Middle Gangetic Plain Research Articles

Effect of biotic and abiotic factors on the population dynamics of Nilaparvata lugens in the middle Gangetic Plains of India

Aim: To investigate the effect of biotic and abiotic factors on the population dynamics of brown planthopper Nilaparvata lugens (Stal) (Hemiptera: Delphacidae) in the middle Gangetic plains of India. Methodology: Field trials were conducted in the middle Gangetic plains of India at Agricultural Research Farm, B.H.U., Varanasi, Uttar Pradesh, India during Kharif season of 2018 and 2019 on the variety Swarna sub-1 to study the population dynamics and certain biotic and abiotic interaction with brown planthopper. Results: During Kharif 2018 and 2019, the highest mean number of brown planthopper population (45.00 ± 2.31 and 39.33 ±1.82 nos., respectively) were recorded during September in both seasons. Abiotic factors such as rainfall (r = - 0.556), relative humidity in the morning (r = 0.476), maximum temperature (r = 0.511), and sunshine hour (r = - 0.546) influenced planthopper population dynamics, and predictions were made with reasonable accuracy (R2 = 0.89) using the principal component regression analysis technique. Crop phenology was the most influential biotic factor on pest population density. The crop's booting stage had the highest incidence of planthoppers. Three different predatory populations (wolf spider, damselfly and ladybird beetle) were observed to feed on planthoppers in Kharif 2018 and four different predatory populations (wolf spider, damselfly, ladybird beetle and green mirid bug) were observed to feed on planthoppers in Kharif 2019, resulting in a reduction in crop pest density. Interpretation: These findings can be used to develop the precise management strategies for brown planthopper in the rice ecosystem. Key words: Abiotic, Biotic factors, Brown planthopper, Crop phenology, Middle Gangetic Plains, Natural enemies, Rice

Herbicide evaluation in direct seeded rice in the middle Gangetic plains of India

AbstractA field experiment was conducted in Samastipur district of Bihar, India during kharif season of 2021 and 2022 to identify suitable herbicides for control of composite weed flora in direct seeded rice. Compared to weedy check, application of bispyribac sodium + pyrazosulfuron ethyl as tank mixture effectively reduced weed density at 50 days after seeding during both the cropping season (82% and 86%, respectively) and weed dry weight (7.62 and 7.18 g m−2, respectively) over control and as a result yielded maximum during both the cropping season (47.92 and 51.32 q ha−1, respectively). Based on overall performance, bispyribac sodium + pyrazosulfuron ethyl may be considered as viable weed management option in direct seeded rice for the rice growers of middle Indo‐Gangetic region.

KUFRI DAKSH: A NEW WATER-USE EFFICIENT TABLE POTATO VARIETY WITH CROSS TOLERANCE TO HIGH TEMPERATURE STRESS

Kufri (K) Daksh is a main season, medium maturing, high yielding, water-use-efficient table potato variety that can be grown in regions with limited water availability. It is a clonal selection from the cross between CP1748, having high water use efficiency and LT-1 tolerating high temperature stress. Its plants are tall and vigorous with field resistance to late blight. Its tubers are white-cream (light yellow), ovoid with shallow to medium eyes and cream flesh with good keeping quality. It is fertilizer responsive and can yield 30-35 t/ha under low water (≤ 20%) availability in middle Gangetic plains. K Daksh has better trade-off for high CO2 gain and low water loss through optimization in plant canopy leaf area and plant height components. K Daksh can be an excellent choice to tolerate high temperature and water stress regimes in changing climatic scenarios.

Impact of Crop Phenology and Environmental Factors on Rice Leaf Folder Infestation in Middle Gangetic Plains of India

Impact of Crop Phenology and Environmental Factors on Rice Leaf Folder Infestation in Middle Gangetic Plains of India

Precision nitrogen management strategies and high yielding genotypes for enhanced growth, yield, economics, and nitrogen use efficiency in wheat

