Risk Of Environmental Pollution Research Articles

Performance Evaluation of Delonix regia Sawdust as Cement Retarder in Oil and Gas Well

Sawdust, a byproduct of wood exploitation and processing, poses environmental pollution risks if not managed appropriately. Its substantial carbon footprint can lead to pollution, habitat disruption, and fire hazards. However, repurposing sawdust as a chemical additive in cement slurry within the oil and gas industry offers an environmentally friendly solution. This practice aligns with sustainability goals, enhances cement slurry properties, promotes wellbore stability, and replaces more hazardous additives, thereby reducing environmental impact. This study is aimed at the production of a retarder (sodium lignin) from sawdust waste obtained from the Delonix regia species, and examining its effect on the thickening time/consistency, compressive strength, and rheological properties on the slurry of a Class G cement At a Bottom Hole Circulating Temperature (BHCT) of 90°C, thickening time tests conducted on the slurry samples revealed that as the concentration of the locally synthesized retarder increases, the thickening time of the concrete also increases, with minimal effect on compressive strength. The optimal thickening time result of 6 hours and 13 minutes was achieved with 0.5% Sodium Lignin (Retarder from Delonix regia sawdust) replacing a portion of the cement. At a bottomhole static temperature (BHST) of 100°C, increasing the concentration of the formulated sample led to higher Plastic Viscosities (PV) and yield points in the slurries. The findings indicate that slurries formulated with sodium lignin maintain viscosities within recommended values, making them suitable for pumping.

Identification and Application of Streptomyces rapamycinicus CQUSh011 against Potato Late Blight.

Using chemical fungicides is the main strategy for controlling potato late blight (PLB), a devastating pre- and postharvest disease caused by Phytophthora infestans, resulting in environmental pollution and health risks. It is of great importance to develop a biofungicide from microorganisms. Through isolating potato rhizosphere microorganisms, CQUSh011 was found to have antioomycete activity with strong inhibition on vegetative growth and virulence of P. infestans. Morphological and molecular identification indicated that CQUSh011 belongs to Streptomyces rapamycinicus. Based on genome, metabolome, and HPLC quantification, rapamycin and salicylic acid were found to be the two active metabolites against P. infestans. Continuous field trials showed that CQUSh011 has sustainable control efficiency against PLB, and the efficiency was better when combined with Infinito, along with an increased endophytic microbial community and biodiversity in potato roots. The results demonstrated the potential of CQUSh011 as a biofungicide against PLB and provided an alternative strategy for reducing the application of chemical fungicides.

Visual aptasensor based on PtNPs/g-C3N4 and DNase I for the field detection of acetamiprid.

A visual aptasensor based on the combination of graphitic carbon nitride loaded with platinum nanoparticles (PtNPs/g-C3N4) and deoxyribonuclease I (DNase I) was developed for detecting acetamiprid. The prepared PtNPs/g-C3N4 exhibited excellent peroxidase (POD)-like activity, demonstrating the capacity to oxidize the colourless o-phenylenediamine (OPD) to produce the coloured product diaminophenazine (DAP) in the presence of hydrogen peroxide (H2O2). The DNA aptamer of acetamiprid can adsorb onto the surface of PtNPs/g-C3N4, thereby inhibiting its POD activity. The binding of acetamiprid to its aptamer results in the aptamer desorbing from the surface of PtNPs/g-C3N4 and subsequent digestion by DNase I. Ascribed to the synergistic effect of these factors, the aptasensor can achieve the rapid on-site detection of acetamiprid based on the acetamiprid-induced the colour change of the solution just with the smartphone. Furthermore, due to the remarkable fluorescence signal of DAP at 570nm, the aptasensor under fluorescence mode enables highly sensitive and quantitative detection of acetamiprid with a linear range of 1 ng/mL to 4µg/mL and a detection limit as low as 0.31 ng/mL.Theaptasensor has successfully realized the detection of acetamiprid in river water and cucumber samples, offering a novel perspective for the rapid assessment of environmental pollution and food safety risks associated with acetamiprid residues.

