Organic Field Research Articles

Cooperative interaction of Glomus intraradices with plant growth-promoting rhizobacteria promotes plant development and essential oil yield of Pogostemon cablin and reduces disease occurrence under organic field conditions

Cooperative interaction of Glomus intraradices with plant growth-promoting rhizobacteria promotes plant development and essential oil yield of Pogostemon cablin and reduces disease occurrence under organic field conditions

Peran Sekolah Lapangan Organik (Slapo) dalam Mengurangi Kemiskinan Menurut Perspektif Ekonomi Islam di Nagari Sumpur Kudus Kabupaten Sijunjung

The agricultural sector is one of the sectors that plays an important role in the economic growth of a country, while programs held by the government for farmers can be channeled through gapoktan platforms and farmer groups. Therefore, the formation of farmer groups often becomes a formal organization. By creating this farmer group, problems that arise can be resolved jointly by farmers starting from the technical aspects of carrying out production, meeting production facilities, and marketing their products.This study aims to find out how the role of Organic Field Schools (SLAPO) in Reducing Poverty According to the Perspective of Islamic Economics. This study used a qualitative research method with research informants Wali Nagari Sumpur Kudus and 10 members of the organic field school in Nagari Sumpur Kudus. The data collection techniques used were observation, interviews and documentation. The results of this study indicate that the role of organic field schools in Nagari Sumpur Kudus has been able to increase the income of the community, especially members of farmer groups, although there are still not many who can reduce poverty rates, they have been able to increase farmer productivity, namely by using organic fertilizers with ingredients that are easy to find in around the environment. So farmers no longer spend a lot of money in cultivating farmers' fields. With the existence of an organic field school in Nagari Sumpur Kudus with the aim of increasing knowledge, skills and being able to overcome the obstacles faced by farmers. Keyword: Islamic economics, Poverty, Organic Field School

Isoselenazole Synthesis by Rh-Catalyzed Direct Annulation of Benzimidates with Sodium Selenite

Organoselenium compounds have attracted significant research interest because of their potent therapeutic activities and indispensable applications in the organic chemistry field. The selenation reactions conventionally rely on the use of sensitive Se reagents; thus, new synthetic methods with improved efficiency and operational simplicity have recently been of particular interest. In this manuscript, we report a Rh-catalyzed direct selenium annulation using tractable sodium selenite (Na2SeO3) as the limiting reagent. The selenite species was converted to highly electrophilic SeO(OBz)2 in situ upon treatment with Bz2O, thereby undergoing C–H/N–H double nucleophilic selenation. A series of benzimidates successfully underwent selenation under mild reaction conditions to afford isoselenazole derivatives.

Occurrence of chlorpyrifos and organochlorine pesticides in a native bumblebee (Bombus pauloensis) living under different land uses in the southeastern Pampas, Argentina

Pollinators such as Apidae bees are vital for ecosystems and food security. Unfortunately, their populations have declined due to several factors including pesticide use. Among them, the organophosphate insecticide chlorpyrifos, poses a global threat, while legacy compounds like organochlorine pesticides (OCPs) easily bioaccumulate, increasing the concern. Bombus pauloensis, a widely distributed native bee in Argentina, is used for commercial pollination; however, information regarding their health status is scarce. This study assessed chlorpyrifos and OCP levels in B. pauloensis (workers and males) and related environmental matrices living from three different land uses schemes, by means of GC-ECD and GC–MS. The ornamental horticulture field (OP) showed the highest total pesticide concentrations in workers (13.1 ng/g), flowers and soils, whereas the organic agriculture field (OA) exhibited the lowest. Chlorpyrifos was the most abundant compound, accounting for at least 20 % of pesticide load across all matrices. The food production horticulture field (FH) had the highest chlorpyrifos concentration in workers, males and soils (5.0, 4.4 and 3.3 ng/g, respectively), suggesting a local greater usage, whereas OA showed the lowest. Regarding OCPs groups, Drins and DDTs were predominant in most matrices, with FH males registering the highest levels (4.0 and 2.5 ng/g, respectively), closely followed by OP. However, metabolites' contribution indicated historical use and atmospheric inputs in all sites. Multivariate analyses confirmed the significance of site and bumblebee sex to explain pesticide composition. Males from all sites exhibited higher chlorpyrifos levels than workers and this trend was similar for some OCP groups. Overall, OA differed from FH and OP, indicating a correlation between production modes and pesticide profiles. This study demonstrates the value of B. pauloensis as a pesticide biomonitor but also offers insights into its populations' health in the area. In this sense, this information could be useful towards the preservation of this crucial pollinator.