Current agricultural production systems face challenges of poor economic returns, soil fatigue and negative environmental outcomes from excess use of nitrogenous fertilizers, especially in wheat production under middle gangetic plains. To overcome these challenges, the current study was conducted to optimize nitrogen management in different wheat genotypes with precision nitrogen management tools and approaches. The field experiment was laid out in split-plot design, with three genotypes assigned to the main plot and six nitrogen management practices to the sub-plot. The soil of the experimental field was sandy loam in texture, with low levels of organic carbon and available nitrogen, and medium levels of available phosphorus and potassium. Results revealed that the HD-2967 genotype outperformed others in terms of growth, grain yield (4.7 and 4.81 t ha−1), gross return (1417.41 and 1505.48 US$ ha−1), net return (953.43 and 1019.76 US$ ha−1), and B-C ratio (2.04 and 2.08) in 2015-16 and 2016-17, respectively. Among the nitrogen management practices, application of 150 kg N ha−1 in three equal splits demonstrated improved crop growth, grain yield (4.7 and 4.81 t ha−1), and economic returns (gross return, 1500.40 and 1607.65 US$ ha−1, net return, 1025.40 and 1110.38 US$ ha−1 and B: C ratio, 2.17 and 2.23) in 2015-16 and 2016-17, respectively. However, it resulted in higher nitrogen losses. Green seeker guided N application significantly reduced apparent nitrogen losses compared to all other nitrogen applied treatments. These findings provide valuable insights for optimizing wheat production by selecting appropriate genotypes and implementing precision nitrogen management techniques to enhance yield, profitability, and environmental sustainability.

Prevalence and Phylogenetic Analysis of E. coli in Diarrhoeic Goats in Eastern Plain Zone of Uttar Pradesh

Background: The pathogens associated with diarrhoea in small ruminants include Escherichia coli, Rotavirus, PPR virus and Salmonella spp. either singly or in combination. Many researchers have worked on E. coli strains of goats almost in all agro-climatic zones of India but most of the studies were limited to only small study areas and no study has been conducted on E. coli prevalence in goats in Eastern Plain Zone of Uttar Pradesh. Methods: The study was conducted in eight district of Eastern Plain zone of Uttar Pradesh including goat farm of ANDUAT, Kumarganj, Ayodhya which comes under Agro-climatic zone IV (Middle Gangetic Plain region). Faecal samples were collected for one year (September, 2021 to August, 2022) from dead goats having history of diarrhoea. Result: The overall prevalence of E. coli isolates on PCR analysis was 52.27%. The prevalence was highest in Varanasi district as 63.63% (7/11) while lowest was reported in Ghazipur district as 36.36% (4/11). The occurrence of E. coli isolates was higher in Age Group I (79.31%) followed by Age Group II (41.17%) and Age Group III (36.00%). The E. coli isolates revealed higher positivity in female (57.69%) than male (44.44%). The occurrence of E. coli isolates was highest in summer (75.86%) followed by rainy (42.42%) and lowest in winter (38.46%) season. The obtained PCR amplicons on sequencing was identified as Escherichia coli strain U 5/41 16S ribosomal RNA as it showed highest similarity of 98.96 % with accession no. NR_024570.1

Deciphering soil-plant-animal continuum in relation to trace elements in middle Gangetic plain region of India.

The soil-plant-animal continuum represents an evolving realm in biological research that's why this study was undertaken in the middle Gangetic plain region of India. Trace and ultra-trace elements were analyzed in 100 soil samples, 147 feed and fodder samples, as well as 69 blood and 127 hair samples with the help of inductively coupled plasma optical emission spectroscopy (ICP-OES). The levels of trace and ultra-trace elements in the soil were significantly higher than those in the feed, and similarly, the concentrations in the feed were notably higher than those in the blood of dairy cattle. Blood and hair samples from the cattle showed deficiencies in copper (Cu) and manganese (Mn), with reaching approximately 20% and 50%, respectively. Correlation analysis indicated significant (P < 0.05) associations between the trace and ultra-trace elements in plants and the corresponding elements found in cattle's hair, specifically for iron (Fe) and molybdenum (Mo). Conversely, a significant (P < 0.05) negative correlation was observed between soil composition and cattle's blood, while a positive correlation was evident only in the case of silver content between plant and cattle's hair. Regression analyses revealed positive linear relationships between minerals in soils and plants, as well as between plants and cattle. However, the correlation coefficients were statistically insignificant. The regression equations established to predict mineral concentrations in cattle based on soil and plant mineral contents indicated a positive relationship for both trace and ultra-trace elements, suggesting the potential to measure the mineral status in dairy cattle through this approach.