The administration of Glycyrrhiza polysaccharides mitigates liver injury in mice caused by mancozeb via the Keap1-Nrf2/NF-κB pathway

The extensive utilization of mancozeb (MCZ) poses environmental pollution risks, threatens human health, particularly hepatotoxicity. Glycyrrhiza polysaccharides (GP) exhibit antioxidant, anti-inflammatory and other biological activities. The aim of this study is to explore the mechanism of liver injury in mice exposed to MCZ and the protective effect of GP on alleviating MCZ induced liver injury. Initially, 70 female mice were divided into 7 groups, and the optimal dose of MCZ induced liver injury in mice was screened by oral administration different doses of MCZ (0, 50, 100, 150, 200, 250 and 300 mg/kg MCZ). The results demonstrated that, compared to the blank control group, as the concentration of MCZ increased, several physiological and biochemical parameters were significantly affected. Specifically, body weight and liver index significantly decreased, while the activities of SOD and CAT also decreased. Additionally, the content of ROS increased, the levels of Keap1 and Nrf2 proteins increased, the mRNA levels of Gpx2 and HO-1decreased, and the mRNA levels of Gstt2, GcLc and NQO1 were upregulated. Based on the test data, select 100mg/kg MCZ as the optimal modeling dose for experimental animals. Sixty female mice were divided into six groups and orally administered: control group A (0.2mL deionized water), model group B (100mg/kg MCZ), positive control group F (100mg/kg MCZ+100mg/kg VC), the high-dose GP group C (100mg/kgMCZ+200mg/kgGP), the medium-dose GP group D (100mg/kg MCZ+150mg/kgGP) and the low-dose GP group E (100mg/kg MCZ+100mg/kgGP). The results showed that compared to the model group, adding GP alleviated the effects of MCZ on body weight, liver index, CAT and SOD activity, MDA content, HO-1, TNF-α, and IL-1β. Additionally, the addition of GP decreased the expression of Keap1, Nrf2, NF-kB, and NQO1, GcLc, and Gstt2 mRNA. GP ameliorated liver vacuolar degeneration, steatosis and nuclear pyknosis ameliorate by MCZ. The results show that MCZ triggers hepatotoxicity via the activation of the Keap1/Nrf2 signaling pathway, whereas GP has the potential to mitigate liver damage caused by MCZ exposure by inhibiting this pathway.

Assessment of nitrogen and phosphorus losses due to erosion in compost-treated and non-treated vineyard soils: effect of rainfall intensity

Vineyards in Mediterranean areas suffer from significant soil degradation through erosion, due to rainfall and soil characteristics, as well as soil management practices. Previous studies pointed out the nutrient losses produced by erosion and the benefits that some management practices could have on reducing erosion. This research tried to evaluate the effect of events of different intensities and to assess whether the beneficial effect of compost amendment may pose a potential risk of nutrient loss and environmental pollution in particular under high-intensity events. The study compared soil and nutrient losses in compost-treated and non-treated vineyard soils after rainfall events of different intensities analyzed over 2 years in two vineyards. Runoff samples were collected by triplicate in treated and non-treated soils. Sediment and nitrogen and phosphorous concentrations in the runoff samples were analyzed. The results reveal a reduction in runoff rates and an increase in soil water content in compost-treated soils, which represents a benefit for rainfed vineyards. Both nitrogen and phosphorus losses depended on rainfall characteristics. Although for low intensities there were no significant differences in the amount of nutrient lost by runoff in both treated and non-treated soils, nitrogen and phosphorus losses were higher after high-intensity rainfall events in compost-treated soils. With the expected increase in high-intensity rainfall events associated with climate change in the Mediterranean region, organic amendments should be applied in several splits or incorporated into the soil to avoid increased nutrient loss to water bodies.

High-Entropy Layered Oxide Cathode Materials with Moderated Interlayer Spacing and Enhanced Kinetics for Sodium-Ion Batteries.

Sodium-ion batteries (SIBs) with low cost and environmentally friendly features have recently attracted significant attention for renewable energy storage. Sodium layer oxides stand out as a type of promising cathode material for SIBs owing to their high capacity, good rate performance, and high compatibility for manufacturing. However, the poor cycling stability of layer oxide cathodes due to structure distortion greatly impacts their practical applications. Herein, a high entropy doped Cu, Fe, and Mn-based layered oxide (HE-CFMO), Na0.95Li0.05Mg0.05Cu0.20Fe0.22Mn0.35Ti0.13O2 for high-performance SIBs, is designed. The HE-CFMO cathode possesses high-entropy transition metal (TM) layers with a homogeneous stress distribution, providing a moderated interlayer spacing to maintain the structure stability and enhance Na+ ion diffusion. In addition, Li doping in TM layers increases the Mn valence state, which effectively suppresses John-Teller effect, thus stabilizing the layered structure during cycling. Furthermore, the use of nontoxic and low-cost raw materials benefits future commercialization and reduces the risk of environmental pollution. As a result, the HE-CFMO cathode exhibits a super cycling performance with a 95% capacity retention after 300 cycles. This work provides a promising strategy to improve the structure stability and reaction kinetics of cathode materials for SIBs.

