Asian Soil Research Journal

Hydrogeochemical Assessment of Groundwater for Drinking and Irrigation in the Tandur Limestone Area, Vikarabad District, Telangana, India

Gardas Naveen Kumar — 2026-03-21

Groundwater constitutes the principal source of water for drinking and irrigation in semi-arid regions of Telangana State, particularly in limestone-dominated terrains affected by mining and intensive agriculture. The present study evaluates the hydrogeochemical characteristics of groundwater in and around the Tandur Limestone area, Vikarabad District, Telangana, with the objectives of assessing its suitability for drinking and irrigation and understanding the geochemical processes governing groundwater composition. Thirty-five groundwater samples were collected during pre-monsoon and post-monsoon seasons and analysed for major physico-chemical parameters and ions following standard procedures. Hydrochemical facies were identified using Piper diagrams, and irrigation suitability was assessed using indices such as SAR, RSC, Kelly’s Ratio, and per cent sodium. The results indicate that groundwater chemistry is predominantly controlled by carbonate weathering processes, resulting in Ca–Mg–HCO₃ type waters, with localized influence of anthropogenic activities reflected by elevated nitrate, fluoride, and chloride concentrations in certain locations. Seasonal variations suggest enhanced water–rock interaction during the post-monsoon period. While most samples are suitable for drinking and irrigation, a few exceed permissible limits, warranting continuous monitoring and groundwater management measures in this mining-dominated limestone terrain.

Environmental Impact Assessment of Lithium Mining on Soil Quality in Libata Mining Site, Ngaski L.G.A. Kebbi State, Nigeria

M. M. Warrah — 2026-03-31

The mining of lithium has grown at a very high rate all over the globe owing to the rising demand in lithium-ion batteries in renewable energy technology and in electric vehicles. Nonetheless, mining operations can cause heavy metals to enter the local soils, which can be fatal to the environment and ecology. The study evaluated the environmental effects of lithium mining on soil quality in the Libata mining site in the Ngaski Local Government area of Kebbi state in Northwestern Nigeria. Samples of soil were collected from five mining locations (SL1-SL5) and a control site that was located several kilometres away from the mining site. The concentrations of the chosen heavy metals (As, Cd, Cr, Cu, Co, Mn, Ni, Pb and Zn) were measured by means of Atomic Absorption Spectrophotometry (AAS). The Contamination Factor (CF), Geo-Accumulation Index (Igeo), and Pollution Load Index (PLI) were used to assess environmental contamination. The findings indicated that mining areas had higher heavy metal concentrations in the soils than the control site. Zinc and copper showed the highest concentrations with maximum values reported at SL5 and SL2 respectively. The analysis of contamination factors showed that several metals were moderately or considerably contaminated, As, Cd, Cu, and Ni. All the mining sites had higher values of the calculated PLI that exceeded unity (PLI > 1), which showed that the quality of soil was being deteriorated as a result of mining. The statistical test using one-way ANOVA indicated that the concentration of heavy metals significantly differed (p < 0.05) between sampling locations. The findings conclude that the lithium mining processes have enhanced the heavy metal content of soils in the research site. It therefore suggested to engage in continuous environmental monitoring and adopt sustainable mining practices to reduce any further environmental degradation.

Farmers’ Awareness, Perceptions, and Practices of Azolla Use in Rice Production at Kitere Irrigation Scheme, Mtwara, Tanzania

Daudi Katigula Kasabuku — 2026-04-24

Azolla is increasingly recognised as a low-cost, environmentally friendly input with the potential to enhance soil fertility, conserve moisture, and improve rice productivity. This study assesses farmers’ awareness, perceptions, and management practices regarding Azolla use in rice production within the Kitere Irrigation Scheme (KIS), to evaluate its integration into smallholder cropping systems and its implications for sustainable rice production. The study was conducted in Lilido, Chemchem, and Amboni villages during the short (September–February) and long (April–July) rainy seasons. Data were collected from 66 rice farmers using structured questionnaires and analysed through descriptive and inferential statistics.

Results indicated that 97% of farmers were aware of Azolla and its benefits, particularly for improving soil fertility and conserving moisture. Approximately 76% reported that Azolla occurs naturally in their fields, while 74% indicated its presence for more than seven years. Although 23% observed that excessive mat formation can occasionally interfere with rice growth, overall perceptions remained positive. Fertiliser use varied among farmers, with average application rates of 123.6 kg DAP ha⁻¹ (≈24.8 kg P ha⁻¹) at planting and 126.0 kg urea ha⁻¹ (≈58.0 kg N ha⁻¹) for top dressing. Reported rice yields declined from 3.82 t ha⁻¹ in 2022/23 to 3.02 t ha⁻¹ in 2023/24, suggesting the presence of management-related constraints.

The findings highlight that although farmers recognise the value of Azolla, challenges such as unmanaged mat growth and inconsistent fertiliser application limit its effectiveness. Strengthening integrated Azolla management, including improved biomass regulation and optimised fertiliser use, could significantly enhance productivity, resource-use efficiency, and sustainability in smallholder irrigated rice systems.

