Application Of Organic Materials Research Articles

Photon-Dipole-Spin Interactions in M(TCNE)x/P(VDF-TrFE) Multiferroic Heterostructure Available for Bimodal Control of Multistate Data-Storage.

Organic multiferroic heterostructure is one of the most promising structures for the future design of high-density flexible energy-efficient data storage. Here, we fabricate organic ferromagnetic M(TCNE)x/ferroelectric P(VDF-TrFE) multiferroic heterostructures, where the excited state in M(TCNE)x interacted with localized dipole in P(VDF-TrFE) provides a key link for the interfacial coupling. Thus, aligned dipoles in P(VDF-TrFE) by external electric field can affect the magnetization of Fe(TCNE)x effectively to result in a pronounced magnetization-voltage (M-V) hysteresis loop. Moreover, light-induced electron-hole pairs in Fe(TCNE)x with long lifetime will effectively interact with the dipoles in P(VDF-TrFE) to lead to an effect in external light control of electric polarization of P(VDF-TrFE). Overall, the organic multiferroic heterostructure provides the possibility of realizing two storage modes, light control of dipole as well as electric field control of spin, which can broaden multifunctional applications of organic multiferroic materials in the area of multistate storage. This article is protected by copyright. All rights reserved.

Effects of Application of Different Organic Materials on Phosphorus Accumulation and Transformation in Vegetable Fields

Presently, the improvement of soil organic matter is the basis to ensure food security, but the accumulation and transformation characteristics of soil phosphorus (P) as affected by organic matter remain unclear. The accumulation, transformation, and migration characteristics of soil P in different soil layers of vegetable fields were researched under the application of organic materials. Six treatments were set up in the experiment:control (no fertilization), traditional fertilizer application by farmers, biochar, chicken manure, food waste, and straw application. Available phosphorus (Olsen-P), water-soluble phosphorus (CaCl2-P) content, soil phosphorus forms, soil organic matter (SOM), and pH were determined during the pepper harvest period. In the 0-5 cm and 5-10 cm soil layers, the available phosphorus content of traditional fertilization of farmers was higher, and the available phosphorus content of the four organic materials was in the order of straw > biochar > chicken manure > food waste. Compared to that with food waste, the straw and biochar treatments increased soil available phosphorus by 59.6%-67.3% and 29.1%-36.9%, respectively. The straw treatment could easily enhance the soil labile P pool, and soil labile P in the 0-5 cm soil layer increased by 47.3% and 35.1% compared with that under the chicken manure and food waste treatments, respectively. With the increase in soil depth, the proportion of available phosphorus in the chicken manure treatment decreased the least, and available phosphorus of the 20-30 cm soil layer accounted for 55.9% of the topsoil layer but only accounted for 16.0%-34.0% under treatment with the other three materials. Compared with that under the traditional fertilization of farmers, the pH significantly increased by 0.18-0.36 units after the application of organic fertilizer, and the pH of the chicken manure and food waste treatments was significantly higher than that of biochar and straw (P < 0.05). SOM content under the biochar treatment significantly increased by 7.7%-17.6% compared to that under the other three organic materials. Among the four organic materials, the straw treatment boosted the labile P pool the most, which was conducive to the rapid increase in plant-available P. Phosphorus was most likely to migrate downward under the chicken manure treatment. In the field management based on soil fertility enhancement, the application of biochar could not only improve soil pH and SOM but also avoid excessive accumulation of phosphorus in the surface layer, which decreases environmental risks.

Efficient photocatalytic molecular oxygen activation by TTF-based heterojunction for water purification

