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[Display omitted] • Decomposition decreased Cr(VI) removal by straws regardless of straw types. • Mechanisms of Cr(VI) removal decrease were different for the two straws. • Cr(VI) could be removed by straws via interfacial and solution reactions. • Straw-derived DOM contributed to 12.0%–35.8% of total Cr(VI) removal. Mobility and bioavailability of hexavalent chromium (Cr(VI)) in agricultural soils are affected by interactions between Cr(VI) and returned crop straws. However, the effect of straw decomposition on Cr(VI) removal and underlying mechanisms remain unclear. In this study, Cr(VI) removal by pristine and decomposed rice/rape straws was investigated by batch experiments and a series of spectroscopies. The results showed that straw decomposition inhibited Cr(VI) removal, regardless of straw types. However, the potential mechanisms of the inhibition were distinct for the two straws. For the rice straw, a lower zeta potential after decomposition suppressed Cr(VI) sorption and subsequent reduction. In addition, less Cr(VI) was reduced by the decomposed rice straw-derived dissolved organic matter (DOM) than the pristine one. In contrast, for the rape straw, due to the increased zeta potential after decomposition, the decreased Cr(VI) removal was mainly ascribed to less Cr(VI) reduction by the rape straw-derived DOM. These results emphasized the significant roles of straw surface potential and DOM in Cr(VI) removal, depending on straw types and decomposition, which facilitate the fundamental understanding of Cr(VI) removal by straws and are helpful for predicting the environmental risk of Cr and rational straw return in Cr(VI)-contaminated fields. [ABSTRACT FROM AUTHOR]

Recycling organic waste and water treatment residues in nanoform is a promising technology in various farming systems, and its effect on aggregate stability, biological activity, and canola production in degraded soils is largely unknown. Hence, we evaluated the effect of nano-biochar (nB) and nano-water treatment residues (nWTR) at levels 50, 100, and 250 mg kg−1 as compared to soil without amendments on the aggregate stability, biological activity, and canola yield in degraded soil. The results showed that the structure coefficient (SC) values are higher when nB and nWTR are added at 100 mg kg−1 soil than at levels 50 and 250 mg kg−1. In our study, the high aggregate stability in the soil treated with nB and nWTR is likely due to their higher content of nutrients, organic carbon, clay, and CEC. The seed weight of the canola plant increased with increasing nB by more than 64%, while it decreased with increasing nWTR. Microbial biomass carbon (MBC) and the activity of dehydrogenase (DHA) and catalase (CLA) increased significantly in the treated pots with the addition of nB and nWTR at various rates. The results of the pot experiment recommended that the applications of nWTR and nB could be used as a promising strategy to improve soil quality and crop yield while also increasing the recycled efficiency of WTR and rice straw. [ABSTRACT FROM AUTHOR]

Abstract\nHIGHLIGHTSThe biomethanization of lignocellulosic wastes remains an inefficient and complex process due to lignin structures that hinder the hydrolysis step, therefore, some treatments are required. This work describes the addition of an enriched microbial consortium in the biomethanization of rice straw. The experiment was carried out in lab batch reactors following two strategies: (i) pretreatment of rice straw for 48 h using the enriched microbial consortium (dilution 1:100), and (ii) addition of this enriched microbial consortium (dilution 1:100) directly to the anaerobic reactors (bioaugmentation). The kinetic behavior was described using three models. As a result, the microbial consortium molecular characterization showed 58 different bacterial species, predominantly the Lactobacillaceae family (45.7%), and the Clostridiaceae family (19.1%), which were responsible for the positive effect obtained by bioaugmentation with methane yield increases of 16% (290 LNCH4/kgVS) respect to the control. All kinetic models applied fitted the experimental data for cumulative methane production, although the modified Hill model showed the best fit. Bioaugmentation strategies demonstrate their effectiveness in lignocellulosic biodegradation, but the novelty of this research lies in the application of an enriched microbial consortium obtained by the authors through soil isolation techniques, which are very inexpensive and affordable for developing countries.An enriched microbial consortium developed by using the effective microorganism’s technology and soils isolated was characterized.Rice straw anaerobic digestion was bioaugmented by the addition of the enriched microbial consortium.Bacterial community dynamics during rice straw anaerobic digestion were influenced by pretreatment or bioaugmentation strategies.Bioaugmentation increases the celluloses biomass availability and the methane yield (16%).Specific methanogenic activity and kinetic were influenced by adding the enriched microbial consortium.An enriched microbial consortium developed by using the effective microorganism’s technology and soils isolated was characterized.Rice straw anaerobic digestion was bioaugmented by the addition of the enriched microbial consortium.Bacterial community dynamics during rice straw anaerobic digestion were influenced by pretreatment or bioaugmentation strategies.Bioaugmentation increases the celluloses biomass availability and the methane yield (16%).Specific methanogenic activity and kinetic were influenced by adding the enriched microbial consortium. [ABSTRACT FROM AUTHOR]