Understanding arsenic and manganese enrichment in the aquifers of the Ghaghara river basin, Middle Gangetic Plain (MGP), India: A multivariate statistical, compositional data analysis (CoDA), and receptor model approach

The focus of this study was to comprehend the spatial distribution, source apportionment, evaluation of natural background level (NBL), and mobilization mechanisms of arsenic (As) and manganese (Mn) in the Ghaghara river basin, located in the middle Gangetic plain (MGP) of India. A combination of analytical tools was employed, including multivariate statistical analysis (MSA), correlation analysis, and receptor models such as positive matrix factorization (PMF) and principal component analysis-multi linear regression (PCA-MLR). Taking into consideration the compositional constraints of the geochemical data, compositional data analysis (CoDA) methods were applied on the raw data prior to the correlation analysis and MSA. The results of MSA, correlation analysis and receptor models showed that major ion chemistry and As, Mn enrichment in groundwater were largely controlled by carbonate weathering, Fe and Mn oxyhydroxides dissolution. Anthropogenic activities, such as the infiltration of dissolved organic matter-rich water from local surface water bodies used as dumping sites and the infiltration of fertilizer-rich water from agricultural lands, were found to notably impact the groundwater geochemistry and release of As in the research area. The lower NBL of As (5.92 μg/L) compared to its mean concentrations (17.9 μg/L) in the study area also indicated that the rate of As release in groundwater through natural processes was comparatively low but various anthropogenic activities operating in the study region possibly acted as a trigger for the mobility of As from the mineral phases of the subsurface sediments. This study also highlighted the significance of applying CoDA techniques on geochemical data prior to statistical analysis, and the importance of receptor models, to better understand the nature and contribution of various natural and anthropogenic processes governing the hydrochemistry of groundwater in the alluvial aquifers.

Sorption and mobility assessment of tembotrione in soils of upper, trans and middle Gangetic plain zones of India.

The presence of undesired agrochemicals residues in soil and water poses risks to both human health and the environment. The behavior of pesticides in soil depends both on the physico-chemical properties of pesticides and soil type. This study examined the adsorption-desorption and leaching behavior of the maize herbicide tembotrione in soils of the upper (UGPZ), trans (TGPZ) and middle Gangetic plain zones of India. Soil samples were extracted using acetone followed by partitioning with dichloromethane, whereas liquid-liquid extraction using dichloromethane was used for aqueous samples. Residues of tembotrione and its metabolite TCMBA, {2-chloro-4-(methylsulfonyl)-3-[(2,2,2-trifluoroethoxy) methyl] benzoic acid}, were quantified using liquid chromatography-tandem mass spectrometry. The data revealed that tembotrione adsorption decreased with increasing pH and dissolved organic matter but increased with salinity. The maximum adsorption occurred at pH4, 0.01m sodium citrate and 4g/L NaCl, with corresponding Freundlich constants of 1.83, 2.28 and 3.32, respectively. The hysteresis index <1 indicated faster adsorption than desorption. Leaching studies under different flow conditions revealed least mobility in UGPZ soil and high mobility in TGPZ soil, consistent with groundwater ubiquity scores of 4.27 and 4.81, respectively. Soil amendments decreased tembotrione mobility in the order: unamended > wheat straw ash > wheat straw > farm yard manure > compost. The transformation of tembotrione to TCMBA and its mobility in soil columns were also assessed.

Understanding arsenic behavior in alluvial aquifers: Evidence from sediment geochemistry, solute chemistry and environmental isotopes