Tetrathiafulvalene (TTF), one of the well-known organic photoelectric materials, was served as active sites to accelerate the activation of molecular oxygen to degrade organic pollutants. Herein, a kind of Z-scheme heterojunction photocatalysis was constructed based on g-C3N4 and TTF. According to the experimental results, the mechanism of Z-scheme heterojunction was supported, in which photogenerated electrons transferred from g-C3N4 to TTF. More importantly, TTF on the catalyst surface could serve not only as electron donor, but also as the terminal active site to transfer photoexcited electrons to adsorbed oxygen molecules, producing mass of ⋅O2–. Meanwhile, the activation rate constant of TCN-5 for RhB was 0.0624 min−1, which was 10 and 5 times of g-C3N4 and TTF, respectively. In addition, the results of EPR spectra, rotating disk electrode measurement and molecular oxygen activation measurement also demonstrated that this catalyst was energetically favorable to generate ⋅O2– through the single-electron reduction pathway of molecular oxygen. Finally, four possible photodegradation routes for RhB were proposed based on the results of HPLC-MS. This work provides a new insight on the application of organic photoelectric materials in the purification of wastewater by the molecular oxygen activation.

Soil condition determines how crop residues affect soil compressive characteristics

AbstractExcessive soil compaction is a major cause of environmental problems and reduced agricultural soil productivity. Soil conditions can affect soil compressive characteristics. The application of organic materials reduces soil susceptibility to compaction. However, the direct effect of incorporated organic matter and interactions among soil conditions and incorporated organic materials on soil compressive characteristics are poorly understood. In this study, uniaxial compressive experiments were conducted to determine the compression curves of repacked brown earth from Northeast China. The effect of variable levels of incorporated corn straw (20, 40, 60, 80, and 100 g kg−1) and soil conditions (moisture content 0.14, 0.18, and 0.22 g g−1, and bulk density 1.20, 1.30, 1.45, and 1.60 g cm−3) on the compressive characteristics were investigated. The results showed that compressive characteristics were directly affected by soil conditions and corn straw‐derived organic matter (p < 0.01). Compressive characteristics were also significantly influenced by the interaction between soil conditions and corn straw‐derived organic matter (p < 0.01). By constructing a Entropy Weight Method (EWM) Technique for Order Preference by Similarity to Ideal Solution model (EWM‐TOPSIS), the conflicting indicators of soil resistance was comprehensively evaluated. The evaluation results indicated that moisture content at 0.14 g g−1, bulk density at 1.30 g cm−3 and corn straw‐derived organic matter at 34 g kg−1 was the optimal mode for soil resistance in our experiment. The results suggested that the interaction of soil conditions and incorporated organic matter should be considered to evaluate the susceptibility to compaction in the fields accurately.

Sugarcane leaf litter biomass and its effects on increasing sugarcane drought stress tolerance and reducing CO₂ emissions

Burning biomass on sugarcane plantations can lead to pollution (CO₂ emissions) and degradation in soil properties. Adopting non-burning technology can increase the value of biomass by applying it directly to the soil, although this may result in nutrient immobilization, which can hinder optimal plant growth due to high lignin and cellulose content or high CN ratio. On the contrary, composting waste with a decomposer will boost plant nutrient availability and enhance other soil characteristics. This research was aimed to assess the effect of several types of sugarcane organic matter on improving soil characteristics, growth of sugarcane and the CO₂ emissions. The study was conducted using a Completely Randomized Factorial Design with two factors: type of organic matter (control, fresh litter and compost of sugarcane biomass) and level of drought stress (100, 75, 50 and 25%). Incubation occurred over 16 weeks, divided into two phases of 8 weeks each. The results showed that the application of organic materials in the form of compost could reduce water loss caused by environmental heat and sugarcane growing process. Furthermore, compost application improved soil chemical and biological properties by increasing soil pH, total nitrogen (N), total phosphate (P), total potassium (K), and the total microbial population, although differences were not significant compared to the control. Additionally, applying organic matter in the form of compost or litter helped suppress or reduce emissions, with compost treatment proving more effective than litter in reducing CO₂ emissions.

Organometallic Chirality Sensing via "Click"-Like η6-Arene Coordination with an Achiral Cp*Ru(II) Piano Stool Complex.