This work aimed to extract silica from combination of rice husk (RH and Rice straw (RS) by optimizing the ash digesting process parameters with the aid of response surface methodology (RSM). The effects of three independent ash digestion process factors like sodium hydroxide concentration (1–3 M), temperature (60–120 °C) and time (1–3 h), for silica production from the mixture of rice husk (RH) and rice straw (RS) were studied. A quadratic model was used to correlate the interaction effects of the independent variables for maximum silica production at the optimum process parameters by employing central composite design (CCD) with RSM. The work indicates that the temperature is the most significant parameter among the model terms, followed by NaOH concentration, then time for digestion of ash for silica production. It may be because of the larger F-value for temperature, which influences to high extent of ash digestion for silica production. The proximate analysis discovered that RH/RS possessed compositions of high ash, volatile matter and fixed carbon content whereas low moisture content, i.e., 20.5 ± 0.46, 67.1 ± 0.78, 15.8 ± 0.35 and, 6.6 ± 0.37 wt.%, correspondingly. The characterization of RH/RS and silica were performed by employing thermogravimetric (TG) and differential thermal (DT), Fourier transforms infrared spectroscopy (FTIR), X-ray fluorescence spectroscopy (XRF) and Brunner–Emmet–Teller (BET) for confirmation of the silica production. Hence, this current study concludes that silica materials obtained from RH/RS (with purity > 97.35 wt.%) may be new materials in the Si–C–O system that may be used in construction, ceramics and silica gel that helps to absorb moisture. [ABSTRACT FROM AUTHOR]

In the present study, rice straw‐derived cellulose was converted into carboxymethylcellulose (CMC) using alkalization followed by an etherification reaction. The synthesis conditions for this chemical modification were optimized such that CMC with a high degree of substitution (1.02) was obtained. Infrared spectra of the synthesized CMC clearly showed an increased intensity of the C═O bond at 1600 cm−1, confirming successful carboxymethylation. Further, X‐ray diffraction analysis demonstrated a decrease in cellulose crystallinity owing to partial rearrangement from a crystalline to an amorphous phase during initial alkalization reaction. The obtained CMC biopolymer was subsequently cross‐linked to form a composite hydrogel matrix reinforced with bentonite clay. The hydrogel showed about 91% adsorption capacity for methylene blue dye as a model contaminant in aqueous media. Therefore, this study shows that lignocellulosic agrowaste is a rich source of cellulose, and its derivatives such as CMC possess the potential to realize the waste to wealth sustainability goal. [ABSTRACT FROM AUTHOR]

The objective of this study was to examine the impact of rice straw brittleness on its efficacy as roughage for ruminants, in comparison to a wild-type variety, utilizing an in vitro study approach. The experimental design was a complete randomized design (CRD). The experimental treatments included various breeds of rice straw (RS), such as the wild-type (WT, T1), the green brittle bred line 8 and line 13 with brittleness level-3 (GBL8-B3, T2 and GBL13-B3, T3), and the purple brittle bred line 8 with brittleness level-5 (PBL8-B5, T4). The findings revealed that the brittleness RS group had higher levels of crude protein and hemicellulose, and lower levels of cellulose compared to the wild-type group. Brittleness RS varieties showed a significantly greater gas production accumulation (p = 0.001) and IVDMD (p = 0.003) compared to the WT group. At 8 h post-incubation, the brittleness RS group showed significantly higher (p = 0.004) total of volatile fatty acids concentration compared to the WT group. After 1 h of post-incubation, GBL8-B3 exhibited the highest (p = 0.032) proportion of propionate and the lowest (0.009) C2:C3 ratio. Additionally, the brittleness RS did not have any effect on the population of ruminal microorganisms. Based on the brittleness of RS, it can be deduced that it has a greater potential as a roughage source when compared to the wild-type variety, consequently enhancing the quality of RS for roughage intake by ruminants. [ABSTRACT FROM AUTHOR]

