Abstrak Indonesia merupakan salah satu negara dengan sebaran lahan gambut yang luas. Gambut dikenal sebagai tanah yang bermasalah dalam pekerjaan konstruksi karena memiliki daya dukung yang rendah ...sehingga tidak dapat menopang pondasi infrastruktur. Tujuan penelitian ini adalah untuk menganalisis karakteristik tanah gambut di Kalimantan, sehingga penanganan yang tepat dapat ditentukan untuk mengatasi permasalahannya. Studi kasus pada penelitian ini adalah tanah gambut di Bereng Bengkel, Palangkaraya. Karakteristik tanah gambut diidentifikasi melalui serangkaian pengujian tanah berdasarkan Peat Testing Manual 1979. Selain itu, dilakukan juga pengujian Scanning Electron Microscopy untuk melihat morfologi tanah gambut, serta pengujian Fourier Transform Infra-Red untuk mengidentifikasi jenis senyawa yang terdapat di dalamnya. Hasil pengujian tanah di laboratorium menunjukkan bahwa tanah gambut memiliki sifat yang buruk secara geoteknik. Dari hasil pengujian SEM, diketahui adanya makropori dan mikropori pada tanah gambut yang sebagian besar ditempati oleh air. Kemudian, berdasarkan hasil pengujian FTIR, diketahui bahwa tanah gambut memiliki senyawa yang bersifat hidrofilik. Kata kunci: tanah gambut, serat gambut, infrastruktur Abstract Indonesia is one of the countries with a wide distribution of peatlands. Peat is known as a problematic soil in construction work because it has a low bearing capacity that cannot support infrastructure foundations. The objective of this research is to analyze the characteristics of peat soils in Kalimantan, so that appropriate treatments can be determined to overcome the problem. A case study of this research is the peat soil in Bereng Bengkel, Palangkaraya. The characteristics of the peat soil were identified through a series of soil tests based on the Peat Testing Manual 1979. In addition, Scanning Electron Microscopy testing was carried out to look at the morphology of the peat soil, as well as Fourier Transform Infra-Red testing to identify the types of compounds contained therein. The results of soil testing in the laboratory showed that the peat soil had poor geotechnical properties. SEM testing revealed macropores and micropores in the peat soil, most of which were occupied by water. FTIR testing showed that peat soil has hydrophilic compounds. Keywords: peat soil, peat fiber, infrastructure
Wetland buffer zones (WBZs) are riparian areas that form a transition between terrestrial and aquatic environments and are well-known to remove agricultural water pollutants such as nitrogen (N) and ...phosphorus (P). This review attempts to merge and compare data on the nutrient load, nutrient loss and nutrient removal and/or retention from multiple studies of various WBZs termed as riparian mineral soil wetlands, groundwater-charged peatlands (i.e. fens) and floodplains. Two different soil types (‘organic’ and ‘mineral’), four different main water sources (‘groundwater’, ‘precipitation’, ‘surface runoff/drain discharge’, and ‘river inundation’) and three different vegetation classes (‘arboraceous’, ‘herbaceous’ and ‘aerenchymous’) were considered separately for data analysis. The studied WBZs are situated within the temperate and continental climatic regions that are commonly found in northern-central Europe, northern USA and Canada. Surprisingly, only weak differences for the nutrient removal/retention capability were found if the three WBZ types were directly compared. The results of our study reveal that for example the nitrate retention efficiency of organic soils (53 ± 28%; mean ± sd) is only slightly higher than that of mineral soils (50 ± 32%). Variance in load had a stronger influence than soil type on the N retention in WBZs. However, organic soils in fens tend to be sources of dissolved organic N and soluble reactive P, particularly when the fens have become degraded due to drainage and past agricultural usage. The detailed consideration of water sources indicated that average nitrate removal efficiencies were highest for ground water (76 ± 25%) and lowest for river water (35 ± 24%). No significant pattern for P retention emerged; however, the highest absolute removal appeared if the P source was river water. The harvesting of vegetation will minimise potential P loss from rewetted WBZs and plant biomass yield may promote circular economy value chains and provide compensation to land owners for restored land now unsuitable for conventional farming.
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•The efficiency of wetland buffer zones for nutrient retention was reviewed.•Organic and mineral soils as nutrient filters or sources were compared.•Processes driving phosphorus and nitrogen fluxes were described.•The indirect and direct impact of vegetation were unraveled.•Implications for wetland restoration and open research questions were specified.
Abstract Constructed wetlands are sustainable wastewater treatment technology and have been used to treat a variety of wastewaters for decades, including domestic and industrial wastewaters. They ...take advantage of many of the same processes that occur in natural wetlands but do so in a more controlled or engineered system. To date, surface flow and subsurface flow wetlands are the two main categories of constructed wetland applications. On the other hand, peat soil is the decomposed organic matter that have built up over thousands of years, with high moisture content. Peat soil management is imperative to maintain the mire ecosystem. The use of rhizosphere biodegradation, phyto-stabilization and phyto-accumulation have shown the possibility of improving water quality of wetland associated with peat soil. Thus, the aim of this work is to present a review in the role of constructed wetland system for peat soil management and the water quality as restoration measures of the peat soil ecosystem to promote its suitability for agricultural purpose.
•Restored, managed wetlands sequestered carbon by inhibiting ecosystem respiration.•Agricultural land uses on degraded peat soils lost soil carbon to the atmosphere.•Large CH4 emissions result in ...restored wetlands being short-term greenhouse gas sources.•Restoration often resulted in greenhouse gas switchover times of more than a century.
