Search

In most of India, rice is an important staple crop. After harvesting, the waste rice straw is frequently burned in the open fields because there is insufficient time before planting the next crop to remove and dispose of it in a more controlled manner. This can affect the regional environment as well as anthropogenic climate change. Due to its high C:N ratio, it takes time to decompose, therefore it is not suitable for direct composting. To identify their best alternative industrial uses, the present study was investigated with various biochemical parameters of 13 rice straw cultivars grown in the northern region of India. Total sugar varied from 6.16±0.29 to 8.40±0.11% with the highest value found in paddy variety PR-126, while reducing sugar ranged from 3.50±0.30 to 5.47±0.55%, and highest in CSR-47. Maximum non-reducing sugars was found in PB-1121. Total protein content ranged from 1.96±0.10 to 5.06±0.29% with the greatest value found in Pusa-1509, while soluble protein in Pusa-441. The highest amount of volatile solid found in the HB-2 variety. The PR-114 variety had the greatest total phenol content (0.31±0.07%), whereas the PR-113 variety had the lowest (0.07±0.06%). The fat level of these cultivars ranged from 5.9±0.41 to 19.8±0.44% with the variety Pusa-1509 having the highest fat percentage. Based on non-structural carbohydrates analysis of rice straw cultivars could be used for biorefinery process, hemicellulose and cellulose are decomposed to sugars for bioethanol and animal feed production and leave lignin to be recovered for further valorization of dispersants, adhesives and surfactants are the best alternative for industrial uses to cut-off the menace of straw burning. [ABSTRACT FROM AUTHOR]

Improving the efficiency of traditional composting in humic acid (HA) formation and heavy metal (HM) remediation is widely concerned. This study investigated the effects of three pretreatments (ultrapure water, citric acid, and ethylenediaminetetraacetic acid disodium (EDTA)) on the evolution of humification and HMs during the co-composting of rice straw and sediment. The results showed that EDTA pretreatment established an EDTA-Fenton-like system in the co-composting, and observably improved the remediation of HMs and the formation of humic substances (HS). The co-composting with EDTA pretreatment had a lower content of Cr (62.00 mg/kg) and Cd (1.18 mg/kg) than the co-composting without pretreatment (Cr: 83.76 mg/kg, Cd: 3.44 mg/kg). Furthermore, the combined treatment increased the residual fractions of Cr and Cd by 10.35 % and 5.80 %, respectively, and simultaneously promoted the formation of HS and HA by 5.20 g/kg and 9.58 g/kg, respectively. In particular, redundancy analysis and structural equation models evidenced that the EDTA-Fenton-like system enhanced the passivation of HMs by facilitating humification during the combined treatment. Our research demonstrates that the EDTA-Fenton-like system could be conducive to the remediation of HM pollution in sediments by co-composting. • EDTA pretreatment could establish EDTA-Fenton-like system during co-composting. • The EDTA-Fenton-like system enhanced humification in pretreatment and co-composting. • EDTA pretreatment effectively decreased the quantity of Cr and Cd in the sediment. • Co-composting with EDTA pretreatment efficiently passivated Cr and Cd. [ABSTRACT FROM AUTHOR]

Selecting and breeding rice cultivars that enable strong cadmium (Cd) accumulation in rice straw but low accumulation in brown rice is a promising way to achieve Cd phytoremediation as well as to ensure the food safety of rice. Herein, we isolated a gene OsWNK9 from the quantitative trait locus associated with reducing Cd translocation from rice straw to brown rice and decreasing the Cd concentration in brown rice (BRCdC). Continuous strong expression of OsWNK9 was observed in nodes and internode and was induced after Cd supply. OsWNK9 was localized in the rice cell nucleus and participated in the regulation of Cd transport in yeast. Two independent oswnk9 rice mutants were generated via CRISPR/Cas9 gene-editing and showed significantly higher BRCdC than that of the wild type (WT). The BRCdC of knockout oswnk9 mutants was 0.227 mg kg−1and 0.238 mg kg−1, increased by 14 % and 19 % compared with that of the WT due to the lower Cd allocation in the basal stem, internode, and node III, which was unrelated to Cd uptake. Interestingly, OsWNK9 could promote iron (Fe) accumulation in rice under Cd-contaminated conditions, suggesting that OsWNK9 is an ideal gene for Cd phytoremediation and Fe biofortification in rice to support safe food production. • OsWNK9 was a protein kinase-coding gene for regulating Cd content in brown rice. • OsWNK9 was localized in cell nucleus of rice mesophyll protoplast. • OsWNK9 was highly expressed in the nodes and restrained Cd translocation. • OsWNK9 was an ideal gene for promoting Fe accumulation in brown rice. [ABSTRACT FROM AUTHOR]

Researchers' attention has been greatly focused on the use of lignocellulosic wastes to produce bioethanol and biogas due to the depletion of non-renewable energy resources. In our effort to find a potent cellulase-producing fungal strain, the fungus NAS51 was isolated among eight isolates from a sponge collected from the Red Sea, Jeddah, and selected as it displayed the highest cellulase activity including (FP-ase, CMC-ase, and β-glucosidase enzymes) at levels of 3.13 U/ml, 2.52 U/ml, and 0.69 U/ml, respectively. The fungus was identified morphologically and genetically by sequencing its 18SrRNA gene as Aspergillus sp. NAS51. The cellulase activity of Aspergillus sp. NAS51 was optimized and maximum enzyme production was obtained at initial pH7, temp 30oC, incubation period 11 days, moisture content 70%, urea as a nitrogen source, and K2HPO4 (2 g/L). The crude cellulases from strain NAS51 were characterized, and results showed that the enzyme is stable over a wide pH range (6–10), with peak activity at pH 7.0 and 40 °C. The cellulase gene has been sequenced and the protein 3D structure was generated via in silico homology modeling. Determination of binding sites and biological annotations of the constructed protein was carried out via COACH and COFACTOR based on the I-TASSER structure prediction. To reach the maximum enzyme hydrolysis, the rice straw collected from Al-Ahsa, Kingdom of Saudi Arabia was pretreated with NaOH 1.5% to remove lignin and to enhance the saccharification process by Cellulase. The saccharified product was measured using HPLC, fermented by S. cerevisiae and the bioethanol yield produced from the fermentation was 0.454 mL ethanol/g fermentable sugars. This study indicates the potential application of fungal enzymes such as cellulase enzymes in biofuel generation and waste management. • Making bioethanol from lignocellulosic waste offers a viable option to diversify our energy sources and move away from non-renewable ones. • Identifying a cellulase-producing fungus is critical for improving bioethanol yield and efficiency. • In silico modeling of Aspergillus sp. NAS51 cellulose enzyme for bioethanol production from Hassawi rice straw. [ABSTRACT FROM AUTHOR]

Through Government Regulation No. 79, issued in 2014 on National Energy Development, the Indonesian government aimed to diversify raw materials from biomass, including rice straw, an abundant resource. To realize the national goals, farmers' participation in rice straw utilization and management plays an essential role in determining the direction and succession of these valorization programs by considering sustainability aspects. Statistical analysis by clustering methods using multiple correspondence analysis (MCA) and hierarchical agglomerative clustering (HAC) was employed to visualize and extract information about farmers' willingness and participation. The survey results of 300 farmers in three regions of East Java found that most farmers utilized rice straw in small portions, depending on the weather, for animal feed and planting purposes , such as mushroom media planting, fertilizer, and mulch. More than 60% of farmers have a significant perception that better rice straw management, when complemented by the government's role in supporting physical and nonphysical facilities, will improve farmers' socioeconomic quality and mitigate greenhouse gas emissions. The findings of this study will help to minimize the challenges and barriers to bioenergy development and optimize their opportunities by continuing to synergize to set future strategies. [Display omitted] • We assessed farmers' willingness to participate in rice straw valorization in Indonesia. • Farmers' perceptions are of critical importance in the construction of the supply chain for rice straw. • The primary factors determining the participation of farmers are economic and environmental considerations. • The government's involvement had a significant impact on farmers' expectations of rice straw valorization. • Rice straw valorization had a greater positive impact on sustainable development. [ABSTRACT FROM AUTHOR]