Ensiling straw for livestock feeding is an emerging technique for addressing the fodder shortage in the country, as it optimizes nutrient storage and utilization. In this study, rice straw was mixed with pea waste (pods) and brewer's grains in the ratio of 35:50:15 respectively, and ensiled in triplicate, with mini-silos opened and sampled at intervals of 30, 40, and 50 days.. These ingredients were mixed with exogenous fibrolytic enzyme (EFE, xylanase; X derived from Trichoderma citrinoviride, 1500 IU/kg), coupled with either a solitary homofermentative inoculant (Pediococcus acidilactici NCDC 609; PA), heterofermentative inoculant (Leuconostoc mesenteroides NCDC 421; LM), or a combination of both. Ensiling of peapods, brewer's grain, and additives reduced (p<0.05) pH from 4.4 to 3.9 (control vs combination of xylanase with homo and heterofermentative bacteria (X+PA+LM group), ammonia-N from 0.20 to 0.18% of DM (control vs X+PA+LM group), butyric acid (0.0114 to 0.0110% of DM), and fiber content from 39.91 to 37.20% of DM (control vs X+PA+LM group) in the treatment groups in which ingredients were supplemented with a combination of homofermentative and heterofermentative bacteria with the exogenous enzyme at all time intervals, i.e., 30th, 40th, and 50th days. However, the best quality silage in terms of pH, lactic acid content, and NH3-N was formed after 50 days of fermentation. The addition of enzymes solubilized the fiber-bound nitrogen fraction of ingredients and made it available to LAB, hence enhancing (p<0.05) its crude protein content. Therefore, it is advisable to ensile the rice straw with peapods and brewer's grain in the suggested ratio to meet the feed demands of livestock and address environmental issues. [ABSTRACT FROM AUTHOR]

Agriculture waste needs proper management for a balanced ecosystem. The management of such waste can be used to produce bioenergy, conserving nonrenewable resources and producing nanoparticles. This study reports the utilization of rice husk and straw in an innovative bio-transformative route to isolate silica nanoparticles (SiNPs). The rice husk and straw were initially subjected to mushroom cultivation, followed by the extraction of SiNPs from the spent substrates. The SiNPs obtained from the raw straw and husk samples and from the spent substrates were characterized by using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transforms infrared spectroscopy (FTIR), and energy-dispersive X-ray spectroscopy (EDS). FESEM results showed that the particle size of SiNPs lies between 15 and 30 nm and 25 and 30 nm for rice husk and straw, respectively. The mushroom yield of Pleurotus florida was 26.9% and 53.1% for rice husk and rice straw, respectively. The total yield of SiNPs from spent husk and straw was 67.5% and 26.2%, respectively. The nanoparticles derived from rice husk and straw inhibited the growth of Staphylococcus aureus (59.9 ± 1.3% and 65.3 ± 2.4%, respectively) and Escherichia coli (68.5 ± 2.8% and 70.1 ± 2.5%) at a 100 mg/ml SiO2 concentration. Present study results suggest that raw husk and straw and spent husk and straw could serve as a potential source for the production of SiNPs. [ABSTRACT FROM AUTHOR]

In the present work, the processability of poly(lactic acid) (PLA) in the extrusion foaming process was improved by using rice straw (RS) as an agricultural waste. In order to extrude a sustainable lightweight foam, the soda‐pulping and bleaching modification were performed on the RS particles, which resulted in the attainment of purified micron‐sized cellulosic fibre with higher aspect ratio. The addition of these fibres, with larger interfacial area between filler and matrix, to the PLA melt enhanced the foam void fraction and cell density more than one order of magnitude. The use of a reactive compatibilizer in the biocomposite showed further beneficial effects on the PLA foamability. The used reactive compatibilizer, with the ability of simultaneous reactions with the end groups of PLA macromolecules and hydroxyl groups of the lignocellulosic pulp, in the biocomposite noticeably improved the viscoelastic properties of melt and lengthened the macromolecule relaxation times. As a result, the biocomposite melt with higher melt strength was obtained, which kept the melt integrity during the bubble growth stage, hindered the cell coalescence, and retained a larger volume of gas inside the melt. Contrary to these influences, the compatibilization activity of this additive weakened the heterogeneous nucleation role of the cellulosic fibres. However, by choosing proper pulp loading, the extrusion of a lightweight biodegradable PLA‐based biocomposite foam can be feasible, which can be used in interior construction applications. [ABSTRACT FROM AUTHOR]

