Salt stress amelioration and nutrient strengthening in spinach (Spinacia oleracea L.) via biochar amendment and zinc fortification: seed priming versus foliar application.

Soil salinity is a major nutritional challenge with poor agriculture production characterized by high sodium (Na+) ions in the soil. Zinc oxide nanoparticles (ZnO NPs) and biochar have received attention as a sustainable strategy to reduce biotic and abiotic stress. However, there is a lack of information regarding the incorporation of ZnO NPs with biochar to ameliorate the salinity stress (0, 50,100 mM). Therefore, the current study aimed to investigate the potentials of ZnO NPs application (priming and foliar) alone and with a combination of biochar on the growth and nutrient availability of spinach plants under salinity stress. Results demonstrated that salinity stress at a higher rate (100 mM) showed maximum growth retardation by inducing oxidative stress, resulted in reduced photosynthetic rate and nutrient availability. ZnO NPs (priming and foliar) alone enhanced growth, chlorophyll contents and gas exchange parameters by improving the antioxidant enzymes activity of spinach under salinity stress. While, a significant and more pronounced effect was observed at combined treatments of ZnO NPs with biochar amendment. More importantly, ZnO NPs foliar application with biochar significantly reduced the Na+ contents in root 57.69%, and leaves 61.27% of spinach as compared to the respective control. Furthermore, higher nutrient contents were also found at the combined treatment of ZnO NPs foliar application with biochar. Overall, ZnO NPs combined application with biochar proved to be an efficient and sustainable strategy to alleviate salinity stress and improve crop nutritional quality under salinity stress. We inferred that ZnO NPs foliar application with a combination of biochar is more effectual in improving crop nutritional status and salinity mitigation than priming treatments with a combination of biochar.

Elucidating the role of rice straw biochar in modulating Helianthus annuus L. antioxidants, secondary metabolites and soil post-harvest characteristics in different types of microplastics.

The emergence of microplastics (MPs) as pollutants in agricultural soils is increasingly alarming, presenting significant threats to soil ecosystems. Given the widespread contamination of ecosystems by various types of MPs, including polystyrene (PS), polyvinyl chloride (PVC), and polyethylene (PE), it is crucial to understand their effects on agricultural productivity. The present study was conducted to investigate the effects of different types of MPs (PS, PVC, and PE) on various aspects of sunflower (Helianthus annuus L.) growth with the addition of rice straw biochar (RSB). This study aimed to examine plant growth and biomass, photosynthetic pigments and gas exchange characteristics, oxidative stress indicators, and the response of various antioxidants (enzymatic and non-enzymatic) and their specific gene expression, proline metabolism, the AsA-GSH cycle, cellular fractionation in the plants and post-harvest soil properties. The research outcomes indicated that elevated levels of different types of MPs in the soil notably reduced plant growth and biomass, photosynthetic pigments, and gas exchange attributes. Different types of MPs also induced oxidative stress, which caused an increase in various enzymatic and non-enzymatic antioxidant compounds, gene expression and sugar content; notably, a significant increase in proline metabolism, AsA-GSH cycle, and pigmentation of cellular components was also observed. Favorably, the addition of RSB significantly increased plant growth and biomass, gas exchange characteristics, enzymatic and non-enzymatic compounds, and relevant gene expression while decreasing oxidative stress. In addition, RSB amendment decreased proline metabolism and AsA-GSH cycle in H. annuus plants, thereby enhancing cellular fractionation and improving post-harvest soil properties. These results open new avenues for sustainable agriculture practices and show great potential for resolving the urgent issues caused by microplastic contamination in agricultural soils.

Rhizophagus irregularis and biochar can synergistically improve the physiological characteristics of saline-alkali resistance of switchgrass.

