Peat Research Articles

Use of Local Resources from Oil Palm Bunch Ash combined with Cow Manure to Grow and Produce Sweet Corn (Zea mays saccharata Sturt) Planted in Peat Soil to Support Smart Agriculture

Use of Local Resources from Oil Palm Bunch Ash combined with Cow Manure to Grow and Produce Sweet Corn (Zea mays saccharata Sturt) Planted in Peat Soil to Support Smart Agriculture

Phosphorus release from rewetted agricultural peat soils varies strongly in dependence of the phosphorus resorption capacity

Rewetting of drained agricultural lowland peat soils is followed by the risk of increased phosphorus (P) release to downstream systems, thereby challenging their restoration as nutrient sinks for years to decades. While extensive knowledge is available on P mobilization under anaerobic conditions caused by reductive (Fe(III))-oxide dissolution, the net P release to the aqueous phase (PSol) is only poorly understood due to unknown significance of P re-sorption to aluminum (Al) oxides and non-reduced Fe(III)-oxides. We therefore hypothesize that PSol is a function of the sorption capacity and P saturation of Al-oxides and non-reduced Fe(III)-oxides. A comprehensive set of 47 Danish topsoil and subsoil samples from agricultural lowlands were incubated for up to 148 days in the laboratory under anoxic and water-saturated conditions at room temperature. Oxalate-extractable Fe, Al and P (Feox, Alox and Pox) varied by three orders of magnitude, with Feox ranging between 1.8 and 1590 mmol kg−1; Alox and Pox also showed high variation with maximum contents of 883 and 153 mmol kg−1, respectively. Bicarbonate-dithionite generally extracted 2 times less Fe, Al and P (FeBD, AlBD, PBD) than oxalate. Oxalate extraction data were used to calculate the degree of P saturation (DPS) and P sorption capacity (PSC). The extent of Fe(III)-oxide reduction measured as 0.1 M HCl extractable Fe(II)HCl was well described by first-order kinetics with rate constants ranging between 0.01 and 0.3 d-1.The estimated maximum Fe(II)HCl produced (Fe(II)max) ranged between 3 and 1490 mmol Fe(II) kg−1, with Feox corresponding to Fe(II)max values very closely. For most soils almost full dissolution of the entire Feox pool was achieved within 21 days of incubation. PSol concentrations, measured in the soil solution extract, ranged between 0.05 and 5.05 mg L-1, increasing with incubation time for most of the soils. While PSol was not correlated with FeBD:PBD and Feox:Pox, DPS, total P (PT) or total Fe (FeT):PT ratio, the investigations revealed a strong reciprocal relationship between the residual sorption capacity (RSC) of the soils, i.e., PSC subtracted the Fe(III)-oxides reduced, and the PSol/Pox ratio. Moreover, the results showed low or lack of P release to the aqueous phase, even for the soil samples where all Feox pools were reduced, if the RSC of the soil was above 100 mmol kg−1. This highlights the importance of redox-stable Al-oxides to capture mobilized P from rewetted lowland peat soils.

Biosafety evaluation for some remediants and their effectiveness in detoxication peaty soils with heavy metals

Contamination soils with heavy metals is a problem with high interest, because contamination with heavy metals affect food chains and human health by intake and accumulation in living beings. Although all of these methods not quite effective for recovering contaminated environments, however they are still good options for recovering contaminated soils. In this research evaluated the recovering potential in different concentrations and combinations of dolomite with additives like zerovalent iron, Fe-Mn concretions, iron powder, ferrihydrite and iron nanoparticles. With these treatments, achieved reduction of concentration of all heavy metals founded (Co, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) and also reduction in toxicity, confirmed with a biotest with Daphnia magna. These findings confirms that the optimal remediants are nanoparticles with biochar and iron powder with and without biochar.

Assessment of the disturbance of peat bogs of the Mogilev region

The analysis of high- and ultra-high-resolution satellite images of 1,385 peat bogs (with an area of more than 10 hectares) located on the territory of the Mogilev region of the Republic of Belarus showed that about 37 % of the total area of 221 thousand hectares of peat bogs were preserved in their natural state, the rest was subjected to hydraulic reclamation. The share of drained lands with peat soils of agricultural use was about 30 %, covered with forest vegetation - about 7 %, disturbed swamps - 26 %.