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Agriculture needs a reduced dependency on synthetic chemical fertilizers and renewable biomaterials to add nutrients to soil, ameliorating degraded soil and gaining agronomic yield of crops. Biochar mixed with inorganic fertilizer has been effective in improving the crop yield. However, the influence of composite biochar (C‐BC) obtained from poultry feathers (PFs), cow bones (CBs), and rice straw (RS) waste streams as sources of N, P, and K, respectively, is still unclear. This study aimed to unveil a tripartite relationship of biochar composite applications with soil properties and agronomic attributes of sunflower var. orisun. Biochars associated with nutrient acquisition were characterized through Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and energy dispersive x‐ray (EDX) spectroscopy. To assess the bioavailability of nutrients and their impact on agronomic yield, a greenhouse trial was set up with sunflower, using each biochar individually as well as in composite application at three levels of amendments (0%, 2%, 4%, and 6% w/w) along with commercial fertilizer. The surface characterization through FTIR, SEM, and EDX of each biochar illustrated the presence of a wide range of functional groups, porosity, and multiple nutrients. C‐BC showed a significantly positive response to soil properties and exhibited the high availability of nutrients (N, P, and K) in soil as compared to commercial fertilizer. Application of C‐BC at 4% was found effective for dry biomass (47 g) and seed yield (35.16 g), resulted in oil and protein concentrations as high as 44.8% and 23.5%, respectively. Feather‐derived biochar (PF‐BC), bone char (CB‐BC), and RS‐derived biochar (RS‐BC) in the form of biochar composite can become an applicable substitute for chemical fertilizer in sustainable agriculture. [ABSTRACT FROM AUTHOR]

Introduction: China is rich in straw resources. The utilization of straw in the cultivation of edible fungi partially resolves the resource conflicts between mushroom cultivation and forest industry and also contributes to environmental protection. Methods: In this study, based on the technology of replacing wood by grass, the straw formula for mycelial culture of Hericium erinaceus was optimized with Simplex-lattice method commonly used in mixture design. By measuring the growth rate and the activity of lignocellulose degrading enzymes of mycelia in different formulations, and further combining with model optimization, the optimal formulation was screened and validated for mushroom cultivation. Results: In the experiments, different kinds of straw used as the main material showed interaction effects, further affecting the growth rate of mycelia and the activities of laccase, cellulase, and neutral xylanase. The screened optimal formula was composed of 16.3% rice straw, 59.7% cob, 20.0% wheat bran, 2.0% gypsum, 1.0% sucrose, and 1.0% calcium superphosphate. In the mushroom cultivation, 445.69 g of fresh mushroom were obtained and the biological efficiency reached 89.14%. The growth period of the first mushroom was shortened by 7-9 days. Some nutritional components of fruiting bodies, such as crude fats (6.10%), crude proteins (152.02 g/kg), K (19.71 g/kg), P (2.48 g/kg), and Se (6.06 g/kg), were significantly higher than those of the control formula. Discussion: These above indicators indicated that the screened formula could be applied in the high-yield and high-quality cultivation of H. erinaceus. Our study lays the foundation for expanding cultivation and strains improvement of H. erinaceus , and is conducive in promoting the rapid development of H. erinaceus industry. [ABSTRACT FROM AUTHOR]

Burning rice straw is now a significant issue faced by different regions in India, as its burning releases harmful gases, mainly carbon dioxide. Various techniques are now in trend to utilize the rice straw, e.g., producing compressed natural gas using rice straw, bioethanol, etc., as a substrate for various microorganisms. A high quantity of non-utilized rice husk generates more ideas for its proper utilization. The cellulose, hemicellulose, and lignin found in rice straws can be a fungi growth medium. In this research, the delignification of rice husk is done by acid (2% and 4% H2SO4) and alkali (2% and 4% NaOH) at 121 °C at 103 kPa for 1 h to obtain crude carbon source which is further utilized for biomineralization. The glucose is subjected to qualitative and quantitative analysis using Molisch's and Dinitro salicylic tests. The delignification process showed a positive outcome when 2% H2SO4 is utilized maximum yield of 5.9 ug/ml free sugar concentration. Representing the highest glucose yield compared to the experiment's other acid and base substances used. Various techniques such as field emission-scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and Fourier transformed infra-red (FTIR) spectroscopy are employed to examine surface and chemical alterations. The 2% H2SO4 pretreated rice husk is utilized for microbial-induced calcite precipitation using fungal isolates S1 (3), S1 (18), and S4 (1). The calcite and vaterite produced by biomineralization are confirmed using XRD for fungal isolates namely, S1 (3), S1 (18), and S4 (1) having percentage crystallinity of 59%, 46.428%, and 62.69% percentage crystallinity respectively. [ABSTRACT FROM AUTHOR]