Brassinosteroids (BRs) can regulate various processes in plant development and defense against environmental stress. In this study, the contribution of BRs in the degradation of isoproturon (IPU) in rice has been established. IPU has a significant effect on rice growth, chlorophyll content, and membrane permeability. When treated with 1.0 μmol/L 24-epibrassinolide (EBR), a BR analogue, the associated symptoms of rice poisoning were alleviated as the IPU levels in the rice and growth media were decreased. In the presence of EBR, the activities of several IPU-related detoxification enzymes were enhanced to cope with the stress due to IPU. An RNA-sequencing (RNA-Seq) has been performed to determine the variation of transcriptomes and metabolic mechanisms in rice treated with EBR, IPU, or IPU+EBR. Some of the differentially expressed genes (DEGs) were Phase I-III reaction components of plants, such as cytochrome P450 (CYP450), glutathione S-transferase (GST), glycosyltransferases (GTs), and the ATP-binding cassette transporter (ABC transporter). The expression of some signal transduction genes was significantly up-regulated. The relative content of low-toxicity IPU metabolites increased due to the presence of EBR as determined by UPLC/Q-TOF-MS/MS. The IPU metabolic pathways include enzyme-catalyzed demethylation, hydroxylation, hydrolysis, glycosylation, and amino acid conjugation processes. The results suggest that EBR plays a key role in the degradation and detoxification of IPU. This study has provided evidence that BRs regulate the metabolism and detoxification of IPU in rice, and offers a new approach to ensuring cleaner crops by eliminating pesticide residues in the environment. [Display omitted] • Exogenous EBR alleviates IPU-induced inhibition in rice growth phenotype. • Exogenous EBR decreases IPU residue in rice and its environment. • EBR activates BRs signal transduction by upregulating the expression of BZR4. • EBR facilitates the expression of pesticide degradation genes. • EBR promotes metabolic reactions and the production of IPU derivatives in rice. [ABSTRACT FROM AUTHOR]

This study investigated the impacts of different types of auxiliary materials on the humification process and bacterial dynamics during kitchen waste composting. Five types of auxiliary materials, including sawdust (SD), garden waste (GW), aquatic plants (AP), rice straw (RS), and rice husk (RH), were compared. The relationship between humic acid carbon and nitrogen components as well as bacterial community was analyzed by structural equation model and redundancy analysis. The results d indicated that SD and RS exhibited better thermophilic stage duration, germination index, and organic fraction s degradation than other groups, which had higher degree of polymerization and the humification index of kitchen waste composting. AP, SD and RS had higher total nitrogen (TN) content and ammonia nitrogen accumulation, and RS had more humic acid nitrogen in TN with more amino acids and polyphenols precursors compared to other groups. High-throughput sequencing indicated that sawdust affected the variation of community structure and bacterial genera associated with lignocellulose degradation more than others. Redundancy analysis showed that Pseudoxanthomonas helped to the NH 4 +-N conversion to humic acid nitrogen for TN preservation. Structural equation modelling suggested that the conversion and utilization efficiency of microbes directly influenced the accumulation of humic acid carbon and nitrogen based on the types of intermediate metabolites. This study highlighted the role of auxiliary materials on improving the humification process of rapid kitchen waste composting. [Display omitted] • Different auxiliary materials were compared to improve kitchen waste composting. • SD and RS had longer thermophilic stage and higher GI and humification degree. • RS had more humic acid nitrogen in TN and polyphenols precursors accumulation. • SD had more bacterial genera with lignocellulose degradation function. • Pseudoxanthomonas helped to the conversion of NH 4 +-N to HA-N for TN preservation. [ABSTRACT FROM AUTHOR]

Copyright of Polimery is the property of Industrial Chemistry Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Rice straw and millet husk are produced globally in huge quantities as a by-product. Agricultural by-products can be used for a variety of applications, and processing agricultural solid wastes have several advantages, including reduced greenhouse gas emissions. This investigation determines the suitability of using rice straw and millet husk as raw materials in the production of paper, resulting in the reduction of virgin woods usage as the primary pulping material. Millet husk and rice straw have adequate cellulose levels and low lignin contents, making them ideal as an alternative low-cost raw material for papermaking. The initial process of softening the raw materials for pulp production was carried out with 12-15% of diluted sodium hydroxide solution. For comparative evaluation, different compositions of raw materials (100% rice straw, 100% millet husk, 50% millet husk:50% rice straw, 80% rice straw:20% millet husk) were used. The produced sheets were subjected to various analyses such as GSM, Thickness, Bulk density, Moisture content, Ash content, pH, Absorbency, and Biodegradability. The paper made of 100% millet husk had the highest GSM value, while the paper made of 100% rice straw had the highest bulk density. The moisture and the ash content of the paper made of 50% millet husk: 50% rice straw presented with the lowest values of 7.46 % and 6.45 % respectively. Based on preliminary investigation, the results indicate the eligibility of rice straw and millet husk as raw materials for paper production; a better way to recycle agricultural wastes. [ABSTRACT FROM AUTHOR]

In this study, a rice root plaque associated bacterium was identified as Burkholderia sp. EIKU24 and evaluated its potentials in the management of heavy metal(loid)s (HMs) contamination in agricultural soil though rice-based pot experiment. The mesophilic, drought and HMs tolerant strain thrived in wide range of pH. The isolated strain removed more than 96% arsenic (As), 98.7% copper (Cu) and 83.4% nickel (Ni) from aqueous solution following different sorption kinetics, while it reduced up to 49.7% hexavalent chromium (Cr(VI)). The bacterium exhibited multiple plant growth promoting (PGP) traits including solubilization of phosphate, potassium, ZnO, ZnCO 3 and Zn 3 (PO 4) 2. Enhance solubilization of ZnCO 3 and Zn 3 (PO 4) 2 in As amended liquid culture of the bacterium was noticed, while, ZnO solubilization declined in 15 days of incubation. The solubilization of Zn was found to be related to the drop in pH of the culture medium during growth. Soil augmentation of EIKU24 in pot experiments showed a significant reduction of As translocation to the rice plant which was evident from the As content in the root and shoot of rice seedlings grown under different treatments. Additionally, the root and shoot length and their biomass enhanced in EIKU24 amended soil, even in As spiked pots, suggests the beneficial role of EIKU24 in rice seedling health growing in the As contaminated soil. Burkholderia sp. EIKU24, a root plaque-associated bacterium, emerged as a promising candidate for bioremediation, expression of PGP, and micronutrient solubilization, and thus, might be augmented for sustainable rice cultivation in As affected areas. • Root plaque-associated Burkholderia sp. EIKU24 isolated from As contaminated soil. • Up to ∼90% removal of As(III), As(V), Cu and Ni from solution within 72h by EIKU24. • EIKU24 showed multiple in-vitro PGP traits–IAA, Siderophore, ACC deaminase. • Positive influence of As on mineral solubilization was noticed in presence of EIKU24. • EIKU24 significantly inhibit the As translocation in rice parts, promote its growth. [ABSTRACT FROM AUTHOR]

Anaerobic co-digestion offers a promising approach to enhancing biogas production from surplus by-products of wastewater treatment plants (WWTPs) and agricultural waste while reducing environmental negative impact. This study investigated the co-digestion of anaerobic thickened sewage sludge (ATSS) and rice straw (RS) under mesophilic conditions (35 ± 1 °C). In phase 1 of the experiment, lab-scale reactors with varying MRs of RS (0 %, 4 %, 8 %, and 16 % based on sludge weight) were employed to determine the optimal MR for maximizing biogas quantity and methane content. Phase 2 examined the impact of mechanical mixing (MM) on biogas production, pathogen and trace element reduction, and the calorific value (CV) of the co-digested mixture compared to the digested thickened sludge (DTS) and RS individually to assess the potential energy of co-digestion. Results revealed that the 8 % MR yielded the highest biogas volume, approximately 2.5 times that of the DTS alone, with methane and carbon dioxide contents within the typical ranges. MM in phase 2 further increased biogas volume by 2.8 times compared to DTS. The CV of the co-digested mixture was 24,937 kJ/kg and 21,929 kJ/kg for the DTS. Pathogens were effectively eliminated, and trace elements remained below the permissible limits. The 8 % MR with MM was identified as the optimal MR that produces the highest biogas quantity before reaching the turning point. Moreover, co-digestion at this MR enhanced the CV of ATSS by 14 %. [ABSTRACT FROM AUTHOR]

This research investigated wastewater treatment efficiency along with agricultural residue utilization for biogas production of anaerobic co-digestion system. The purpose of this work was to study effect of ratio between rice straw and swine wastewater at 1:20, 1:40 and 1:80 by weight including effect of wastewater changing interval for every 2, 3 and 4 weeks on effluent characteristics, wastewater treatment efficiency and biogas production. The finding will provide alternative way for agricultural waste utilization. Results showed pH and total Kjeldahl nitrogen (TKN) in effluent of all tested systems were in the Thailand’s swine effluent standard. Besides most of TSS in effluent of the co-digestion system, average COD and BOD5 were higher than those in influent of the system and in the effluent standard. For treatment efficiencies, lowest values were frequently found in the co-digestion system with the ratio of 1:80 but highest values obtained from control unit. Average biogas production rate and average specific methane yield of all co-digestion systems were 105.7-202.7 mL/d and 52.1-217.0 mL biogas/g VSadd, respectively with 9090.0- 17430.0 mL of average biogas accumulation for 3 months of operation. The co-digestion system with every 2 weeks of wastewater changing interval and the system with co-fermentation ratio of 1:40 provided high biogas accumulation yield. [ABSTRACT FROM AUTHOR]