Microscale heat and mass transfer characteristics of CO2 flooding in nanotubes of tight oil reservoirs

AbstractThe mechanism of heat and mass transfer in tight oil reservoirs after CO2 injection is complex. In this paper, first, a CO2 transfer model within microscale adjacent nanotubes in tight oil reservoirs is established. Then, the typical heat and mass transfer characteristics of microscale CO2 in tight oil reservoirs is analyzed, and the influence of grid density on the calculation results is discussed. Finally, the influence of thermal conductivity of tight oil reservoirs on CO2 physical properties parameters is revealed. Results show that: (a) From the inlet end of the thick nanotube to the outlet of the nanotube, the pressure of CO2 drops from 3.5 to 3.3697 MPa. (b) When the mesh length is equal to 5 nm, the CO2 pressure in the thin nanotube drops from 3.5 to 3.3329 MPa, and the CO2 pressure in the thick nanotube drops from 3.5 to 3.2018 MPa. (c) Organic amines react with CO2 to form salts, which can seal high permeability layers and cracks, but there is a risk of environmental pollution.

The Role of Environmental Accounting in Mitigating Environmental Pollution Risk and its Disclosure

This research explores the critical role of environmental accounting in mitigating environmental pollution risks and improving disclosure practices. Environmental pollution has become a significant global concern, amplified by industrial activities and mismanagement of natural resources. As stakeholders increasingly demand corporate responsibility, environmental accounting has emerged as a pivotal tool for organizations to quantify their environmental impacts, integrate eco-ethics into their financial systems, and enhance transparency in environmental risk disclosures. This study examines how environmental accounting frameworks can aid in reducing corporate pollution by identifying the cost of pollution-related activities and aligning them with financial decision-making processes. Additionally, the research investigates the regulatory frameworks that promote environmental transparency and the challenges that companies face in implementing these practices. Case studies on corporate environmental accounting demonstrate both the potential and limitations of current practices. The research concludes with recommendations on the strategic integration of environmental accounting to foster sustainability and risk mitigation. These findings underscore the importance of consistent environmental disclosure in enhancing corporate accountability and in reducing environmental risks.

Enhancing aeolian sand stability using microbially induced calcite precipitation technology

This study investigates the effectiveness of Microbially Induced Calcite Precipitation (MICP) technology in enhancing the stability of aeolian sand. Applying MICP to desert sand samples from Kashi, Xinjiang, the results demonstrated significant structural stability and erosion resistance in treated soils during wind erosion tests. Particularly after 14 days of treatment, the soil samples exhibited optimal wind erosion resistance and surface crust strength. Additionally, the formation of calcite significantly improved the soil’s penetration strength and wind erosion resistance, with SEM analysis confirming that calcite “bridges” between soil particles enhanced inter-particle bonding. Environmental impact assessments indicated that MICP technology is not only environmentally friendly but also effectively reduces the risk of soil environmental pollution. These findings validate the potential application of MICP technology in enhancing the stability and environmental adaptability of aeolian sand.

Detrimental effects of glyphosate on muscle metabolism in grass carp (Ctenopharyngodon idellus)