Piano stool complexes have been studied over many years and found widespread applications in organic synthesis, catalysis, materials and drug development. We now report the first examples of quantitative chiroptical molecular recognition of chiral compounds through click-like η6-arene coordination with readily available half sandwich complexes. This conceptually new approach to chirality sensing is based on irreversible acetonitrile displacement of [Cp*Ru(CH3CN)3]PF6 by an aromatic target molecule, a process that is fast and complete within a few minutes at room temperature. The metal coordination coincides with characteristic circular dichroism inductions that can be easily correlated to the absolute configuration and enantiomeric ratio of the bound molecule. A relay assay that decouples the determination of the enantiomeric composition and of the total sample amount by a practical CD/UV measurement protocol was developed and successfully tested. The introduction of piano stool complexes to the chiroptical sensing realm is mechanistically unique and extends the scope of currently known methods with small-molecule probes that require the presence of amino, alcohol, carboxylate or other privileged functional groups for binding of the target compound. A broad application range including pharmaceutically relevant multifunctional molecules and the use in chromatography-free asymmetric reaction analysis are also demonstrated.

High-capacity dilithium hydroquinone cathode material for lithium-ion batteries.

Lithiated organic cathode materials show great promise for practical applications in lithium-ion batteries owing to their Li-reservoir characteristics. However, the reported lithiated organic cathode materials still suffer from strict synthesis conditions and low capacity. Here we report a thermal intermolecular rearrangement method without organic solvents to prepare dilithium hydroquinone (Li2Q), which delivers a high capacity of 323 mAh g-1 with an average discharge voltage of 2.8V. The reversible conversion between orthorhombic Li2Q and monoclinic benzoquinone during charge/discharge processes is revealed by in situ X-ray diffraction. Theoretical calculations show that the unique Li-O channels in Li2Q are beneficial for Li+ ion diffusion. In situ ultraviolet-visible spectra demonstrate that the dissolution issue of Li2Q electrodes during charge/discharge processes can be handled by separator modification, resulting in enhanced cycling stability. This work sheds light on the synthesis and battery application of high-capacity lithiated organic cathode materials.

Organic amendments increased Chinese milk vetch symbiotic nitrogen fixation by enriching Mesorhizobium in rhizosphere.

Symbiotic nitrogen fixation of Chinese milk vetch (Astragalus sinicus L.) can fix nitrogen from the atmosphere and serve as an organic nitrogen source in agricultural ecosystems. Exogenous organic material application is a common practice of affecting symbiotic nitrogen fixation; however, the results of the regulation activities remain under discussion. Studies on the impact of organic amendments on symbiotic nitrogen fixation have focused on dissolved organic carbon content changes, whereas the impact on dissolved organic carbon composition and the underlying mechanism remain unclear. In situ pot experiments were carried out using soils from a 40-year-old field experiment platform to investigate symbiotic nitrogen fixation rate trends, dissolved organic carbon concentration and component, and diazotroph community structure in roots and in rhizosphere soils following long-term application of different exogenous organic substrates, i.e., green manure, green manure and pig manure, and green manure and rice straw. Remarkable increases in rate were observed in and when compared with that in green manure treatment, with the greatest enhancement observed in the treatment. Moreover, organic amendments, particularly pig manure application, altered diazotroph community composition in rhizosphere soils, therefore increasing the abundance of the host-specific genus Mesorhizobium. Furthermore, organic amendments influence the diazotroph communities through two primary mechanisms. Firstly, the components of dissolved organic carbon promote an increase in available iron, facilitated by the presence of humus substrates. Secondly, the elevated content of dissolved organic carbon and available iron expands the niche breadth of Mesorhizobium within the rhizosphere. Consequently, these alterations result in a modified diazotroph community within the rhizosphere, which in turn influences Mesorhizobium nodulation in the root and symbiotic nitrogen fixation rate. The results of the present study enhance our understanding of the impact of organic amendments on symbiotic nitrogen fixation and the underlying mechanism, highlighting the key role of dissolved organic carbon composition on diazotroph community composition in the rhizosphere.