Introduction: Susbtantial agricultural wastes are produced globally which need urgent management policies. To explore the effective utilization of agricultural waste in enhancing soil quality and carbon sequestration capacity, straw and its biochar can be applied as soil ameliorants. Methods: This study was designed to investigate the impact of different return-to-field methods of rice straw on the transformation between different carbon components in the soil of Siraitia grosvenori i fields. We hypothesize that rice straw and its biochar, as soil amendments, can influence the transformation and cycling of different carbon components in the soil of S. grosvenorii fields through various return-to-field methods. Rice straw, rice straw biochar, and "rice straw + rice straw biochar" were applied as additives in a 2-year field experiment. Results: The results showed that the field application of rice straw and its biochar increased the content of soil organic carbon, the amount of organic carbon mineralization, particulate organic carbon, mineral-associated organic carbon, dissolved organic carbon, and readily oxidizable organic carbon content, while reducing the content of soil microbial biomass carbon. The combined application of rice straw and biochar in S. grosvenorii cultivation fields had a more significant effect on various soil carbon fractions compared to the use of either rice straw or biochar alone. The co-application of rice straw and its biochar to the soil increased the content of soil organic carbon by 117.4%, enhanced the mineralization of organic carbon by 100.0%, and reduced the content of soil microbial biomass carbon by 61.6%. The metabolic entropy and microbial entropy of rice straw and its biochar mixed application in the field were 5.2 and 0.18 times higher than of the control group, respectively. Discussion: In summary, the return of rice straw and biochar to the field improves soil structure and the content of recalcitrant organic carbon, providing a habitat for microorganisms, thereby promoting the stability and cycling of soil organic carbon. [ABSTRACT FROM AUTHOR]

The study characterized rice straw biochar and its magnetic derivative, both intercalated with and without urea, and evaluated their effects on soil nitrogen release, rice growth, and yield. Rice straw and magnetic rice straw were subjected to pyrolysis at 450°C to produce biochar, and further treated with urea. The resulting biochars were chemically and structurally analyzed. Treatments included rice straw biochar (RB1) and magnetic rice straw biochar (MRB1) at 30 t ha−1 each, biochar combined with urea at 80 kg N ha−1 (RB2 and MRB2), biochar intercalated with urea at 40, 60 and 80 kg N ha−1 (URB1–3 and UMRB1–3), sole urea at 80 kg N ha−1 and control. Gleysol collected from a research site at the Obafemi Awolowo University was analyzed for routine properties, amended according to treatments and planted to rice, with growth and yield parameters monitored. The FTIR spectra of UMRB revealed sharp peaks of amine and N/O-alkyl functional groups, strong Fe-O peaks, and the presence of aliphatic and carboxylic compounds, suggesting higher adsorptive capacity for cations and a greater ability to reduce nitrate conversion to N2O. After 30 days, UMRB treatments exhibited higher concentrations of both ammonium and nitrate compared to other treatments. The plant number of panicles, tiller length, dry matter, and grain yield significantly increased with UMRB application, particularly with urea at 40 kg N ha−1. Overall, the study suggests that urea-intercalated magnetic rice straw biochar holds potentials as a slow-release nitrogen fertilizer, enhancing rice growth and yield in water-logged rice cultivation. [ABSTRACT FROM AUTHOR]