Glyphosate, a commonly used herbicide, has been associated with environmental pollution and potential health risks to aquatic organisms. This study investigated the effects of glyphosate on the muscle metabolism of grass carp (Ctenopharyngodon idellus) following exposure to environmentally relevant concentrations. Over a 14-day exposure period to varying glyphosate levels, significant disruptions were observed in antioxidant capacity and muscle health. These disruptions were evidenced by reductions in total antioxidant capacity (T-AOC), increases in malondialdehyde (MDA) levels, and decreases in activities of glutathione peroxidase (GSH-PX) and catalase (CAT). Furthermore, exposure to glyphosate resulted in a reduction of vitamin E content and an elevation of hormonal levels, suggesting the potential for endocrine disruption. Metabolomics analysis identified 605 distinct metabolites, with notable alterations in amino acid, carbohydrate, and nucleotide metabolism pathways. Specifically, arginine and glutathione metabolisms were severely impacted, with decreases in key amino acids such as glycine and glutathione at higher glyphosate concentrations. Nucleotide metabolism, particularly purine synthesis, was also significantly affected, with reduced levels of deoxyguanosine and other purine-related compounds. The study further investigated the origins of these differential metabolites using the MetOrigin platform, suggesting a potential involvement of the intestinal microbiota in the metabolic response to glyphosate. These findings highlight the multifaceted adverse effects of glyphosate on fish muscle, including oxidative stress and metabolic dysregulation, which may contribute to diminished muscle quality and health risks for aquatic organisms.

Certain aspects of the implementation of imputed insurance of environmental risks in the Russian Federation

Purpose: of this article is to justify the implementation of insurance of environmental risks in the Russian Federation in the form of a pilot project based on imputed insurance with the definition of the main conditions of insurance coverage.Methods: the presented work uses statistical and predictive methods and the integrated approach for processing data on natural, climatic and human activity risks. Correlation-regression analysis and actuarial modeling were used to determine the conditions for insuring environmental risks and calculate tariff rates.Results: the paper substantiates the possibility of carrying out insurance of environmental risks in the form of a pilot project using an imputed form of insurance. Approaches to the calculation of the main parameters of business civil liability insurance for causing environmental damage as a result of an accident within the framework of a pilot project are proposed, including the determination of the minimum and maximum non-aggregate insurance limit, the minimum number of insurance companies, and the calculation of tariff rates. Due to the lack of Russian statistics on insurance coverage of environmental risks, statistical data on global insurance catastrophic losses from natural events, climate risks and human actions, as well as judicial statistics on disputes over the application of environmental protection legislation, were used for the calculation. The regions of the Russian Federation were identified for the implementation of a pilot project of environmental risk insurance.Conclusions and Relevance: the implementation of a pilot project of environmental risk insurance in certain regions on the basis of imputed insurance will make it possible to assess the current and forecast level of environmental risks in the Russian Federation, the need for insurance and reinsurance protection, the possibility and necessity of state participation in covering environmental damage. Using insurance statistics, insurers will be able to develop adjustment factors that encourage enterprises to take preventive measures. Reflection in a special reporting section of the results of the participation of insurance companies in the insurance of environmental pollution risks will be considered as the implementation of ESG principles.

Optimization of household medical waste recycling logistics routes: Considering contamination risks.

The escalating generation of household medical waste, a byproduct of industrialization and global population growth, has rendered its transportation and logistics management a critical societal concern. This study delves into the optimization of routes for vehicles within the household medical waste logistics network, a response to the imperative of managing this waste effectively. The potential for environmental and public health hazards due to improper waste disposal is acknowledged, prompting the incorporation of contamination risk, influenced by transport duration, waste volume, and wind velocity, into the analysis. To enhance the realism of the simulation, traffic congestion is integrated into the vehicle speed function, reflecting the urban roads' variability. Subsequently, a Bi-objective mixed-integer programming model is formulated to concurrently minimize total operational costs and environmental pollution risks. The complexity inherent in the optimization problem has motivated the development of the Adaptive Hybrid Artificial Fish Swarming Algorithm with Non-Dominated Sorting (AH-NSAFSA). This algorithm employs a sophisticated approach, amalgamating congestion distance and individual ranking to discern optimal solutions from the population. It incorporates a decay function to facilitate an adaptive iterative process, enhancing the algorithm's convergence properties. Furthermore, it leverages the concept of crossover-induced elimination to preserve the genetic diversity and overall robustness of the solution set. The empirical evaluation of AH-NSAFSA is conducted using a test set derived from the Solomon dataset, demonstrating the algorithm's capability to generate feasible non-dominated solutions for household medical waste recycling path planning. Comparative analysis with the Non-dominated Sorted Artificial Fish Swarm Algorithm (NSAFSA) and Non-dominated Sorted Genetic Algorithm II (NSGA-II) across metrics such as MID, SM, NOS, and CT reveals that AH-NSAFSA excels in MID, SM, and NOS, and surpasses NSAFSA in CT, albeit slightly underperforming relative to NSGA-II. The study's holistic approach to waste recycling route planning, which integrates cost-effectiveness with pollution risk and traffic congestion considerations, offers substantial support for enterprises in formulating sustainable green development strategies. AH-NSAFSA offers an eco-efficient, holistic approach to medical waste recycling, advancing sustainable management practices.