Organic Anodes with Nearly 100% Initial Coulombic Efficiency Enabled by Wet‐Chemically Constructed Artificial Solid‐Electrolyte Interphase Film toward High‐Energy‐Density Organic Full Batteries

AbstractLithium‐ion batteries (LIBs) built on inorganic anodes have achieved great commercial success. By contrast, the practical application of organic anode materials encounters key bottlenecks including electronic insulation, high solubility, and poor initial coulombic efficiency (ICE). Among them, improving ICEs (normally 30–60%) faces enormous challenges in both theory and technology, and there has been no substantial breakthrough yet. Herein, a wet chemical pretreatment technology to increase the ICE of maleic acid (MA)‐based anodes from 43.2% to nearly 100% is proposed for the first time, and this strategy demonstrates universal applicability. Typically, the wet chemical pretreatment involves reacting with lithium‐biphenyl to form LixMA intermediates (x = 4–6) and further forming a compact artificial solid‐electrolyte interphase (SEI) film through the spontaneous reaction between active LixMA and battery organic electrolytes. This wet chemically‐constructed artificial SEI layer can almost completely suppress lithium loss in the initial cycle of the MA electrode and significantly boost the actual output energy density, rate capability, and cycling durability of MA anode‐based full batteries. Significantly, the study further demonstrated that a series of organic anode materials with high ICEs can be achieved through similar wet chemical pretreatment. This work will open up the true application of high‐ICE organic anodes in LIBs.

Effects of the combined application of livestock manure and plant residues on soil organic carbon sequestration in the southern Loess Plateau of China

Increasing soil organic carbon (SOC) sequestration enhances the stability and productivity of agricultural ecosystems. Organic material application is a direct and effective way to maintain and improve SOC sequestration. However, currently, there is little knowledge on efficient practices for combined organic material application to improve SOC sequestration. In this study, we evaluated the effect of three organic materials alone or in combination on SOC sequestration in a 4-year field experiment. Eight treatments were included: control (CK, conventional chemical fertilizer), green manure (G), straw (S), decomposed sheep manure (M), green manure plus straw (GS), green manure plus sheep manure (GM), straw plus sheep manure (SM), green manure, and straw plus sheep manure (GSM). In 2020, decomposed sheep manure application (M, SM, GM and GSM) resulted in the greatest cumulative SOC sequestration (9.5–10.8 Mg C ha−1), followed by those in treatments S (6.1 Mg C ha−1) and GS (6.9 Mg C ha−1). The SOC sequestration efficiency in the M treatment (44.8 %) was greater than that in the others (15.2–34.8 %). A random forest model revealed that organic material quantity and quality, enzyme activity, and microbial community composition were the primary factors determining SOC sequestration. Sheep manure application increased SOC sequestration by increasing lignin quantity and proportion. Incorporating green manure and straw return enhanced SOC sequestration by promoting microbial growth and increasing soil C-acquiring enzyme activity. However, interactions between sheep manure and plant residues resulted in decreases in SOC sequestration efficiency compared with sheep manure application alone. This is because combined fertilization stimulated microbial growth and enzyme activity, causing changes in microbial community structure and accelerating organic material and SOC decomposition. Thus, we do not recommend combining livestock manure with straw or green manure to improve SOC sequestration and soil quality in the southern Loess Plateau.

Changing Cinnamaldehyde Skeleton Achieves Antibacterial Nanoswitch.

Changeable substituent groups of organic molecules can provide an opportunity to clarify the antibacterial mechanism of organic molecules by tuning the electron cloud density of their skeleton. However, understanding the antibacterial mechanism of organic molecules is challenging. Herein, we reported a molecular view strategy for clarifying the antibacterial switch mechanism by tuning electron cloud density of cinnamaldehyde molecule skeleton. The cinnamaldehyde and its derivatives were self-assembled into nanosheets with excellent water solubility, respectively. The experimental results show that α-bromocinnamaldehyde (BCA) nanosheets exhibits unprecedented antibacterial activity, but there is no antibacterial activity for α-methylcinnamaldehyde nanosheets. Therefore, the BCA nanosheets and α-methylcinnamaldehyde nanosheets achieve an antibacterial switch. Theoretical calculations further confirmed that the electron-withdrawing substituent of the bromine atom leads to a lower electron cloud density of the aldehyde group than that of the electron-donor substituent of the methyl group at the α-position of the cinnamaldehyde skeleton, which is a key point in elucidating the antimicrobial switch mechanism. The excellent biocompatibility of BCA nanosheets was confirmed by CCK-8. The mouse wound infection model, H&E staining, and the crawling ability of drosophila larvae show that as-prepared BCA nanosheets are safe and promising for wound healing. This study provides a new strategy for the synthesis of low-cost organic nanomaterials with good biocompatibility. It is expected to expand the application of natural organic small molecule materials in antimicrobial agents.