Redox potential is a robust indicator for decomposition processes in drained agricultural peat soils: A valuable tool in monitoring peatland wetting efforts

Peat decomposition driven by soil metabolic processes is responsible for approximately 2 % of global annual anthropogenic greenhouse gas emissions. A peat soil's redox potential (Eh) and pH reflect its biogeochemical state and are therefore linked to the rate of peat decomposition and greenhouse gas production. In this study, we aim to establish if continuous Eh measurements are an effective tool to monitor metabolic peat decomposition processes and thus to quantify the effects of peat wetting efforts. We applied continuous in-situ Eh measurements (>150 sensors 2020–2022) as a proxy for metabolic peat decomposition processes, which we validated under field conditions with extensive sampling of porewater chemistry (pH, NO3–, SO42−, Mn(II), Fe(II), S2− and CH4, >2000 samples) for five agricultural, drained, minerotrophic peatland sites in the Netherlands. These 5 sites consisted of plots with and without subsoil irrigation (SSI), where SSI aims to raise groundwater levels and thus wet the peat soil. We found that in-situ continuous Eh measurements closely reflected spatial and temporal heterogeneity in pore water chemistry. Therefore, we concluded that Eh is a robust proxy for peat decomposition processes. Building on this result, we used continuous Eh measurements to study the prevalence of specific metabolic processes from site-to-site in relation with groundwater level changes. We found that, while groundwater levels are an important driver for (an)aerobic conditions, groundwater levels do not explain the full dynamics and extent of (an)aerobic conditions. O2 intrusion was mostly limited to approximately 0.5 m depth at deep (>0.8 m) groundwater levels, likely due to air diffusion limitation. Higher and more constant groundwater levels year-round at SSI plots decreased oxygen intrusion and tended to deplete porewater Fe(II) and SO42−, which led to more reducing Eh and higher porewater CH4 concentrations. The depletion of electron acceptors and occurrence of methanogenesis differed from site to site. In summary, high-frequent Eh monitoring is found to be an effective tool to monitor metabolic peat decomposition processes and quantify the effects of peatlands wetting efforts. Therefore, this methodology is suitable to evaluate and further optimize peatland monitoring and preservation.

Carbon Losses from Topsoil in Abandoned Peat Extraction Sites Due to Ground Subsidence and Erosion

Peat erosion has a significant impact on soil fertility, agricultural productivity, and climate change dynamics. Through this process, the topsoil rich in organic matter and carbon (C) is removed and can travel long distances, causing a net C loss. Additionally, peat undergoes oxidation, resulting in further C loss. In our study, we evaluated C losses from 11 peat extraction fields in two study sites, abandoned for more than 15 years and overgrown by vegetation of different densities. We used high-resolution airborne laser scanning point clouds and multispectral aerial images acquired periodically within a 9-year period, as well as chemical analyses of the topsoil layer. In our study, we found a strong correlation between peat subsidence, C loss, and the vegetation density (NDVI value). NDVI also determines most of the uncertainty in elevation data. We found also that both erosion and peat subsidence are significant sources of C losses from peat extraction sites. At a site monitored for over 9 years, our estimated ground elevation changes ranged from 0.1 cm y−1 to 0.58 cm y−1; however, at a different site monitored over a 4-year period, the values ranged from 2.14 cm y−1 to 5.72 cm y−1. Accordingly, the mean annual C losses varied from 0.06 to 0.22 kg C m−2 y−1 and from 1.21 to 3.57 kg C m−2 y−1.

Changes of water in different states during peat soil compression

Changes of water in different states during peat soil compression

Determining parameters of peat soil for finite-element analysis using the Cam Clay model

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.