Inoculation of arbuscular mycorrhizal fungi (AMF) or biochar (BC) application can improve photosynthesis and promote plant growth under saline-alkali stress. However, little is known about the effects of the two combined on growth and physiological characteristics of switchgrass under saline-alkali stress. This study examined the effects of four treatments: (1) no AMF inoculation and no biochar addition (control), (2) biochar (BC) alone, (3) AMF (Rhizophagus irregularis, Ri) alone, and (4) the combination of both (BC+Ri) on the plant biomass, antioxidant enzymes, chlorophyll, and photosynthetic parameters of switchgrass under saline-alkali stress. The results showed that the above-ground, belowground and total biomass of switchgrass in the BC+Ri treatment group was significantly higher (+136.7%, 120.2% and 132.4%, respectively) than in other treatments compared with Control. BC+Ri treatment significantly increased plant leaves' relative chlorophyll content, antioxidant enzyme activity, and photosynthesis parameters. It is worth noting that the transpiration rate, stomatal conductance, net photosynthetic rate, PSII efficiency and other photosynthetic-related indexes of the BC+Ri treatment group were the highest (38% to 54% higher than other treatments). The fitting results of light response and CO2 response curves showed that the light saturation point, light compensation point, maximum carboxylation rate and maximum electron transfer rate of switchgrass in the Ri+BC treatment group were the highest. In conclusion, biochar combined with Ri has potential beneficial effects on promoting switchgrass growth under saline-alkali stress and improving the activity of antioxidant enzymes and photosynthetic characteristics of plants.

Biochar effect on sheep feed intake, growth rate and ruminant in vitro and in vivo methane production.

Biochar, which is the product of biomass pyrolysis, has been suggested as a feed supplement to improve performance in livestock systems and reduce greenhouse gas emissions. The aim of the current study was to investigate in vitro and in vivo potential of biochar to favourably modify rumen fermentation (e.g., an increase in total Short Chained Fatty Acid (SCFA) concentration and a change in SCFA profile), reduce methane emission and increase sheep growth performance. Four concentrates were produced with biochar inclusion of 0, 10, 23 and 46 g/kg DM. The experimental diets for the in vitro experiments consisted of straw and concentrate in a 60:40 ratio and included measurements of total gas and methane (CH4) production, pH, ammonia nitrogen, SCFA, and microbial assays (total bacteria and methanogenic archaea). Two in vivo experiments were performed where the animals received ad libitum forage with 0.4 kg concentrate daily. Experiment 1 investigated the daily DM intake of sheep while experiment 2 investigated daily growth rate and CH4 emission of lambs. The inclusion of biochar had no impact on in vitro total gas production (ml/200 mg DM substrate) (P = 0.81) and CH4 production (ml/200 mg DM substrate) (P = 0.93). In vitro total SCFA concentration increased (P < 0.05) while acetate to propionate ratio (A:P) tended to decrease (P = 0.05) with both doses of biochar. Total bacteria decreased with the highest biochar inclusion in vitro (P < 0.05). Sheep's DM intake (kg/d) increased when low and medium levels but not when a higher level of biochar was added to the diet (P < 0.001). The inclusion of biochar did not significantly impact the lamb's daily growth rate (g/d) (P = 0.61) or enteric CH4 emissions (g/kg DM) (P = 0.43). We conclude that biochar supplementation had no favourable impacts on in vitro and in vivo CH4 production or on lamb's growth rate. Further research with well-characterised biochar is needed to gain a better understanding of the potential of biochar as a feed additive for ruminant livestock.

Effects of biochar types on seed germination, growth, chlorophyll contents, grain yield, sodium, and potassium uptake by wheat (Triticum aestivum L.) under salt stress.