Ketersediaan Nitrogen pada Ultisol dengan Aplikasi Kotoran Walet dan Arang Kayu

The application of organic matter with a high nitrogen (N) content in combination with the application of wood charcoal is a common soil fertility management practice in Ultisols. This study aims to determine the availability of N in Ultisols, which are applied to swallow droppings and wood charcoal. The experimental design used was a two-factor Completely Randomized Design (CRD), with the first factor being swallow droppings (0.5 and 10 t ha−1) and the second factor being wood charcoal (0, 10, and 20 t ha−1), with as many as three repetitions. As much as 200 g of soil was put into the incubation site, then swallow droppings and wood charcoal were added according to the treatment, stirred until evenly distributed, and then incubated at 70% field capacity for 14 days. The contents of NH4+, NO3-, and pH were observed at the end of the incubation period. The results showed that the application of swallow droppings and wood charcoal increased the content of NH4+, NO3-, and mineral N but lowered soil pH. The best treatment was given to swallow manure at 10 t ha-1 which increased mineral N by 59%, and a combination of swallow manure 10 t ha-1+10 t ha-1 wood charcoal which increased nitrate content by 1,666%. The results of this study indicate that the application of swallow droppings combined with wood charcoal can increase the availability of N in Ultisols.

Manipulation of the Self‐Assembly Morphology by Side‐Chain Engineering of Quinoxaline‐Substituted Organic Photothermal Molecules for Highly Efficient Solar‐Thermal Conversion and Applications

AbstractOrganic photothermal materials have attracted increasing attention because of their structural diversity, flexibility, and compatibility. However, their energy conversion efficiency is limited owing to the narrow absorption spectrum, strong reflection/transmittance, and insufficient nonradiative decay. In this study, two quinoxaline‐based D–A‐D–A‐D‐type molecules with ethyl (BQE) or carboxylate (BQC) substituents were synthesized. Strong intramolecular charge transfer provided both molecules with a broad absorption range of 350–1000 nm. In addition, the high reorganization energy and weak molecular packing of BQE resulted in efficient nonradiative decay. More importantly, the self‐assembly of BQE leads to a textured surface and enhances the light‐trapping efficiency with significantly reduced light reflection/transmittance. Consequently, BQE achieved an impressive solar‐thermal conversion efficiency of 18.16 % under 1.0 kW m−2 irradiation with good photobleaching resistance. Based on this knowledge, the water evaporation rate of 1.2 kg m−2 h−1 was attained for the BQE‐based interfacial evaporation device with an efficiency of 83 % under 1.0 kW m−2 simulated sunlight. Finally, the synergetic integration of solar‐steam and thermoelectric co‐generation devices based on BQE was realized without significantly sacrificing solar‐steam efficiency. This underscores the practical applications of BQE‐based technology in effectively harnessing photothermal energy. This study provides new insights into the molecular design for enhancing light‐trapping management by molecular self‐assembly, paving the way for photothermal‐driven applications of organic photothermal materials.

Manipulation of the Self-Assembly Morphology by Side-Chain Engineering of Quinoxaline-Substituted Organic Photothermal Molecules for Highly Efficient Solar-Thermal Conversion and Applications.