To assess the effects of straw return coupled with deep nitrogen (N) fertilization on grain yield and N use efficiency (NUE) in mechanical pot-seedling transplanting (MPST) rice, the seedlings of two rice cultivars, i.e., Yuxiangyouzhan and Wufengyou 615 transplanted by MPST were applied with N fertilizer at 150 kg/hm2 and straw return at 6 t/hm2 in early seasons of 2019 and 2020. The experiment comprised of following treatments: CK (no fertilizer and no straw return), MDS (deep N fertilization and straw return), MBS (broadcasting fertilizer and straw return), MD (deep N fertilization without straw return), MB (broadcasting fertilizer without straw return). Results depicted that the MDS treatment significantly increased the rice yield by 41.69%–72.22% due to total above-ground biomass, leaf area index and photosynthesis increased by 54.70%–55.80%, 38.52%–52.17% and 17.89%–28.40%, respectively, compared to the MB treatment. In addition, the MDS treatment enhanced the total N accumulation by 37.74%–43.69%, N recovery efficiency by 141.45%–164.65%, N agronomic efficiency by 121.76%–134.19%, nitrate reductase by 46.46%–60.86% and glutamine synthetase by 23.56%–31.02%, compared to the MB treatment. The average grain yield and NUE in both years for Yuxiangyouzhan were higher in the MDS treatment than in the MD treatment. Hence, deep N fertilization combined with straw return can be an innovative technique with improved grain yield and NUE in MPST in South China. [ABSTRACT FROM AUTHOR]

Controversial issues have been raised regarding the use of plastic mulches, as they can have a destructive effect on agricultural production systems and because of the reliance on fossil fuels for the manufacturing. Investigating the use of organic materials as alternatives to black plastic mulch is thus crucial to enhance both the productivity and the sustainability of agricultural systems. A field experiment was carried out in three years, assessing the efficacy of several organic mulch materials, in comparison with black plastic mulch, for suppressing weeds in tomato production. The results showed that, mulching with shredded date leaves + sawdust, had the highest inhibiting impact in reducing the total weed density by approximately up to 31.3 weeds m-2 at 70 days after transplanting in all three years. The highest marketable yield of the tomatoes was obtained for plants grown with shredded date leaves + sawdust mulch in 2015, 2016 and 2017. Additionally, mulching with coco fibre, sawdust, wheat straw + sawdust, corn residue + sawdust and wood chips + sawdust resulted in similar values for marketable yield as the black plastic. The results revealed that shredded date leaves + sawdust could be a practical alternative to the use of black plastic in the production of processing tomatoes. The use of wheat straw + sawdust, barley straw + sawdust, rice straw + sawdust, corn residue + sawdust, coco fibre + sawdust, sawdust and especially coco fibre, as replacements for black plastic, would be rational options when there is no access to shredded date leaves + sawdust. [ABSTRACT FROM AUTHOR]

Exact information of mechanical properties of straw are necessary to be executed for designing the equipment's and machineries being used for harvesting, threshing and other post-harvest practices. This study in this importance was carried out to assess the mechanical properties of rice straw as effected by different moisture, variety and loading rates, which have never been accounted before. Three different rice varieties i.e. Yue76, Qianjindao and Yue61 when harvested were collected for experimentation. Mechanical properties of rice straw were evaluated at three internodes (IN1, IN2 and IN3) down from ear, and were subject to two different moisture contents (11 and 18%) and loading rates (10 and 20 mm min·1 ). The experimental design was subject to randomized complete block design, replicated thrice. The results revealed that the rice straw parameters and their interactions were significantly affected (p:S0.05) by different moisture content, variety and loading rate. The average values obtained were significantly different from each other, the average values for shear strength were observed to be 14.18, 9.95 and 11.99 MPA, for specific shearing energy the average values were observed to be 17.30, 13.34 and 15.93 mJ mm-2, for bending strength the averages values were observed to be 11.33, 7.40 and 9.54 MPa, and for young's modulus the average values were observed to be 1.06, 0.73 and 0.99 GPa for Yue76, Qianjindao and Yue61 varieties respectively. The study revealed that shear strength and specific shearing energy increased with increasing moisture content and loading rate, where the bending strength and young's modulus decreased. The outcomes of current study revealed a wide variation between the parameters observed, which makes it necessary to assess the mechanical properties of rice straw before designing and judging the equipments and machineries being used for post-harvest operations. [ABSTRACT FROM AUTHOR]

• Lignin was recovered from the solid waste of a lignocellulosic biorefinery process. • The kinetics of the delignification reaction were analyzed. • Major delignification mechanisms were identified. • High-purity lignin can be obtained for subsequent high-value utilization. Lignin recovery and valorization is desirable to optimize the process economics of the biorefinery with lignocellulose biomass as a feedstock. The recovery of high purity lignin from the brown solid (BS) residual obtained from a mid-stream waste of the rice straw biorefinery using the soda extraction process by adding ethylene glycol (EG) as a co-solvent is investigated in this study. The best extraction result was obtained with a lignin recovery of 94% and lignin content (purity) of 92% when the reaction time was 300 min at 190 ℃. The addition of EG increased the lignin solubility in the solution so that higher lignin yield and recovery could be obtained than that from the neat Soda process. The kinetic analysis indicated that the delignification reaction was composed of a fast bulk phase and a slow residue phase with a transition time at 60 min, corresponding to different levels of fragmentation, depolymerization and solubilization of lignin. In the fast phase, about 80% lignin can be solubilized in the solution quickly due to the predominant nucleophile attacks on the ether linkages (C-O-C, α-O-4, β-O-4, etc.). In the slow phase, the carbon-carbon (C-C) bonds are broken in the remaining residue lignin. [Display omitted] [ABSTRACT FROM AUTHOR]

The addition of sugar and the reversal of compost ingredients during this time are common in the hope that the composting process can take place faster. The addition of sugar is expected to increase microbial activity, while a more routine reversal is expected to meet the oxygen needs of microbes in aerobic composting. This research aims to analyze the effect of reversal and sugar addiction on the process of composting aerobic waste of rice straw. To date, there have been no studies that state that the addition of sugar to aerobic composting provides better compost maturity and quality following SNI-7763-2018 standards. To prove, research was conducted using 20 kg of rice straw with sugar doses of 0.4% and 0.8%. 2 treatments are reversals every 3 days and 6 days, with a composting time of 30 days. Each treatment was repeated 3 times, resulting in 18 trials in total. Based on the results of the study obtained C/N ratio on compost age 15 days have not been included in the category of mature compost. While the C/N ratio of compost at the age of compost of 30 days is in the range of 17.64-24.06. The results showed the C/N ratio between treatments at 30-day compost was no different (p>0.05). This means that the addition of sugar and more regular reversal frequencies are not required in aerobic composting of rice straw. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the in vitro true digestibility (IVTD) and in vitro NDF digestibility (IVNDFD) of some leguminous hays (field pea, common vetch, alfalfa) and graminaceous straws (wheat and rice) in combination with the rumen fluids collected from water buffaloes or Holstein cows as inoculum. Each filter bag, which contained one of the five feed blends, buffer solution and rumen fluid, was placed in a Daisy11 incubator digestion jar. Each feed treatment was replicated 8 times and the incubation period was 48 hours. There were significant differences between the effects of the rumen fluids of the water buffaloes and Holstein cows on some fermentation characteristics of different substrates. The mean TVFA and NH3-N concentrations for both ruminant species were significantly higher for leguminous hays than graminaceous straws. These concentrations were not significantly different between rumen fluid applications of water buffalo and Holstein cow for leguminous hays, and the same was true for wheat straw. The rumen fluid of the water buffaloes increased the IVTD and IVNDFD values of the low quality feeds (wheat and rice straw) in comparison to the rumen fluid of Holstein cows. This study also demonstrated that leguminous hays have higher nutritional quality than graminaceous straws due to their higher nitrogen and lower fibre contents. Additionally, the results of this experiment suggest that the water buffalo rumen fluid generated higher microbial biomass production when combined with the graminaceous straws than with the rumen fluids of Holstein cows, which was reflected in a higher level of synthesis of VFAs. [ABSTRACT FROM AUTHOR]