Soil salinity is a significant challenge in agriculture, particularly in arid and semi-arid regions such as Pakistan, leading to soil degradation and reduced crop yields. The present study assessed the impact of different salinity levels (0, 25, and 50 mmol NaCl) and biochar treatments (control, wheat-straw biochar, rice-husk biochar, and sawdust biochar applied @ 1% w/w) on the germination and growth performance of wheat. Two experiments: a germination study and a pot experiment (grown up to maturity), were performed. The results showed that NaCl-stress negatively impacted the germination parameters, grain, and straw yield, and agronomic and soil parameters. Biochar treatments restored these parameters compared to control (no biochar), but the effects were inconsistent across NaCl levels. Among the different biochars, wheat-straw biochar performed better than rice-husk and sawdust-derived biochar regarding germination and agronomic parameters. Biochar application notably increased soil pHs and electrical conductivity (ECe). Imposing NaCl stress reduced K concentrations in the wheat shoot and grains with concomitant higher Na concentrations in both parts. Parameters like foliar chlorophyll content (a, b, and total), stomatal and sub-stomatal conductance, and transpiration rate were also positively influenced by biochar addition. The study confirmed that biochar, particularly wheat-straw biochar, effectively mitigated the adverse effects of soil salinity, enhancing both soil quality and wheat growth. The study highlighted that biochar application can minimize the negative effects of salinity stress on wheat. Specifically, the types and dosages of biochar have to be optimized for different salinity levels under field conditions.

Agricultural waste-based modified biochars differentially affected the soil properties, growth, and nutrient accumulation by maize (Zea mays L.) plants.

Biochar (BC) is an organic compound formed by the pyrolysis of organic wastes. Application of BCs as soil amendments has many benefits including carbon sequestration, enhanced soil fertility and sustainable agriculture production. In the present study, we acidified the different BCs prepared from rice straw, rice husk, wheat straw, cotton stalk, poultry manure, sugarcane press mud and vegetable waste; following which, we applied them in a series of pot experiments. Comparisons were made between acidified and non- acidified BCs for their effects on seed germination, soil properties (EC, pH) nutrient contents (P, K, Na) and organic matter. The treatments comprised of a control, and all above-described BCs (acidified as well as non-acidified) applied to soil at the rate of 1% (w/w). The maize crop was selected as a test crop. The results showed that acidified poultry manure BC significantly improved germination percentage, shoot length, and biomass of maize seedlings as compared to other BCs and their respective control plants. However, acidified BCs caused a significant decrease in nutrient contents (P, K, Na) of soil,maize seedlings, and the soil organic matter contents as compared to non- acidified BCs. But when compared with control treatments, all BCs treatments (acidified and non-acidified) delivered higher levels of nutrients and organic matter contents. It was concluded that none of the BCs (acidified and non-acidified) had caused negative effect on soil conditions and growth of maize. In addition, the acidification of BC prior to its application to alkaline soils might had altered soil chemistry and delivered better maize growth. Moving forward, more research is needed to understand the long-term effects of modified BCs on nutrient dynamics in different soils. In addition, the possible effects of BC application timings, application rates, particle size, and crop species have to be evaluated systemtically.

Bioanode boosts efficacy of chlorobenzenes-powered microbial fuel cell: Performance, kinetics, and mechanism.

Microbial fuel cell (MFC) is a promising device for water decontamination and energy generation. However, the correlation between power generation and pollutant degradation has not been clarified. Herein, a ruthenium-activated carbon (Ru-AC) bioanode was constructed for chlorobenzenes (CBs) treatment. The pollutant tolerance was improved by Ru-AC anode, and the minimum removal efficiencies of CB and ortho-dichlorobenzene (o-DCB) reached 75.1 % and 69.3 %, respectively, which were considerably higher than those of other MFCs (16.3 %-39.7 %). Correspondingly, the maximum output voltage reached 360.7 mV for the Ru-AC anode, whereas the values obtained from others reached 45.2-149.6 mV. Interaction models were introduced to quantify the relationship between power generation and pollutant degradation. The conversion of highly toxic chlorophenols to organic acids could be accelerated by boosting the mass and electron transfer, thereby simultaneously enhancing CBs removal and power generation. This work provided important insights into pollutant-powered MFC development.

Effectiveness of feeding different biochars on growth, digestibility, body composition, hematology and mineral status of the Nile tilapia, Oreochromis niloticus.