Investigation of Dust Concentration and Analysis of Its Effective Environmental Factors Applied on Yazd Province, Iran

Zhila Maleki — 2026-05-02

The dust phenomenon is considered one of the most important environmental hazards in arid and semi-arid regions. Yazd province (located in central Iran, between 31° to 34° N latitude and 53° to 57° E longitude), due to its geographical location, arid climate, presence of active sand dunes (ergs), and proximity to internal and transboundary dust sources, is highly exposed to this phenomenon. The present study aims to investigate the dust concentration status in Yazd province and analyze the environmental factors affecting it. For this purpose, Moderate Resolution Imaging Spectroradiometer (MODIS) satellite images, Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS) precipitation data, the SRTM digital elevation model, and the Google Earth Engine system were used. The dust concentration map was prepared using the Aerosol Optical Depth (AOD) index for the period from 2020 to 2024. Subsequently, the Pearson pixel-based correlation analysis between the dust concentration layer and the parameters of elevation, temperature, precipitation, vegetation cover (NDVI), and the location of sand dunes was calculated. The results showed that the highest dust concentrations are intensified in the northern and central regions of the province. Sand dunes with an average concentration coefficient of 0.63 and elevation with a correlation coefficient of -0.53 had a significant (p < 0.01) impact on dust concentration, respectively. Furthermore, the direct relationship with temperature (0.43) and the inverse relationship with precipitation (-0.38) (based on n = 75,000 pixels) and vegetation cover (-0.19) confirmed the impact of arid climatic conditions. In addition to internal factors, the influx of dust from neighboring provinces and countries northeast of Iran also may play a role in exacerbating this phenomenon. Dust concentration in Yazd province is a multi-causal phenomenon, and its management requires a comprehensive approach including stabilization of sand dunes, development of vegetation cover, establishment of a monitoring system, and regional coordination.

Physicochemical Characteristics and Heavy Metal Distribution in Agricultural Soils of Nasarawa State, Nigeria

Y. A. Ameh — 2026-05-02

The baseline data of soil quality and trace metal distribution is essential to assess agro-environmental sustainability in highly cultivated areas. This research evaluated the physicochemical characteristics and spatial distribution of heavy metals in agricultural soils in the three senatorial areas of Nasarawa State, Nigeria, to explain the factors that are controlling and the likelihood of contamination. The samples of composite topsoil (0-30 cm) were taken at Awe (South), Nasarawa Eggon (North) and Kokona (West) and analyzed following standard protocols of pH, electrical conductivity (EC), organic carbon (OC), organic matter (OM), moisture content (MC), macronutrients, and trace metals. The soils were almost neutral to slightly acidic (pH 6.82-6.88) and non-saline (EC: 1.11-1.17 dS m -1), and were mostly sandy-textured, which means that they had low sorption capacity. The values of moderate OC and OM were found, and nitrogen and phosphorus were relatively enriched in the southern zone. Concentrations of trace metals were strongly spatially heterogeneous, with Pb and Zn always predominant, with Cd, Cr and Ni being local enriched. The patterns of distribution of metals were characterized by different zonal patterns: Nasarawa North (Zn > Pb >> Mg ≈ Cu ≈ Fe > Cr > Cd), Nasarawa South (Pb > Zn >> Fe > Mg > Cu > Ni), and Nasarawa West (Pb > Zn >> Fe). PCA showed that there was evident segregation of fertility related variables, soil texture, and metal related variables, which imply that there, were mixed lithogenic and anthropogenic controls. Whilst the general levels of metals were within the allowable range, localized enrichment of Cd in the south and Ni/Pb in the west hints at developing hotspots of contamination. These results enable important baseline data and the necessity of specific soil management and constant monitoring to reduce the threat of ecological and food safety risks in the long term.

Long-Term Use of Agrochemicals: Mycological and Physicochemical Indices Suggest Shifts in Bio-Physicochemical Patterns

T. L. Ataikiru — 2026-05-08

Introduction: Agrochemicals used over time reshape soil, with fungal and physicochemical signals marking shifts in bio‑physicochemical patterns

Aim: This study investigated fungal diversity and abundance in agrochemical contaminated soil from Kwale, Delta State, Nigeria, emphasizing their tolerance to heavy metals.

Methodology: Soil samples were collected from contaminated and uncontaminated sites. Soil physicochemical parameters were assessed. Heavy metal concentrations were determined using inductively coupled plasma optical emission spectroscopy (ICP-OES) while fungal isolation and enumeration were carried out on Rose Bengal Chloramphenicol agar and Potato dextrose agar following standard protocol.