Introduction: This study aimed to examine the effects of fermented rice husk powder feed on growth performance, apparent nutrient digestibility, and rumen microbial communities in fattening Hu sheep. Methods: Twenty-one male Hu sheep with similar body weights (32.68 ± 1.59 kg) were randomly assigned to three groups: a control group (CON) receiving a TMR with soybean straw, a rice husk powder group (RH), and a fermented rice husk powder group (FHR). Results: The results indicated that the FHR group exhibited a significant increase in ADG and FBW of Hu sheep compared to the other two groups (p < 0.05). The digestibility of CP and EE was significantly higher in the CON and FHR groups than in the RH group (p < 0.01). Furthermore, the digestibility of DM in the CON group was higher than in the FHR and RH groups (p < 0.01). The FHR group showed lower NDF and ADF digestibility compared to the CON group, but higher than the RH group (p < 0.05). Additionally, serum ALB and ALT levels in the CON group were elevated compared to those in the two groups (p < 0.05). The rumen concentrations of TVFA, butyrate, and valerate in the FHR group were significantly elevated compared to the other two groups (p < 0.05). At the genus level, the relative abundances of Rikenellaceae RC9 gut group , Succinimonas , UCG-010_norank , UCG-005 , p-251-o5_norank , and Lachnospiraceae AC2044 group were significantly diminished in the FHR group compared to the CON group (p < 0.05). In contrast, the relative abundance of Succinivibrio was significantly higher (p < 0.05), while the abundances of Eubacterium coprostanoligenes group_norank and Quinella were significantly lower (p < 0.05) in the RH group compared to the CON group. Spearman correlation analysis revealed negative correlations between the Rikenellaceae RC9 gut group and propionate, butyrate, and TVFA, as well as between Prevotellaceae UCG-003 and both propionate and TVFA. Conversely, Ruminococcus showed a positive correlation with propionate and TVFA. Discussion: In conclusion, replacing 15% of soybean straw with fermented rice husk powder feed modified the rumen microbiota and improved the growth performance of fattening Hu sheep. [ABSTRACT FROM AUTHOR]

A novel effective sorbent for the extraction of antimony(III) from rice straw has been generated, having a specific surface area of 470 m²/g. The material was subjected to a series of analyses, including scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffraction analysis, and FT-IR spectroscopy. The sorption properties relative to Sb(III) ions were characterised in dynamic conditions in a column experiment. The total dynamic exchange sorption capacity of 113.92 mg/g renders this material suitable for use as a permeable reactive barrier (sorption barrier) with the objective of protecting soils from antimony contamination. To identify the optimal conditions for soil protection, the chemical composition, acid-base properties, and sorption parameters of soils of varying types were characterised. The sorption properties of the soils were determined in static conditions to obtain the sorption isotherm. The maximal sorption capacity was identified for the soil sample with low base saturation and a high organic component content, a finding that was corroborated by DTA analysis. The results of the column experiment with layers of soil and aluminosilicate sorbent indicate the promising use of the new sorbent as a sorption barrier for the effective protection of soils from antimony contamination. [ABSTRACT FROM AUTHOR]

This study investigated the application of agricultural waste rice straw as fibre or filler in asphalt mixtures. Initially, the physical, chemical, mineralogical and morphological characterisation of rice straw products were analysed. Subsequently, the performance of stone matrix asphalt (SMA) mixtures containing rice straw fibre was evaluated in terms of rutting, crack resistance and moisture susceptibility, compared to cellulose fibre. Additionally, the properties of asphalt concrete (AC) mixtures incorporating rice straw filler to replace conventional mineral filler partially were examined. The findings revealed that rice straw products exhibited similar characteristics to cellulose fibre or mineral filler, indicating their suitability for use in asphalt mixtures. The appropriate addition of rice straw fibre or filler demonstrated enhancement in the high-temperature performance, low-temperature crack resistance and moisture stability of asphalt mixtures. Through experimental tests, the optimum content of rice straw fibre in SMA-13 mixtures was determined to be 0.4%, while for the rice straw filler in AC-13 mixtures, it was 20%. The mechanisms of rice straw fibre and filler added in asphalt mixtures to strengthen their road performance were binder adsorption and reinforcement effect through scanning electron microscope (SEM) images. Furthermore, rice straw filler also contributed to void filling within asphalt mixtures. [ABSTRACT FROM AUTHOR]