Methane Gas Ebullition Dynamics From Different Subtropical Wetland Vegetation Communities in Big Cypress National Preserve, Florida Are Revealed Using a Multi‐Method, Multi‐Scale Approach

AbstractMethane (CH4) emissions from peat soils are highly variable in space and time and are influenced by changes in biogeochemical controls and other environmental factors. Areas or times with disproportionally high CH4 emissions in wetlands may develop where conditions are especially conducive for microbial processes like methanogenesis. Currently, eddy covariance methods are employed to quantify CH4 exchanges over several extensive subtropical forested wetland communities in the Big Cypress National Preserve, Florida. In this work, we investigate the importance of multi‐scale measurements to characterize CH4 ebullition dynamics from subtropical wetlands. Our approach uses a combination of gas traps, time‐lapse photography, and capacitance probes to characterize ebullition dynamics from two different wetland vegetation communities for comparison to eddy covariance CH4 measurements at the site. Ground‐penetrating radar surveys and soil sampling are used to assess differences in subsurface properties between sites that influence ebullition. Our results show that the mean measurement bias between fluxes measured in this study and the eddy covariance measurements over the same period was 10–14 times larger during the wet season when ebullition rates were greatest, than the dry season, when ebullition rates were smallest. This suggests that eddy covariance measurements may underestimate the CH4 contribution of ebullition across heterogeneous wetland vegetation communities and that the comparability of CH4 fluxes from methods varying in spatio‐temporal scale changes in response to subtropical Florida seasonality. Our work suggests that these methods can be used to complement eddy covariance measurements and improve the characterization of ebullition dynamics in subtropical wetlands.

Soil Formation Features in Drained Lake Basins of the Bolshezemelskaya Tundra

The features of the structure, properties, and temperature regimes of soils functioning in two different drained lake basins of the Bolshezemelskaya tundra are characterized. The basins differ significantly in the features of landscape development, the composition of bottom (soil-forming) sediments, and the patterns of the soil and vegetation cover. In a naturally drained basin composed of mineral (sandy and clayey) bottom sediments, soils belonging to the departments Gley, and Poorly developed are formed, which are typical for the watershed landscapes of the region. Soils function as ecosystem-modified permafrost-affected profiles, partially protected from thaw. The soil profile is acidic, not saturated with bases, with moderate carbon content in the mineral horizons. In the artificially drained basin, covered with a layer of silted peat, predominantly peaty permafrost-affected soils were formed, including peat soils of tundra meadows, which are unique for the landscapes of the Bolshezemelskaya tundra. Peaty soils of the basin appear to be as ecosystem-protected, i.e. protected from thawing, and they are characterized by high ash content and slightly acidic reaction. A significant differentiation of the studied soil parameters are determined by different basins, which are different according to the composition of parent sediments, the specifics of landscape development, and manifestations of present-day cryogenic processes.

Impacts of changes in peat soils due to agricultural activities on greenhouse gases (especially N2O) emissions and their mitigations

Impacts of changes in peat soils due to agricultural activities on greenhouse gases (especially N2O) emissions and their mitigations

Content and Mobility of Metals in Oligotrophic Peat Soils of the Cryolithozone in Western Siberia

Content and Mobility of Metals in Oligotrophic Peat Soils of the Cryolithozone in Western Siberia

Content and Mobility Metals in Oligotrophic Peat Soils of the Cryolithozone of Western Siberia

The ongoing climatic changes have the greatest impact on natural ecosystems in high-latitude areas, as warming climate, as well as increasing anthropogenic load associated with the development of Arctic zone, contribute to the degradation of frozen peatlands and an increase in the thickness of seasonally thawed layer of soil. The relevance of studying peat oligotrophic soils (Cryic Histosols) of the northern territories of Western Siberia is associated with the fact that their degradation enriches natural waters by organomineral substances, which containing a large number of chemical elements, including heavy metals, contributing to changes in the hydrogeochemical properties of natural waters of the North. The article describes the main properties of peats sampled from different horizons of soil profiles laid down at key areas covering the territory of YNAO from north to south and from west to east. The chemical composition of soils was analyzed at the IPA SB RAS using standard methods. The concentrations of gross and mobile forms of metals (Fe, Ca, K, Na, Mg, Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn) were investigated by optical atomic emission spectrometry and flame atomic absorption spectrometry, respectively. It has been determined that a characteristic feature of the distribution of concentrations of chemical elements in peat oligotrophic soils of the northern part of Western Siberia is the presence of two maxima within the soil profile. The first is confined to the upper horizons showing signs of degradation, while the second is confined to the upper part of the permafrost. Statistical analysis using principal component method showed that low ash content, pH and C/N ratio are associated with high mobility of K, Cu, Zn and Mg. The mobility of Fe, Mn, Pb, Cd, and Cr is associated with an increase in ash content, pH, and Ntotal in the upper part of permafrost organogenic rocks.

