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In this study, two green extraction methods are explored to valorize rice straw into cellulose fibers (CFs), namely subcritical water extraction (SWE) and combined ultrasound‐heating treatment (USHT). The resultant fibers are, thereafter, successfully pretreated with (3‐glycidyloxypropyl) trimethoxysilane (GPS) and incorporated at 3% wt into poly(butylene succinate) (PBS) by melt‐mixing. The green composites are shaped into films by thermo‐compression and characterized in terms of their performance for food packaging applications. The chemical analysis of the fibers reveals that SWE is more effective to selectively remove hemicelluloses than USHT, whereas silanization promotes the removal of lignin in both fiber types. Fiber incorporation, more notably in the case of the silanized fibers, restricts the movement of the PBS chains, indicating good interaction with the biopolyester matrix. In particular, CFs act as antinucleating agents in PBS, delaying both glass transition and crystallization from the melt phenomena and hindering crystal formation. Furthermore, the fibers mechanically reinforce and improve the oxygen barrier of the PBS films. The highest barrier enhancement is obtained for the thermo‐compressed composite film with silanized fibers obtained by SWE, yielding a decrease of nearly 20% in the permeability to oxygen versus the unfilled PBS film. [ABSTRACT FROM AUTHOR]

To explore the specific effects of pig manure and rice straw on cadmium‐contaminated soils and the effect of different mass fractions of calcium carbonate on cadmium efficacy, a pot experiment was conducted with different rates of pig manure, rice straw, and calcium carbonate. The results showed that pig manure addition increased the soil humic acid/fulvic acid ratio, thereby reducing the available Cd. The addition of calcium carbonate increased the soil pH and reduced the available Cd. The addition of pig manure and calcium carbonate significantly reduced the Cd content of wheat grains by 51.96% and 45.95%, respectively, at 3% and 5% application rates. Rice straw application reduced the soil pH, improved the soil Cd availability, and increased the accumulation of Cd in wheat grains. Compared with that in the control, the grain biomass increased significantly with 3% pig manure and 3% rice straw application, and the grain biomass increased significantly, by 58.86% and 39.11%, and 93.3% and 75.08%, respectively, in 2020 and 2021. With the application of calcium carbonate, the grain biomass of wheat first decreased and then increased. Additionally, the grain biomass significantly increased by 26.36% and 71.22%, respectively, at the 5% calcium carbonate application rate. Therefore, high application rates of pig manure (3% and 5%) have potential application in the safe production of wheat in Cd‐contaminated soils. [ABSTRACT FROM AUTHOR]

For agricultural countries in Aisa, rice straw is a waste product, but also a valuable bioresource, with its recycling methods often drawing widespread attention. In this study, a novel multicomponent extraction method was proposed to perform comprehensive extraction of holocellulose and lignin from rice straw powder (RSP), resulting in modified rice straw powder (MRSP) with different micro‐morphologyies. The results indicate that the cosolvent tetraethylammonium chloride (TEAC) is more effective for extracting holocellulose and lignin compared to others, and different surfactants have decisive impacts on the extraction of holocellulose and lignin from RSP. Among them, anionic surfactants aid in the extraction of holocellulose, with sodium allylate sulfonate (SAS) being superior due to its greater changes in allyl polarity. Conversely, cationic surfactants facilitate the extraction of lignin, with octadearyl trimethyl ammonium chloride (OTAC) being superior due to the length of its alkyl‐carbon chain. And the quantized contribution of hydrophilic and hydrophobic groups of surfactants to the extraction of holocellulose and lignin, as well as, the different micromorphology of MRSP is obtained. Additionally, compared to the traditional PU (polyurethane) modified by eucalyptus wood powder (EWP/PU), the MRSP was used to prepare a series of biomass composite polyurethane synthetic leather (MRSP/PU), its tensile strength and peel strength of MRSP/PU coatings are greatly enhanced at the feedstock of 18 %. [ABSTRACT FROM AUTHOR]

This work presents a reasonable strategy of optimizing the N : P molar ratio of municipal wastewater to simultaneously restore N‐NH4+ and P‐PO43− via struvite precipitation employing biochar modified with magnesium as the seeding material. The phosphate removal efficiency and ammonium removal efficiency could reach up to 71 % and 100 %, respectively. The remaining phosphate can be restored by other techniques for low phosphate concentration input, such as electrocoagulation. The XRD patterns indicate the appearance of struvite with high nutrient contents including Mg, N and P in the resulting precipitate, suggesting its potential agricultural application. The biochar from rice husk and rice straw modified with MgCl2 solution via a simple procedure could be used as a new seeding material in struvite precipitation to simultaneously restore phosphate and ammonium from wastewater. It has been found that modifying with MgCl2 concentration of 0.5 M and 1 M were enough to improve 14.7 % and 26.5 % of the phosphate removal efficiencies of rice straw‐based and rice husk‐based biochar, respectively. Along with the highly compatible of the post‐precipitated product with soil amendment, the magnesium modified biochars from rice husk and rice straw were highly suitable for enhancing the restoration of phosphate and ammonium via struvite precipitation. [ABSTRACT FROM AUTHOR]

A self‐healable hydrogel for advanced authentication applications was successfully developed. In the presence of an aqueous solution of ammonium hydroxide as a cheap passivating agent, the hydrothermal carbonization of cellulose diacetate extracted from rice straw yielded nitrogen‐doped carbon dots (NdCD) in a straightforward and ecologically beneficial manner. NdCD achieved a maximum quantum yield of 25.11%. Self‐healing biocomposite inks with different emission properties were created by using different concentrations of NdCD nanoparticles (NPs). In order to create a transparent layer of NdCD@PLA hydrogel, stamps were used to press homogenous films onto paper surfaces. Polylactic acid (PLA) hydrogel was embedded with NPs of NdCD. Self‐healing security hydrogel inks are highly durable. The NdCD@PLA hydrogel is efficiently self‐healable at room temperature. The current NdCD@PLA hydrogel can attach to different surfaces, such as glasses, plastics, and papers. The self‐healable nanobiocomposite was photostable when exposed to UV light. Under UV light, NdCD‐containing nanobiocomposite inks have a bluish color, as proved by both colorimetric parameters and fluorescence spectra. The morphological properties of NdCD were studied by transmission electron microscopy to suggest a particle diameter of 10–15 nm. The morphology of the fluorescent prints was analyzed using a number of different analytical methods. The hydrogel rheology and the mechanical performance of printed papers were tested. The printed films showed excitation and fluorescence bands at 401 and 488 nm, respectively. The present smart ink shows significant promise as a potential industrial production technique to simply produce anti‐counterfeiting prints. Highlights: Rice straws were used to prepare nitrogen‐doped carbon dots with a quantum yield of 25.11%.Self‐healable polylactic acid hydrogel was immobilized with N‐doped carbon dots (10–15 nm).Transparent printed films shifted in color to blue (488 nm) when excited at 401 nm.Ultraviolet‐stimulated photochromic authentication prints were prepared.Printed paper demonstrated non‐cytotoxicity, high photostability, and durability. [ABSTRACT FROM AUTHOR]

In present work, synthesis of a nanohybrid material using Fe and MoS2 has been performed via a cost‐effective and environmentally friendly route for sustainable manufacturing innovation. Rice straw extract was prepared and used as a reducing and chelating agent to synthesize the nanohybrid material by mixing it with molybdenum disulfide (MoS2) and ferric nitrate [Fe (NO3)3.9H2O], followed by heating and calcination. The X‐ray diffraction (XRD) pattern confirms the formation of a nanohybrid consisting of monoclinic Fe2(MoO4)3, cubic Fe2.957O4, and orthorhombic FeS with 86% consisting of Fe2(MoO4)3. The properties were analyzed through Fourier‐transformed infrared spectroscopy (FTIR), atomic force microscopy (AFM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results of the dynamic light scattering (DLS) study revealed a heterogeneous size distribution, with an average particle size of 48.42 nm for 18% of particles and 384.54 nm for 82% of particles. Additionally, the zeta potential was measured to be −18.88 mV, suggesting moderate stability. X‐ray photoelectron spectroscopy (XPS) results confirmed the presence of both Fe2+ and Fe3+ oxidation states along with the presence of Molybdenum (Mo), oxygen (O), and Sulphur (S). The prepared nanohybrid material exhibited a band gap of 2.95 eV, and the photoluminescence intensity increased almost twice that of bare MoS2. The present work holds potential applications in photo luminescent nanoplatform for biomedical applications. [ABSTRACT FROM AUTHOR]