In order to solve the problem that straw mulching inhibits seed germination and seedling growth, biofertilizer was made by inoculating Piriformospora indica solution on rice straw and the activity of the biofertilizer and its effect on rice seed germination and seedling growth were discussed to provide theoretical basis for the application of straw mulching and biofertilizer. In this study, two kinds of biofertilizer were made using straw and peat as carriers, and the toxicity of the two carriers on Piriformospora indica and the change of the number of viable colony forming units (CFU) during the storage period of the biofertilizer was detected to determine whether straw was a suitable carrier for Piriformspora indica. Then, two kinds of fertilization (biofertilizer as base fertilizer and seed soaking with biofertilizer extract) with three fertilizer treatments [straw treatment (ST), biofertilizer treatment (BF) and conventional fertilization as control (CK)) and five seed soaking treatments (four biofertilizer extract gradients of 25%, 50%, 75% and 100%, and sterile water as control (CK)] were set up to treat the seeds of Lvhan 1. Then, the comparative analyses of the germination indexes, agronomic traits, root morphology and physiological indices under different treatments were conducted, and the fertilization effect was evaluated, and finally the appropriate fertilization concentration and fertilization method were selected. Results showed that: (1) the number of viable CFU was significantly increased by 2.89 times and 1.89 times during 0~6 days after inoculation on straw and peat carriers, respectively (P<0.05). During the 180 days of straw carrier-based Piriformospora indica biofertilizer stored at room temperature (25°C), the number of viable CFU of the biofertilizer showed a trend of first increased and then decreased with the extension of storage time. The number of viable CFU was significantly increased by 32.08% and 31.13% at 30th and 60th day, and significantly decreased by 61.23%, 96.60% and 98.70% at 120th, 150th and 180th day than that of the initial (P<0.05). (2) Compared with straw treatment, plant weight, stem length, root length, projection area, surface area, root activity, the contents of both chlorophyll a and chlorophyll b were significantly increased under biofertilizer treatment. (3) Rice seed germination was inhibited by biofertilizer extract, and the inhibition effect was strengthened with the increase of concentration of the extract. Biofertilizer extracts of different concentrations showed different effects, namely low concentration promoted growth and high concentration inhibited growth, on germ length, radicle length, seedling root morphological indices, stem length, longest leaf length and plant weight, and they were obviously promoted by 25% biofertilizer extract. However, germ length, root morphological indexes and plant weight were significantly reduced by 34.07%, 43.53%-63.97% and 19.51% by the original extract solution(100%), respectively (P<0.05). This study showed that combined with straw mulching, the biofertilizer made by inoculating Piriformospora indica solution on straw-carrier was a suitable rice planting strategy. Mixing compound fertilizer and Piriformospora indica biofertilizer at 3:1 and seed soaking with 25% biofertilizer extract were two fertilization methods and fertilization concentrations appropriate to both rice seed germination and seedling growth. [ABSTRACT FROM AUTHOR]

Microcystin-leucine arginine (MC-LR) poses a serious threat to aquatic animals during cyanobacterial blooms. Recently, biochar (BC), derived from rice straw, has emerged as a potent adsorbent for eliminating hazardous contaminants from water. To assess the joint hepatotoxic effects of environmentally relevant concentrations of MC-LR and BC on fish, male adult zebrafish (Danio rerio) were sub-chronically co-exposed to varying concentrations of MC-LR (0, 1, 5, and 25 μg/L) and BC (0 and 100 μg/L) in a fully factorial experiment. After 30 days exposure, our findings suggested that the existence of BC significantly decreased MC-LR bioavailability in liver. Furthermore, histopathological analysis revealed that BC mitigated MC-LR-induced hepatic lesions, which were characterized by mild damage, such as vacuolization, pyknotic nuclei, and swollen mitochondria. Compared to the groups exposed solely to MC-LR, decreased malondialdehyde (MDA) and increased catalase (CAT) and superoxide dismutase (SOD) were noticed in the mixture groups. Concurrently, significant changes in the mRNA expression levels of Nrf2 pathway genes (cat, sod1, gstr, keap1a, nrf2a, and gclc) further proved that BC reduces the oxidative damage induced by MC-LR. These findings demonstrate that BC decreases MC-LR bioavailability in the liver, thereby alleviating MC-LR-induced hepatotoxicity through the Nrf2 signaling pathway in zebrafish. Our results also imply that BC could serve as a potentially environmentally friendly material for mitigating the detrimental effects of MC-LR on fish. [ABSTRACT FROM AUTHOR]