On the Importance of Chemical Precision in Organic Electronics: Fullerene Intercalation in Perfectly Alternating Conjugated Polymers

AbstractThe true structure of alternating conjugated polymers—the state‐of‐the‐art materials for many organic electronics—often deviates from the idealized picture. Homocoupling defects are in fact inherent to the widely used cross‐coupling polymerization methods. Nevertheless, many polymers still perform excellently in the envisaged applications, which raises the question if one should really care about these imperfections. This article looks at the relevance of chemical precision (and lack thereof) in conjugated polymers covering the entire spectrum from the molecular scale, to the micro and mesostructure, up to the device level. The different types of polymerization errors for the alkoxylated variant of the benchmark (semi)crystalline polymer poly[2,5‐bis(3‐tetradecylthiophen‐2‐yl)thieno[3,2‐b]thiophene (PBTTT) are identified, visualized, and quantified and a general strategy to avoid homocoupling is introduced. Through a combination of experiments and supported by simulations, it is shown that these coupling defects hinder fullerene intercalation and limit device performance as compared to the homocoupling‐free analog. This clearly demonstrates that structural defects do matter and should be generally avoided, in particular when the geometrical regularity of the polymer is essential. These insights likely go beyond the specific PBTTT derivatives studied here and are of general relevance for the wider organic electronics field.

Assessing crop sequence diversity and agronomic quality in grassland regions

Industrial inputs have replaced crop rotations for fertility and pest management in input-intensive agriculture, resulting in a high number of crop sequence permutations and negative impacts on ecosystems and human health. Strengthening diversified and agronomically optimised crop sequences is critical to promoting sustainable practices. Comprehensive crop sequence diagnosis methods play an important role in evaluating and improving current crop sequence practices. However, recent literature has focused on annual crops, leading to biased results in crop sequence analysis for organic farming and livestock regions, where multiannual temporary fodder crops are a key aspect of crop sequences. This paper extends two methods of crop sequence analysis by including multiannual temporary fodder crops. By applying these generalised methods to a case study in the beef grassland regions of Belgium, using IACS crop data from 2015 to 2020, we reveal significant differences in the agronomic quality of the crop sequences across the territory and between organic and non-organic fields. In contrast to the existing literature, the inclusion of multiannual temporary fodder crops highlights the prevalence of high diversity and high agronomic quality sequences in livestock farming regions. Maize monoculture (of low agronomic quality), temporary grasslands (associated with high quality crop sequences) and organic certification are the main drivers of crop sequence quality in the regions studied.

Polyarylene ether nitrile dielectric films modified by HNTs@PDA hybrids for high-temperature resistant organic electronics field

Abstract In this work, mussel-inspired surface functionalization of halloysite nanotubes (HNTs) were coated by in situ self-polymerization of polydopamine (PDA) to synthesize core-shell structural composites (HNTs@PDA), and then incorporated into polyarylene ether nitrile (PEN) matrix. Due to the strong adhesion of the PDA modification layer and the formation of hydrogen bonds between the polar nitrile group of PEN and the catechol group of PDA, the dispersion and interfacial compatibility of HNTs@PDA in the PEN matrix are improved. The results show that the dielectric constant of PEN/HNTs@PDA 20 nanocomposites reaches 11.56 (1 kHz), which is 3.2 times that of pure PEN. In addition, after heat treatment, a chemical cross-linking reaction occurred between the PEN matrix to form a cross-linked PEN (CPEN) based nanocomposites, which further improved the thermal stability of the nanocomposites. The results show that the T g of CPEN/HNTs@PDA 20 nanocomposites reaches 215.5°C, which is 47.7°C higher than that of PEN/HNTs@PDA 20. Moreover, the dielectric constant-temperature coefficient of all CPEN nanocomposites is less than 7 × 10−4°C−1 at the temperature range of 25–180°C. All in all, this work provides a simple and environmentally friendly strategy to adjust the dielectric properties of polymer-based ceramic nanocomposites, which provides a pathway for its application as a dielectric material in the film capacitors field.