This study aims to comprehensively examine the influence of three distinct additives, namely carboxymethyl cellulose (CMC), hydroxypropyl methylcellulose (HPMC), and cellulose nanofibers (CNF), on the performance enhancement of corrugated base paper. For this purpose, steam‐exploded rice straw was treated with varying concentrations (2, 4, 6, 8, and 10 wt%) of CMC, HPMC and CNF. Analysis of the rice straw pre and post expansion, as well as the modified corrugated base paper, was conducted using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TG), tensile performance testing, and scanning electron microscopy (SEM). Results indicated that adding CMC, CNF, and HPMC to corrugated base paper significantly improved bonding between paper layers, particularly at 2 %, 6 %, and 8 % concentrations, respectively. This enhancement notably increased tensile strength and elastic modulus of the corrugated base paper. Tensile performance saw increases of 57.76 %, 59.01 %, and 60.25 %, while elastic modulus showed increments of 52.7 %, 9.4 %, and 136.69 %, respectively. These findings provide valuable insights for the preparation of corrugated base paper and highlight the potential of CMC, HPMC, and CNF in enhancing paper mechanical properties. [ABSTRACT FROM AUTHOR]

The cost of polymer precursors and high energy need in carbonization for the preparation of carbon materials are two limiting factors in the commercialization of carbon‐based materials. In this study, carbon nanofiber films were prepared by adding a very small concentration of polymer polyacrylonitrile in nanocellulose (extracted from agro waste i.e., rice straws) with an overall aim of producing carbon nanomaterials with cost effective, renewable and sustainable carbon source. Polyacrylonitrile (PAN) added nanocellulose solution was drop‐casted to prepare Nanocellulose/Polyacrylonitrile‐based nanofibers film (NC/PAN). It was further stabilized in air atmosphere at 280 °C followed by carbonized in nitrogen atmosphere at 700 °C. It was found that addition of NC/PAN have 18 % lower activation energies than PAN. Results of tunneling electron microscopy showed that polyacrylonitrile/nanocellulose films carbonized at 700 °C temperature exhibited amorphous carbon nanofibers structure similar to bare polyacrylonitrile based carbon film carbonized at higher temperature of 1000 °C‐1200 °C. Furthermore, polyacrylonitrile/nanocellulose based carbon nanofibers have showed high degree of carbonization ((ID)/(IG)=0.87) as compared to bare polyacrylonitrile based carbon nanofibers film ((ID)/(IG)=1.02). This may be attributed to chiral nature of nanocellulose which served as a template to orientation of graphene planes and showed efficient carbonization. [ABSTRACT FROM AUTHOR]

BACKGROUND: An attempt has been made to explore the nutritional profile of pink oyster mushrooms that have been grown in various agricultural residues, including sugarcane bagasse, rice straw, coconut coir and sawdust, along with other nutrient supplements such as defatted mustard and chickpea powder, for appropriate growth and fruiting body formation in a short span of time. The spawn production was experimented with five different grain varieties. The study became interesting when the observations differed slightly from the traditional practices, with the addition of defatted mustard supplements resulting in a positive correlation with respect to reducing the fruiting time, as well as improving yield and the nutritional profile of Pleurotus djamor. RESULTS: An elevated yield of 651.93 g kg−1 was recorded in the medium where the RS and DM were used in the ratio of 1:0.01 (rice straw +1% w/w defatted mustard) bag, whereas, in terms of protein content, a maximum yield of 32.57 ± 0.79 mg g−1 was observed when SB:DM was in the same ratio (sugarcane bagasse +1% w/w defatted mustard) bag. CONCLUSION: To confer the best outcomes from the screened substrates, a series of experiments were performed by varying the concentration of RS and SB, with 1% w/w DM. It is worth noting that the highest protein content of 32.76 ± 0.38 mg g−1 was obtained along with the total yield of 702.56 ± 2.9 g kg−1 of mushroom when the ratio of RS:SB was 0.7:0.3. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

A mechanized direct seeding of rice with less labor and water usage, has been widely adopted. However, this approach requires varieties that exhibit uniform seedling emergence. Mesocotyl elongation (ME) offers the main drive of fast emergence of rice seedlings from soils; nevertheless, its genetic basis remains unknown. Here, we identify a major rice quantitative trait locus Mesocotyl Elongation1 (qME1), an allele of the Green Revolution gene Semi‐Dwarf1 (SD1), encoding GA20‐oxidase for gibberellin (GA) biosynthesis. ME1 expression is strongly induced by soil depth and ethylene. When rice grains are direct‐seeded in soils, the ethylene core signaling factor OsEIL1 directly promotes ME1 transcription, accelerating bioactive GA biosynthesis. The GAs further degrade the DELLA protein SLENDER RICE 1 (SLR1), alleviating its inhibition of rice PHYTOCHROME‐INTERACTING FACTOR‐LIKE13 (OsPIL13) to activate the downstream expansion gene OsEXPA4 and ultimately promote rice seedling ME and emergence. The ancient traits of long mesocotyl and strong emergence ability in wild rice and landrace were gradually lost in company with the Green Revolution dwarf breeding process, and an elite ME1‐R allele (D349H) is found in some modern Geng varieties (long mesocotyl lengths) in northern China, which can be used in the direct seeding and dwarf breeding of Geng varieties. Furthermore, the ectopic and high expression of ME1 driven by mesocotyl‐specific promoters resulted in rice plants that could be direct‐seeded without obvious plant architecture or yield penalties. Collectively, we reveal the molecular mechanism of rice ME, and provide useful information for breeding new Green Revolution varieties with long mesocotyl suitable for direct‐seeding practice. [ABSTRACT FROM AUTHOR]

In the present study, sustainable upscaling of rice straw, an agri‐residue, is explored as the way to obtain active material to prepare anode for use in lithium‐ion batteries (LIBs). The biochar having high carbon and low silica content is prepared by initial chemical treatment of rice straw followed by its pyrolysis. The pristine and modified biochar are characterized using Brunauer‐Emmett‐Teller surface area, energy dispersive X‐ray spectroscopy, carbon hydrogen nitrogen sulphur elemental analysis, scanning electron microscopy, X‐Ray power diffraction, Fourier transform infrared spectroscopy and Raman analysis and the modified biochar show an enhancement in graphitic carbon content. A coin cell is assembled using anode prepared from modified biochar. The coin cell is subjected to electrochemical testing and had a discharge capacity of 352 mA.h g−1. Further, the coin cell is tested for 100 cycles and a columbic efficiency of 99.7% was obtained. Therefore, biochar derived from pyrolysis of rice straw has the potential to be used as anode material for LIBs. [ABSTRACT FROM AUTHOR]

In response to the growing awareness of environmental preservation, there has been a surge in studies employing the life cycle assessment (LCA) approach which helps to identify and minimize environmental impacts associated with rice straw recovery processes. However, there is lack of comprehensive and trend analysis related to the development of critical methodological steps of LCA within this field. To fill the gap, this review examines 43 primary LCA studies from 2004 to 2023 period concerning the use of rice straw for bioenergy production and categorized into two groups: the "first‐year group" covering 2004–2013 and the "second‐year group" spanning from 2014 to 2023. This categorization serves to facilitate the examination of trends and patterns within each decade, offering insights into the evolution of research objectives, methodological advancements, and changes in research outcomes over time. The analysis reveals a shift from studying individual technologies to comparing various technologies, includes scenarios development and consideration of economic and social aspects. Furthermore, the "second‐year group" (2014–2023) exhibits a notable uptick in the exploration of gasification, pyrolysis, anaerobic digestion, and fermentation, whereas combustion technologies have experienced a slight decrease in the number of studies. Challenges in LCA studies arise from nonstandardized methodologies, introducing bias and uncertainty. To enhance the reliability and comparability of environmental assessments, it is recommended to establish standardized guidelines, improve transparency, and update databases. Overall, this review provides a foundational resource for future waste‐to‐energy studies and recommends steps to enhance the applicability and validity of LCA in forthcoming research. This article is categorized under:Sustainable Energy > BioenergyClimate and Environment > Pollution PreventionClimate and Environment > Circular Economy [ABSTRACT FROM AUTHOR]