• The highest hydrolysis efficiency was to apply 0.5 M HCl to treat 5% rice straw. • 5-HMF and furfural concentrations in the HCl hydrolysate were both highest. • Furans inhibitors in the 2-fold hydrolysates were entirely biodetoxified within 12 h. • Higher H 2 content and volume were obtained when using the biodetoxified rice straw hydrolysate. • Biodetoxification process could be incorporated into biohydrogen production plant. Thermal acid hydrolysis is the most common pretreatment method used to deal with waste lignocellulosic biomass. However, furan derivatives (5‑hydroxy-methylfurfural (5-HMF) and furfural) are unavoidably produced and influence downstream biofuel production. Biological methods are superior to physical and chemical methods in detoxifying 5-HMF and furfural because of economic concerns. Integrating the biodetoxification process into the lignocellulose pretreatment and downstream biofuel production procedure is an important issue. The previous novel strain Burkholderia cepacia H-2 capable of quickly degrading 5-HMF and furfural was applied in the biodetoxification process. In this study, the acid sorts and concentration effects on thermal acid rice straw hydrolysis were investigated first. Rice straw hydrolysates with various dilution ratios were then biodetoxified using on-site inoculating novel strain B. cepacia H-2. The biodetoxified rice straw hydrolysate was then used for biohydrogen production using dark fermentation. The highest hydrolysis efficiency and reducing sugar were 49% and 15.6 g/L, respectively when applying 0.5 M HCl to deal with 5% rice straw at 121°C for 15 min. The 5-HMF and furfural in the 2-fold diluted rice straw hydrolysate could be completely biodetoxified within 12 hrs. The hydrolysate hydrogen yields with and without biodetoxification were 0.90 and 0.64 mmol H 2 /mmol sugar, respectively. The biodetoxification process using the novel strain B. cepacia H-2 was successfully established and could be integrated into the lignocellulose pretreatment and downstream biofuel production procedure as using the rice straw as the feedstock. [Display omitted] [ABSTRACT FROM AUTHOR]

• Lignin model compounds showed positive effect on azo dye decolorization by fungus. • Both lignin model compounds and EMAL stimulated laccase production in dye cultivation system. • Laccase overexpression improved dye decolorization and accelerated fungal growth. Improvement of dye removal efficiency is beneficial to development of bioremediation for textile effluent. In this study, the effect of lignin model compounds (LMCs) and enzymatic/mild acidolysis lignin (EMAL) from rice straw as co-substrate on dye decolorization by Ganoderma lucidum EN2 were evaluated. Two azo dyes, Remazol Brilliant Violet 5R (RBV5) and Sunset Yellow (SY) were tested. Eight of the thirty tested LMCs could significantly improve both RBV5 and SY decolorization, including 3,4,5-trimethoxycinnamic acid, 4-hydroxycinnamic acid, 3,5-dimethoxy-4 -hydroxybenzaldehyde, 3-hydroxybenzoic acid, 3‑hydroxy-4-methoxycinnamic acid, guaiacol, acetosyringone, and 2,6-dimethoxyphenol. The decolorization of RBV5 (from 87.04% to 97.90%) and SY (from 62.41% to 97.40%) by G. lucidum EN2 could be efficiently enhanced in the presence of EMAL. The addition of EMAL could increase the decolorization of higher concentration of azo dyes which is more difficult to be decolorized alone. Noteworthy, laccase activity increased with the increasing amount of EMAL. EMAL showed a positive effect on fungal growth but a negligible effect on pH. These results indicated that EMAL may act as inducer to stimulate the laccase production, and the increase of laccase activity accelerated dye decolorization. [Display omitted] [ABSTRACT FROM AUTHOR]

Carbon-fixing functional strain-loaded biochar may have significant potential in carbon sequestration given the global warming situation. The carbon-fixing functional strain Bacillus cereus SR was loaded onto rice straw biochar pyrolyzed at different temperatures with the anticipation of clarifying the carbon sequestration performance of this strain on biochar and the interaction effects with biochar. During the culture period, the content of dissolved organic carbon (DOC), easily oxidizable organic carbon, and microbial biomass carbon in biochar changed. This finding indicated that B. cereus SR utilized organic carbon for survival and enhanced carbon sequestration on biochar to increase organic carbon, manifested by changes in CO 2 emissions and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) enzyme activity. Linear regression analysis showed that the strain was likely to consume DOC on 300 °C biochar, although the Rubisco enzyme activity was higher. In contrast, the strain had a higher carbon sequestration potential on 500 °C biochar. Correlation analysis showed that Rubisco enzyme activity was controlled by the physical structure of the biochar. Our results highlight the differences in the survival mode and carbon sequestration potential of B. cereus SR on biochar pyrolyzed at different temperatures. • Carbon-fixing strain Bacillus cereus SR survived on biochar by using organic carbon compositions of biochar. • Increase in organic carbon fractions of biochar by RubisCO enzyme of strain. • The strains changed the pore size structure of biochar. • Physical properties of biochar limited the function of carbon-fixing strain. [ABSTRACT FROM AUTHOR]

Co-degradation of coal and straw can significantly increase methane production compared to coal and straw degradation alone, but little is known about the effect of co-degradation on the fermentation of refractory fractions. In this paper, lignite and rice straw were degraded multiple times to obtain the refractory fractions which were then co-degraded with rice straw (RSL10) and lignite (LRS10), respectively. The methane production of lignite and rice straw after ten degradations reached 969.38 μmol and 582.47 μmol, respectively, which were 7.83 times and 31.25 times higher than degradation one time, suggesting that they have significantly higher methane production potentials than expected. The methane production of RSL10 and LRS10 only increased by 9.05 μmol and 5.67 μmol, and the structure of refractory fractions barely changed after co-degradation for both lignite and rice straw, revealing that the metabolism of refractory fractions rarely contributed to methane production in co-degradation. FTIR and 13C NMR analysis verified that the aromatics, methyl carbon, and oxygen containing functional groups in lignite, carbonyl groups and glycosidic linkages in rice straw were utilized to produce methane in multiple degradations. Desulfomicrobium increased to 20.67% in RSL10, while Pseudomonas and Clostridium increased to 18.85% and 9.17% in LRS10, which were mainly induced by the added raw lignite and rice straw. It revealed that co-degradation mainly enhanced the fermentation of degradable components instead of refractory organics in lignite and rice straw. The methane potential of degradable components can be released by co-degradation and multiple degradations. Our results are beneficial for the better understanding of co-degradation mechanism and biomethane generation in the coal seams. [Display omitted] • The metabolism of refractory components rarely contributes to methane production in co-degradation. • Co-degradation releases the methane production potential of degradable components of lignite and rice straw. • High methane production potentials of lignite and rice straw by multiple degradations were observed. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) accumulates in the vegetative tissues of rice and wheat crops, posing a serious threat in the food chain. A long-term field experiment was conducted to investigate the effects of rice husk biochar (RHB), farm manure (FM), press mud (PrM), and poultry manure (PM) on the growth, yield, and economics of wheat and rice crops grown with sewage water. The results showed that RHB increased wheat plant height (27%, 66%, 70%), spike-length (33%, 99%, 56%), straw yield (21%, 51%, 49%), and grain yield (42%, 63%, 65%) in year-1, year-2, and year-3, than respective controls. For rice crop, RHB showed the maximum increase in plant height (64%, 92%, 96%), spike length (55%, 95%, 90%), straw yield (34%, 53%, 55%), and grain yield (46%, 66%, 69%) each year (2019–2021), compared to their respective controls. The Cd immobilization was increased by the application of RHB while other treatments followed FM > PrM > PM > control in each year of wheat and rice crops. For year-1, benefit-cost ratio remained maximum with the application of FM while for the 2nd and 3rd years in sequence, RHB proved more economical than other treatments and consistently produced wheat and rice with lower Cd concentration than FM, PrM, and PM in grains. This long-term experiment suggested that the application of organic amendments consistently increased biomass of rice and wheat and decreased the Cd concentration in tissues. The RHB remained more effective compared with FM, PrM, and PM in terms of yield, low Cd accumulation and economics of rice and wheat crops. [Display omitted] • Organic amendments enhanced wheat and rice yield under Cd stress. • Amendments differentially affected Cd availability in soil and plant uptake. • Farm manure was more effective in reducing Cd uptake by crops in 1st year. • RHB was more effective in reducing Cd uptake by crops in 2nd and 3rd year. [ABSTRACT FROM AUTHOR]