Oreochromis niloticus fingerlings (5.15 ± 0.02 g; n = 315) were fed with different types of biochar (BC)-supplemented sunflower meal-based (SFM) diet to investigate the effects of various BC inclusions on their nutritional digestibility, body composition, hematology and mineral status for 60 days. Seven different diets were formulated based on the SFM based diet: one was a control (TD-I, CON) and the other six diets were supplemented with 2% BC derived from different sources. These BCs were derived from the following: cotton stick (CSBC, TD-II), wheat straw (WSBC, TD-III), corn cob (CCBC, TD-IV), house waste (HWBC, TD-V), grass waste (GWBC, TD-VI), and green waste (GwBC, TD-VII) biochar. There were three replicates for each test diet. Each tank had fifteen tilapia fingerlings, and they were fed with 5% of their live wet weight and twice daily. The outcomes showed that the supplementation of CCBC significantly elevated the growth, nutrient absorption, and body composition of the O. niloticus fingerlings (p < 0.05); with concomitant lowering of the quantity of nutrients released into the water bodies whereas HWBC gave negative impacts. The maximal mineral absorption efficiency (Ca, Na, K, Cu, Fe, P, and Zn) was achieved by the supplementation of 2% CCBC. All hematological parameters showed positive improvements (p < 0.05) with CCBC. Interestingly, CCBC significantly improved the growth, digestibility, body composition, hematology, and mineral status of O. niloticus.

Fulvic acid enhancing pyrene biodegradation by immobilized Stenotrophomonas maltophilia: Effect and mechanism.

Immobilization technology is a promising way to improve effectiveness and stability of microbial remediation for polycyclic aromatic hydrocarbons (PAHs), in which carrier material is one of key factors restricting removal efficiency. In this study, fulvic acid-wheat straw biochar (FA/WS) composites were applied for immobilization of an efficient PAHs degrading bacterium Stenotrophomonas maltophilia (SPM). FA/WS&SPM showed superior degradation capacity than free bacteria and biochar-immobilized bacteria, with the removal efficiency of pyrene (20 mg L-1) reaching 90.5 % (7 days). Transcriptome analysis revealed that FA in the carrier materials can promote transportation and degradation of pyrene, and cell growth, as well as inhibit cell apoptosis. Enzyme activity and degradation products detection showed that SPM utilized both phthalic acid and salicylic acid metabolic pathways to degrade pyrene. Practicality of FA/WS&SPM for different kinds of PAHs remediation had been verified in contaminated soil, demonstrating a great potential in the field of PAHs polluted sites remediation.

The impact of biochar addition on morpho-physiological characteristics, yield and water use efficiency of tomato plants under drought and salinity stress.

The use of saline water under drought conditions is critical for sustainable agricultural development in arid regions. Biochar is used as a soil amendment to enhance soil properties such as water-holding capacity and the source of nutrition elements of plants. Thus, the research was carried out to assess the impact of biochar treatment on the morphological and physiological characteristics and production of Solanum lycopersicum in greenhouses exposed to drought and saline stresses. The study was structured as a three-factorial in split-split-plot design. There were 16 treatments across three variables: (i) water quality, with freshwater and saline water, with electrical conductivities of 0.9 and 2.4 dS m- 1, respectively; (ii) irrigation level, with 40%, 60%, 80%, and 100% of total evapotranspiration (ETC); (iii) and biochar application, with the addition of biochar at a 3% dosage by (w/w) (BC3%), and a control (BC0%). The findings demonstrated that salt and water deficiency hurt physiological, morphological, and yield characteristics. Conversely, the biochar addition enhanced all characteristics. Growth-related parameters, such as plant height, stem diameter, leaf area, and dry and wet weight, and leaf gas exchange attributes, such rate of transpiration and photosynthesis, conductivity, as well as leaf relative water content were decreased by drought and salt stresses, especially when the irrigation was 60% ETc or 40% ETc. The biochar addition resulted in a substantial enhancement in vegetative growth-related parameters, physiological characteristics, efficiency of water use, yield, as well as reduced proline levels. Tomato yield enhanced by 4%, 16%, 8%, and 3% when irrigation with freshwater at different levels of water deficit (100% ETc, 80% ETc, 60% ETc, and 40% ETc) than control (BC0%). Overall, the use of biochar (3%) combined with freshwater shows the potential to enhance morpho-physiological characteristics, support the development of tomato plants, and improve yield with higher WUE in semi-arid and arid areas.