Organic photothermal materials have attracted increasing attention because of their structural diversity, flexibility, and compatibility. However, their energy conversion efficiency is limited owing to the narrow absorption spectrum, strong reflection/transmittance, and insufficient nonradiative decay. In this study, two quinoxaline-based D-A-D-A-D-type molecules with ethyl (BQE) or carboxylate (BQC) substituents were synthesized. Strong intramolecular charge transfer provided both molecules with a broad absorption range of 350-1000 nm. In addition, the high reorganization energy and weak molecular packing of BQE resulted in efficient nonradiative decay. More importantly, the self-assembly of BQE leads to a textured surface and enhances the light-trapping efficiency with significantly reduced light reflection/transmittance. Consequently, BQE achieved an impressive solar-thermal conversion efficiency of 18.16 % under 1.0 kW m-2 irradiation with good photobleaching resistance. Based on this knowledge, the water evaporation rate of 1.2 kg m-2 h-1 was attained for the BQE-based interfacial evaporation device with an efficiency of 83 % under 1.0 kW m-2 simulated sunlight. Finally, the synergetic integration of solar-steam and thermoelectric co-generation devices based on BQE was realized without significantly sacrificing solar-steam efficiency. This underscores the practical applications of BQE-based technology in effectively harnessing photothermal energy. This study provides new insights into the molecular design for enhancing light-trapping management by molecular self-assembly, paving the way for photothermal-driven applications of organic photothermal materials.

Returning Different Organic Materials to the Field: Effects on Labile Soil Nitrogen Pool under Drip Irrigation with Film Mulching in a Semi-Arid Soil

The purpose of this study was to observe the changes in soil nitrogen pools (active organic and inorganic nitrogen fractions) after applying organic materials under drip irrigation with film mulching in a semi-arid soil. The two-year field experiment included four fertilization treatments: maize straw, fodder grass, sheep manure, and a control treatment with no organic material applied (CK). The results showed that the application of maize straw and sheep manure significantly increased the soil total nitrogen content by 9.02~13.33% and 11.02~17.27%, respectively, while no significant improvement was found with the use of fodder grass. Compared with CK, returning organic materials to the field increased the soil active nitrogen pools, except for ammonium nitrogen content. Meanwhile, the content of particulate organic nitrogen was significantly increased by 42.11~78.85% under the application of organic materials, which took the highest proportion of active nitrogen pools and was sensitive to fertilization treatments. Among the three organic materials, maize straw and sheep manure increased the soil active nitrogen content the most. In conclusion, both maize straw and sheep manure are the optimum organic materials, which could be applied for improving soil nitrogen storage under drip irrigation with film mulching within semi-arid areas.

Ultra‐Long Lifespan Ni Based Porphyrin Complex Cathode for Organic Alkali Metal Batteries

AbstractThe high solubility and low intrinsic electronic conductivity are the key challenges for application of organic materials in electrochemical energy storage. Herein, a functionalized porphyrin complex of [5,15‐Bis(ethynyl)‐10,20‐diphenylporphinato]nickel(II) (NiDEPP) is proposed as new cathode material for alkali metal ion batteries. Owing to the in‐situ electropolymerization, NiDEPP became extremely stable after initial cycling. Therefore, the NiDEPP electrode delivers remarkable reversible capacity of 153 mAh g−1 at 1 A g−1, a high specific energy density of 459 Wh kg−1 and extremely stable cyclability for 4000 cycles with negligible capacity decay in organic lithium batteries. It can further be cycled upto 10000 cycles. Due to the bipolar capability of porphyrin ring, this cathode can also be extended in both sodium and potassium based organic cells. Similar charge storage mechanism enables highly reversible capacity and long‐term cycling stability. This study would open a pathway toward new organic electrodes with long cycling life and high energy densities for renewable charge storage devices.

Breakthrough applications of porous organic materials for membrane-based CO2 separation: a review.

Over the last decades, porous organic materials (POMs) have been extensively employed in various industrial approaches including gas separation, catalysis and energy production due to possessing indisputable advantages like great surface area, high permeability, controllable pore size, appropriate functionalization and excellent processability compared to traditional substances like zeolites, Alumina and polymers. This review presents the recent breakthroughs in the multifunctional POMs for potential use in the membrane-based CO2 separation. Some examples of highly-selective membranes using multifunctional POMs are described. Moreover, various classifications of POMs following with their advantages and disadvantages in CO2 separation processes are explained. Apart from reviewing the state-of-the-art POMs in CO2 separation, the challenges/limitations of POMs with tailored structures for reasonable application are discussed.