2-Methyl-1-butanol (2MB) and 3-Methyl-1-butanol (3MB) are microbial volatile organic compounds (VOCs) and found in indoor air. Here, we applied rice as a bioindicator to investigate the effects of these indoor microbial volatile pollutants. A remarkable decrease in germination percentage, shoot and root elongation, as well as lateral root numbers were observed in 3MB. Furthermore, ROS production increased by 2MB and 3MB, suggesting that pentanol isomers could induce cytotoxicity in rice seedlings. The enhancement of peroxidase (POD) and catalase (CAT) activity provided evidence that pentanol isomers activated the enzymatic antioxidant scavenging systems, with a more significant effect observed in 3MB. Furthermore, 3MB induced higher activity levels of glutathione (GSH), oxidized glutathione (GSSG), and the GSH/GSSG ratio in rice compared to the levels induced by 2MB. Additionally, qRT-PCR analysis showed more up-regulation in the expression of glutaredoxins (GRXs), peroxiredoxins (PRXs), thioredoxins (TRXs), and glutathione S-transferases (GSTUs) genes in 3MB. Taking the impacts of pentanol isomers together, the present study suggests that 3MB exhibits more cytotoxic than 2MB, as such has critical effects on germination and the early seedling stage of rice. Our results provide molecular insights into how isomeric indoor microbial volatile pollutants affect plant growth through airborne signals. [Display omitted] • This study highlights the response of rice seedlings to 2MB and 3MB. • Both 2MB and 3MB inhibited germination and rice seedling growth. • Both 2MB and 3MB treatments induced oxidative stress in rice seedlings. • Antioxidant system in rice seedlings was influenced by 2MB and 3MB. • 3MB is more toxic than 2MB in rice. [ABSTRACT FROM AUTHOR]

China is the world's largest consumer of chemical fertilizers, with a strong reliance on imports of mineral K fertilizer up to 50 %. Inexpensive and renewable straw-K recycling is crucial for enhancing soil K fertility and carbon (C) sequestration. Here, national management networks for inorganic- and straw-K were systematically integrated to identify yield gaps and C mitigation potential in Chinese typical crop rotation systems. National spatio-temporal changes in soil K fertility in the past 40 years were also mapped, indicating that about 52 % of national cereal arable cropland was still under low-K status in 2020. Compared with the inorganic K system (INK), grain yields of maize, wheat, and rice were respectively reduced by 9.4 %, 14.9 %, and 13.4 % under 0 K system, and increased by 5.2 %, 6.2 %, and 3.0 % under straw-based K recycling system (SBK system). Estimated net C emissions with the SBK system were 11.6 % (maize) and 47.4 % (wheat) lower than with the INK system, mainly due to the larger increase in soil C sequestration than in N 2 O production. Conversely, the SBK system increased net C emissions in rice by 57.6 % than the INK system due to larger increase in CH 4 emissions. Scenario analyses showed that the annual C mitigation potential in the SBK system would approach 16.9 % (spring maize), 46.4 % (wheat-maize), 62.9 % (rice-wheat), and 22.4 % (rice-rice) by optimising the annual chemical fertilizer rate and seasonal straw distribution. Integrated inorganic- and straw-K management could also be extended to other K-limited developing and less-developed regions to enhance global food security and agricultural green development. [Display omitted] [ABSTRACT FROM AUTHOR]

• Biowaste rice straw (RS) is a low cost and eco-friendly precursor. • RS derived activated carbon with nitrogen dropped treatment show the high-performance in supercapacitor. • A highest specific surface area of 2651 m2/g of activated carbon can be obtained from our process using RS. • The NAC-850 is a promising electrode material with specific capacitance of 324 F/g. Environmental-friendly and low-cost biomass-derived materials have been attracted many attentions to produce porous activated carbon (AC) with high surface area for supercapacitor (SC) application. In this study, rice straw (RS), an agricultural waste, is used to prepare ACs with a two-step process of carbonization and KOH activation. As-produced AC has a high specific surface area (SSA) of 2651 m2g-1 with hierarchical pore structure. In order to enhance the performance of SC, nitrogen-doping strategy is carried out to increase nitrogen functional groups in the AC using melamine as a precursor. The SSA of the nitrogen-doped AC is 2537 m2g-1 and the capacitance of 324 F/g is achieved using nitrogen-doped AC at a current density of 0.5 Ag-1 in 6 M KOH aqueous electrolyte. The capacitance retention is 95% after 10,000 charge and discharge cycles at a current density of 5.0 Ag-1. In addition, ionic liquid is employed as the electrolyte for the supercapacitor. The energy density of 48.9 Wh/kg at a power density of 750 W/kg can be achieved using EMI-TFSI electrolyte. We think that the proposed method can be used for a variety of biomass for preparation of ACs with high specific surface area and nitrogen functional groups for the energy storage applications. [Display omitted] [ABSTRACT FROM AUTHOR]

The potential use of chitosan films as a replacement to synthetic polymers in food packaging applications is receiving remarkable attention due to their biodegradability and antimicrobial properties. This study presents the preparation of composite films from chitosan as polymeric matrices, and rice straw and nano rice straw fibres as reinforcements. The films were produced via wet mixing and casting techniques with various reinforcement contents (25–35 wt%). The aim of this research is to investigate the physical, mechanical, chemical, and thermal properties of the synthesized composite films and determine their feasibility for use in food packaging. The synthesized composite films will degrade by the time food is consumed leaving zero waste. Experimental results showed that rice straw fibres and nano-rice straw fibres enhanced the yield strength, fracture strength, and Young's modulus in comparison to the unreinforced material, and with reference to Egyptian plastic bags material. Thermal degradation temperature of the chitosan was improved by adding rice straw and nano rice straw compared to chitosan composites, which indicates that the composite thin films can perhaps compete with current thermoplastic synthetic polymers fabricated by melting techniques and serve as an alternative for synthetic plastics. The use of a local (shrimp and rice straw) waste as the source for biodegradable bags, turns food waste problem to being part of the solution of synthetic plastic waste. [ABSTRACT FROM AUTHOR]

Luffa cylindrica M. Roem, is commonly called sponge gourd or Egyptian cucumber. In September 2018, several plants showing symptoms of powdery mildew were observed in some fields at different locations in Egypt. Identification and pathogenicity tests indicated that the causal fungus of powdery mildew disease of luffa cylindrica was Podosphaera xanthii. Results of surveyed luffa plants grown at different field localities of northern Egypt, for powdery mildew disease incidence revealed that the maximum record (57.33%) of disease occurrence was recorded in some fields belonging to Beheira governorate followed by, Alexandria and Sharqia (53.67% and 48.00%, respectively). Meanwhile, fewer occurrences were observed in Kafer El-Sheekh governorate (45.33%). We applied biocontrol agents as a foliar spray against powdery mildew in vitro and under field conditions. The effects of some essential oils, organic acid and bioproducts were also studied. All treatments significantly reduced P. xanthii compared to untreated plants. Chaetomium globosum and Saccharomyces cerevisiae alone or grown on rice straw and/or bagas showed highly reduced disease incidence compared to the other treatment. From the present study it could be suggested that the usage of biocontrol formulated on rice straw might be used as an easily applied, safe and cost effective control method against powdery mildew diseases. [ABSTRACT FROM AUTHOR]

Governance of innovation needs to cater in a democratic way for heterogeneity of knowledges. Many initiatives in the democratisation of innovation aspire to some sort of consensus among relevant actors. However, consensus tends to silence dissenting voices, typically those of marginalised groups. In situations of high epistemic and epistemological diversity, this problem can be expected to aggravate. Against consensus-seeking theories of deliberative democracy, Chantal Mouffe has proposed the aspiration to grant the possibility of contestation. While one central principle in many theories of democracy is that it should never silence dissenting or minority positions, Mouffe elevates contestation, rather than the pursuit of consensus, to be the linchpin of democracy. I will explore what a contestation-oriented view of democratisation could mean in the case of governing innovation, specifically in the case of biogasification of rice straw. The latter is commonly presented as a potentially beneficial use of rice straw, which is currently considered waste and (illegally) burned by farmers on the Indian countryside. However, our research has shown that this view indeed unduly suppresses valuable yet marginalised knowledges. Lessons for frameworks such as Responsible Research and Innovation, and particularly an alternative to the dominant aim of democratising innovation through deliberation, will be drawn. [ABSTRACT FROM AUTHOR]

This article aims to reflect on the role of Science, Technology and Society (STS) research(ers) in co-constructing Responsible Research and Innovation (RRI) in the Global South. By reporting on RRI research in the Global South, here the Indo-Dutch NWO-MVI project on rice straw burning in Punjab, we make an argument for approaching RRI as a symmetric process of knowledge production mobilised by local actors and researchers alike. For STS researchers to responsibly engage with local innovation systems, their activities need to go beyond knowledge provision and towards facilitating the ownership and circulation of local meanings and means to responsibly innovate. Rather than understanding RRI as a fixed framework to govern innovation practices, this article reflects on RRI as an approach that combines research with intervention. We propose that following the principle of symmetry can turn RRI into a productive tool for the mobilisation of embedded local principles that can organise innovation systems in a responsible way. In particular, symmetry allows the re-location of meanings and practices of innovation as well as the re-negotiation of multiple notions of responsible governance. [ABSTRACT FROM AUTHOR]