Effects of Processing-Induced Contamination on Organic Electronic Devices.

Organic semiconductors are a family of pi-conjugated compounds used in many applications, such as displays, bioelectronics, and thermoelectrics. However, their susceptibility to processing-induced contamination is not well understood. Here, it is shown that many organic electronic devices reported so far may have been unintentionally contaminated, thus affecting their performance, water uptake, and thin film properties. Nuclear magnetic resonance spectroscopy is used to detect and quantify contaminants originating from the glovebox atmosphere and common laboratory consumables used during device fabrication. Importantly, this in-depth understanding of the sources of contamination allows the establishment of clean fabrication protocols, and the fabrication of organic field effect transistors (OFETs) with improved performance and stability. This study highlights the role of unintentional contaminants in organic electronic devices, and demonstrates that certain stringent processing conditions need to be met to avoid scientific misinterpretation, ensure device reproducibility, and facilitate performance stability. The experimental procedures and conditions used herein are typical of those used by many groups in the field of solution-processed organic semiconductors. Therefore, the insights gained into the effects of contamination are likely to be broadly applicable to studies, not just of OFETs, but also of other devices based on these materials.

Land-use pattern and landscape structure impact butterfly diversity and abundance in organic agroecosystems

ContextAgricultural intensification and land-use patterns impact biodiversity and reduce ecosystem functions. Organic farming is often seen as a more biodiversity friendly way of farming. However, not all organic farming is equally supportive for biodiversity, structural diversity of the farms has a great impact and the often high intertwinement of organic and conventional farmland causes spill-over problems.ObjectiveOn organic farmland in central Italy, we analysed butterfly diversity and community structures in different land-use categories across a heterogeneous landscape. We aim to analyse the impact of the different land-use structures such as hedges and forest edges on this farmland, as well as the influence of adjoining conventionally farmed areas.MethodsWe studied butterflies on organic farmland including olive and hazelnut plantations, as well as meadows and fallow land, surrounded by hedges and forests. Hereby we considered the effects of land-use on the studied site and the adjoining land, e.g., semi-natural habitats (as hedges or forest edges), organic or conventional farmland. We counted butterflies along line transects and recorded habitat parameters for each transect. All encountered butterflies were classified according their ecological demands, behaviour, and life-history.ResultsWe found highest mean butterfly species richness in fallow land and lowest in hazelnut plantations. Species community structures differed hardly between plantations and meadows, but considerably compared to fallow land. Butterfly abundances are reduced for olive plantations adjacent to agricultural fields treated with pesticides, compared to such surrounded by organic fields. Habitat para-meters such as the number of flowering plant species and shade impact butterfly diversity and abundance. Forest edges producing considerable shadow to the transects had a significantly negative effect on diversity and abundance, while the influence of hedges was positive.ConclusionsBased on our findings, we conclude that also organic farmland has different degrees of biodiversity depending on a variety of land-use pattern. In particular, habitat heterogeneity and a high diversity of flowers positively influence butterfly diversity. The intensive mixing of organic and conventional agriculture must be seen critical for conservation as negative effects might spill over to organic fields, but might be compensable by landscape structures like hedges.

Potential soil degradation of paddy fields through observation approaches from various sources of environmental diversity

Soil is classified as a vital and non-renewable natural resource for food production. We also could produce good-quality, healthy, and nutritious food through healthy soil. Good quality soil was rare to find. Typically, land used for food crop cultivation is regarded as having substantially degraded soil, characterized by a low proportion of soil macro primer nutrients and organic C content. This study aimed to determine the soil degradation of paddy field through environmental diversity that occur on the field. This research result showed that conventional paddy field cultivation is classified as degraded soil. Moreover, organic paddy field cultivation was classified as low degraded soil. After classifying the soil, proceed challenges of recommendations have been formulated this research aims. Monitoring the soil degradation level is necessary to set some recommendations for cultivation to prevent the ongoing degradation of rice fields and threaten food security. This research will produce a guideline and a body of literature highlighting the necessity of monitoring soil degradation levels and identifying limiting variables so that a paddy soil management strategy based on soil health can be adopted to sustain food security.