Chemiresistive triethylamine detection based on the novel Ti3C2Tx/Co-BDC gas sensor

Triethylamine (TEA), a representative volatile organic environmental pollutant, poses significant environmental pollution risks and can adversely affect the liver and nervous system, potentially leading to fatal outcomes. However, existing gas sensors for TEA detection have pressing drawbacks, such as safety hazards associated with high-temperature operation and poor timeliness due to time-consuming testing. Herein, the Ti3C2Tx/Co-BDC sensor demonstrates ultra-sensitive detection of TEA at a low temperature of 100 °C. This temperature is below the threshold for explosion-proof operation, ensuring safe application in flammable and explosive environments. Meanwhile, the introduction of the metal-like MXene with ultra-high conductivity accelerates the response and recovery process (11 s/20 s), facilitating highly efficient TEA detection within a sub-minute timeframe. The Ti-O-Co interfacial bonds between Ti3C2Tx and Co-BDC, confirmed by both XPS analysis and theoretical calculations, enhance carrier mobility across the two materials, significantly boosting gas-sensing performance. The rapid detection of TEA at low temperatures makes the Ti3C2Tx/Co-BDC sensor more suitable for practical environmental monitoring in flammable and explosive areas, further contributing to human health and production safety.

A Novel Approach to Detecting Blockages in Sewers and Drains: The Reflected Wave Technique

Blockages in sewers and drains often result in overflows and flooding that cause significant environmental pollution and public health risks, particularly in hospitals, where the consequences can be catastrophic. Due to their low “visibility”, sewers and drains are inherently difficult to monitor and maintain, resulting in a reactive management approach whereby maintenance or repair is carried out only after a system failure has occurred. This paper investigates the feasibility of applying the reflected wave technique, a unique sonar-like monitoring approach capable of identifying changes in the geometry of closed-pipe conduits, as a means of proactive system monitoring. The technique uses a 10 Hz sinusoidal air pressure wave which is transmitted into the drainpipe. When the pressure wave encounters a system boundary, a reflection is generated which alters the measured test pressure response. Analysis of the reflections generated by a changed system boundary, such as the formation of a blockage, can provide information related to the location of that boundary within the system. An experimental setup was developed to simulate a horizontal drain using standard pipework of 100 mm diameter and 70 m length. The technique was able to detect applied blockages with cross-sectional coverage of 30% and 75%, and lengths ranging from 30 mm to 3000 mm. Accuracy was improved when the pressure sensor was positioned closer to the blockage. When the sensor was 3.4 m from the blockage, location estimates were very accurate (−2% to 3% error). At a 14 m distance from the blockage, the error increased to between 4% and 33%. The accuracy of blockage detection and location improved with increasing blockage cross-sectional area and length. Overall, the reflected wave technique could provide a potentially continuous monitoring solution for blockage detection in sewers and drains.

Performance Evaluation of Green Supply Chain Management in Canned Fish (Sardines) Production Unit: A Case of Indonesia

Indonesia's fishing industry, especially in East Java Province, shows great potential but also harms the environment. CV. Pasific Harvest Surabaya (CV. PHB) is a fish canning industry in Banyuwangi Regency, which is currently facing problems such as the supply of raw materials, which continues to decline; the company has not measured and planned the total consumption of energy, fuel, water and the problem of workers who have not received environmental training. Although a waste processing system is in place, the production process still carries the risk of environmental pollution. The researchers collected data through observation, interviews, literature studies, and paired comparison questionnaires. The results of the research reveal that CV. PHB manages three supply chain flows with four supply chain actors. The final performance score is 81.77, with 24 verified KPIs. The KPIs that need performance improvement are packaging time until the product is picked up by the delivery service (D4), time for handling customer complaints (R3), and environmental training for workers (E1).