Potential of amino acids-modified biochar in mitigating the soil Cu and Ni stresses - Targeting the tomato growth, physiology and fruit quality.

Trace heavy metals (HMs) such as copper (Cu) and nickel (Ni) are toxic to plants, especially tomato at high levels. In this study, biochar (BC) was treated with amino acids (AA) to enhance amino functional groups, which effectively alleviated the adverse effects of heavy metals (HMs) on tomato growth. Hence, this study aimed to evaluate the effect of glycine and alanine modified BC (GBC/ABC) on various tomato growth parameters, its physiology, fruit yield and Cu/Ni uptake under Cu and Ni stresses. In a pot experiment, there was 21 treatments with three replications having two rates of simple BC and glycine/alanine enriched BC (0.5% and 1% (w/w). Cu and Ni stresses were added at 150 mg kg-1 respectively. Plants were harvested after 120 days of sowing and subjected to various analysis. Under Cu and Ni stresses, tomato roots accumulated more Cu and Ni than shoots and fruits, while GBC and ABC application significantly enhanced the root and shoot dry weight irrelevant to the stress conditions. Both rates of GBC decreased the malondialdehyde and hydrogen peroxide levels in plants. The addition of 0.5% GBC with Cu enhanced the tomato fruit dry weight by 1.3 folds in comparison to the control treatment; while tomato fruit juice content also increased (50%) in the presence of 0.5% GBC with Ni as compared to control. In summary, these results demonstrated that lower rate of GBC∼0.5% proved to be the best in mitigating the Cu and Ni stress on tomato plant growth by enhancing the fruit production.

Effects of crayfish shell powder and bamboo-derived biochar on nitrogen conversion, bacterial community and nitrogen functional genes during pig manure composting.

This study investigated the effects of crayfish shell powder (CSP) and bamboo-derived biochar (BDB) on nitrogen metabolism, bacterial community and nitrogen functional genes during pig manure composting. Four treatments were established: CP (with no additives), TP1 (5 % BDB), TP2 (5 % CSP) and TP3 (2.5 % BDB + 2.5 % CSP). Compared to CP, the germination index (GI) of TP reached > 85 % 10 days earlier. Meanwhile, TP3 reduced NH3 and N2O emissions by 42.90 % and 65.9 %, respectively, while increased TN (total nitrogen) concentration by 5.43 g/kg. Furthermore, additives changed the bacterial structure and formed a beneficial symbiotic relationship with essential N-preserving bacteria, thereby enhancing nitrogen retention throughout the composting process. Metagenomic analysis revealed that additives upregulated nitrification genes and downregulated denitrification and nitrate reduction genes, ultimately improving nitrogen cycling and mitigating NH3 and N2O emissions. In conclusion, the results confirmed that TP3 was the most effective treatment in reducing nitrogen loss.

Simultaneous elimination of antibiotic-resistant bacteria and antibiotic resistance genes by different Fe-N co-doped biochars activating peroxymonosulfate: The key role of pyridine-N and Fe-N sites.