Pinaceae Pine Resins (Black Pine, Shore Pine, Rosin, and Baltic Amber) as Natural Dielectrics for Low Operating Voltage, Hysteresis-Free, Organic Field Effect Transistors.

Four pinaceae pine resins analyzed in this study: black pine, shore pine, Baltic amber, and rosin demonstrate excellent dielectric properties, outstanding film forming, and ease of processability from ethyl alcohol solutions. Their trap-free nature allows fabrication of virtually hysteresis-free organic field effect transistors operating in a low voltage window with excellent stability under bias stress. Such green constituents represent an excellent choice of materials for applications targeting biocompatibility and biodegradability of electronics and sensors, within the overall effort of sustainable electronics development and environmental friendliness.

Solution Processed Active Materials for Pixel Sensor Element and Integrated Circuits

We describe an integrated planar circuit for an active pixel sensor consisting of Metal-semiconductor-Metal (MSM) photodetector with hybrid perovskite as the semiconductor and organic field effect transistors (OFETs) as a readout circuitry. The adopted fabrication approach reduces the complexity of implementing these circuits over a large area, for a variety of substrates from flexible to rigid ones. The features of this circuit include low threshold voltage and a reasonable switching speed of ≈ 100 μs. The achievable channel length of ≈ 2.5 μm for both the photodetector element and OFETs, implies possibility of high pixel density for imaging applications.

High-performance organic field effect transistor of liquid crystalline organic semiconductor using silver electrodes with bottom-gate top-contact configuration

We have investigated organic field effect transistors (OFETs) fabricated with liquid crystalline organic semiconductor, 2-decyl-7-phenyl-[1]benzothieno[3,2-b][1]benzothiophene (Ph-BTBT-10), and silver (Ag) source-drain electrodes. Ph-BTBT-10 OFETs using Ag source-drain electrodes in bottom-gate top-contact configuration exhibit high mobility of 8.2 cm2 Vs−1, which is similar to those of gold (Au) electrodes. Contact resistance of Ph-BTBT-10 OFETs using Ag electrodes achieved 0.49 kΩcm by transfer length method, which is lower than those of Au electrodes, 2.7 kΩcm. Ph-BTBT-10 OFET using Ag source-drain electrodes in bottom-gate top-contact configuration is a promising candidate for high-performance and low-cost OFETs.

Oil radish, winter rye and crimson clover: root and shoot performance in cover crop mixtures

Abstract Purpose The current knowledge of belowground interactions in intercropping systems is limited due to methodological constraints. The current study aimed to investigate cereal-brassica and cereal-legume-brassica cover crop mixtures regarding mixture effects on root and shoot biomass as well as root traits, vertical root niche differentiation, and complementarity. Methods Sole crops and two- and three-species-mixtures of winter rye (Secale cereale L.), crimson clover (Trifolium incarnatum L.), and oil radish (Raphanus sativus L. var. oleiformis Pers.) were grown in Germany in a two-year organic field experiment. Root traits were analysed using the monolith method. For discrimination of species root mass Fourier transform infrared (FTIR) spectroscopy was used. Results Oil radish dominated mixtures above- and belowground. Oil radish and its mixtures had highest root length density (RLD) and root mass density (RMD) in subsoil. Rye had highest root biomass and RLD in topsoil. Clover was uncompetitive and had low RLD and RMD. Large but non-significant mixture effects occurred in the shoot, especially for shoot nutrient uptake. Mixture effects were positive for RLD and RMD in subsoil and positive for specific root length (SRL) throughout the whole profile. There was no clear evidence for vertical root niche differentiation and root mass complementarity. Conclusion Oil radish as a mixing partner increased rooting in subsoil. When comparing mixtures and sole crops, morphological changes, i.e. higher SRL in mixtures, were found. Contrary to expectations, changes in root allocation patterns, such as vertical niche differentiation or complementarity of root mass, were not observed.