This paper employs RRI's mandate of 'commitment to care' to understand the 'problem' of rice straw burning in India and the possible ways of engaging with it. Straw burning is often framed as a linear technology or policy deficit 'problem' in need of an immediate and quick fix. Interventions and solutions emerging from such framings have so far remained ineffective. The 'commitment to care' approach enables us to situate the current practices of straw burning in a complex web of relationalities, dependencies, vulnerabilities, and affect. By doing so, the 'problem' of straw burning is rearticulated and redefined as a cumulative effect of multiple interventions, transformations, and contradictions that led to the shaping of modern agricultural systems in India. This re-articulation demands for a rethinking of engagement, remedies and responsibilities in ways that move beyond the individualization of blame and action. [ABSTRACT FROM AUTHOR]

Neither cadmium (Cd) nor lead (Pb) is necessary for crop growth, but they both can accumulate in soil and crop tissues, resulting in land degradation and crop reduction. Few researchers have explored how to detect Cd–Pb co-accumulation in leaves using proximal sensing techniques, especially by low-cost, easy-to-use leaf clips that capture hyperspectral reflections at suitable foliar positions. In this study, a hyperspectral imager was employed to collect images of the rice canopy from a designed greenhouse experiment that included 16 pretreatments of Cd–Pb co-accumulation, followed by spectral extractions from 3 foliar positions: the blade root, the middle of the leaf, and the leaf apex. A support vector machine with leave-one-out cross-validation was performed to diagnose the contaminative levels based on the feature wavelengths selected by an improved successive projection algorithm. Partial least squares regression was used to predict Cd–Pb concentrations in rice blades. The results indicated that diagnostic accuracies were varied using spectra of different foliar positions. The blade root and leaf apex of rice blades were the optimal foliar position for detecting Cd and Pb contamination, respectively. At the optimal foliar positions, diagnostic accuracies exceeded 0.80 for distinguishing whether the rice is subject to Cd–Pb contamination. The Cd prediction performed 'very good' with a residual prediction deviation (RPD) of 2.21, a R2 of 0.79, and a root mean square error (RMSE)of 6.14, while that of Pb was 1.62, 0.61, and 186.54. Important wavelengths were identified at 659–694 nm and 667–694 nm to detect Cd and Pb contamination. In summary, our results verified the feasibility and clarified the optimal foliar positions of rice blades to detect Cd–Pb contamination. The wavelengths selecting have the great potential in the design of future leaf clips, and the optimal foliar position can provide suggestions to improve diagnostic performances in field applications. [Display omitted] • Hyperspectral images of rice canopy under Cd–Pb cross-contamination were measured. • Spectra of three foliar positions were extracted to detect Cd–Pb contamination. • The blade root and leaf apex of blades were the optimal detecting foliar position. • 659–694 nm and 667–694 nm have the potential in the design of future leaf clips. [ABSTRACT FROM AUTHOR]

Employing biochar for environmental remediation has been widely practiced. Nonetheless, the reduction mechanisms of hexavalent chromium (Cr(VI)) in the presence of biochar have not been fully elucidated (i.e., direct or indirect reduction of Cr(VI) by biochar). In particular, the effect of light on Cr(VI) reduction by biochar was rarely reported. Thus, to clarify the reduction mechanisms of Cr(VI) by biochar at the fundamental level, this study laid great emphasis on the photo-induced reduction of Cr(VI) in the application of biochar. Biochar releases dissolved organic matter (DOM), the DOM can extract Fe(III) from soil by complexation, and the complexes can be photo-reacted under the light. In these respects, Fe(II) formed by the photo-induced reaction of DOM-Fe(III) was particularly evaluated in this study. To evaluate that, three biomass samples (rice straw, granular sludge from an up-flow anaerobic sludge blanket, and spent coffee ground) were torrefied to biochar. To circumvent the adsorption of Cr(VI) onto biochar, biochar extractives (served as a source for DOM) and Fe(III) solution were tested with/without UV light to prove Fe(II) formation. This study experimentally proved that the more Fe(II) under the UV radiation was formed in the co-existence with biochar extractives and Fe(III). All experimental data from three biochar samples were indeed very similar. Cr(VI) reduction by Fe(II) from GB, RB, and CB reached up to 96, 79, and 100%, respectively. The different reduction efficiency signified that the low molecular weight of organic acids, such as oxalate, were more sensitive to the UV light, thereby resulting in the enhanced Fe(II) formation. Such Fe(II) formation subsequently led to the high reduction efficiency of Cr(VI). Image 1 • Biochar application increases significantly the reduction of Cr(VI) under the light condition. • A reductant Fe(II) was transformed via photoreaction of DOM-Fe (III) complexes. • Photo-induced indirect reduction is a major mechanism of Cr(VI) reduction by biochar. The indirect photo-reduction is more important mechanisms for the reduction of Cr(VI) by biochar and the mechanism is faster than the direct reduction via electron donation. [ABSTRACT FROM AUTHOR]

In two field experiments, the effect of some weed control treatments (citric acid at the rate of 10, 15 and 20%, acetic acid at the rate of 20, 30 and 40%, oxadiargyl, oxyflurfen, rice straw mulch, hand hoeing and an unweeded check control treatment) on weed growth and onion productivity in sandy soils at the Agricultural Experimental Station of the National Research Centre, Egypt was studied. The results indicated that all weeded treatments reduced the dry weight of broadleaf, grassy and total weeds as compared with the weedy check. Oxadiargyl, followed by two hand hoeing, rice straw mulch and acetic acid 40% recorded the greatest weed control efficiency. Insignificant differences were noticed between these treatments. Applying rice straw mulch increased bulb length, bulb diameter, bulb weight and onion yield by 67.52, 57.55, 45.74 and 66.22% over the weedy check, respectively. The highest values of N, P and K were obtained from rice straw mulch treatment followed by hand hoeing, oxadiargyl and acetic acid 40% treatments. It may be concluded that farmers can certainly depend on mulching or acetic acid at 40% instead of using chemical herbicides especially in organic farm systems for controlling onion weeds. [ABSTRACT FROM AUTHOR]

Proper management of waste crop residues has been an environmental concern for years. Yellow mealworms (larvae of Tenebrio molitor Linnaeus, 1758) are major insect protein source. In comparison with normal feed wheat bran (WB), we tested five common lignocellulose-rich crop residues as feedstock to rear mealworms, including wheat straw (WS), rice straw (RS), rice bran (RB), rice husk (RH), and corn straw (CS). We then used egested frass for the production of biochar in order to achieve clean production. Except for WS and RH, the crop residues supported mealworms' life activity and growth with consumption of the residues by 90% or higher and degraded lignin, hemicellulose and cellulose over 32 day period. The sequence of degradability of the feedstocks is RS > RB > CS > WS > RH. Egested frass was converted to biochar which was tested for metal removal including Pb(II), Cd(II), Cu(II), Zn(II), and Cr(VI). Biochar via pyrolysis at 600 °C from RS fed frass (FRSBC) showed the best adsorption performance. The adsorption isotherm fits the Langmuir model, and kinetic analysis fits the Pseudo-Second Order Reaction. The heavy metal adsorption process was well-described using the Intra-Particle Diffusion model. Complexation, cation exchange, precipitation, reduction, deposition, and chelation dominated the adsorption of the metals onto FRSBC. The results indicated that crop residues (WS, RS, RB, and CS) can be utilized as supplementary feedstock along with biochar generated from egested frass to rear mealworms and achieve clean production while generating high-quality bioadsorbent for environment remediation and soil conditioning. Image 1 • Clean production study with 5 crop residues as feedstock of mealworms for insect biomass production. • The sequence of selection of feedstock was rice straw > corn straw > wheat straw based on consumption rates. • Mealworms ate more than 93% of rice straw and digested 49.78% lignin. • Biochars generated from mealworm frass adsorbed heavy metal ions effectively. • Biochar from rice straw frass showed best adsorption capacity and mechanisms were investigated. This research describes a novel clean production approach that agricultural waste residues (wheat straw, rice straw, rice bran, rice husk and corn straw) were used as feedstock to grow mealworms for insect biomass production; biochar was generated using mealworm frass; rice straw was the best feedstock tested based on digestibility and the frass derived showed optimal adsorption performance for heavy metal removal; and adsorption mechanisms were characterized. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of increasing the proportion of concentrate in the diet on the rumen pH and bacterial community in Japanese Black beef cattle at different fattening stages. Six rumen-cannulated beef cattle were studied in the middle (Mid group, n=3, age 21-22 months) and late (Late group, n=3, age 31 months) fattening stages. The cattle were fed rice straw with control (CON period) or high-concentrate (HC period) diets for 14 consecutive days in each period. Rumen pH was measured continuously and the rumen fluids were collected on the last day of each period. The 24-hr mean and minimum rumen pH in the Mid group were significantly (P<0.05) lower during the HC period compared with the CON period, whereas those in the Late group were continuously low during both periods. In the Late group, the ruminal volatile fatty acid and lactic acid concentrations were significantly (P<0.05) higher during the HC period. During the HC period, the proportions of Prevotella and Caloramator were significantly (P<0.05) higher and lower, respectively, in the Mid group. From these findings, significant changes in the rumen pH and bacterial community induced by dietary changes were mainly observed in the Mid group. Therefore, the ruminal fermentative function in response to a higher concentrate diet might adapt differently in Japanese Black beef cattle at the two different fattening stages. [ABSTRACT FROM AUTHOR]