The hydro-geochemistry and isotopic variations in groundwater, coupled with sediment geochemistry, were investigated in the Middle Gangetic Plain, India, to better understand the aquifer dynamics that influence the arsenic (As) evolution and mobilization. Eighty-four groundwater samples, thirteen River water samples, and two sediment cores (33 mbgl) were studied. The samples were analyzed for major ions and trace metals, including As and stable isotopic variability (δ2H, δ18O, and δ13C). The study area was categorized into older and younger alluvium based on existing geomorphological differences. Younger alluvium exhibits higher As enrichment in sediment and groundwater, ranging of 2.59–31.52 mg/kg and bdl to 0.62 mg/L. Groundwater samples were thermodynamically more stable with As(OH)3 species ranging from 88.5% to 91.4% and FeOOH from 69% to 81%, respectively. PHREEQC and mineralogical analysis suggested goethite and siderite act as a source and sink for As. However, statistical analysis suggested reductive dissolution as the primary mechanism for As mobilization in the study area. Spatio-temporal analysis revealed elevated concentrations of As in the central and northeastern regions of the study area. Stable isotope (δ2H and δ18O) analysis inferred active recharge conditions primarily driven by precipitation. The depleted d-excess value and enriched δ18O in the groundwater of younger alluvium indicate the effect of groundwater recharge with significant evaporation enrichment. Groundwater recharge potentially decreased the quantity of arsenic in groundwater, whereas evaporation enrichment increased it. Rainwater infiltration during recharge introduces oxygenated water into the aquifer, leading to changes in the redox conditions and facilitating biogeochemical reactions. The carbon isotope (δ13C) results suggest that high microbial activity in younger alluvium promotes As leaching from sediment into the groundwater.

Analysing spatio-temporal drought characteristics and copula-based return period in Indian Gangetic Basin (1901-2021).

Uncertainty and uneven distribution of monsoonal rainfall and its consequences on crop production is a matter of serious concern in India, specifically, in theIndo-Gangetic plainregion. In this study, drought patterns were investigated through standardised precipitation index (SPI) of varying timescales, using the India Meteorological Department (IMD) precipitation data (1901-2021). We analysed the spatio-temporal pattern of different drought characteristics (frequency, duration, severity, intensity) of the Indian Gangetic basin using run theory. The bivariate copula method has been incorporated to combine two drought properties (severity and duration). Copula integrates multivariate distribution and considers the dependency rate among the variables. The five most widely used copulas from various copula families, elliptical (normal, t-copula) and Archimedean (Clayton, Gumbel, Frank), were estimated for modelling, and the best fit copula was selected. The study revealed that seasonal drought is more frequent and intense in the Upper and Middle Gangetic Plain, whereas annual drought is quite scattered in nature. It is worthy to mention that downward drought trends were observed in this agricultural belts significantly after 1965; specifically, in the Upper, Middle, and Trans Gangetic Plain regions. With increasing drought duration and severity, the drought return period raised, but the frequency decreased gradually. Most of the droughts characterised by less duration and severity occurred with a return period below 10years for the whole region. The major 100 + years return period droughts were to be found after 1960 and their frequencies were significantly higher after 2000. The most recent remarkable droughts with more than 100years of return occurred during 2008-2011 and 2016-2018 in the Upper and Middle Gangetic plains, whereas in the Lower Gangetic plain, a hundred-year return period drought was occurred during 2010-2013. This study provides agroclimatic-zones-wise significant information of drought characteristics and its nature of occurrence in the Indian Ganga Basin. The results enhance the understanding of drought management and formulation of adaptive strategies to mitigate the adverse impact of droughts.

Spatio-temporal evaluation of the impact of anthropogenic stressors on physico-chemical characteristics and water quality of the River Ganga using GIS-based approach in the middle Gangetic Plains at Patna, Bihar, India.

The present study aimed to assess the impact of anthropogenic stressors on the physico-chemical characteristics and water quality of the River Ganga employing a GIS-based approach in the middle Gangetic Plain at Patna, India. After the survey, sand mining, bridge construction, and disposal of untreated domestic and sewage wastes were selected as major anthropogenic stressors. A total of 48 samples were collected in pre-monsoon and post-monsoon seasons of 2022 and were analyzed for 16 physico-chemical parameters, namely water temperature (WT), pH, electrical conductivity (EC), total dissolved solids (TDS), turbidity, dissolved oxygen (DO), biological oxygen demand (BOD), total hardness (TH), Ca2+, Mg2+, Na+, K+, Cl- and SO42- ions, following standard protocols. The WQI was calculated using the Weighted Arithmetic Water Quality Index (WAQWI) method and spatial maps were created using ArcGIS software. The result revealed significant seasonal variation in several physico- chemical parameters except for Ca2+, K+ and TA (p > 0.05). ANOVA revealed significant variation for BOD and COD at Ghagha and Triveni, whereas for nitrate at Gai Ghat reference and impact sites, respectively. The Water Quality Index (WQI) revealed a deterioration in water quality by 60% in post-monsoon season. HCA revealed that the WQI was mostly governed by TDS, TH, TA, and EC.

