International Journal of Environment and Climate Change

Physiological and Yield Performance of Some Upland Rice Cultivars of Assam under Aerobic and Normal Moisture Regimes

2026-06-20T11:35:31+00:00

Upland rice (broadcast summer rice) is a major component of rice production in Assam, particularly during flood and post-flood periods. The present study evaluated selected upland rice cultivars under normal irrigated and aerobic moisture regimes to identify physiological, biochemical and yield-related responses associated with moisture-stress tolerance. The experiment was conducted during the Rabi season at the Department of Crop Physiology, Assam Agricultural University, Jorhat. Five upland rice genotypes (Banglami, Inglongkiri, Boga ahu, Ronga ahu and Bengungutia ahu), selected after preliminary screening from 169 genotypes, were compared with the national check variety CR Dhan in a fractional randomised block design with three replications. Normal plots were maintained at 17-19% soil moisture, whereas aerobic plots were maintained at 7-8% soil moisture through life-saving irrigation. Aerobic conditions reduced mean flag leaf area by 29.94%, photosynthetic rate by 32.10%, internal CO2 concentration by 15.12%, transpiration rate by 12.73%, total leaf chlorophyll content by 22.95%, nitrate reductase activity by 29.78%, panicle number per hill by 29.56%, grain yield by 20.84% and harvest index by 30.26%. In contrast, mean leaf proline content increased by 43.98% under aerobic conditions. Among the genotypes, Inglongkiri recorded the highest grain yield under aerobic conditions (489.89 g m-2), closely followed by Banglami (488.21 g m-2) and Ronga ahu (468.23 g m-2). These genotypes also maintained relatively favourable physiological and biochemical traits under aerobic conditions. The findings indicate that Inglongkiri, Banglami and Ronga ahu may be more suitable for cultivation under aerobic moisture regimes, whereas Boga ahu and Bengungutia ahu showed relatively greater susceptibility to moisture stress in the present study.

Assessment of Land Use and Land Cover Change Dynamics Using Google Earth Engine

2026-06-20T12:48:05+00:00

This study assessed land use and land cover (LULC) dynamics in the Subarnarekha River Basin, eastern India, using multi-temporal satellite datasets and cloud-based geospatial analysis. The study aimed to map LULC changes during 2019–2021, evaluate their spatial and temporal variability, and compare the performance of Random Forest and Support Vector Machine classifiers within Google Earth Engine. Sentinel-2 multispectral imagery and Sentinel-1 synthetic-aperture radar data were integrated to reduce limitations associated with cloud cover and spectral ambiguity. Seasonal, annual and combined LULC maps were generated for seven classes: trees, shrubland, grassland, cropland, built-up areas, bare/sparse vegetation and permanent water bodies. The overall classification accuracy ranged from 65.16% to 73.87%, while the kappa coefficient ranged from 0.61 to 0.69. Combined multi-temporal datasets produced higher classification accuracy than single-season datasets, indicating the value of temporal integration for reducing classification uncertainty. The results showed a gradual decline in forest cover, accompanied by increases in cropland and built-up areas. Grassland and bare/sparse vegetation showed moderate variability, whereas permanent water bodies remained comparatively stable with seasonal fluctuations. These changes indicate increasing anthropogenic pressure associated with agricultural expansion and urban development. The findings provide baseline spatial information for understanding land-transformation processes and supporting sustainable land and water resource management in the Subarnarekha River Basin.

Influence of Meteorological Variables on the Population Dynamics of Insect Pests of Pea in North-Western India

2026-06-22T09:13:37+00:00

Pea (Pisum sativum L.) is a short-duration legume crop valued for its protein-rich seeds, fodder use and contribution to soil fertility through nitrogen fixation. The present study examined the population dynamics of major insect pests of pea and their association with selected meteorological variables during the rabi season of 2024–25 at Khalsa College, Amritsar, Punjab, India. The experiment was laid out in a randomised block design with thirteen treatments and three replications. Weekly observations were recorded from the first appearance of pests until harvest on five randomly selected plants from each plot. Aphids were assessed on a 10 cm apical twig per plant, leaf miner and thrips populations were recorded from three canopy leaves per plant, and pod borer incidence was determined by counting larvae per plant. The major insect pests observed were aphid, leaf miner, thrips and pod borer. Aphid infestation began during the 49th Standard Meteorological Week (SMW) and peaked during the 4th SMW with 35.00 aphids per 10 cm apical twig. Leaf miner first appeared during the 48th SMW and reached 17.23 larvae per plant during the 4th SMW. Thrips incidence started during the 48th SMW and peaked at 6.85 thrips per plant during the 7th SMW, whereas pod borer infestation began during the 4th SMW and reached 1.90 larvae per plant during the 7th SMW. Aphid, leaf miner and thrips populations showed significant negative associations with maximum temperature, minimum temperature and relative humidity. Pod borer showed non-significant negative associations with these variables, and rainfall had a non-significant effect on all pests. Multiple regression analysis showed that weather parameters explained 66.5%, 59.6%, 61.2% and 46.2% of variation in aphid, leaf miner, thrips and pod borer populations, respectively.