To better understand the Sb phytoavailability in rice, we studied Sb accumulation in rice (Zhongjiazao-17, widely cultivated in Hunan province) at different growth stages based on adding SbIII and SbV to waterlogged soils in 10, 50 and 100 mg kg−1 treatment levels. Proportional exogenous SbIII and SbV remained in the soil solution after equilibration. In SbIII treatments, the iron plaque (IP) amounts and Sb in rice roots sharply increased from tillering to jointing stages and then reduced at the following stages. However, in SbV treatments, they increased continuously from tillering to maturing stages. The accumulation trends of Sb in straws, ears and grains were consistent in SbIII and SbV treatments, rising from tillering to jointing stages followed with reducing from jointing to flowering stages slightly, and rising again significantly from flowering to maturing stages. The Tfsoil-grain values in all the Sb treatments were low (0.77 × 10−3-5.1 × 10−3), However, when Sb in waterlogged soils were higher than 50 mg kg−1, it could pose human health risk for residents. Image 1 • Jointing stage is critical for Sb uptake in SbIII treatment. • Flowering stage is critical for Sb uptake in SbV treatment. • Rice straw accumulated the highest concentration of Sb at maturing stage. • Transfer ability of Sb decreased with increasing Sb treatment level. • More than 50 mg kg−1 of Sb in soils is risky for residents. Proportional of SbIII and SbV still remained in soil solutions; The Sb accumulation trends at different rice growth stages were various. [ABSTRACT FROM AUTHOR]

For the soil-plant ecosystem, knowledge about the effects of biochars on the soil silicon (Si) cycle is still tenuous. In this study, the effect of biochars on the yield, Si uptake and Si distribution within different tissues of rice plants and the soil Si cycles in a soil-plant system were investigated. Si-rich (RH300-700) and Si-deficient (WB300-700) biochars prepared from rice husk and wood sawdust were applied to high-Si soil (HSS) and low-Si soil (LSS). Biochar addition increased the yield of grain and straw and had no effect on the yield of root, and the increase in the yield with Si-rich biochars was obvious; this effect had a high response to LSS. Si-rich biochars increased the plant Si content of grain and root and had no effect on straw. RH300 amendment increased the Si concentration in grains, compared to RH500 and RH700. The addition of Si-deficient biochar to HSS had little effect on the Si content, while Si-deficient biochar-amended LSS had a great impact on the reduced Si content in rice straw and root, and WB700 decreased the Si concentration in grains, compared to WB300 and WB500. Finally, the Si-rich biochars increased the total Si uptake within rice, while Si-deficient biochars decreased the total Si uptake in LSS. According to the FTIR and SEM-EDX spectra of biochars before and after rice harvest, a new band of Si O Si at 471 cm−1 was found after aged WB700, and the minerals of iron and Si were found on the surface of aged WB700; biochars can fix the dissolved Si on its surface as a temporary store to prevent Si loss. Therefore, biochars can be considered reservoirs of soil Si, which is a slow release source of available Si, to impact the speed of biogeochemical cycling of soil Si in agricultural paddy soil. Image 1 • Si-rich biochar additions increased the Si content in rice grain and roots. • Si-rich biochar amendments promoted the total Si uptake by rice plants. • Si-deficient biochar decreased the total Si uptake of rice in low-silicon soil. • Biochars are adsorbents that can fix the dissolved Si on its surface as a reservoir. • Si biocycling in soil–plant systems can be readily affected by biochar aging. Si-rich biochar additions increased the Si content in rice grain and roots, and promoted the total Si uptake by rice plants, but Si-deficient biochar decreased the total Si uptake of rice in low-silicon soil. [ABSTRACT FROM AUTHOR]

Abstract A 90 day experiment was conducted in the laboratory to investigate the potential effects of transgenic Cry1Ab - expressing rice (Bacillus thuringiensis (Bt) rice: T775 and its F1 hybrid) straw return on earthworm Eisenia fetida , compared to non-Bt rice (TYHZ) straw. Juvenile E. fetida could survive, grow up, mature and reproduce offspring well in a Bt rice treated test during the whole experiment. The significantly higher relative growth rate (RGR) was found in earthworms from Bt rice treatment than from non-Bt rice treatment on the 7th day. The period of sexual maturity for earthworms from Bt rice treatments was shortened significantly, compared to non-Bt rice treatments. Adult E. fetida survived with weight loss under Bt rice treatments. On the 7th and 15th day, earthworm RGR decreased and glutathione peroxidase (GSH-PX) activity increased under Bt rice straw treatments. Significantly fewer offspring were produced by earthworms from Bt rice than non-Bt rice treatments on the 60th and 75th day. Enzyme-linked immunosorbent assay (ELISA) determined a sharp decrease of Cry1Ab in straw mixed soil along with the experimental time, regardless of juvenile or adult earthworm treatments. Cry1Ab concentration in the earthworms from the juvenile group was significantly higher than those from the adult group. Bt rice straw return had significant effects on soil nutrients, especially on the content of total and available phosphorus. In view of two bioassays, Bt rice (T775 and its F1 hybrid) straw return presented different effects on E. fetida from the juvenile (no deleterious effect) and adult (a little negative effect) groups, that were not directly related to Cry1Ab presence and nutrient differences among the three rice variety treatments. Highlights • Bt rice straw return had no deleterious effects on juvenile E. fetida. • Bt rice straw return had a little negative effects on adult E. fetida. • Higher GSH-PX activity was found in Bt rice treated E. fetida in short time. • Different effect was not directly caused by Cry1Ab presence in earthworm. • Different effect was not caused by nutrient differences among rice hybrids. [ABSTRACT FROM AUTHOR]

Abstract Co-pyrolysis technology gain much popularity in recent years compared to other thermochemical conversion techniques due to its environmental and socio-economic advantages. The present study focuses on the liquid fuel production through co-pyrolysis of polythene waste and rice straw in varying composition and characterization of the liquid products. The laboratory scale co-pyrolysis experiments have been carried out in a fixed bed LPG heating reactor under temperature between 4000-500 0C to obtain maximum liquid yield. The feed sizes were 20mm × 20mm for polythene and 15mm × 5mm for rice straw and they were mixed in different proportions. The liquid and char products were collected separately while the gas was flared into atmosphere. The maximum liquid yield was 61 wt. % for mixture ratio 1:1 at a temperature of 430 0C while the minimum liquid yield was 40 wt. % for mixture ratio 1:4 at a temperature of 500 0C. On the other hand, about 80 wt. % and 35 wt.% liquid were produced for individual feed of polythene and rice straw, respectively. It has also observed that the liquid yield decreases with increasing amount of rice straw in the mixture. The liquid products possess favorable fuel properties: density, viscosity, pour point, flash point and calorific value to be used as alternative fuel. [ABSTRACT FROM AUTHOR]