Modulating molecular aggregation of luminogens: Bridging the gap between solutions and solids

In the past two decades, the advancement of aggregation-induced emission (AIE) has greatly advanced our understanding of organic luminescence and facilitated the application of organic luminescent materials. AIE luminogens (AIEgens) emit weakly in solutions but strongly in aggregated states. This significant difference in luminescence between solutions and aggregated states of AIEgens has shown that there is much to explore in the mesoscopic world (the intermediary phase). Accordingly, the research paradigm of aggregate science is proposed. The path to new aggregate materials relies not only on molecule syntheses but also on the control of molecular aggregation, which bridges the gap between solutions and solids. In this Perspective, we outline three general strategies for managing molecular aggregation to stimulate new ideas and provide guidance on controllable molecular aggregation.

Effects of Organic Matter Addition on Soil Carbon Contents, CO2 Emissions, and Bacterial Compositions in a Paddy Field in South China

Increasing soil organic carbon (SOC) contents and reducing carbon dioxide (CO2) emissions in paddy soil fields can result in positive impacts on climate change mitigation and soil quality. However, SOC accumulation and its microbial driving factors under enhanced fertilization strategies (e.g., organic matter application) are still unclear. Therefore, we investigated the effects of organic matter addition on SOC variations, CO2 fluxes, and their relationships with soil bacterial compositions and functions through a 6-year fertilizer experiment in rice fields involving two fertilization types, namely chemical fertilizer (NPK) and chemical fertilizer combined with organic matter (NPK+OM). The results showed significantly higher and lower SOC contents (p < 0.05) in the 10–20 cm soil layer under the NPK+OM treatment before rice transplanting and after rice harvest, respectively, than those under the NPK treatment. The lower SOC contents after rice harvest might be due to the great nutrient consumption, resulting in higher rice yields in the NPK+OM than those in the NPK treatment by 6.68 to 32.35%. Compared with NPK, NPK+OM reduced the in-situ CO2 fluxes by 38.70–118.59%. However, the ex-situ SOC mineralization rates were not affected by NPK+OM in the 0–10 and 10–20 cm soil layers. The 16S rRNA sequence indicated a significant increase in the abundance of non-singleton amplicon sequence variants (ASVs) in the NPK+OM treatment scenario compared to those in the NPK treatment scenario. The top three most important soil bacterial phylum influenced by NPK+OM were LCP-89, BRC1, and Rokubacteria in April, as well as Firmicutes, Nitrospinae, and BRC1 in July. Soil Actinobacteria was negatively correlated with the SOC contents in April and July. The results of the present study demonstrate the economic and ecological benefits of the organic matter addition in rice production, as well as the contribution of soil bacteria to SOC accumulation and CO2 emission reduction.

Peningkatan pH dengan Pemberian Bahan Organik pada Pengelolaan Air Asam Tambang Menggunakan Metode Passive Treatment

Mining is the process of extracting beneficial minerals from the surface of the earth that have an impact on the formation of acid mine drainage (AMD). One method of passive AMD management is passive treatment. This study used the Nested Factorial Experiment Design method. The types of organic matter used were empty fruit bunch oil palm (EFB) and cow dung, with doses of 0 Mg ha-1 (control), 50 Mg ha-1, 100 Mg ha-1, 150 Mg ha-1 and 200 Mg ha-1. Each treatment was three repeats so that 30 units of experimental units were obtained. The pH value of AMD in the untreated (control) reactor was 3.67. The initial reaction (pH) of AMD (0 days) with EFB application at a dose of 50 – 200 Mg ha-1 ranged from 3.63 – 4.28 and the initial pH of cow dung was 3.84 – 4.13. The reaction (pH) of the 1st to 4th weeks of AMD after adding EFB organic matter at a dose of 50 – 200 Mg ha-1 show a pH range (6.38 – 7.59) and cow manure at a dose of 150 – 200 Mg ha-1 show a pH (6.09 – 7.01). The conclusion are that the application of EFB organic matter on constructed wetland media for 4 weeks had a very real effect on increasing the pH of the AMD dose of 100 – 200 Mg ha-1 while cow dung 150 – 200 Mg ha-1 are the most effective against increasing pH.