India is one of the leading producers of rice in the world. Gasification and pyrolysis are two thermochemical processes. In the gasification process, biomass is transformed into syngas, which serves as an energy source. This conversion occurs under high temperatures with a carefully regulated and restricted air supply. On the other hand, pyrolysis, which transpires at lower temperatures without the presence of air, generates pyrolysis oil as a by‐product. This oil can be further refined into liquid fuels. For the purpose of investigating the feasibility of biofuel production, the current study involved the characterization of rice straw biomass using various techniques such as thermogravimetry differential thermal analysis (TG/DTA), Fourier transform infrared (FTIR), carbon, hydrogen, nitrogen, sulphur and oxygen (CHNS/O), inductively coupled plasma optical emission spectroscopy (ICP‐OES), among others. These analytical methods were employed to assess the potential of rice straw biomass for the production of biofuels. The existence of a significant amount of cellulose (32.1%), volatiles (approximately 67.06%), and high heating value (HHV) (13.18 MJKg−1) in rice straw inferred their capability to be used as feedstocks in the production of biofuel. The activation energy of approximately 173.20 KJ/Mol (Flynn Wall Ozawa [FWO]) indicated the viability of the burning process. From master plot (Z(α)) analysis, the experimental curve was seen passing through different theoretical curves, indicating the complex nature of the pyrolysis process for rice straw. [ABSTRACT FROM AUTHOR]

Biomass energy is a renewable energy source that is carbon‐neutral, versatile, and can never go extinct. In the current study, a simulation model of an anaerobic digester with parameters such as pretreatment temperature (PTT), hydraulic retention time (HRT), and feed‐to‐water (F/W) ratio was developed and a design of experiment was created. The results showed that the higher hemicellulose content in sugarcane bagasse (SB) gave a decent H2 yield (13–23 %). The significance sequence was PTT > F/W > HRT. The optimal values were HRT of 15–16 d; F/W of 1.5 (SB), 1.26 [rice straw (RS)], and 0.5 [sawdust (SD)]; and PTT of 63.3 (SB), 68.8 (RS), and 75 °C (SD). The optimal H2 yield was 19.80 (SB), 20.94 (RS), and 21.41 % (SD). Therefore, the present simulation and optimization showed concrete results to raise H2 yield. [ABSTRACT FROM AUTHOR]

Biomass has been considered a potential source for preparing carbon materials due to its environmentally friendly and renewable characteristics. In this work, N, S co‐doping activated carbon materials were easily prepared by using rice straw as the carbon source. In addition to being heteroatom source, thiourea can fragment the carbon particles into smaller pieces and create plenty of micropores during the carbonization process. Both theoretical and experimental analyses demonstrate that the incorporation of S and N species into carbon can improve the electrochemical performance of supercapacitors. The as‐made N, S co‐doping activated carbon materials, when used as electrodes, exhibit a high specific capacitance of 256 F g−1 at a current density of 1 A g−1 and maintain a good rate capacitance of 65 % even at a high current density of 50 A g−1. This work may offer valuable guidance for the application of rice straw derived carbon in supercapacitors. [ABSTRACT FROM AUTHOR]

In this study, co‐generation from rice straw based on pyrolysis and gasification was studied by experimental and modeling approaches. Pyrolysis experiment results show that improving pyrolysis temperature will benefit the yield of gas and bio‐oil, while reducing the yield of bio‐char. The BET (Brunauer, Emmett, and Teller) surface area of bio‐char reached a maximum of 143.26 m2/g when the temperature was increased to 550°C. For co‐generation in this study, an optimized pyrolysis temperature of 500°C was selected. With respect to gasification, air equivalence ratio (ER) largely influenced the syngas yield and composition. At ER = 0.25, the concentration of H2 and CO reached a maximum of 17.8 wt% and 16.2 wt%. Based on the experimental results, an Aspen Plus model was built to evaluate the mass and energy balance during co‐generation. Furthermore, a life cycle assessment method was used to evaluate the greenhouse gas emission during co‐generation process initialed from rice straw planting. Results show that the greenhouse gas emission intensities of the two co‐generation systems were 2.92 and 3.51 g CO2/MJ respectively, which were much lower than traditional fossil fuels. [ABSTRACT FROM AUTHOR]

The use of hydrolyzed rice straw (HRS) and hydrolyzed rice husk (HRH) as feedstock for pyrolysis was evaluated through kinetic and thermodynamic studies. HRS and HRH were obtained from subcritical water hydrolysis (SWH) at different temperatures (180, 220, and 260°C). The Coats‐Redfern method was used to analyze the thermal behavior through thermogravimetry (TG) and derivative thermogravimetry (DTG) curves. TG profiles showed higher decomposition in the range of 250–400°C, especially for rice straw (RS) and HRS (80 wt %). The pyrolysis curves were well predicted by a first‐order reaction model. The kinetic analysis showed a variation in activation energy (EA) between 24.3 to 41.3 kJ mol−1 and 40.4 to 54.7 kJ mol−1 for RS/HRS and rice husk (RH)/HRH, respectively. The enthalpy (ΔH), Gibbs free energy (ΔG), and entropy (ΔS) varied from 25.9 to 39.6 kJ mol−1, 35.4 to 69.6 kJ mol−1, and −64.1 to −6.7 J mol−1 K−1, respectively, for RS/HRS, and 35 to 49.8 kJ mol−1, 43.2 to 79.3 kJ mol−1, and −53.5 to −10.2 J mol−1 K−1, respectively, for RH/HRH. These results showed that the pyrolysis reactivity using HRS is higher than HRH, which indicates the pyrolysis of HRS is more advantageous than HRH. [ABSTRACT FROM AUTHOR]

Summary: Grass lignocelluloses feature complex compositions and structures. In addition to the presence of conventional lignin units from monolignols, acylated monolignols and flavonoid tricin also incorporate into lignin polymer; moreover, hydroxycinnamates, particularly ferulate, cross‐link arabinoxylan chains with each other and/or with lignin polymers. These structural complexities make grass lignocellulosics difficult to optimize for effective agro‐industrial applications. In the present study, we assess the applications of two engineered monolignol 4‐O‐methyltransferases (MOMTs) in modifying rice lignocellulosic properties. Two MOMTs confer regiospecific para‐methylation of monolignols but with different catalytic preferences. The expression of MOMTs in rice resulted in differential but drastic suppression of lignin deposition, showing more than 50% decrease in guaiacyl lignin and up to an 90% reduction in syringyl lignin in transgenic lines. Moreover, the levels of arabinoxylan‐bound ferulate were reduced by up to 50%, and the levels of tricin in lignin fraction were also substantially reduced. Concomitantly, up to 11 μmol/g of the methanol‐extractable 4‐O‐methylated ferulic acid and 5–7 μmol/g 4‐O‐methylated sinapic acid were accumulated in MOMT transgenic lines. Both MOMTs in vitro displayed discernible substrate promiscuity towards a range of phenolics in addition to the dominant substrate monolignols, which partially explains their broad effects on grass phenolic biosynthesis. The cell wall structural and compositional changes resulted in up to 30% increase in saccharification yield of the de‐starched rice straw biomass after diluted acid‐pretreatment. These results demonstrate an effective strategy to tailor complex grass cell walls to generate improved cellulosic feedstocks for the fermentable sugar‐based production of biofuel and bio‐chemicals. [ABSTRACT FROM AUTHOR]

Activated carbon derived from biomasses with different oxygen‐bearing chemical constituents has been explored as supercapacitor electrode. The rice straw (RS) and eucalyptus wood biomasses were selected owing to their contrasting composition of cellulose, hemicellulose, and lignin contents. The activated carbons of these biomasses are obtained by pyrolysis at 550°C followed by thermal activation (700°C) after treatment with optimized KOH. The specific capacitance of RS‐based activated carbon (ACRS‐700), measured from galvanostatic charging‐discharging studies at 0.5 A g−1, is much higher (eg, 365 F g−1) than that of ACEW‐700 (168 F g−1). The higher specific capacitance of ACRS‐700 is attributable to: (i) significantly higher surface area (3345 m2 g−1) comprising of interconnected micro‐ and mesoporous structure; (ii) porosity of about 2.0 cm3/g; and (iii) oxygen‐rich hemicellulose contents. The possible charge storage mechanism in ACRS‐700 has been discussed. The real‐time application of ACRS‐700 has been demonstrated by lighting up red LEDs using ACRS‐700//ACRS‐700 symmetric supercapacitor device, operated with aqueous and freshly synthesized [Bu4N+][NO3−] ionic liquid as electrolytes. The maximum energy density (42.7 Wh kg−1) and the power density (1.9 kW kg−1) for ionic liquid electrolyte are favourable for supercapacitor applications. [ABSTRACT FROM AUTHOR]