Ichthyofaunal Diversity and Physicochemical Water Quality of Dahod Reservoir, Raisen, Madhya Pradesh, India

2026-06-22T09:21:46+00:00

This study assessed ichthyofaunal diversity and selected physicochemical water quality parameters of Dahod Reservoir in Raisen district, Madhya Pradesh, India. The reservoir, constructed in 1958, is used for irrigation and water supply and also supports aquatic biodiversity. Monthly sampling was conducted from December 2025 to April 2026 at four selected sites, namely Bithori, Dahod, Landing Centre and Imaliya Gondi, with the assistance of local fishermen. Fish specimens were collected using gill nets, cast nets and drag nets of different mesh sizes, and species were identified using standard taxonomic keys. Water quality was evaluated through measurements of air temperature, water temperature, transparency, pH, free carbon dioxide, dissolved oxygen, total hardness and total alkalinity. The study recorded 18 aquatic taxa distributed across 7 orders and 10 families. Cypriniformes was the dominant order, contributing 47% of the total recorded fauna, followed by Siluriformes (24%), Perciformes (8%), Cichliformes (6%), Beloniformes (5%), Osteoglossiformes (6%) and Decapoda (5%). The family Cyprinidae was represented by eight species and was the most abundant family. Shannon diversity values ranged from 1.519 to 1.890, while Shannon equitability ranged from 0.547 to 0.667, indicating moderate diversity with uneven species distribution. Physicochemical parameters remained within ranges generally favourable for freshwater fish survival, with pH from 6.9 to 8.5, dissolved oxygen from 6.0 to 9.8 mg/L, total hardness from 110 to 136 mg/L and total alkalinity from 136 to 190 mg/L. Overall, the findings indicate that Dahod Reservoir supports moderate aquatic diversity and maintains water quality conditions suitable for fish productivity, while continued monitoring is needed to address increasing anthropogenic pressures and the presence of exotic species.

Effect of Heat Stress Mitigators on Growth Performance of Wheat (Triticum aestivum L.) under Varying Sowing Windows

2026-06-22T10:06:05+00:00

Rising temperature adversely affects cereal production and threatens global food security. Wheat is highly vulnerable to heat stress, which reduces its growth, development and productivity. A field experiment was conducted during the rabi seasons of 2024–25 and 2025–26 at Bihar Agricultural University, Sabour, to evaluate the effect of heat stress mitigators on wheat growth under different sowing windows. The experiment was laid out in a split-plot design with three replications. Three sowing windows, namely timely sown, late sown and very late sown, were assigned to the main plots, while five foliar treatments, namely water spray, 2% potassium nitrate, melatonin at 100 µM, sodium nitroprusside at 100 µM and progesterone at 1 µM, were assigned to the subplots. Growth parameters were recorded at 30, 60 and 90 days after sowing and at harvest. Timely sowing produced the highest plant height, leaf area index and number of tillers m⁻², whereas very late sowing recorded the lowest values. Among the foliar treatments, 2% potassium nitrate produced the highest growth values and remained statistically comparable with sodium nitroprusside for most observations. At harvest, 2% potassium nitrate recorded a plant height of 98.80 cm, a leaf area index of 3.44 and 292.02 tillers m⁻². The corresponding values under water spray were 88.77 cm, 2.98 and 270.17 tillers m⁻². The interaction between sowing windows and heat stress mitigators was non-significant. The findings indicate that delayed sowing reduced wheat growth, while foliar application of potassium nitrate and sodium nitroprusside improved growth performance under the tested conditions.