Restoring degraded peat soils presents an attractive, but largely untested, climate change mitigation approach. Drained peat soils used for agriculture can be large greenhouse gas sources. By restoring subsided peat soils to managed, impounded wetlands, significant agricultural emissions are avoided, and soil carbon can be sequestered and protected. Here, we synthesize 36 site-years of continuous carbon dioxide and methane flux data from a mesonetwork of eddy covariance towers in the Sacramento-San Joaquin Delta in California, USA to compute carbon and greenhouse gas budgets for drained agricultural land uses and compare these to restored deltaic wetlands. We found that restored wetlands effectively sequestered carbon and halted soil carbon loss associated with drained agricultural land uses. Depending on the age and disturbance regime of the restored wetland, many land use conversions from agriculture to restored wetland resulted in emission reductions over a 100-year timescale. With a simple model of radiative forcing and atmospheric lifetimes, we showed that restored wetlands do not begin to accrue greenhouse gas benefits until nearly a half century, and become net sinks from the atmosphere after a century. Due to substantial interannual variability and uncertainty about the multi-decadal successional trajectory of managed, restored wetlands, ongoing ecosystem flux measurements are critical for understanding the long-term impacts of wetland restoration for climate change mitigation.
Peat is commonly described as a soil that is possess to high rate of compressibility due to present of high organic substance derived from plant origins. Peat soil naturally associated with ...settlement and consolidation characterized by its high initial void ratio, organic content and water holding capacity. This paper presents the performance of peat soil treated with powdered melamine urea formaldehyde resin (MUF-P) in term of compression and consolidation behaviour under standard compressibility test. In this study, series of one-dimensional oedometer test were carried out with the load increment method from 12.5 to 400 kPa after 24 hours of each loading. Peat soils under high moisture condition were mixed with MUF-P within 3 days of stipulated periods of curing times. The results indicate that increasing the MUF-P proportion has improved the compressibility characteristics of peat soil. The result shows the values of compression index (Cc) decreased from 4.12 to 0.9, and secondary compression index (Cα) were also decreased from the range of 0.026 to 0.320 to the range of 0.080 to 0.161 with the increase of peat MUF-P proportions up to maximum 350 kg/m3.
Peatlands in permafrost region are large carbon pools sensitive to global warming. However, the effects of increased temperature on carbon emissions and associated microbial abundances of peatlands ...under anaerobic condition remain largely unknown, especially when considering depths. For supplementing the deficiency about this, we collected soil from 0 to 150 cm depth of a permafrost peatland in the Great Hing'an Mountain and incubated at 5 and 15 °C for 55 days under anaerobic condition. Soil CO2 and CH4 emissions were detected during incubation, and inorganic nitrogen, dissolved organic carbon, and carbon-cycling microbial abundances were analyzed at the end of incubation. Results showed that emission rates and cumulative emissions amount of CO2 and CH4 at 15 °C across all soil depths were higher than those observed at 5 °C. Specifically, 0–20 cm and 20–40 cm layers had the highest CO2 emission rates and cumulative emission amounts, whereas the 40–60 cm and 60–80 cm layers had the highest CH4 emission rates and cumulative emission amounts. Mean temperature sensitivity (Q10) values of CO2 and CH4 were 2.39 and 55.49 respectively. Q10 values of bacteria, fungi, archaea, methanogen, and methanotroph abundances were 1.17, 3.85, 1.75, 1.68, and 1.66 respectively, which were calculated by the abundance ratio of microbial functional gene at 15 °C and 5 °C. Similar to the trend of CO2 emissions, high bacteria, fungi, archaea, methanogen, and methanotroph functional gene abundances were also observed in 0–20 cm and 20–40 cm layers, and such abundances increased along with temperature increasing. In sum, elevated temperature enhances the carbon emission of peatland in permafrost region, and the warming simulated CO2 emission is linked to the abundances of carbon-cycling microorganisms.
•Soil CO2 and CH4 emissions at 15 °C are higher than at 5 °C across all soil depths.•Active layer soil has the highest CO2 emission amounts in permafrost peatland.•CH4 emissions are highest in the transition layer and its adjacent active layer.•Warming stimulated CO2 emission is linked to C-cycling related microbial abundance.
The use of mineral soil analysis procedures in peat soils is considered unsuitable. Peat soil is vulnerable to disturbance, which leads to the damage of peat inert structure, such as the sifting and ...drying process. The objective of this study was to obtain the proper methods of preparation and extraction to be used in peat soils that can reflect the conditions on field. The experiment was carried out in the laboratory of Soil Science Department UGM by using the peat soil samples taken from Padang Island, Riau, arranged in a factorial randomized block design with three factors (peat soil preparation, the extraction method, and the levelof peat maturity). The variables observed included the available cation and Cation Exchange Capacity (CEC) of the peat soil. The results showed that there was no significant effect of the treatment interactions on each variable observed. The preparation method for original soil at each level of peat maturity reflected more of the physical condition on the field more than other methods. Meanwhile, sapric peat showed significant effect on cations and CEC. After being converted to bulk density (BD) values at each level of peat maturity, the result of the leaching extraction method showed that the value of available cation and CEC that reflected more of the value on the field. The peat soil analysis method should be carried out without air drying and shaking extraction treatment for further research.
Peat soil is rich in organic matter, which is the main reason for its poor engineering properties. The content and compositions of organic matter of peat soil lead to the various physical and ...mechanical properties of this kind of soil. In order to clarify the influence of organic matter content, a series of laboratory tests are conducted on dozens of groups of amorphous peat soil samples with different organic matter content, and the laws of physics, deformation, strength and permeability with organic matter content are systematically analyzed. In order to compare the difference in engineering properties caused by the different organic matter components, the experimental data of the fiber peat soil from domestic and foreign literatures are collected and compared systematically with the physical and mechanical indexes of the amorphous peat soil. The results show that there is a certain linear relationship between the basic physical and mechanical indexes of the amorphous peat soil and the organic matter conten
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