Achieving ultrasensitive detection of glyphosate in fruits and vegetables using a triple-mode strategy based on carbon dots nanozymes derived from expired drugs

Rapid and sensitive detection of glyphosate (GLP) holds significant importance in the monitoring of environmental pollution and potential risks to human health. In this study, carbon dots nanozymes (CDszymes) with peroxidase-like activity were synthesized rapidly using a microwave-assisted method, employing expired drugs as raw materials. In the presence of H2O2, CDszymes catalyze the oxidation of TMB to generate blue oxTMB, which exhibits a photothermal effect under near-infrared light irradiation; an inner filter effect (IFE) may occur between oxTMB and CDszymes. By coupling the cascade catalysis of AChE and ChOx to generate H2O2, GLP effectively inhibits the activity of AChE, constructing a colorimetric/fluorescent/photothermal response platform for GLP. In colorimetry, the detection limit of GLP was 0.33 ng/mL. The detection limits of GLP by fluorescence method and photothermal method were 0.02 ng/mL and 0.41 ng/mL, respectively. The efficacy of this methodology has been successfully demonstrated in fruit and vegetable, it also provides a strategy for the high-value conversion of expired drugs.

Effects of liquid urea rates on nitrogen dynamics, growth, and yield of corn (Zea mays L.)

Arbitrary use of urea fertilizer reduces nitrogen use efficiency (NUE) and increases the risk of environmental pollution. An experiment was conducted at the Universiti Putra Malaysia from November 2019 to March 2020 to evaluate the application methods and rates of liquid urea (LU) on the yield performance of corn. The treatments were, U0 = control, GU100 = Granular urea (GU) 100%, LU100 = LU 100%, LU50 = LU 50% and LU33 = LU 33%, in two equal splits at 10th and 28th days after sowing (DAS) in randomized completely block design, replicates four. Results showed that plant height (206.99 cm, 216.92 cm, 214.61 cm), ear height (88.13 cm, 88.63 cm, 86.00 cm), days of maturity (88.75, 89.00, 86.75 days), number of grains per kernel row (32.25, 34.50, 33.75), fresh cob weight (10,886.60 kg ha−1, 10,946.60 kg ha−1, 10,927.93 kg ha−1) and 100-grain weight (20.51 g, 22.50 g, 21.39 g) of corn were not different significantly (p ≤ 0.05) in GU100, LU100 and LU50 treatments, respectively. The highest yield of corn was found with LU100 (6249.03 kg ha−1) treatment whereas the yield in LU50 (5666.50 kg ha−1) and GU100 (5746.64 kg ha−1) were not different significantly. Nitrogen (%) in plants was the highest in LU100 followed by LU50 treatment which was significantly higher than GU100 treatment. The total N content was also the highest in LU100 (102.83 kg ha−1) though the total N content was not different significantly in LU50 (77.62 kg ha−1) and GU100 (83.84 kg ha−1) treatments. The NUE was the highest in LU50 (66.92%) treatment followed by LU100 (51.47%) treatment. The results of the study suggested that LU was superior to GU and the LU100 was the best application rate while LU50 treatment was comparable to GU100 in corn cultivation.

Multidimensional Approach for the Assessment of Environmental Pollution and Health Risk Associated With V, Ni, Cr, Cu, and Zn in the Recent Sediments of Kabini Interstate River, Southeastern Western Ghats, India

ABSTRACTThe present work intends to study the variation of heavy metals (HMs) to scrutinize the scenario of pollution index and associated environmental risk, as well as source weathering conditions along the Kabini River. The decreasing order of concentration of HMs along the basin is Cr > V > Ni > Zn > Cu. The paper spotlights the pollution grade in sediments, assessed by the geo‐accumulation index (Igeo), contamination factor (Cf), pollution load index (PLI), and enrichment factor (Ef). The assessment of ecological risk is studied as potential ecological risk index (RI), toxic risk index (TRI), and modified hazard quotients (mHQs). As per the Igeo and Cf, V and Cr concentrations are higher in the region. Further, PLI confirmed that 35% of samples exceeded the limits of sediment quality guidelines. The RI and TRI values show that a higher ecological risk is associated with Ni, V, and Cr and with Cu and Cr, respectively. Additionally, the 23% Ni and 20% Cu samples from mHQ indicate the severity of pollution in the aquatic environment. The inputs from anthropogenic and natural sources change the concentration of these HMs along the region. Moreover, the study of CIA and plagioclase index of alteration plots confirmed the low to intense weathering conditions. The statistical approach shows the linkage between Cr–V, Cu–Zn, and principal component analysis–derived prominent sources: industrial and agricultural runoff, as well as higher silicate weathering, contribute to the HMs concentration in the region. The Kabini River passes through different climatic and land‐use domains of Kerala and Karnataka, which eventually regulate the HM concentration and geo‐environmental processes in the region and affect the health risk to humans in one or the other way. The reference data generated from the present work are absolutely new and would be significant in the future for deriving sustainable development plans for the well‐being of human beings and precious natural resources.