The coexistence of antibiotic resistance genes (ARGs) and antibiotic-resistant bacteria (ARB) in the environment poses a potential threat to public health. In our study, we have developed a novel advanced oxidation process for simultaneously removing ARGs and ARB by two types of iron and nitrogen-doped biochar derived from rice straw (FeN-RBC) and sludge (FeN-SBC). All viable ARB (approximately 108 CFU mL-1) was inactivated in the FeN-RBC/ peroxymonosulfate (PMS) system within 40 min and did not regrow after 48 h even in real water samples. Flow cytometry identified 96.7 % of dead cells in the FeN-RBC/PMS system, which verified the complete inactivation of ARB. Thorough disinfection of ARB was associated with the disruption of cell membranes and intracellular enzymes related to the antioxidant system. Whereas live bacteria (approximately 200 CFU mL-1) remained after FeN-SBC/PMS treatment. Intracellular and extracellular ARGs (tetA and tetB) were efficiently degraded in the FeN-RBC/PMS system. The production of active species, primarily •OH, SO4•- and Fe (IV), as well as electron transfer, were essential to the effective disinfection of FeN-RBC/PMS. In comparison with FeN-SBC, the better catalytic performance of FeN-RBC was mainly ascribed to its higher amount of pyridine-N and Fe0, and more reactive active sites (such as CO group and Fe-N sites). Density functional theory calculations indicated the greater adsorption energy and Bader charge, more stable Fe-O bond, more easily broken OO bond in FeN-RBC/PMS, which demonstrated the stronger electron transfer capacity between FeN-RBC and PMS. To encapsulate, our study provided an efficient and dependable method for the simultaneous elimination of ARGs and ARB in water.

Reverse electron transfer: Novel anaerobic methanogenesis pathway regulated through exogenous CO2 synergized with biochar.

Acid accumulation and carbon emission are two major challenges in anaerobic digestion. Syntrophic consortia can employ reverse electron transfer (RET) to facilitate thermodynamically unfavorable redox reactions during acetogenesis. However, the potential mechanisms and regulatory methods of RET remain unclear. This study examines the regulatory mechanisms by which exogenous CO2 affects RET and demonstrates that biochar maximizes CO2 solubility at 25.8 mmol/L to enhance effects further. CO2 synergized with biochar significantly increases cumulative methane production and propionate degradation rate. From the bioenergetic perspective, CO2 decreases energy level to a maximum of -87 kJ/mol, strengthening the thermodynamic viability. The underlying mechanism can be attributed to RET promotion, as indicated by increased formate dehydrogenase and enrichment of H2/formate-producing bacteria with their partner Methanospirillum hungatei. Moreover, the 5 % 13CH4 and methane contribution result show that CO2 accomplishes directed methanogenesis. Overall, this investigation riches the roles of CO2 and biochar in AD surrounding RET.

Powdered activated carbon facilitated degradation of complex organic compounds and tetracycline in stressed anaerobic digestion systems.

Tetracycline exerts an inhibitory effect on anaerobic digestion, inducing stressed microbial activities and even system failure. Continuous-flow reactors (CFRs) and sequencing batch reactors (SBRs) were employed along with the dosage of powdered activated carbon (PAC) to enhance tetracycline removal during anaerobic digestion of complex organic compounds. PAC increased the maximum methane production rate by 15.6% (CFRs) and 13.8% (SBRs), and tetracycline biodegradation by 24.4% (CFRs) and 19.2% (SBRs). CFRs showed higher tetracycline removal and methane production rates than SBRs. Geobacter was enriched in CFRs, where Methanothrix was enriched with the addition of PAC. Desulfomicrobium harbored abundant propionate degradation-related genes, significantly correlating with tetracycline removal. The genes encoding carbon dioxide reduction in Methanothrix along with the detection of Geobacter might indicate direct interspecies electron transfer for methanogenesis in CFRs and PAC-added reactors. The study offers new insights into anaerobic digestion under tetracycline-stressed conditions and strategies for optimizing tetracycline removal.

Virus adsorbent systems based on Amazon holocellulose and nanomaterials.