Study on Fish Biodiversity of Upper Lake, Bhopal, M.P, India

2026-06-23T06:56:17+00:00

Understanding the ecological importance of fish is fundamental, particularly because of their role in sustaining healthy aquatic ecosystems. Fish communities, including habitat-associated species, are directly influenced by local habitat features and function as important components of aquatic food webs. They contribute to nutrient cycling, prey-predator dynamics and ecosystem stability. The present study investigates the fish biodiversity and water-quality parameters of Upper Lake (Bhoj Wetland), Bhopal, Madhya Pradesh, India. The wetland showed moderate water-quality conditions in relation to anthropogenic activities, including the inflow of domestic sewage, urbanisation and encroachment in the catchment area. The study focused on three sampling sites, namely S1, Van Vihar Site (Shymala Hills); S2, Manav Sangrahalaya; and S3, VIP Apartment Housing Society, Khanugaon. The results indicated a total of 28 fish species belonging to 10 orders and 13 families. Species diversity was assessed using diversity indices that captured both species richness and evenness. Evenness describes variation in the relative abundance of species within a community. Statistical analyses were performed using Microsoft Excel and Species Diversity and Richness (SDR). The ichthyofaunal diversity of Upper Lake comprised ten orders, with dominance of Cypriniformes, represented by five families and 15 species, followed by Siluriformes, represented by three families and eight species. Cypriniformes (45%) was the dominant order, and the family Cyprinidae showed the highest diversity and abundance, including major carps and barbs. Biodiversity indices varied among the three study sites during the winter season. Site S2 exhibited the highest overall species diversity, with a Shannon-Wiener index (H’) of 2.45 and a Simpson’s index of diversity (1-D) of 0.85. Conversely, Site S1 yielded the lowest diversity indices (H’ = 2.095; 1-D = 0.80), despite showing the highest standardised species richness value (0.75) among the sampled locations. Future studies should use advanced ecological modelling to analyse shifting community dynamics at the sampling sites.

Evaluation of the Physico-chemical and Bacteriological Quality of Well Water along the Tilé River in N’Zérékoré, Guinea

2026-06-23T08:19:49+00:00

Water resources used for domestic purposes require continuous quality assessment, particularly in urban areas where surface water and shallow groundwater are exposed to domestic effluents, solid waste and runoff. This study evaluated the physico-chemical and bacteriological quality of well water along the Tilé River in the urban commune of N’Zérékoré, Guinea. The investigation was based on direct site observation and laboratory analyses of water samples collected from riverside wells and the Tilé River across nine districts. A total of 180 samples were analysed, comprising 10 well-water samples and 10 river-water samples per district. The measured parameters included temperature, pH, dissolved oxygen, colour, total dissolved solids, electrical conductivity, turbidity, total coliforms and faecal coliforms. The results were compared with World Health Organization guideline values for drinking water. Well-water temperatures ranged from 25.7°C to 26.1°C, whereas river-water temperatures ranged from 27.2°C to 27.7°C. The pH showed marked spatial variation, with acidic conditions recorded in Bellevue (3.52) and a higher value in Kwitiapoulou (7.79). Conductivity and total dissolved solids were generally higher in wells than in the river, indicating stronger groundwater mineralisation. In contrast, turbidity and colour were more pronounced in the Tilé River, with particularly high values in some districts. Bacteriological results indicated contamination by total and faecal coliforms, with concentrations ranging from 4 to 2,200 CFU/100 mL in the reported samples. These findings indicate that the Tilé River and adjacent wells are vulnerable to physico-chemical variation and faecal contamination. The water should not be consumed without appropriate treatment, and regular monitoring is required to support safer local water use.

Evolving Research Dynamics at the Climate–Migration Nexus: A Global Bibliometric Analysis (1995–2024)

2026-06-23T12:19:28+00:00

Climate change is increasingly recognized as a critical driver of human mobility, with environmental stressors such as droughts, flooding and sea-level rise shaping migration patterns globally. Despite substantial scholarly attention, research on climate-induced migration remains fragmented across disciplines and geographies. This study provides a comprehensive bibliometric analysis of global literature on climate-induced migration from 1995 to 2024, employing 1,980 publications retrieved from the Dimensions database. Analytical methods included performance analysis, co-authorship network mapping, source citation analysis, institutional collaboration profiling, and keyword co-occurrence mapping, implemented via Biblioshiny and VOSviewer. Results reveal a marked surge in research output post-2019, with the United States, United Kingdom, and Germany dominating publication volume and citation impact. India ranks fourth in output but exhibits limited international collaboration. Key intellectual clusters are identified around prominent scholars such as Clark Gray, Robert McLeman, and Caroline Zickgraf. Keyword analysis highlights central themes including “displacement,” “drought,” and “livelihood,” reflecting the field’s focus on rural vulnerability and adaptive capacity. Thematic evolution indicates a shift from deterministic “environmental refugee” narratives toward household-centered adaptation frameworks and climate justice paradigms. The study underscores structural disparities between empirical foci in the Global South and intellectual authority in the Global North, proposing pathways to foster South-South collaborations and integrate mobility research into climate adaptation policies. Findings provide a systematic taxonomy of climate-migration scholarship, supporting evidence-based policy-making and guiding future interdisciplinary research.