Biochar is currently used as a phosphate adsorbent in water and subsequently as a soil amendment. In this study, modified biochar was prepared directly by co‐pyrolysis of MgO and rice straw, and a preliminary ecotoxicological assessment was performed before the application of modified biochar to soil. The effects of single factors, such as pyrolysis temperature, dosage, pH, and coexisting ions, on phosphate adsorption performance were investigated. In addition, after phosphate adsorption, the effects of modified biochar leachate on the germination of corn and rice seeds were examined. The results showed that phosphate adsorption by the modified biochar first increased and then decreased as the pyrolysis temperature increased, with modified biochar prepared at 800 °C showing the greatest adsorption. In addition, a comprehensive cost analysis showed that the best phosphate adsorption effect of modified biochar was achieved at a dosage of 0.10 g and a solution pH of 3. In contrast, the presence of competitive coexisting ions, Cl−, NO3−, CO32−, and SO42−, reduced the phosphate adsorption capacity of the modified biochar. The adsorption kinetics results revealed that the process of phosphate adsorption by the modified biochar was more in line with the pseudo‐second‐order model and dominated by chemisorption. Moreover, the adsorption isotherm results indicated that the process was more in line with the Langmuir model and dominated by monomolecular layer adsorption, with a maximum adsorption of 217.54 mg/g. Subsequent seed germination tests showed that phosphate‐adsorbed modified biochar leachate had no significant effect on the germination rate of corn seeds, whereas it improved the germination rate of rice seeds. Together, these results provide guidance for the application of modified biochar firstly as an adsorbent of phosphate and subsequently as a soil remediator. [ABSTRACT FROM AUTHOR]

This study aims to explore novel, environmentally friendly technologies for converting organic waste into biochar for land application for sustainable management. However, the impact of biochar on the soil environment and crop yield depends on the specific feedstock and its interaction with the soil. Through pot experiments, we investigated the effects of three different biochars (sawdust biochar, rice straw biochar and coconut shell biochar) on the growth of Dictyophora rubrovolvata at two different input levels (1% and 2%). It was found that contrary to expectations, high input levels of sawdust biochar had a negative impact on D. rubrovolvata yield, while rice straw biochar and coconut shell biochar increased D. rubrovolvata yield by 16.0% to 159.1% and 54.4% to 64.0%, respectively, at the two input levels. The study revealed the key role of soil factors (such as total phosphorus, nitrogen/phosphorus ratio, water holding capacity, ammonium nitrogen, nitrate nitrogen, CaCl2-phosphorus, dissolved organic carbon and invertase activity) in affecting the growth of D. rubrovolvata. Through structural equation modelling analysis, the application of sawdust biochar resulted in a low N/P ratio, thereby limiting the growth of D. rubrovolvata, while the application of straw biochar and coconut shell biochar promoted mushroom growth by increasing sucrase activity and DOC content. The increase in D. rubrovolvata biomass and nutrient content indicated the superiority of RSBC and CSBC as soil amendments. However, further research is needed to determine the appropriate application scenarios for SDBC. The findings also show that the application of biochar can help improve soil physicochemical biological properties, thus having potential benefits in sustainable agricultural practices. Overall, this study provides insights into the potential of biochar technology in sustainable agricultural practices, its role in improving soil quality and crop productivity, and explores for the first time a new field of biochar application in D. rubrovolvata cultivation. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) is one of the environmental pollutants contaminated in our food. Several previous reports showed that rice polishing cannot be efficient to reduce Cd content in white rice, implying the characteristic Cd distribution in rice grain. However, Cd distribution has not been fully elucidated so far. Herein, 109Cd radiotracer experiment was performed using the rice seedlings at various time points after flowering to obtain autoradiographs of the brown rice to visually understand the Cd transport and distribution during the grain‐filling process. It was shown that 109Cd accumulated in the outermost area of the brown rice, and also in the middle part of the starchy endosperm, resulting in the appearance of the double circle distribution pattern, which was not observed in the autoradiographs of 65Zn. The inner circle of 109Cd located around the center of the endosperm was developed particularly at around 8 and 10 days after flowering. After this period, 109Cd started to deposit at the outer part of the endosperm, which was also found in the autoradiograph of 14C‐sucrose. Considering the physiology of grain development, the contribution of water transport and protein synthesis in the endosperm on the characteristic Cd distribution pattern was hypothesized. [ABSTRACT FROM AUTHOR]

Biomass pyrolysis process from a drop tube reactor was modelled in a plug flow reactor using Aspen Plus process simulation software. A kinetic mechanism for pyrolysis was developed considering the recent improvements and updated kinetic schemes to account for different content of cellulose, hemicellulose, and lignin. In this regard, oak, beechwood, rice straw, and cassava stalk biomasses were analyzed. The main phenomena governing the pyrolysis process are identified in terms of the characteristic times. Pyrolysis process was found to be reaction rate controlled. Effects of pyrolysis temperature on bio‐oil, gases, and char yields were evaluated. At optimum pyrolysis conditions (i.e., 500°C), a bio‐oil yield of 67.3, 64, 43, and 52 wt.% were obtained from oak, beechwood, rice straw, and cassava stalk, respectively. Oak and beechwood were found to give high yields of bio‐oil, while rice straw produced high gas and char yields compared to other biomasses. Although temperature is the main factor that plays a key role in the distribution of pyrolysis products, the composition of cellulose, hemicellulose, and lignin in the feedstock also determines the yield behaviour and composition of products. With the rise in pyrolysis temperature, further decomposition of intermediate components was initiated favouring the formation of lighter fractions. Comparably, species belonging to the aldehyde chemical family had the highest share of bio‐oil components in all the investigated feedstocks. Overall, the present study shows a good agreement with the experimental study reported in the literature, confirming its validity as a predictive tool for the biomass pyrolysis process. [ABSTRACT FROM AUTHOR]

Soil and groundwater salinity associated with limited rainfall are the challenges for checking salinity build‐up in semi‐arid regions. This field experiment was conducted to test the impact of deficit saline irrigation (DSI) (in winter) with mulching and tillage on salinity build‐up, yield and nutritive value of rainfed‐forage sorghum. Tillage (reduced, conventional and zero), saline water (8.0 dS m−1) irrigation (100%, 80% and 60% of water requirement [WR] in wheat) and mulch were allocated following split factorial layout. DSI with mulching produced at par wheat and sorghum yield compared with 100WR irrigation with harvested rainwater. Mulching improved wheat grain yield and the soil water content by ~13% throughout the cropping season. Forage sorghum yield was increased by DSI and mulching in the previous season compared with irrigation with 100WR saline water. Reduced tillage declined the neutral detergent fibre (NDF), acid detergent fibre (ADF) and acid detergent lignin (ADL) with an increase in cell soluble constituents. DSI and mulching also increased the digestible nutrient, crude protein (CP), ash and reduced ADF of sorghum. Soil salinity showed a negative correlation with CP, positive correlation with ADF, ADL and cellulose. Therefore, it is recommended that DSI and reduced tillage with mulching can be a reliable option for productive use of saline soils and water by cropping system intensification. These results also showed the potential for achieving 2030 agenda for sustainable development goals as well as targets of land degradation neutrality in salt‐affected soils by savings irrigation, doubling cropping intensity and preventing salinity build‐up. [ABSTRACT FROM AUTHOR]

Lignin‐modifying enzymes (LMEs), which include laccases (Lacs), manganese peroxidases (MnPs), versatile peroxidases (VPs), and lignin peroxidases (LiPs), have been considered key factors in lignin degradation by white‐rot fungi because they oxidize lignin model compounds and depolymerize synthetic lignin in vitro. However, it remains unclear whether these enzymes are essential/important in the actual degradation of natural lignin in plant cell walls. To address this long‐standing issue, we examined the lignin‐degrading abilities of multiple mnp/vp/lac mutants of Pleurotus ostreatus. One vp2/vp3/mnp3/mnp6 quadruple‐gene mutant was generated from a monokaryotic wild‐type strain PC9 using plasmid‐based CRISPR/Cas9. Also, two vp2/vp3/mnp2/mnp3/mnp6, two vp2/vp3/mnp3/mnp6/lac2 quintuple‐gene mutants, and two vp2/vp3/mnp2/mnp3/mnp6/lac2 sextuple‐gene mutants were generated. The lignin‐degrading abilities of the sextuple and vp2/vp3/mnp2/mnp3/mnp6 quintuple‐gene mutants on the Beech wood sawdust medium reduced drastically, but not so much for those of the vp2/vp3/mnp3/mnp6/lac2 mutants and the quadruple mutant strain. The sextuple‐gene mutants also barely degraded lignin in Japanese Cedar wood sawdust and milled rice straw. Thus, this study presented evidence that the LMEs, especially MnPs and VPs, play a crucial role in the degradation of natural lignin by P. ostreatus for the first time. [ABSTRACT FROM AUTHOR]