(Invited) Nanostructuration and Application of Supramolecular Materials through 1D, 2D and 3D-Hydrogen Bond-Directed Self-Assembly

Self-assembly is a useful tool in Chemistry for the development of organized supramolecular systems stabilized by non-covalent interactions.[1] The rational design of organic molecules that suitably integrate different interacting sites into their structure becomes an attractive approach to control the molecular arrangement by exploiting the driving force of those non-covalent interactions.[2] With this objective in mind, we have synthesized a series of π-conjugated molecules that incorporate the 7-azaindole unit as building block to induce the supramolecular self-assembly in the solid state through reciprocal hydrogen bonding.[3] The judicious alteration of the molecular geometry has demonstrated the adequacy of this self-assembly strategy to achieve the control on the directionality of N-H···N hydrogen bond interactions. Consequently, 1D, 2D and 3D-supramolecular systems have been obtained with interesting structural properties.[4] In this communication we present our recent advances in this approach towards supramolecular materials, particularly focusing on their application as organic semiconductors in devices such as Organic Field Effect Transistors and perovskite solar cells.[5] The performance of these novel molecules as hole transporting materials has revealed a remarkable robustness despite their non-covalent nature. Accordingly, these results offer a proof of concept about the potential utility of supramolecular self-assembly in the development of novel nanostructured materials.

Synthesis and Properties of a Fused Antiaromatic Hydrocarbon By Oxidative Transformation of Carbacorrole Analogue

Polycyclic aromatic hydrocarbons (PAHs) containing fused pyrrole moieties are known as unique nitrogen-doped pi-conjugated molecules, e.g., azacoronenes, which possess a large π-conjugated planar structure and show rich redox properties. The related molecules are thus expected to be applied to redox-responsible optoelectronic materials. Furthermore, PAH-based compounds containing [4n]π-electron antiaromatic segments, such as pentalene and indacene are contributed to the ambipolar semiconducting material applications due to the distinct high HOMO and low LUMO energy levels.In this work, we have synthesized and characterized a novel N-doped poly-antiaromatic hydrocarbon (PAH) by the oxidative transformation of a dibenzocarbacorrole isomer, namely, dibenzocorrorin (1). X-ray crystal structure of the fused product (2) revealed a highly planar pi-conjugated structure containing a unique diaza-dicyclopentaazulene moiety. The distinct 12pi antiaromatic resonance structure led to the emergence of a near-infrared band beyond 1000 nm in the absorption spectrum and facile redox properties determined in the cyclic voltammetry. Furthermore, crystalline compound 2 showed carrier mobility in the single-crystal organic field effect transistor.

Optimizing the dielectric characteristics of polyvinyl alcohol for organic electronics

This article discusses the use of polyvinyl alcohol (PVA) as a dielectric in Organic Field Effect Transistors. PVA is a promising candidate for use as a dielectric due to its flexibility, high dielectric constant, and high resistivity, as well as its solubility in water, low cost, wide commercial availability, non-toxicity, and versatility. The article explores different regimes of PVA layer preparation and their effects on the dielectric characteristics of metal-PVA-silicon capacitors. The study analyzes the parameters of previous purification of PVA, crosslinking, and spin coating deposition velocity of PVA solutions. The article also investigates gate voltage hysteresis with PVA as a gate dielectric and the causes of mobile charges that can interfere with the performance of the dielectric. The study aims to optimize the dielectric characteristics of PVA and discover the best parameters for PVA use in electronic applications.

Electrochemistry of Polyfluorinated Organic Molecules in Nonaqueous Electrolyte Solutions