Isolation and Biochemical Characterization of Endophytic Bacterium from Native Gluconacetobacter diazotrophocus Sugarcane Cultivar of Middle Gangetic Plains of India

Isolation and Biochemical Characterization of Endophytic Bacterium from Native Gluconacetobacter diazotrophocus Sugarcane Cultivar of Middle Gangetic Plains of India

Managing climatic risks in rice–wheat cropping system for enhanced productivity in middle Gangetic plains of India

Rice followed by wheat is the dominant cropping system in the middle Indo-Gangetic plains (IGP). Lower productivity (4.8 t ha−1) of this cropping system in Bihar, compared to the national average (6.8 t ha−1) due to several climate- and production-related issues, is a matter of concern for the farmers and the policymakers. Keeping all these in view, an experiment with rice–wheat cropping system was carried out during 2020–21 and 2021–22 in 17 adopted villages of 13 districts of Bihar under the Project “Climate Resilient Agriculture Program (CRAP)” to evaluate the feasibility of early transplanting of rice in the month of June with the aim of achieving higher system productivity by early harvesting of rice and subsequent timely sowing of wheat before 15 November with the provision of assured irrigation. In this study, the concept of an innovative community irrigation approach and single-phase 3-hp submersible pump was employed. Long-duration rice variety (150 days) Rajendra Mahsuri-1 was sown during 20–25 May in the nursery and transplanted through puddling operation during 15–20 June in 17 locations. Under delayed conditions, the nursery sowing and transplanting window were 10–15 June and 10–15 July, respectively. Timely sown rice grown with the provision of a community irrigation system achieved a grain yield of 5.2 t ha−1 and 85.8% higher water productivity, compared to late-sown crops. Following the harvest of rice, the HD-2967 variety of wheat was planted in the first fortnight of November and harvested in the first week of April, yielding 4.9 t ha−1 with the application of 2–3 irrigations based on soil type and evaporative demand. Timely harvesting of wheat facilitated farmers of the region to take an additional crop of summer green gram. With an assured irrigation system and shifting planting dates and thereby managing climatic risks, the overall productivity of the rice–wheat cropping system was achieved to the tune of 10.1 t ha−1 with a cropping intensity of 300% for better adaptation and sustainable production.

Original

The World Health Organization (WHO) has identified noise pollution as the third most hazard-ous form of pollution, posing significant health risks in urban areas, following air and waterpollution. Prolonged noise exposure causes adverse health effects, including hypertension, anxi-ety, depression, hormonal imbalances, and elevated blood pressure, which can ultimately leadto heart problems. Lucknow city, in the Middle Gangetic Plain, faces exacerbated noise pollu-tion due to transport, industrial activities, and machinery. The rapid industrialization and urban-ization, coupled with an unplanned transport system, congested roads, the prevalence of oldervehicles, and high population density, have escalated the already dire situation to its peak in thecity. The study aims to assess the impact of noise on the health of the population. The primarydata was collected from 35 stations within study area. Both thematic mapping and perceptionstudies have been conducted to gain insights into the distribution pattern of noise pollution andits impact on health. The noise levels in the city exceed the standard limits across variouszones, including residential areas (55 dBA), commercial zones (65 dBA), industrial zones (75dBA), and even silence zones (50 dBA). A statistical analysis of health issues, such as hearingloss, mental disorders, heart problems, cholesterol levels, headaches, and nausea, has revealeda significant direct correlation between the prevalence of these problems and the noise levelswithin the study area.

Responses of phenology, yield attributes, and yield of wheat varieties under different sowing times in Indo-Gangetic Plains.