BACKGROUND: Ethiprole has been registered to control planthoppers in rice fields for many years in Asia. However, its dissipation and residues in rice under natural field conditions and health hazards are largely unclear. In the present study, a modified QuEChERS (i.e. Quick Easy Cheap Effective Rugged Safe) and high‐performance liquid chromatography‐tandem mass spectrometry method was established to detect ethiprole and its metabolites, ethiprole amide and ethiprole sulfone, in brown rice, rice husks, and rice straw. The field experiments were implemented in 12 representative provinces of China under Good Agricultural Practices aiming to investigate the fate and terminal residues of ethiprole and its metabolites in rice. Finally, the dietary risk of ethiprole was evaluated. RESULTS: The average recoveries of these analytes in all matrices were 86.4–99.0% with a repeatability of 0.575–9.38%. The limits of quantification for each compound were 0.01 mg kg−1. Dissipation of ethiprole followed the single first‐order, first + first‐order, and first‐order multi‐compartment kinetic models with a half‐life of 2.68–8.99 days in rice husks. The dissipation half‐life of ethiprole combining all metabolites was 5.20–16.2 days in rice husks. The terminal residues of ethiprole and its metabolites at preharvest intervals of 21 days were < 0.011, 0.25, and 0.20 mg kg−1 in brown rice, rice husks, and rice straw, respectively. Ethiprole amide was undetectable in all matrices, and the risk quotient of ethiprole was far less than 100%. CONCLUSION: Ethiprole rapidly converted to ethiprole sulfone in rice, and ethiprole and ethiprole sulfone mainly remained in rice husks and straws. The dietary risk of ethiprole was acceptable for Chinese consumers. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Highly weathered tropical soils are susceptible to disaggregation due to disruptive forces like water and mechanical disturbances. However, a few studies have investigated how biochar and cropping systems together affect the aggregate stability of tropical soils. This study investigated the long‐term (∼7 years) effect of rice straw biochar on the aggregate stability of a tropical Acrisol using the dry aggregate stability (DAS) method and SLAKES (a wet aggregate stability technique), and assessed the extent of agreement or otherwise of the aggregate stability quantified by the two methods for different treatments. Maize (Zea mays L.) and okra (Abelmoschus esculentus L.) were rotated on plots amended with rice straw biochar at rates of 0, 15, and 30 Mg ha−1. Seven years after biochar amendment, bulk soil samples were collected at 0–15 cm depth for laboratory analyses. Aggregate stability was assessed by determining erodible fraction (EF) and DAS, and by quantifying the SLAKES parameters (slaking index [SI] and slaking index at 600 seconds [SI‐600]). Neither biochar nor crop type or their interaction significantly changed the soil aggregate stability assessed by the two methods (p > 0.05). The EF and DAS weakly correlated with SI and SI‐600, which could be attributed to the differences in the mechanisms underlying soil aggregate breakdown assessed by the two methods. The study highlighted that observed challenges of the SLAKES method namely, inability in some cases to detect soil aggregates and the disaggregation process could offset its advantages as a tool for rapid detection of soil structural problem areas within agricultural fields. Core Ideas: Soil aggregate stability was assessed using the dry aggregate stability test and SLAKES.Soil organic matter was not significantly affected ∼7 years after biochar amendment.Neither the dry aggregate stability test nor the SLAKES method detected changes in aggregate stability. [ABSTRACT FROM AUTHOR]

The use of straw biomass for energy can reduce the use of fossil energy and alleviate air pollution. Herein, the cohydrothermal carbonization (Co‐HTC) of rice straw and wheat straw with corn straw is investigated, and synergistic effects of multistraw biomass are observed in the Co‐HTC process. When the corn straw ratio is 75%, the energetic recovery efficiency, C content, and heating value increase compared to the calculated values of the Co‐HTC products. At 260 °C, the energetic recovery efficiency increases by 8.96% and the heating value increases by 2.28 MJ kg−1, which is beneficial for its application. The positive synergistic effect is probably caused by the enhanced dehydration and decarboxylation reactions. For the combustion behavior analysis, the entire combustion process is divided into two stages. When the corn straw ratio is greater than 50%, compared to the calculated values of the Co‐HTC products, the comprehensive combustibility index and activation energy of stage I increase and the activation energy of stage II decreases at 180 °C, while the activation energy of stage I decreases and the activation energy of stage II increases at 260 °C. These findings demonstrate that the Co‐HTC of multistraw biomass is suitable for solid biofuel production. [ABSTRACT FROM AUTHOR]

Poplars and their hybrids are widely planted in both plantation forestry and agroforestry systems of the world. Along with the utilization and plantation management processes, a large amount of biomass residues are produced, but the relationship between biochar properties and soil CO2 emissions is largely unknown. Here, a laboratory incubation study was conducted to assess the effects of different biochars and their corresponding biomass residues on soil CO2 emissions during the 180 days of incubation. Poplar residue‐derived biochars were larger in the surface area and total pore volume but lower in nutrients and pH values than the rice straw‐derived biochar. Increasing pyrolysis temperature led to a decrease in the total nitrogen (TN) content of poplar leaf‐ and rice straw‐derived biochars, but enhanced the TN in the poplar twig‐ and poplar bark‐derived biochars. After 180‐day incubation, the total cumulative CO2 emission decreased by 33.1%–73.8% in the biochar amendments compared to their corresponding biomass residue addition, whereas the biochars derived from poplar twig and bark residues had more positive effects on reducing soil CO2 emissions, but depended on the pyrolysis temperature. Correlation analysis showed a significant and positive correlation between the CO2 emissions and TN content of bio‐based materials but the negative relationships to total carbon content and C/N ratio. Meanwhile the positive correlations of CO2 emissions to the surface area, t‐plot micropore area, and volume of the biochars were detected. Our results suggest that application of poplar twig‐ and poplar bark‐derived biochars has a great potential for mitigating global warming. [ABSTRACT FROM AUTHOR]

The production of tetraethyl orthosilicate (TEOS) from biomass provides a new way for TEOS production and biomass valorization. In this study, rice straw was treated using different fractionation methods, and the content, state, and reactivity of Si in the treated samples were investigated. It was found that acid treatment and ethanol extraction kept most Si in the biomass, while alkali treatment caused significant Si loss. Si was mainly present in the SiOx, Si−O−C, and Si−O−Si states in the surface of raw rice straw, cellulose and Klason lignin. The results showed that the Si−O−Si state in rice straw was beneficial for the formation of TEOS. The removal of lipids from rice straw facilitated the production of TEOS, giving the highest TEOS yield of 76.2 %. In contrast, the production of TEOS from other samples became difficult; the simultaneous conversion of the three organic components of rice straw also facilitated the production of TEOS. [ABSTRACT FROM AUTHOR]

Typically, organic amendment additions like rice straw (RS) are used in agriculture to improve soil quality. The application of RS may influence the production of methane and nitrous oxide (N2O), which may increase the amount of accessible nutrients and organic matter (OM). When compared to farmers' practices of continuous flooding irrigation (CFI), water management (WM) techniques like alternative wetness and dryness irrigation (AWDI) in paddy rice cultivation boost water use efficiency and may result in lower greenhouse gas (GHGs) emissions. A randomized complete block design (RCBD) was employed to evaluate the impacts of WM (CFI and AWDI), RS (15.0 and 30.0 ton ha−1), and their interaction (RS*WM) on the N2O emission and rice yield in a rice paddy calcareous soil. In comparison to control, a single application of RS at 15.0 and 30.0 ton ha−1 significantly reduced N2O emissions by 16.20% and 31.40% (p < 0.01). AWDI regime increased N2O emissions by 67.0% in comparison to the CFI regime (p < 0.01). According to two tailed Pearson correlation, the correlations between AWDI and N2O emissions in the days following rice planting were significantly positive at 0.01 levels. In AWDI regime, adding RS significantly reduced N2O emissions by 18.68% and 31.55% in 15.0 and 30.0 ton ha−1 added RS, respectively, compared to solo WM treatments (p < 0.01). Both RS rates resulted in a considerable increase in biomass and rice grain while AWDI had no significant effect on them. Our study shows that AWDI saved 18.50% water in comparison with CFI regime. [ABSTRACT FROM AUTHOR]