Substituting partial chemical nitrogen fertilizers with organic fertilizers maintains grain yield and increases nitrogen use efficiency in maize

IntroductionLong-term application of excessive nitrogen (N) not only leads to low N use efficiency (NUE) but also exacerbates the risk of environmental pollution due to N losses. Substituting partial chemical N with organic fertilizer (SP) is an environmentally friendly and sustainable fertilization practice. However, the appropriate rate of SP in rainfed maize cropping systems in semi-arid regions of China is unknown.MethodsTherefore, we conducted a field experiment between 2021 and 2022 in a semi-arid region of Northern China to investigate the effects of SP on maize growth, carbon and N metabolism (C/NM), and NUE. The following treatments were used in the experiment: no N application (CK), 100% chemical N (SP0, 210 kg N ha–1), and SP substituting 15% (SP1), 30% (SP2), 45% (SP3), and 60% (SP4) of the chemical N. The relationship between these indicators and grain yield (GY) was explored using the Mantel test and structural equation modeling (SEM).Results and discussionThe results found that the SP1 and SP2 treatments improved the assimilates production capacity of the canopy by increasing the leaf area index, total chlorophyll content, and net photosynthetic rate, improving dry matter accumulation (DMA) by 6.2%–10.6%, compared to the SP0 treatment. SP1 and SP2 treatments increased total soluble sugars, starch, free amino acids, and soluble protein contents in ear leaves via increasing the enzymatic reactions related to C/NM in ear leaves during the reproductive growth stage compared with SP0 treatment. The highest plant nitrogen uptake (PNU) and nitrogen recovery efficiency were obtained under the SP2 treatment, and the GY and nitrogen agronomic efficiency were higher than the SP0 treatment by 9.2% and 27.8%. However, SP3 and SP4 treatments reduced DMA and GY by inhibiting C/NM in ear leaves compared to SP0 treatment. Mantel test and SEM results revealed that SP treatments indirectly increased GY and PNU by directly positively regulating C/NM in maize ear leaves. Therefore, in the semi-arid regions, substituting 30% of the chemical N with SP could be considered. This fertilizer regime may avoid GY reduction and improve NUE. This study provides new insights into sustainable cultivation pathways for maize in semi-arid regions.

Dense planting and nitrogen fertilizer management improve drip-irrigated spring maize yield and nitrogen use efficiency in Northeast China

Farmers in China often use nitrogen (N) fertilizers to ensure adequate crop growth. However, injudicious applications have increased the risk of environmental pollution, lower maize yields, and reduced profits for farmers. Appropriate N fertilizer management is crucial for improving yield and nitrogen use efficiency (NUE). This study conducted a three-year experiment involving nine N treatments (0, 45, 90, 135, 180, 225, 270, 315, and 360 kg ha-1) on a field under nitrogen fertilizer precision management (NFPM) in Northeast China. These results were compared with studies published within the past decade that analyzed yield and dry matter (DM) content under two management practices in Northeast China: conventional nitrogen fertilization management (CNFM) and water-saving fertilization management (WSFM). The findings reveal that maize yield increases with rising N application rates up to 270 kg ha-1, after which yield decreases. The kernel number (KN) and kernel weights (KW) of maize grown under NFPM were 13.7 and 14.7% higher than those grown under WSFM, respectively. Furthermore, they surpassed crops grown under CNFM by 38.4 and 21.2%, respectively. The maximum total yield of the NFPM treatment was 41.8 and 78.8% higher than WSFM and CNFM, respectively. Additionally, compared with CNFM and WSFM, NFPM significantly increased nitrogen use efficiency (NUE) across various N-level treatments. Optimizing nitrogen management could help farmers achieve higher yields and promote sustainable agricultural development.