The primary objective of this study was to evaluate how chemical pretreatment may affect the ability of biochar to adsorb hexavalent chromate [Cr(VI)]. Rice straw biochars produced at three different pyrolytic temperatures (300 °C, 500 °C and 700 °C) were treated with 0.5 mol L−1 hydrochloric acid (A), 0.5 mol L−1 sodium hydroxide (B); deionized water (C); or ethanol (E) and the changes in surface properties and chemical composition were then determined. The results showed that the elemental composition, functional groups and point zero charge (PZC) of the biochars were all affected by the pyrolytic temperatures and chemical pretreatment methods. Chemical pretreatment dramatically altered the adsorption of Cr(VI), as shown by the trend in Kd (the partition coefficient): 300B > 300A > 300E ≈ 300W, 500A > 500B ≈ 500E ≈ 500W and 700A > 700B > 700E ≈ 700W (number before the letter indicates the pyrolytic temperature). NaOH treatment exerted the greatest effect on the biochar produced at 300 °C, resulting in 300B having the highest PZC and rich in aromatic CO‒ and phenolic ‒OH groups, and hence the strongest capacity for Cr(VI) adsorption under slightly acidic condition. The ash content of the biochar was greatly reduced by HCl treatment, giving rise to reduced PZC and the protonation of functional groups. Thus, all the acid-pretreated biochars (300A, 500A and 700A) yielded the best Cr sorption capacity, with over 90% of the total Cr removed by the acid-treated biochar at pH 2. Both ethanol- and water treatment had little effect on the ability of the biochar to adsorb Cr. The results of Cr K-Edge X-ray absorption Near-Edge Spectroscopy (XANES) revealed Cr(III) as the dominant species adsorbed to the biochars, suggesting that the adsorption of Cr(VI) occurred partly through reduction of Cr(VI) to Cr(III) as well as via anionic adsorption. The finding of this study demonstrated that pretreatment could markedly alter the Cr sorption ability of rice straw-derived biochar, a phenomenon that could have practical application in the remediation of Cr-polluted water. Biochar's sorption ability was determined by pretreatment methods. NaOH pretreatment increased biochar's sorption capacity for Cr(VI). All the acid-pretreated biochars gave similar sorption capacity. Acid-pretreated biochar removed more than 90% of total Cr at pH 2. Cr(VI) adsorption mechanisms involved Cr(VI) reduction and anionic adsorption. [ABSTRACT FROM AUTHOR]

Abstract The transgenic rice line T1C-19 provides high resistance to lepidopteran pests because of the synthesis of the Bacillus thuringiensis (Bt) insecticidal protein Cry1C. It thus shows good prospect for commercial planting in China. Species of Cladocera, an order of aquatic arthropods commonly found in aquatic ecosystems such as rice paddies, might be exposed to the insecticidal protein released from Bt -transgenic rice-straw residues. For the study reported herein, we used Daphnia magna (water flea) as a representative of Cladocera to evaluate whether aquatic arthropods are adversely affected when exposed to Bt rice-straw leachates. We exposed D. magna to M4 medium containing various volume percentages of medium that had been incubated with T1C-19 rice straw or rice straw from its non-transformed near-isoline Minghui 63 (MH63) for 21 days. Compared with pure M4 medium (control), the fitness and developmental and reproduction parameters of D. magna decreased significantly when exposed to rice-straw leachates; conversely, no significant differences between the T1C-19 and MH63 rice-straw leachate treatments were observed, indicating that the Bt rice straw leachate did not adversely affect this non-target species. Highlights • Rice-straw leachate affects water quality and different life-table parameters of Daphnia magna. • D. magna is not affected by rice-straw leachate from Bt rice expressing Cry1C when compared to its corresponding non-Bt rice. • Catalase activity in D. magna exposed to rice-straw leachate was significantly higher than that of blank control. [ABSTRACT FROM AUTHOR]

Abstract This study aimed to investigate the effects of rice straw biochar and lime (RBL) on the remediation of lead (Pb)-contaminated soil and mitigation of Pb translocation in rice plants by using pot experiments. Lead-contaminated soil collected from a farmland near a Pb-zinc (Zn) mine, biochar, limestone powder, and indica rice (Oryza sativa L.) were used in the present study. The experimental treatments included: (1) control (CK), (2) 2.5% biochar (RB1), (3) 5% biochar (RB2), (4) 0.6% lime (L1), (5) 1.2% lime (L2), (6) 2.5% biochar + 0.6% lime (RBL1), and (7) 2.5% biochar + 1.2% lime (RBL2). The results revealed that the treatment with RBL was more efficient than the treatment with only biochar or lime in decreasing CaCl 2 -extractable Pb content in the soil by increasing soil pH and soluble sulfate content in the soil. Treatment with RBL reduced in the accumulation of Pb in the shoot of rice plants, this was mainly attributed to the decrease in the concentration of available Pb in the soil. The RBL2 treatment not only decreased the concentration of Pb in brown rice by 84.33% and Pb distribution in rice embryo, but also increased rice yield by 53.38% from that of the control. Further, unlike biochar treatment, RBL and lime treatments decreased the translocation of Pb in rice plants. The RBL treatment increased the proportion of Pb distributed in the cell wall and reduced the mobility of Pb in plant tissues. Thus, application of biochar and lime in combination is more effective than their individual application in reducing the availability of Pb in the soil and Pb accumulation in brown rice. Graphical abstract fx1 Highlights • RBL increased the soil pH and soluble SO 4 2- more effectively than biochar or lime applied in isolation. • RBL decreased CaCl 2 -extractable soil Pb more effectively than biochar or lime applied in isolation. • RBL decreased Pb content in brown rice more effectively than biochar or lime applied in isolation. [ABSTRACT FROM AUTHOR]

Abstract Due to the large area of Cd-contaminated paddy soils worldwide, low-cost measures to reduce the accumulation of Cd in rice plant are necessary. A field experiment was therefore conducted to investigate the reducing effect of lime combined with foliar applications of Zn (ZnSO 4) or Fe (EDTA·Na 2 Fe) on Cd concentrations in brown rice on a Cd-contaminated paddy soil. The results indicated that liming alone or in combination with foliar sprays of Zn or Fe increased the soil pH by 0.27–0.63 units. However, limited effects of lime or lime combined with foliar applications of Zn/Fe on soil DTPA-extractable Cd, rice grain and rice straw biomass were observed. Liming alone significantly reduced the Cd concentration in brown rice and rice straw by 31.8% and 42.3%, respectively. The Cd concentrations in brown rice decreased by 25.5% and 65.4% and in rice straw by 53.0% and 68.1% after liming combined with foliar applications of Fe and Zn, respectively. In contrast, liming combined with foliar spraying of Fe significantly increased the transfer ratio of Cd from the rice straw to the grain. As a low-cost technique, lime application combined with foliar application of ZnSO 4 could be recommended for the remediation of Cd-contaminated paddy soils. Graphical abstract fx1 Highlights • Lime application reduced the concentrations of Cd in brown rice grain and straw. • Additional Zn spraying enhanced the reduction effect of Cd in rice after lime application. • Foliar application of Fe increased the transfer ratio of Cd from rice straw to the grain. • Liming + spraying Zn could be recommended for Cd-contaminated paddy soils. [ABSTRACT FROM AUTHOR]

Abstract Rice straw is valuable resource that has been used as substrate for cost effective production of xylanase under solid-state fermentation by a newly isolated white rot fungi, S. commune ARC-11. Out of eleven carbon sources tested, rice straw was found most effective for the induction of xylanase that produced 4288.3 IU/gds of xylanase by S. commune ARC-11. Maximum xylanase production (6721.9 IU/gds) was observed on 8th day of incubation at temperature (30 °C), initial pH (7.0) and initial moisture content (70.0%). The supplementation of ammonium sulphate (0.08% N, as available nitrogen) enhanced the xylanase production up to 8591.4 IU/gds. The xylanase production by S. commune ARC-11 was further improved by the addition of 0.10%, (w/v) of Tween-20 as surfactant. The maximum xylanase activities were found at pH 5.0 and temperature 55 °C with a longer stability (180 min) at temperature 45, 50 and 55 °C. This xylanase preparation was also evaluated for the pre-bleaching of ethanol-soda pulp from Eulaliopsis binata. An enzyme dosage of 10 IU/g of xylanase resulted maximum decrease in kappa number (14.51%) with a maximum improvement 2.9% in ISO brightness compared to control. [ABSTRACT FROM AUTHOR]

Abstract Cobalt contamination in wastewater from industries has been increased in many countries including Egypt. Adsorption is the most progressively for heavy metals, removing from wastewater by using agricultural waste and by-products such as rice straw. Unmodified and modified rice straw has been evaluated as their ability to bind with metal ions. In this study, four characterizations of raw rice straw have been conducted. The morphological characteristics by SEM, EDXA, and the functional group present in the rice straw by FTIR spectroscopy and the XRD technique. Rice straw contains about OH functional group that can bind with metal ions. To be able to enhance the sorption capacity of rice straw in metals, removing from waste water, alkali treatment should be done. This shows that rice straw can be used as adsorbent for removing cobalt ions from wastewater. The effect of pH, amount of adsorbent, different concentrations of cobalt, sorption kinetics and isotherms were studied in batch experiments. The good correlation coefficient was obtained from pseudo second-order kinetic model, which agreed with conception as the rate-limiting mechanism. Sorption isotherm test showed that equilibrium sorption data were better represented by Langmuir model than the Freundlich model. The thermodynamic parameters such as Δ H , Δ S , Δ G and E a are also calculated. [ABSTRACT FROM AUTHOR]