There is a strong interest in production of thermally stable nanocelluloses for further applications. Despite the enormous success achieved in preparing cellulose nanocrystals (CNCs) by acid catalyst technique, these products remain a major challenge due to the lack of thermal stability which till now could not be solved. This work deals with assessing the role of alkali, neutral, acid, and organosolvent pulping agents on thermal stability performances of produced rice straw (RS)‐based CNCs. This property was estimated by thermogravimetric analysis. The data obtained indicated that employing a pulping to RS > 4.75 mm with sodium hydroxide in the presence of anthraquinone‐sodium borohydride can help address these challenges by providing CNCs with highest activation energy as well as a lower aspect length‐to‐width ratio according to transmission electron microscopy images. [ABSTRACT FROM AUTHOR]

Summary: The present study involved valorisation of rice straw by conversion of its constituent polymer xylan and chemically modified xylans into biofilms. Hemicellulosic xylan (19.94%) extracted with 10% NaOH (85 °C, 2.6 h) was chemically modified to acetylated (AX) and carboxymethylated xylan (CMX). Biofilms were prepared by reaction of xylan/modified xylan (1% and 2%) with polyvinyl alcohol using eco‐friendly and cheap cross‐linker citric acid and glycerol as plasticiser. 2% xylan biofilms showed maximum inhibition (94.25%) of DPPH at 4 mg mL−1 which was due to large number of free ‐OH groups (highest intensity of ‐OH absorption bands in FT‐IR spectra). 2% CMX biofilms exhibited maximum antibacterial effectiveness with diameter of zone of inhibition 33.5 and 30.5 mm against Bacillus subtilis and Pseudomonas sp., respectively. This may be due to large number of undissociated COO− ions (citric acid) in CMX biofilms which was evident from lesser cross‐linking observed in their SEM images. 2% CMX biofilms also showed the highest biodegradation (86.5%) which may be attributed to formation of ether bonds along with ester bonds leading to their fast degradation. Owing to good bioactive properties of prepared biofilms, it was concluded that these can be appropriate material for food packaging by replacing synthetic plastics. [ABSTRACT FROM AUTHOR]

Summary: The present study involved valorization of rice straw via production of biopolymeric films loaded with lignin and evaluation of their physical, mechanical, structural, antioxidant, antibacterial and biodegradable properties. Lignin (0.1%, 0.2% and 0.3%) loaded films were prepared by solvent casting method involving successful crosslinking between PVA, citric acid and lignin which was confirmed by ester bond formation at 1710 cm−1 in Fourier transform infrared spectrum. Scanning electron micrographs showed smooth surface in control and wavy surface in lignin film with no cracks. Lignin films possessed thickness, tensile strength and elongation at break in the range 0.127–0.142 mm, 22–31.38 MPa and 11.83–17.63%, respectively. Lightness value of films decreased while yellowness index increased as the level of lignin increased in films. Lignin loaded films showed potential antioxidant activity (51.4–74.6%) and antibacterial efficacy against Pseudomonas (diameter of inhibition zone 4.1 cm), thus suggesting their role in prevention of bacterial food contamination and organoleptic changes in food. The biodegradability tests showed that weight loss experienced by films after burial in soil was above 78.7% which offers a great advantage of these biopolymeric films over non‐biodegradable synthetic plastics, hence, these may be explored further as bioplastics to replace plastic wraps in food packaging. [ABSTRACT FROM AUTHOR]

BACKGROUND: Cyantraniliprole, a second‐generation diamide insecticide, was recently introduced in China, where the rice–crayfish integrated system (RCIS) is practiced to control rice pest infestations. The aim of this study was to investigate the residue behavior of cyantraniliprole in RCIS and its potential ecological effects on nontarget Procambarus clarkii in order to recommend safe pesticide application strategies. RESULTS: Cyantraniliprole dissipated in rice plants according to first‐order kinetics, with an average half‐life of 5.25 days and a dissipation rate of >95% over 28 days. The terminal cyantraniliprole residue levels in rice straw, paddy hull and brown rice were all within 0.2 mg kg−1, which is the China‐recommended maximum residue limit. The tissues of P. clarkii accumulated and distributed cyantraniliprole in the descending order gill > hepatopancreas > intestine > muscles. Procambarus clarkii exposed to cyantraniliprole exhibited a moderate decrease in weight gain, specific growth rate and condition factor compared to the control group. Exposure of P. clarkii to cyantraniliprole caused histopathological alterations to the hepatopancreas, but the alterations were not statistically significant in the 60 g ai ha−1 cyantraniliprole group when compared with the control group. CONCLUSION: We suggest that 10% cyantraniliprole oil dispersion be sprayed twice at an interval of 14 days and dosage of 60 g ai ha−1 during the growth stage of rice in RCIS. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Plant residues are often used as soil amendments in laboratory experiments, but they can reportedly release compounds interfering with soil DNA extraction and subsequent molecular biological analyses. Theoretically, for accurate comparison of microbial community composition in soils with and without added plant residues after a period of incubation, no significant difference at the beginning of the experiment is required between the amended and unamended control soils. We mixed plant residue into soil and immediately (within 10 min) commenced DNA extraction, and then performed 16S rRNA gene sequencing and quantitative PCR (qPCR) to determine bacterial community composition and abundance. Soil without plant residue addition served as a control. Five commonly used DNA extraction kits, 16S rRNA gene primer pairs, and soils, and two types (rice straw and alfalfa shoots) and three addition rates (2%, 4%, and 6%; w/w) of plant residue, were tested. In all cases, we found no significant difference in measured bacterial community composition or abundance between the treatments with and without added plant residue. [ABSTRACT FROM AUTHOR]

Due to the worldwide concern about emerging contaminants in aqueous systems, the main objective of the present study is the adsorption of gemifloxacin (GMF), a fluoroquinolone‐type antibiotic, by rice straw‐based activated carbon. The rice straw chemically activated with K2CO3 (RSAC) had very high carbon content (>80%) and low silica content (due to the extraction step after activation), high specific surface area (1668 m2/g), and oxygenated functional groups. The GMF adsorption capacity of RSAC was relatively dependent on the initial pH of the solution and highly dependent on the adsorbent dose. The pseudo‐second order model and the BET isotherm models were the best models for predicting adsorption's kinetic and equilibrium behaviors. The maximum monolayer adsorption capacities of RSAC at 25, 35, and 45°C were 565.6, 552.4, and 525.8 mg/g, respectively. The thermodynamic parameters indicated a spontaneous and exothermic character of the GMF adsorption process. n–π, π–π, electrostatic interactions, and hydrogen bonding were demonstrated as probable mechanisms involved. Thermal regeneration of GMF‐saturated RSAC at 550°C resulted in perfect adsorbent regeneration in the second cycle and reasonable performance in the third cycle. [ABSTRACT FROM AUTHOR]

The cadmium (Cd) contaminated paddy soil has seriously affected the safe production of rice, and returning straw to fields changes the Cd accumulation in crops. To decrease the Cd accumulation in rice and clarify the relationships among phosphorus (P), iron, and Cd contents in rice, the effects of Solanum spp. (including non‐hyperaccumulators Solanum diphyllum and Solanum alatum, and Cd‐hyperaccumulators Solanum nigrum and Solanum photeinocarpum) straws on the P, iron, and Cd uptakes in rice in Cd‐contaminated soil were investigated. The application of four Solanum spp. straws increased the biomass of rice. Only the S. alatum straw increased the chlorophyll a, chlorophyll b, total chlorophyll, and carotenoid contents in rice. Regarding the P, iron, and Cd contents in rice, the four Solanum spp. straws either decreased the P content or had no significant effects, and tended to increase and decrease the iron and Cd contents, respectively. In addition, the Cd content was negatively correlated with the iron content and the soil available P concentration, and was positively correlated with the soil exchangeable Cd concentration. Therefore, Solanum spp. straws can decrease the Cd uptake and increase the iron uptake by rice. Furthermore, the Cd content in rice is related to the iron content in rice as well as the concentrations of soil available P and soil exchangeable Cd. [ABSTRACT FROM AUTHOR]

Vermicomposting involves enrichment of microorganisms that are able to resist higher temperatures and perform simultaneous degradation of lignocellulose, and therefore, such microbial communities are a potential source of cellulolytic enzymes. This study aimed to optimize the production of a processive cellulase by Parageobacillus thermoglucosidasius NBCB1 isolated from vermicompost, under submerged fermentation of rice straw and to characterize the purified enzyme for industrial suitability. Cellulase production in basal medium (7.27 IU/mg) was enhanced to 61 IU/mg by One Factor At a Time approach, which was further improved to 78.46 IU/mg by genetic algorithm based artificial neural networking. The cellulase PtCel1 purified from bacterial culture showed a molecular weight of ≈33 kD, had activity on both crystalline (305 IU/mg) and amorphous (184 IU/mg) cellulose as substrates. It had pH and temperature optima of 5.5°C and 60°C, respectively, and retained 100% activity upon preincubation at 60°C for 1 h indicating thermostability. PtCel1 was tolerant to sodium dodecyl sulfate, glucose and mannose; and the various metal chlorides, such as sodium, magnesium, calcium and zinc, acted as inducers giving 77.54%, 45.15%, 61.10%, and 169.14% augmentation of activity, respectively. Its efficiency on cellulosic substrates and robustness against aforementioned chemical and thermal environment makes it suitable for industrial applications. [ABSTRACT FROM AUTHOR]