A field experiment with wheat was conducted at Pusa (25.98°N, 85.67°E, 52m amsl), Bihar (middle Gangetic plains of India), to assess the responses of phenology, yield attributes, and yield to growing season temperature and heat stress. For this purpose, wheat was planted on five dates (viz., 15 November, 25 November, 5 December, 15 December, and 25 December) for three consecutive years (viz., 2014-2015, 2015-2016, and 2016-2017) with three prominent cultivars of the region (viz., RAU-3711, HD-2824, and HD-2733). Five dates of sowing represent different wheat-growing micro-environments as imposed by varying sowing dates encompassing the entire sowing window. The study observed the significant effect of sowing dates on phenophase duration. In general, with progress in the date of sowing, tiller initiation was delayed, while the reverse trend was observed for later growth phases. Sowing environments significantly influenced the number of effective tillers m-2. Average numbers of effective tillers (ET) m-2 for the wheat sown during 15-25 November were almost 11.6% higher than those of the 25 December sown crop. Grain filling duration (GFD) showed a declining trend with the advancement of sowing dates due to increased thermal load on the crop during the reproductive period. 15 November planted crop exhibited the highest GFD (47 days), which was shortened significantly beyond 25 November, signifying agrometeorological non-suitability of wheat sowing beyond this window. Wheat sown on 25 November recorded the highest grain yield (3.21 Mg ha-1), 48.61% higher than the 25 December sown crop due to the congenial thermal regime. In this context, we have identified optimal and sub-optimal conditions to escape heat stress for higher wheat productivity. Moreover, the sum of deviation of temperature from optimum thresholds, computed for sensitive growth phases (50% flowering to physiological maturity), helped us to identify heat stress and its impact on wheat. Genotype-by-environment (GGE) biplot analysis revealed that RAU-3711 was found to be the most stable cultivar. A decrease in the yield of wheat by 4.9% to 12.0%, sown during November, and 33.8% to 42.4%, sown during December, is predicted in 2050-51 and 2080-81, respectively, under RCP 4.5.

Potential health risk assessment through the consumption of arsenic-contaminated groundwater in parts of the middle Gangetic plain

BackgroundArsenic toxicity in humans is well recognized. It has been classified as a class I human carcinogen by the International Agency of Research on Cancer. Arsenic enters the human body mainly through drinking water, dermal contact, food chain, and inhalation. The Gangetic belt of India is considered as one of the most arsenic-affected sites in India. Health risk assessment of the human population exposed to arsenic in drinking water is important. The present study was conducted to assess the groundwater quality and associated health risks on the people of Samastipur district in the middle Gangetic belt of Bihar. Groundwater samples from 40 different study sites were collected and analyzed for various physico-chemical properties of water.ResultsArsenic (> 0.01 mg/L) was present in 33% of the water samples analyzed. Subsequently, an assessment for carcinogenic risk and non-carcinogenic health risk (HQ) for children, females, and males in the study area was performed. Risk assessment showed that 100% of the population may be at carcinogenic health risk and 35% may be at non-carcinogenic health risk, and among these, children were at maximum risk. Furthermore, the computational assessment of the arsenic–protein interactome revealed the enrichment of cancer-related pathways.ConclusionsIt is recommended to provide arsenic-free alternate sources of water in the study area.

Morphometric Analysis and Prioritization of Watershed for Water Management using Weighted Sum Approach and Geospatial Tools: A Case Study of Harohar Sub-basin, India

Abstract In order to address current global water shortages, geovisualization tools such as remote sensing and geographic information systems aid planners and decision makers in generating more effective and correct judgments for the execution of water harvesting activities for the maximum utilization of rainwater. Keeping in view, a weighted sum approach technique was used to infer hydrological behavior and priorities at watershed level in the Harohar sub-basin of middle Gangetic plains. It was observed that monsoon rainfall (1.7 mm year-1) and post-monsoon rainfall (0.6 mm year-1) has been declined whereas pre-monsoon rainfall (1.5 mm year-1) has significantly increased over the period 1985-2019. Furthermore, morphometric, slope, hydrological, geomorphological, and lithological variations results revealed that 56.30% of areas are prioritized as very high, followed by high (30.5%), and only 2-7% of areas fall under very low to low priority for construction of rain water harvesting structures. Water harvesting facilities such as farm ponds, check dams, tanks, aharpynes, and conservation ditches might be offered in prioritized locations for optimum utilization of surface runoff and ground water recharge. Based on the above scientific findings, this study may be helpful in water resource planning at the basin/watershed level across the globe