Fluoroorganic molecules provide significant benefit for many applications including pharmaceuticals, agrichemicals, and advanced functional materials due to its highly stable carbon fluorine bonds. Fluorination can have profound effects upon tuning the electronic and optical properties of organic molecules. Thus, fluorine is found in many state-of-the-art materials. For example, fluorinated liquid crystals are used for active-matrix liquid crystal displays; fluorinated membranes are utilized as proton transfer elements necessary for the function of fuel cells; fluorinated electrolyte solutions are tested in lithium batteries to improve their long-term stability and cell voltage. Lately, fluorinated and perfluoroalkylated organic semiconductors were reported for its application in organic field effect transistors (OFETs). Fluorination can tune a p-type organic semiconductor into an n-type semiconductor because of the strong electron withdrawing effect of fluorine, though use of multiple fluorine substituents directly on the aromatics or use of trifluoromethyl and perfluoroalkyl substituents on the pi system is essential for such conversion.The high electronegativity of fluorine results in exceptionally strong bonds to carbon (BDE = 110-126 kcal/mol). Moreover, fluorine substitution results in an increase in the C-C bond energy in fluorocarbons. Strong C-F and corresponding strong C-C bonds in fluorocarbons make them less polarizable than typical hydrocarbons. The highly polar, weakly polarizable, non-hydrogen bonding, non-coordinating properties of perfluoroalkylated materials and perfluoropolyether materials, underlie the motto “Nothing sticks to Teflon® and Teflon®-coated products”. Though all these profound properties of fluoroorganics paved the road for applications exemplified above, their superior stability creates significant challenges for their end-of-life recycling and repurposing, as well as remediation of environmental persistent fluoroorganics such as PFAS. Furthermore, the chemical stability of many these materials often refers to the stability under oxidizing conditions. For fluorinated n-type organic semiconductor materials and fluorinated solvents (e.g. fluoroethylene carbonate) in lithium battery applications, access the stability of these materials and understand its decomposition mechanism under reductive conditions are necessary for rationally optimize the conditions for such applications.In this presentation, we will present and discuss our latest electrochemical study of several different types of polyfluorinated organic molecules involving both fluorinated and perfluoroalkylated aromatics, as well as inert hydrofluorocarbons where only sp3-hybridized carbon presents. As an example, our electrochemical and computational chemistry results indicate that aromatic trifluoromethlation is likely a more stable option against reduction than pentafluoroethylation of the same aromatic core, though the electronic effects of trifluoromethyl and pentafluoroethyl substituents on aromatics are almost identical. We hope that these electrochemical results will shine some lights on searching new materials for electronic and energy storage applications and repurposing inert hydrofluorocarbons, for example, pentafluoroethane, a refrigerant with high global warming potential to be phased out in the next 10-20 years.

Probing the Activity Enhancement of Carbocatalyst with the Anchoring of Atomic Metal.

Enhanced catalysis for organic transformation is essential for the synthesis of high-value compounds. Atomic metal species recently emerged as highly effective catalysts for organic reactions with high activity and metal utilization. However, developing efficient atomic catalysts is always an attractive and challenging topic in the modern chemical industry. In this work, we report the preparation and activity enhancement of nitrogen- and sulfur-codoped holey graphene (NSHG) with the anchoring of atomic metal Pd. When employed as the catalyst for nitroarenes reduction reactions, the resultant Pd/NSHG composite exhibits remarkably high catalytic activity due to the co-existence of dual-active components (i.e., catalytically active NSHG support and homogeneous dispersion of atomic metal Pd). In the catalytic 4-nitrophenol (4-NP) reduction reaction, the efficiency (turnover frequency) is 3.99 × 10-2 mmol 4-NP/(mg cat.·min), which is better than that of metal-free nitrogen-doped holey graphene (NHG) (2.3 × 10-3 mmol 4-NP/(mg cat.·min)) and NSHG carbocatalyst (3.8 × 10-3 mmol 4-NP/(mg cat.·min)), the conventional Pd/C and other reported metal-based catalysts. This work provides a rational design strategy for the atomic metal catalysts loaded on active doped graphene support. The resultant Pd/NSHG dual-active component catalyst (DACC) is also anticipated to bring great application potentials for a broad range of organic fields, such as organic synthesis, environment treatment, energy storage and conversion.

Properties of Blue Phosphorene Nanoribbon-P3HT Polymer Heterostructures: DFT First Principles Calculations

Recently, 2D phosphorus allotropes have arisen as possible candidates for technological applications among the family of the so-called Xene layered materials. In particular, the energy band structure of blue phosphorene (BP) exhibits a medium-size semiconductor gap that tends to widen in the case of using this material in the form of ribbons. BP nanoribbons have attracted recent interest for their implication in the improvement in efficiency of novel solar cells. On the other hand, compound poly (3-hexylthiophene) (P3HT) is used as the semiconducting core of organic field effect transistors owing to such useful features as high carrier mobility. Here, we theoretically investigate the electronic properties of a heterostructure combination of BP—in the form of nanoribbons—with a P3HT polymer chain on top in order to identify the features of band alignment. The work is performed using first principles calculations via DFT, employing different exchange correlation approaches for comparison: PBE, HSE06 and DFT-1/2. It is found that, under DFT-1/2, such a heterostructure has a type-II band alignment.