Results: Results showed that the contaminated soil differed notably from the control in physicochemical composition. The pH values were 4.56 (uncontaminated soil) and 5.63 (contaminated soil), indicating acidification. Essential macronutrients such as calcium and magnesium content were 111.24 mg/kg and 32.95 mg/kg in control while in the contaminated soil the values were 223.83 mg/kg and 60.58 mg/kg, respectively. Heavy metal concentrations were substantially higher in the contaminated soil, with values of 159.06 mg/kg (cadmium), 2.911 mg/kg (mercury), 4.37 mg/kg (copper), and 0.46 mg/kg (arsenic), following the trend Cd > Cu > Hg > As. Correspondingly, the total heterotrophic fungal count was 6.70 × 10⁴ CFU/g in the control and 4.36 × 10⁴ CFU/g in the contaminated soil, representing approximately 35% decrease in fungal abundance. Dominant fungi in the control soil included Aspergillus, Mucor, Fusarium, Trichoderma and Penicillium, while the contaminated soil was dominated by stress-tolerant Aspergillus, Fusarium, Rhodotorula, and Trichoderma species.

Conclusion: The findings demonstrate that heavy metal contamination disrupt soil microbial balance, reducing fungal abundance and diversity. However, the persistence of tolerant genera highlights their potential for mycoremediation and soil restoration in contaminated farmlands.

Assessment of Soil Physicochemical Properties and Enzymatic Activities in Municipal Dumpsites of Uyo, Akwa Ibom State, Nigeria

Sule Ayegba Nicholas — 2026-05-21

Soil enzyme activities are sensitive indicators of soil biological functioning and nutrient cycling, particularly in environments impacted by municipal solid waste (MSW) disposal. This study evaluated selected physicochemical properties and enzyme activities of soils from three municipal dumpsites (Calabar–Itu Road, Uyo Village Road, and Eka Street) in Uyo metropolis, southern Nigeria, to assess their soil quality status. Surface soil samples (0–20 cm) were collected in triplicate and analyzed for particle size distribution, pH, electrical conductivity (EC), organic carbon (OC), total nitrogen (TN), available phosphorus (AvP), exchangeable bases, and effective cation exchange capacity (ECEC). Enzyme activities, including actual and potential dehydrogenase, urease, acid phosphatase, and alkaline phosphatase, were determined using standard colourimetric methods. Data were subjected to analysis of variance at p ≤ 0.05. Results indicated that dumpsite soils were predominantly sandy with acidic to slightly acidic pH. Organic carbon and nutrient levels were elevated relative to typical background soils of the region, reflecting continuous organic waste deposition. Enzyme activities varied significantly among dumpsites (p ≤ 0.05), with higher dehydrogenase and urease activities observed in sites with greater organic carbon content. Acid phosphatase activity was generally higher than alkaline phosphatase, consistent with the acidic soil conditions. The findings demonstrate that municipal waste inputs substantially modify soil biochemical functioning, enhancing microbial and enzymatic activities through organic substrate enrichment. However, the altered biochemical dynamics may have long-term implications for nutrient balance and environmental quality. Soil enzyme activities proved to be reliable indicators of ecological changes in dumpsite-affected soils and can serve as valuable tools for soil quality assessment and sustainable waste management planning.

Effect of Agro-Industrial Effluents on Soil Fertility, Pore Size Architecture, and Hydraulic Properties of Tropical Soils with Contrasting Parent Materials

Akanimo M. Ikpe — 2026-06-08

This study evaluated the effects of palm oil mill effluents (POME) and cassava mill effluents (CME) on the physical characteristics, chemical properties, and fertility status of soils derived from diverse parent materials, namely Coastal Plain Sands (CPS), Beach Ridge Sands (BRS), and Sand Stone/Shales (SSS). A total of 108 composite soil samples were collected from effluent-treated and control soils. All statistical analyses were conducted using SPSS Version 31. Results showed that effluent application improved key soil chemical characteristics compared with control soils. POME improved soil conditions by reducing acidity to near-neutral levels (6.89 to 6.71 in CPS, 5.74 to 5.71 in BRS, and 6.37 to 6.53 in SSS), increasing organic carbon and exchangeable bases (10.46, 9.48, and 10.03 cmol kg^-1for CPS, BRS, and SSS, respectively), and improving effective cation exchange capacity (13.66, 12.54, and 13.50 cmol kg^-1for CPS, BRS, and SSS, respectively). CME also improved soil nutrient status, but its effects on soil properties varied by soil type and depth. Effluent-treated soils demonstrated higher nutrient availability and improved structural properties, as indicated by decreased bulk density (1.24 ± 0.04, 1.55 ± 0.10, and 1.39 ± 0.09 g cm^-3), increased porosity (57.07, 56.70, and 55.53%), enhanced moisture content (CV of 80.67, 59.51, and 37.90%) for CPS, BRS, and SSS, respectively, and improved hydraulic conductivity (with minimum and maximum values of 0.15 to 1.23 cm hr^-1 accross all 3 parent materials). These findings demonstrate that agro-industrial effluents enhance nutrient availability and soil quality in tropical sandy soils, with POME showing stronger soil improvement potential. This study highlights the potential reuse of agro-industrial wastes as sustainable soil amendment materials in tropical environments.