Evaluation Of Drainage Canal Mitigation In Banjarmasin City Post Hydrometeorological Disaster

Data from the Environmental Health Risk Assessment (EHRA) study in 2012 stated that 52% of inundation in Banjarmasin City was caused by a problematic drainage system, the causes of which included siltation of the canals and the large number of weeds growing around the drainage canals, which would interfere with the function of the drainage canals. The data used are road canal cross-sectional dimensions, topographical data, canal alignment data, and land use data in North Banjarmasin Sub District. The calculation analysis method uses the Mononobe method. The results of these calculations will later be used for modeling which are indicated to exceed the water capacity, of course also by adding topographical parameters, land use, and canal alignment. Meanwhile, the planned discharge data from the results of the calculated rainfall and the measuring data of the channel cross-sectional dimensions are used for detailed modeling of the channel cross-section using HecRas. The condition of drainage channels is over-capacity, influenced by the presence of several channels covered with bushes and concrete, the amount of sediment that has not been dredged, the absence of an adequate catchment area system due to the characteristics of the soil in the form of peat soil.

Advances in Sago Palm Research: A Comprehensive Review of Recent Findings

The sago palm (Metroxylon sagu Rottb.) is an indigenous plant in Papua New Guinea, Indonesia, Malaysia, and Thailand. It provides substantial needs to the locals, especially through the starch it produces in its trunk. Exhibiting remarkable adaptability, this palm can thrive in challenging environments like swamps and peat soils. This paper provides an overview of the molecular methods previously utilised to decipher the genes responsible conferring the characteristics of sago palm molecular techniques employed to investigate M. sagu molecular properties include molecular markers, genome walking, rapid amplification of cDNA ends (RACE), polymerase chain reaction (PCR) and sequencing. Additionally, this article presents other molecular techniques that can be applied to M. sagu for future crop breeding.

Adsorbent effectiveness of α-cellulose/humatic acid with epichlorohydrin cross-linking agent on methyl orange dye

Adsorption of methyl orange (MO) using epichlorohydrin cross-linked humic acid/cellulose composite has been carried out. This study aims to synthesize epichlorohydrin cross-linked humic acid/cellulose composites, determine the optimum pH, contact time, and initial concentration and study MO desorption. The adsorbent production begins with the isolation of cellulose from empty palm oil bunches (EFB) obtained from North Sumatra and the isolation of humic acid from peat soil obtained from Rawa Pening. Then humic acid was cross-linked to cellulose in an alkaline solution (NaOH), then epichlorohydrin was added as a cross-linking agent while heating at 600C for 2 hours. Epichlorohydrin cross-linked humic acid/cellulose adsorbents (AH/Cell-ECH) were further characterized using FTIR, XRD and SEM spectroscopy. MO solutions before and after adsorption were analyzed using UV-Vis spectrophotometry. MO desorption studies used HCl pH 4, 0.1 and 1.0 M NaCl and 40% and 60% ethanol. FTIR characterization showed that the AH/Sel-ECH adsorbents had active groups, including –OH, -C=O, and –COOH. Characterization using XRD showed diffraction peaks in the 2θ region around 11.41, 20.25, 22.55, and 42.66o, indicating the presence of galactose, xylose, glucose and polysaccharide phases. The SEM-EDX results showed that the surface of the adsorbent had non-uniform pore sizes, and the surface morphology tended to be clean and free of debris. It indicated the presence of C, O, and N elements in AH/ECH-cells and S, N elements after MO adsorption. The optimum interaction of AH/Sel-ECH with MO occurred at pH 2 with 150 mg/L MO, and a contact time of 120 minutes was obtained. MO adsorption by AH/ECH-cells followed a pseudo-second-order kinetics model and the Freundlich isotherm with an MO adsorption capacity of 9.84 x 10-5 mmol/g, respectively. Desorption studies showed that 60% ethanol was the most effective solution for desorption of MO.