The environment preservation has been an important motivation to find alternative, functional, and biodegradable materials to replace polluting petrochemicals. The production of nonbiodegradable face masks increased the concentration of microplastics in the environment, highlighting the need for sustainable alternatives, such as the use of local by-products to create efficient and eco-friendly filtering materials. Furthermore, the use of smart materials can reduce the risk of contagion and virus transmission, especially in the face of possible mutations. The development of novel materials is necessary to ensure less risk of contagion and virus transmission, as well as to preserve the environment. Taking these factors into account, 16 systems were developed with different combinations of precursor materials (holocellulose, polyaniline [ES-PANI], graphene oxide [GO], silver nanoparticles [AgNPs], and activated carbon [AC]). Adsorption tests of the spike protein showed that the systems containing GO and AC were the most efficient in the adsorption process. Similarly, plate tests conducted using the VSV-IN strain cultured in HepG2 cells showed that the system containing all phases showed the greatest reduction in viral titer method. In agreement, the biocompatibility tests showed that the compounds extracted from the systems showed low cytotoxicity or no significant cytotoxic effect in human fibroblasts. As a result, the adsorption tests of the spike protein, viral titration, and biocompatibility tests showed that systems labeled as I and J were the most efficient. In this context, the present research has significantly contributed to the technological development of antiviral systems, with improved properties and increased adsorption efficiency, reducing the viral titer and contributing efficiently to public health. In this way, these alternative materials could be employed in sensors and devices for filtering and sanitization, thus assisting in mitigating the transmission of viruses and bacteria. RESEARCH HIGHLIGHTS: Sixteen virus adsorbent systems were developed with different combinations of precursor materials (holocellulose, polyaniline (ES-PANI), graphene oxide (GO), silver nanoparticles (AgNPs), and activated carbon (AC)). The system that included all of the nanocomposites holocellulose, PANI, GO, AgNPs, and AC showed the greatest reduction in viral titration. The biocompatibility tests revealed that all systems caused only mild or moderate cytotoxicity toward human fibroblasts.

Biochar pH reduction using elemental sulfur and biological activation using compost or vermicompost.

This study aimed to improve biochar's quality for arid land applications by using elemental sulfur as a pH reducer agent co-applied with compost or vermicompost as biological activators. Biochar pH was decreased by the addition of elemental sulfur, with the highest reduction from 8.1 to 7.2 occurring when co-amended with vermicompost. Elemental sulfur increased the water-soluble concentrations of calcium, magnesium, and many other elements, and stimulated substrate-induced respiration, especially when co-amended with vermicompost. The bacterial diversity community structure were significantly affected by all treatments. The Shannon index significantly increased in response to compost and sulfur treatments, while the vermicompost treatments showed higher microbial evenness and equitability diversity indices. Multivariate analyses indicated that elemental sulfur oxidation was associated with specific sulfur-oxidizing bacterial clusters. Integrating biochar with sulfur and (vermi)compost was found to be a promising sustainable technology for managing excessive biochar alkalinity, increasing its fertility and potential for application in aridlands.

Co-applied magnesium nanoparticles and biochar modulate salinity stress via regulating yield, biochemical attribute, and fatty acid profile of Physalis alkekengi L.

While previous studies have addressed the desirable effects of biochar (BC) or magnesium nanoparticles (Mg NPs) on salinity stress individually, there is a research gap regarding their simultaneous application. Additionally, the specific mechanisms underlying the effects of BC and Mg NPs on salinity in Physalis alkekengi L. remain unclear. This study aimed to investigate the synergistic effects of BC and Mg NPs on P. alkekengi L. under salinity stress conditions. A pot experiment was conducted with salinity at 100 and 200 mM sodium chloride (NaCl), as well as soil applied BC (4% v/v) and foliar applied Mg NPs (500 mg L-1) on physiological and biochemical properties of P. alkekengi L. The results represented that salinity, particularly 200 mM NaCl, significantly reduced plant yield (58%) and total chlorophyll (Chl, 36%), but increased superoxide dismutase (SOD, 82%) and catalase (CAT, 159%) activity relative to non-saline conditions. However, the co-application of BC and Mg NPs mitigated these negative effects and improved fruit yield, Chl, anthocyanin, and ascorbic acid. It also decreased the activity of antioxidant enzymes. Salinity also altered the fatty acid composition, increasing saturated fatty acids (SFAs) and polyunsaturated fatty acids (PUFAs), while decreasing monounsaturated fatty acids (MUFAs). The heat map analysis showed that fruit yield, anthocyanin, Chl, and CAT were sensitive to salinity. The findings can provide insights into the possibility of these amendments as sustainable strategies to mitigate salt stress and enhance plant productivity in affected areas.