BACKGROUND: Rice straw (RS) is one of the largest sources of lignocellulosic, which is an abundant raw material for biofuels and chemicals. However, the natural degradation of RS under a low temperature environment is the biggest obstacle to returning straw to the field. RESULTS: In the present study, one bacillus strain W118 was isolated. Strain W118 was identified as Bacillus cereus through morphological and physiological characterization and 16S rDNA sequencing. The optimum growth temperature and pH of strain W118 were 20 °C and 6.5, respectively. Simultaneously, it was found that the strain W118 grew well at low temperature, even at a temperature of 4 °C (OD600 = 1.40 ± 0.01). The decrease of various compositions of RS after the fermentation process at a temperature of 20 °C and 4 °C for 14 days was 27.00 ± 0.02% and 23.70 ± 0.04%, respectively. The composition of RS decreased to 50.71 ± 0.02% after being fermented at 4 °C for 25 days. The results of scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction of RS showed that the compositions of RS were significant decreased. CONCLUSION: This test suggests that the strain W118 is efficient for degrading RS at low temperature, which has great application potential for straw degradation in a low temperature area. [ABSTRACT FROM AUTHOR]

Rice straw nanofibers (RSNF) with high lignin content were used in making nanocomposites with graphene oxide (GO) at loading ratios from 0.625% to 5% (based on weight of RSNF). The prepared RSNF/GO films were characterized regarding their tensile strength, equilibrium moisture content (EMC), and electrical properties. Microstructure of the films was examined using scanning electron microscopy (SEM). Addition of 2.5% of GO resulted in increasing tensile strength and Young's modulus by 33.5% and 21.5%, respectively. Presence of GO significantly reduced moisture sorption of the films. Electrical conductivity measurement showed significant increase in permittivity (ε′) upon increasing GO loading. The ionic conductivity value of films containing 5% of GO was 10−7 S cm−1, which is acceptable value for use as antistatic and/or dissipated films. The electrical properties of the prepared low‐cost high‐lignin‐content RSNF/GO films could have potential use in flexible electronic applications such as in energy harvesting and storage. [ABSTRACT FROM AUTHOR]

Phytogenic silica (PhSi) is suggested to control silicon (Si) cycling in soil–plant systems in tropical and subtropical regions. However, the role of crop residues and its biochar as a source of available Si has not been well investigated in agricultural soils. In our study, we determined and compared the effects of rice straw and its biochar on soil Si forms and Si availability. Soil Si forms were characterised by a sequential extraction method, and soil Si availability was assessed by rice growth and soil Si extraction methods. A soil incubation experiment showed that the addition of rice straw and biochar increased plant‐available Si in soil (including mobile Si and adsorbed Si), as well as soil amorphous Si (especially in rice straw treatments). Moreover, this increase was more significant when higher Si (e.g., Si added at the rates of 1.6 and 2.0 g kg−1 soil) was added via rice straw and its biochar, which is most likely a result of PhSi dissolution. Rice‐straw biochar, particularly at higher Si addition rates, tended to have a higher efficiency in increasing soil Si availability than rice straw, mainly due to its greater proportion of readily labile Si. A rice growth pot experiment showed that it is difficult to determine the extent of Si dissolution from PhSi in rice straw using a short‐term experiment with a normal single‐season straw return rate, where the increased pH played a more crucial role in regulating soil Si availability. Our results imply that, in terms of enhancing Si availability, long‐term biochar application with abundant Si input is more effective than straw retention for improving soil fertility in subtropical and tropical regions with highly weathered soils. Highlights: Effect of phytolith‐rich rice straw and its biochar on soil Si availability was studied.Biochar had greater efficiency in increasing plant‐available Si in soil than rice straw.Over the short term, Si dissolution from PhSi is insignificant with a typical single‐season straw return rate.Increased pH played a crucial role in regulating soil Si availability in a short‐term study. [ABSTRACT FROM AUTHOR]

The spectral range <1,000 nm is commonly used for estimating the chlorophyll content of plants. However, the influence of the response band of leaf water content in the Short‐Wave InfraRed on the chlorophyll estimate model is uncertain. We measured the Visible‐Near InfraRed‐Short Wave InfraRed spectral reflectance and SPAD values of rice (Oryza sativa L.) leaves at different growth stages. The vegetation indices (VIs), red edge positions (REPs), and spectral characteristic parameters (SCPs) were calculated. The correlation between the above parameters and SPAD was analyzed. The effects of chlorophyll and water content on the spectral reflectance absorption characteristics of rice leaves were analyzed by the PROSPECT model. SPAD spectral estimation models were established with different inputs using the Random Forest (RF) regression algorithm. Our results are described as follows: (a) The spectral reflectance after continuum removal of rice leaves was highly correlated with SPAD in 600–690, 720–760, 1,400–1,490, and 1,900–1,980 nm. (b) Compared with VIs and REPs, the SCPs after continuum removal including the Depth (D1) and Area (A1, A2) parameters had the highest correlation with SPAD. (c) By taking into account the influence of leaf water content (LWC), the accuracy of SPAD estimation may be enhanced. The RF SPAD estimate model with SCPs of all absorption valley as inputs performed the best. The findings reveal on the mechanism of the influence of LWC on the accuracy of chlorophyll spectra estimation. It provides technical support for estimating SPAD in rice leaves with high accuracy and for developing chlorophyll tachistoscopes. Core Ideas: Spectral characteristic parameters including the Depth (D1) and Area (A1, A2) parameters had the highest correlation with SPAD.All spectral characteristic parameters were significantly correlated with SPAD in the range of 400–2,500 nm.The estimation accuracy of SPAD can be improved by considering the information of leaf water content. [ABSTRACT FROM AUTHOR]

Rice straw and fly ash are the wastes produced in abundance which need immediate attention for their management. In the present study, the in situ pyrolysis of rice straw in presence of fly ash was carried out and the resultant composites were studied for adsorption of methylene blue (MB). Slow pyrolysis of rice straw in presence of fly ash is evaluated using thermogravimetric analysis (TGA) and Coats–Redfern equation for pseudo‐first‐order reaction kinetics, respectively. The activation energy (Ea) for the pyrolysis of rice straw was 41.75 kJ/mol which was lowered to 37.39 kJ/mol in presence of fly ash. Biochar fly ash composites BFA41–3, BFA51–3, and BFA61–3 were prepared at three 400°C, 500°C, and 600°C pyrolysis temperature, respectively, the subscript indicating three different ratios of rice straw and fly ash (1:3, 1:1, and 3:1 w/w ratio). The composites BF4–61–3 were neutral to alkaline in pH, due to the presence of basic oxide and carbonates minerals. BFA4–61–3 was studied for batch adsorption of MB and optimized for pH, dose, and initial concentration of adsorbate. The maximum MB adsorption capacity of 25.91 mg/g was reported for the composite BFA41. MB adsorption efficiency (qe) followed the trend BFA41–3 > BFA51–3 > BFA61–3, which indicates a strong influence of biochar surface functional groups on dye adsorption, as reiterated by the multiple linear regression (MLR) analysis. Stripping of MB was achieved using methanol as a stripping agent for MB‐adsorbed BFA4–61–3 with desorption efficiency of 7% to 11% in the first cycle and 23% to 100% in the second cycle. Thus, the biochar fly ash composite with optimum ion exchangeable functional organic moieties would be suitable for dye remediation and waste generated in the process could find application in soil amelioration. [ABSTRACT FROM AUTHOR]