Potassium Use Efficiency of Natural Zeolite-Based Potassium Fertilizer in Oil Palm Seedlings (Elaeis guineensis Jacq.) Using Peat Soil Media

Potassium is the most needed macronutrient for oil palm. However, the efficiency of potassium fertilization on peatlands is low due to leaching. One of the exertions to improve this fertilization's efficiency is peat soil amelioration and engineering fertilizer technology so that plants can absorb nutrients more efficiently. This study aims to evaluate the effectiveness of zeka fertilizer, a modified potassium fertilizer made from natural zeolite, on oil palm seedlings in peat soil. The study used a completely randomized design with five treatments and three replications. The treatments were (1) K0 = Control/no fertilizer; (2) K1 = standard fertilizer, namely: urea + TSP + KCl + dolomite; (3) K2 = urea + TSP + zeka-1 + dolomite; K3 = urea + TSP + zeka-2 + dolomite; K4 = urea + TSP + zeka-3 + dolomite. The results proved that, in general, zeka fertilizer (K2, K3, and K4) produced better seedling growth and nutrient use efficiency than the standard fertilization treatment of oil palm seedlings (K1). The best treatment (K3) resulted in the highest growth and nutrient efficiency. K3 treatment resulted in seedling height and stem diameter by 7.7% and 9.2%, respectively, compared to K1. Furthermore, the dry biomass of the shoot and roots produced by the K3 treatment was 39.2% and 33.9% higher, respectively, than that produced by the K1 treatment. The agronomic efficiency, Apparent Recovery efficiency, Physiological efficiency, and Partial Factor Productivity of K3 treatment were 59.91%, 33.23%, 18.57%, and 39.16% higher than K1, respectively.

Correlation of Different Peat Soil Index Properties

The present study focuses on the physical properties of Sarawak peat soil and identifies the correlation between the index properties of peat from the present study and various locations in Malaysia. The physical properties of peat from the present study were obtained on site and in the laboratory, including degree of humification, moisture content, organic content, fibre content, specific gravity, liquid limit, linear shrinkage, and pH. The data obtained in this study and other tropical peats in Malaysia were compiled to identify their correlations. The correlation results reveal that with an increase in organic content, there is also an increase in value of moisture content, while the value of specific gravity reduces. Furthermore, as the bulk density of peat increases, the value of organic content reduces. Also, the moisture content, organic content, and fibre content of peat decrease with the increasing value of degree of humification. The correlations between different peat soil index properties have R2values ranging from 0.75 to 0.85, showing that the peat soil index properties are consistent with findings from previous studies, in which comparable trends are found. Thus, these correlations are expected to be useful for researchers and engineers to understand the peat soil's preliminary behaviour.

Analysis of the Effect of Ultra-Fine Cement on the Microscopic Pore Structure of Cement Soil in a Peat Soil Environment

Treating peat soil foundations around Dianchi Lake and Erhai Lake in Yunnan is a complex problem in practical engineering projects. Peat soil solely reinforced with ordinary cement (OPC) does not satisfy demand. This study aims to solidify soil to achieve better mechanical properties. The preparation of peat soil incorporates a humic acid (HA) reagent into cohesive soil, and cement and ultra-fine cement (UFC) are mixed by stirring to prepare cement soil samples. They are then immersed in fulvic acid (FA) solution to simulate cement soil in the actual environment. X-ray diffraction (XRD), mercury intrusion porosimetry (MIP), scanning electron microscopy (SEM), and pores and cracks analysis system (PCAS) tests are used to study the impact of the UFC on the microscopic pore structure of cement soil in a peat soil environment. The unconfined compressive strength (UCS) test is used for verification. The microscopic test results indicate that incorporating UFC enhances the specimen’s micropore structure. The XRD test results show the presence of C–S–H, C–A–S–H, and C–A–H. SEM and PCAS tests show that the UFC proportion increases by between 0% and 10%, and the percentage reduction in the macropore volume is the largest, at 38.84%. When the UFC admixture is 30%, the cumulative reduction in the percentage of macropore volume reaches 71.55%. The MIP test results show that the cumulative volume greater than 10 µm in pore size decreases from 7.68% to 0.17% with an increase in the UFC proportion. The UCS test results show that the maximum strength growth of cement soil is 12.99% when the UFC admixture is 0–10%. Incorporating UFC to form a compound curing agent solves the problem of the traditional reinforcement treatment of peat soil foundation being undesirable and decreases the amount of cement. This study provides practical guidance for reducing carbon emissions in actual projects.

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.