Impact of feeding biochar sources in rohu (Labeo rohita): Evaluating the growth, nutrient absorption, carcass composition, haematology and mineral status.

Biochar, an organic carbonaceous matter, is a unique feed additive that is now being used in aquaculture industry to formulate a cost-effective and eco-friendly diet. This experiment (in door) was conducted over course of 90 days to determine the most effective form of biochar, produced from various sources, for supplementation in Moringa oleifera seed meal-based diet. These sources were: farmyard manure biochar, parthenium biochar (PB), vegetable waste biochar, poultry waste biochar (PWB) and corncob waste biochar, added at 2 g/kg concentration to determine the effect of supplementation on the growth indices, nutrient absorption, carcass composition, haematology and mineral status of Labeo rohita (rohu) fingerlings. The research design consisted of six test diets with three replications (6 × 3) of each. Total of 270 fingerlings (6.30 ± 0.020 g) were fed at 5% body weight and 15 of them were kept in separate steel tanks. The results indicated that PWB was most effective in improving weight gain (285.58 ± 4.54%) and feed conversion ratio (1.060 ± 0.040) compared to control diet and other test diets. The same type of biochar (PWB) produced the best results for nutrient digestibility, that is, crude protein, crude fat and gross energy and carcass composition. In terms of haematology and mineral status, PWB showed the best results. In conclusion, it was found that PWB significantly enhanced (p < 0.05) L. rohita fingerling's growth, carcass composition, nutrient digestibility, haematological parameters (red blood cells, white blood cells, platelets and haemoglobin) and mineral composition (Ca, Na, P, Mg, Fe, Mn, Zn, K and Cu) whereas PB negatively affected all parameters. It is anticipated that the potential use of biochar will increase in aquaculture industry, as research on its incorporation in fish feeds is still limited.

Comparative effectiveness of carbon nanoparticles and biochar in alleviating copper stress in corn (Zea mays L.).

The application of carbon nanoparticles (CNPs) and biochar in agriculture for improving plant health and soil quality and alleviating metal stress offers alternative approaches to meet the ever-increasing demand for food. However, poor understanding of their roles in improving crop production under Cu stress represents a significant obstacle to their wide application in agriculture. To clarify how CNPs and biochar affect corn (Zea mays L.) seed germination, seedling growth, plant health, and nutrient uptake under different Cu stress levels, soil-less Petri-dish and greenhouse soil-based bioassays were conducted. The results revealed that CNPs and biochar stimulated corn seed germination and seedling growth. Besides, they were effective in immobilizing Cu2+ sorption in sandy soil and alleviating Cu stress for plant growth, as shown by the increased plant height and dry biomass. The plant nutrient uptake efficiency (NUE) was significantly increased by CNPs, with a maximum increase of 63.1% for N and 63.3% for K at the highest Cu2+ stress level (400 mg Cu2+ L-1). In contrast, non-significant effects on NUE were observed with biochar treatments regardless of Cu stress levels. Interestingly, CNPs significantly increased plant uptake of Cu in the Petri dish test, while biochar inhibited plant uptake of Cu under both experimental conditions. Principle component analysis (PCA) and Pearson correlation analysis indicated that CNPs mitigated Cu stress mainly by elevating antioxidant enzyme activities, enhancing plant photochemical efficiency, and increasing plant uptake of N and K, while biochar was more likely to reduce bioavailability and uptake of Cu in the plant. These findings have great implications for the application of CNPs and biochar as plant growth stimulators and de-toxicity agents in agriculture.