Striped stem‐borer (SSB) larvae are one of the most serious insect pests that damages rice. In this study, the combined hyperspectral imaging and chemometric method are proposed detect the early SSB larvae infestation in rice stems. Firstly, hyperspectral reflectance data (390–1040 nm) of rice stems were collected for normal, 3 days of infection, 6 days of infection, and 9 days of infection, respectively. On the spectra, the average spectra of the region of interest of the rice stalk samples were extracted, and 19 characteristic wavelengths were screened by the successive projection algorithm (SPA). Morphological processing was performed on the pseudo‐color (generally known as RGB) images of rice stalk samples on the images. Then five image texture features based on the gray‐scale co‐occurrence matrix (GLCM) and nine image color features based on color moments were obtained. The evaluation models of SSB larval infestation based on full spectra, characteristic wavelengths, GLCM, color moments, and data fusion were developed using partial least squares discriminant analysis (PLS‐DA), respectively. The results show that performance of the PLS‐DA model based on the fusion of characteristic wavelengths and GLCM is best. The accuracy of both the comprehensive modeling set and the prediction set is above 97%. The accuracy of the degree of infestation classification is good for all categories, and only the samples on the third day of infection are slightly less accurate. In conclusion, the hyperspectral imaging technology can be used to effectively detect the infection degree situation of early SSB larval infestation. Practical Applications: Chemical control using insecticides to manage SSB infestation on rice is still the farmers' first choice. However, in the middle and late stages of rice growth, SSB larvae may moth into the inside of the rice stalk, and the rice provides a shelter for SSB so that the sprayed pesticides cannot reach SSB larvae, which produce a large number of overwintering SSB. This leads to the misuse of chemical pesticides, which causes serious pollution to the environment, pesticide residues also cause serious harm to the human body, and it also makes the pest resistance to pesticides rapidly increase. Therefore, it is necessary to find a rapid and effective detection method to detect the early infestation of SSB larvae on rice to reduce the use of pesticides and improve rice yield. [ABSTRACT FROM AUTHOR]

The highlights of this study involve the use of microwave heating for torrefaction and pyrolysis of pelletized rice straw for the generation of high‐quality bio‐char pellets, and thorough energy assessment of the process. The effects of microwave power and final temperature on the product yields and their quality were thoroughly assessed. At 600 W power, the bio‐char yield followed the trend: 33.7 wt.% (800°C) < 35.5 wt.% (600°C) < 55.6 wt.% (300°C). Bio‐char yield was unaffected by microwave power at the final temperature of 300°C. High yield of moisture (23.5 wt.%) with a minimal amount of bio‐oil (10.5 wt.%) and gases (10.7 wt.%) were obtained at 600 W and 300°C. The major functional groups in the bio‐oil were phenols (∼40%), cyclic oxygenates (∼16%), furan derivatives (∼20%) and aliphatic oxygenates (16%). Bio‐char obtained from torrefaction at 600 W and 300°C possessed a calorific value of 17.2 MJ/kg with limiting oxygen index of 36.7%, and power generation potential of 4.8 kWh/kg. Overall, microwave‐assisted torrefaction is shown to be a promising process intensification strategy to derive high‐quality bio‐char in a short time of 5–10 min with high process efficiency (51–56%) and comparable biomass conversion efficiency (∼83%) with respect to conventional pyrolysis. [ABSTRACT FROM AUTHOR]

Polyvinyl alcohol with different cellulose nanocrystals (CNC) content extracted from rice straw were prepared by using solution casting method and their biodegradability in natural soil burial were studied. Ethanedioic acid (EA) was introduced as a crosslinker. The synthesized noncrosslinked and crosslinked PVOH/CNC nanocomposites films and their biodegradation were characterized with Fourier transform infrared spectroscopy (FTIR), tensile test, weight loss, Field Emission Scanning Electron Microscopy (FESEM), differential scanning calorimetry (DSC). The changes in chemical properties before and after biodegradation were confirmed through FTIR. Tensile test revealed that the tensile strength and elongation at break reduced as time of soil burial increases. Morphological study showed the extent of surface deterioration before and after soil burial, where the addition of CNC displayed greater deterioration. Melting temperature and crystallinity increased with addition of CNC but decreased after crosslinking. However, melting temperature and crystallinity of all nanocomposites increased after biodegradation. PVOH degrading bacteria were isolated and identified to be Bacillus cereus strain CCM 2010 and Bacillus cereus strain ATCC 14579. Biodegradation of the bionanocomposites were concluded to be in the following decreasing order: PVOH/CNC > PVOH/EA/CNC > PVOH > PVOH/EA. [ABSTRACT FROM AUTHOR]

Environmental conditions, fertilization systems and cultivation practices in greenhouses differ from those in arable soil. Despite being a widespread intensive management practice, large uncertainties exist on the effects of long‐term fertilization on soil organic carbon (SOC) in greenhouse cultivation. The objective of this study was to explore the effects of 11‐year‐long fertilization on carbon (C) stocks in soil aggregates (>2 mm; 2–0.25 mm; 0.25–0.053 mm; <0.053 mm) and SOC fractions (free light fraction (free LF), intra‐aggregate particulate organic carbon (iPOC), mineral‐associated organic carbon (mAOC)) at 0–20 cm and 20–40 cm depth in a solar greenhouse. Five treatments were examined: control (no fertilizer), chicken manure (M), chicken manure plus straw (M + S), chicken manure plus lime (M + Ca), chicken manure plus straw and lime (M + S + Ca). Over the 11 years of continuous intensive organic fertilization, SOC contents of all fertilization treatments first increased sharply and then stabilized after 5 years. The M + S + Ca treatment increased the proportion of aggregate masses, SOC concentrations as well as SOC stocks of soil aggregates >2 mm, 2–0.25 mm, but straw or lime application alone had no significant effects. The M + S + Ca treatment increased the SOC stock of free LF, fine iPOC, coarse iPOC and mAOC by 97%, 38%, 22% and 25% compared with the M treatment, respectively. Straw treatment alone only significantly increased the soil labile C stock (free LF, iPOC). At 0–40 cm depth, the regression between the C stock and the C input had the steepest slope in bulk soil (slope = 0.223, R2 = 0.87**). After 11 years, about 15% of the C inputs were sequestered in the soils. As the mAOC remained largely unaffected, the increase in SOC seems only short‐lived and reaches a new equilibrium within a few years when C inputs are balanced out by mineralization. Consequently, the intensive fertilization and management practices in greenhouse cultivation allowing obtaining high tomato yields results in an overall negative C balance. [ABSTRACT FROM AUTHOR]

Many plant species that are known as silicon (Si) accumulators can form a so‐called phytolith (silicified structure) within their organs. Together with organic matter, potassium (K) has also been found in phytolith structures (phytK). Annually, billions of tons of Si‐rich biomass wastes are cycled in agricultural and natural systems worldwide. However, the fate of the phytolith and its phytK have not been fully understood. This study aims to examine the dynamic release of phytK from phytoliths of reed, rice straw, maize and sugarcane leaf samples. Phytoliths obtained from the biomasses by performing heat treatment at 600 °C were used for batch kinetic experiments. The phytK was found to have 26.3 ± 10.6, 98.9 ± 17.4, 24.9 ± 14.8 and 58.8 ± 13.9 mg Kg−1 for the reed, rice straw, sugarcane and maize leaves, respectively. These phytK amounts comprised at least >45% of the total K budgets in the biomasses and they were observed to be gradually released with time. The retardation of phytK was tightly related to the dissolution rate of phytoliths. The findings highlight that phytoliths carry certain amounts of K, potentially serving as a slow‐release K source for soil and crops. Additionally, this short communication suggests a premise for the development of refinery strategies or extending the range of agronomic options for billions of tons of Si‐rich biomass wastes worldwide. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

The aim of this study is to evaluate the optimum sodium hydroxide (NaOH) concentrations (2 to 12 wt%) for extraction of cellulose from agricultural waste – rice straw fiber towards preparation of cellulose‐based hydrogel. The increase in weight loss with increasing alkaline concentration, suggested that delignification took place progressively up to 6 wt% NaOH as supported by reduction in color intensity of the fiber and chemical analysis using Fourier transform infrared spectroscopy (FTIR). After extraction, the cellulose was firstly dissolved in N,N'‐dimethylacetamide/lithium chloride solution. Then, hydrogel was regenerated via phase inversion in ethanol. Remarkably, the highest swelling, gel fraction, tensile strength, and elongation at break (EB) were also found for hydrogels when regenerated from cellulose treated with 6 wt% NaOH. This study verifies that 6 wt% of NaOH is the optimum concentration for cellulose extraction that enhances the key aspects of good properties of cellulose hydrogels. The uniqueness findings of the study is, the swelling ratio and EB increase although gel fraction and tensile strength also increases which has never been reported. Ultimately, extraction of cellulose from waste to produce hydrogels may have novel impact for solving under‐utilized biomass as well as good prospects as biomaterials. [ABSTRACT FROM AUTHOR]