Assessment of hydrochemical shift in riverine aquifers of the mid-Gangetic plain of Uttar Pradesh, India

The over-exploitation of groundwater resources in the agriculture-intensive middle Gangetic plains is leading to the depletion of the water table and deterioration of its quality. A total of 100 groundwater samples were collected from the mid-Gangetic plain, specifically from the Mirzapur and Pratapgarh districts of Uttar Pradesh, during two seasons: pre-monsoon (pre-M) and post-monsoon (post-M). Various indices and multivariate statistical analysis were employed to assess groundwater chemistry and suitability for different purposes, including the Water Quality Index (WQI), sodium adsorption ratio (SAR), soluble sodium percentage (SSP), residual sodium carbonate (RSC), and Permeability Index (PI). The findings revealed that HCO3−, NH4+, and PO43− exceeded permissible limits, while hardness, SO42−, Cl−, and SO42− remained within acceptable ranges. Analysis of variance (ANOVA) indicated significant variations (p < 0.05) in pH, electrical conductivity, total dissolved solids, NO3−, Ca2+, dissolved silica, NH4+, HCO3−, NO3−, and PO43−. Groundwater chemistry in the area is influenced by weathering and evaporation processes. In terms of drinking water quality, all analysed samples were found to be poor during the pre-monsoon season, with 68% of samples in Pratapgarh and 56% in Mirzapur showing poor quality during the post-monsoon season. SAR, SSP, RSC, and Na% values indicated water suitability for irrigation, with Magnesium Hazard (MH) and Permeability Index (PI) values suggesting unsuitability for irrigation purposes. Industrial indices such as Langelier Saturation Index (LSI) indicated slightly to non-corrosive water, while Ryznar Stability Index (RSI) indicated light to heavy and intolerable corrosiveness of groundwater in both districts. Consequently, the groundwater in the area was deemed unfit for drinking without treatment but suitable for irrigation. While Pratapgarh's groundwater could be used for industrial purposes, groundwater quality in Mirzapur would require treatment. The findings of this study can aid local stakeholders, government agencies, and water resources managers in the sustainable management of groundwater resources in the study area.

Emerging organic contaminants in the River Ganga and key tributaries in the middle Gangetic Plain, India: Characterization, distribution & controls

The presence and distribution of emerging organic contaminants (EOCs) in freshwater environments is a key issue in India and globally, particularly due to ecotoxicological and potential antimicrobial resistance concerns. Here we have investigated the composition and spatial distribution of EOCs in surface water along a ∼500 km segment of the iconic River Ganges (Ganga) and key tributaries in the middle Gangetic Plain of Northern India. Using a broad screening approach, in 11 surface water samples, we identified 51 EOCs, comprising of pharmaceuticals, agrochemicals, lifestyle and industrial chemicals. Whilst the majority of EOCs detected were a mixture of pharmaceuticals and agrochemicals, lifestyle chemicals (and particularly sucralose) occurred at the highest concentrations. Ten of the EOCs detected are priority compounds (e.g. sulfamethoxazole, diuron, atrazine, chlorpyrifos, perfluorooctane sulfonate (PFOS), perfluorobutane sulfonate, thiamethoxam, imidacloprid, clothianidin and diclofenac). In almost 50% of water samples, sulfamethoxazole concentrations exceeded predicted no-effect concentrations (PNECs) for ecological toxicity. A significant downstream reduction in EOCs was observed along the River Ganga between Varanasi (Uttar Pradesh) and Begusarai (Bihar), likely reflecting dilution effects associated with three major tributaries, all with considerably lower EOC concentrations than the main Ganga channel. Sorption and/or redox controls were observed for some compounds (e.g. clopidol), as well as a relatively high degree of mixing of EOCs within the river. We discuss the environmental relevance of the persistence of several parent compounds (notably atrazine, carbamazepine, metribuzin and fipronil) and associated transformation products. Associations between EOCs and other hydrochemical parameters including excitation emission matrix (EEM) fluorescence indicated positive, significant, and compound-specific correlations between EOCs and tryptophan-, fulvic- and humic-like fluorescence. This study expands the baseline characterization of EOCs in Indian surface water and contributes to an improved understanding of the potential sources and controls on EOC distribution in the River Ganga and other large river systems.