depth. Peat soil in coastal areas contained a mineral soil substrate with a sand content of >70%. It was found that soil had a hemic maturity level and a very acidic to acidic pH value (pH 2.5-5.4). The P2O5 content extracted by 25% HCl varied from low to moderate, while K2O content of 25% HCl extraction was very low. Cations K, Na, and Ca were very low to very high, while Mg spanned from very low to high. Based on its thickness, 25% of peatland were not suitable (Nrc) for general agriculture uses because of >300 cm thickness. Therefore, it is necessary to improve soil fertility and water management in several places.

The Effects of Freeze–Thaw Cycles on Methane Emissions From Peat Soils of a High-Altitude Peatland

The Qinghai– Tibet Plateau (QTP), which embodies the largest area of permafrost at mid–low altitudes of the world, has been experiencing rapid permafrost degradation and changes in freeze–thaw processes for the past decades. However, the responses and potential feedbacks of the methane flux from peatlands on the QTP to changing freeze–thaw cycles (FTCs) remain unknown. In this study, we collected peat soils from the Zoîgé peatlands, the largest peatland complex on the QTP, to examine methane emissions under simulated diurnal FTC scenarios. In incubation experiments of 15 days, two freeze–thaw temperature ranges of −5 to 4°C (mild) and −15 to 4°C (intense) were applied to two sets of peat soil samples, and each of them was characterized by 100% or 80% maximum water holding capacity (MWHC). The results showed that the peak of methane emission from the peat soil occurred after the first freeze–thaw cycle (FTC1), with the highest reaching a value of 0.103 mg kg soil−1·h−1. Generally, the cumulative methane emissions were elevated by FTCs, and relative higher rates of methane emissions were found for the 2nd FTC to the 15th FTC, compared with those from low-altitude peatlands. Methane emissions were significantly correlated to the export of dissolved organic carbon (DOC) and the activities of β-D-cellobiosidase and phenol oxidase in various freeze–thaw conditions. This study highlights the importance of FTCs in stimulating methane emissions and implies that methane emissions during FTCs from high-altitude peatlands would increase under a warmer climate in the future.

A three-dimensional (3D) printing approach to fabricate an isolation chip for high throughput in situ cultivation of environmental microbes.

The full plethora of environmental bacteria is often poorly represented in vitro as the majority remain difficult, if not impossible, to culture under standard laboratory settings. These bacteria often require native conditions for the formation of cell masses that collectively have higher chances of survival. With that, a 3D-printed version of the isolation chip (iChip) was used to cultivate bacteria from a tropical peat swamp in situ prior to growth and maintenance in vitro. Briefly, plates made from either acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), or epoxy resin were tested in terms of their usability and durability under acidic conditions similar to those of peat matter. The epoxy resin plates were then found to be most optimal for the sampling conditions. Peat soil samples were collected from the base of a Koompassia malaccensis tree and reconstituted in molten 10% (wt/vol) tryptone soy agar (TSA) prior to inoculation. The iChips were subsequently assembled and buried in the site of origin. As a comparison, bacteria from the same soil sample were cultivated directly on TSA and incubated at 28 °C for two weeks. Thereafter, agar plugs from the iChip were transferred to TSA plates to allow microcolonies within each plug to grow. Each pure isolate from both cultivation approaches that grew was then pooled and extracted for total DNA prior to 16S rRNA gene amplification and sequencing via Illumina MiSeq. Taxonomic abundance comparison revealed that the bacterial taxa at the level of order were significantly different between the two approaches, particularly in the orders, Burkholderiales, Xanthomonodales, Enterobacteriales, and Actinomycetales (differences of 12.0, 7.1, 8.0, and 4.2%, respectively). This indicated that the 3D-printed iChips present a possible low-cost tool for the isolation of bacterial genera that may not be able to grow on media directly in vitro.

Karakteristik Sifat Fisik Tanah Gambut Ogan Komering Ilir

Some areas of South Sumatra Province are peatlands scattered in the eastern part, starting from the districts of Musi Rawas, Musi Banyuasin, Ogan Komering Ilir, Muaraenim, and Banyuasin. Around 769,000 hectares of peatland are located in the Ogan Komering Ilir Regency area. Ogan Komering Ilir Regency is an area prone to forest fires. Therefore, it is necessary to conduct research on the characteristics of peat soils in the Ogan Komering Ilir area so that they can be used as consideration in efforts to prevent peatland fires. Sampling was carried out in Kotarayo Village, (Kayuagung District), SP 1 (Pedamaran Timur District), and Tulung Selapan Ilir Village (Tulung Selapan District). Peat soil samples were taken with ASTM D 7015-04 guidelines, and the physical properties of peat soil were tested for samples from the three locations. Based on its physical properties, peat soil samples are classified according to ASTM D4427-84. From the results of the research on peat soils in Kayuagung, Tulung Selapan, and Pedamaran Timur sub-districts, Ogan Komering Ilir Regency, peat soil samples can be classified as sapric-peat soil.

Resistivity characteristics of soil saturated with variation of salt water-fresh water mixture

Peat soil has a specific physical character if compare with the other sediments. It has amount of organic matter and has relatively porosity and permeability. This preliminary research is to predict the salt water content in the soil and peat soil aquifer later on. This research is to investigate the resistivity characteristic of peat soil saturated with variation of salt water-fresh water mixture. Six undisturbed soil and peat soil samples were taken from difference sites in the coastal area. The soil and peat soil samples then saturated with difference amount of salt-fresh water mixture. The resistivity measurement then was measured to the soial and peat soil saturated with the salt-fresh water mixture. The result show that the resistivity decreases drastically as the increasing of a little amount of salt water in the salt-fresh water mixture.