Expanding sugarcane (SC) cultivation at the expense of paddy rice (PRC) areas led to soil nutrient cycling changes. The study hypothesized that SC straw return and fertilizer application after land use change (LUC) from PRC to SC cropping would increase the soil-crop systems nutrient balance, ultimately enhancing growth, yield, and nutrient use efficiency of SC. In a field study involving a 17-year chronosequence of sugarcane 6 (SC6), 13 (SC13), and 17 (SC17) years after LUC, the nutrient balance dynamics of SC were monitored in comparison with those of PRC. A phosphorus (P) balance increase of 62–102% after LUC increased soil available P (Pav) from 5.2 to 13.6–16.0 mg kg−1. A potassium (K) balance decrease of 47–55% after LUC led to a decrease in soil exchangeable K (Kex) from 102.5 to 96.2–56.8 mg kg−1. Moreover, LUC increased the % sand, soil organic matter (SOM), total mineral nitrogen (N), and total N. In contrast, the % clay, bulk density, cation exchange capacity (CECpH7), and exchangeable calcium (Caex) decreased after LUC. An increase in soil nutrients increased cane yield and nutrient use efficiency with time after LUC. However, further research in different locations and management practices is required for the LUC investigation. HIGHLIGHTS: LUC in combination with tillage improved soil chemical properties, leading to increased sugarcane yield (SC6 > SC13 > SC17) and nutrient use efficiency. In a system without tillage, after land use change (LUC), the percentage of sand, SOM, Pav and mineral N increased, while the percentage of clay, bulk density, CECpH7, Kex, and Caex decreased. Sugarcane (SC) had a greater P balance than paddy rice (PRC) after LUC, leading to an increase in soil available P. K inputs from rice straw return promoted a greater K balance in PRC than in SC. [ABSTRACT FROM AUTHOR]

Soil extracellular enzymes play an important role in regulating nitrogen (N) mineralization processes in paddy fields. Therefore, in this work, we determine the influence of a long-term fertilizer regime on rhizosphere soil N fertilization rates, soil enzymes, soil microbial community (bacterial ureolytic community (ureC), bacterial chitinolytic community (chiA)) under the double-cropping rice field in southern of China. The field experiment included the following fertilizer regimes: inorganic fertilizer alone (IF), rice straw and inorganic fertilizer (RF), 30% organic manure and 70% inorganic fertilizer (OM), without any fertilizer input as a control (CK). The results showed that rhizosphere soil N transformation rates in the paddy fields with OM and RF treatments were increased, compared with IF and CK treatments. Soil urease, β-glucosaminidase and arginase activities were significantly increased under OM and RF treatments. This result indicated that functional gene abundances of sub, npr and chiA were significantly greater under RF and OM treatments compared to IF and CK treatments. Soil bacterial ureolytic and chitinolytic communities were significantly changed by the different fertilization strategies. The practice of applying rice straw and organic manure seems beneficial for increasing rhizosphere soil N mineralization rates and microbial community diversity in the double-cropping rice fields. [ABSTRACT FROM AUTHOR]

Rice straw hydrolysate produced in rice straw pretreatment, comprising a lot of fermentable sugars, is generally released into the environment. This not only causes environment pollution but also wastes fermentable sugars from rice straw. To alleviate environment impact, maximize ethanol production from rice straw, and reduce the cost of ethanol production, rice straw hydrolysate and NaOH-pretreated rice straw were converted to ethanol using ethanol-type fermentation and simultaneous saccharification and fermentation (SSF) by sludge. Meanwhile, microbial community in sludge was analyzed to find the relationship between ethanol production and microbial community succession during ethanol-type fermentation and SSF. Under the optimal condition of the COD, pH and oxidation–reduction potential (ORP) value of rice straw hydrolysate with 6280.56 mg/L, 6.7, and − 42 mV, ethanol-type fermentation with the sludge of 15 g obtained the highest ethanol concentration (8.34 g/L) and the highest COD removal rate (54.83%). For SSF, the maximum ethanol concentration (3.75 g/L) produced by pretreated rice straw and sludge from ethanol-type fermentation with the sludge of 15 g was higher than that (2.61 g/L) generated by pretreated rice straw and sludge from ethanol-type fermentation with the sludge of 22.5 g. This indicated that sludge from ethanol-type fermentation with the sludge of 15 g more efficiently converted rice straw to ethanol than sludge from ethanol-type fermentation with the sludge of 22.5 g. Microbial community analysis suggested that ethanol production had a negative correlation with the relative abundance changes of Bacteroidetes, when the relative abundance of Firmicutes constantly rose in ethanol-type fermentation and SSF. This study provides a scientific basis for maximizing ethanol production from rice straw by microbial regulation in sludge, which could further reduce the cost of ethanol production. [ABSTRACT FROM AUTHOR]