Water Electrical Conductivity Research Articles

Determining Liquid Limit and Plastic Limit of Clay Soils by Electrical Surface Conduction and Diffuse Double Layer Thickness

The aim of this study was to propose a new approach to determine the liquid limit and plastic limit of clay soils by considering electrical conductivity (EC) measurements. The proposed method included incorporating a new parameter, F, which is the ratio of the volumetric water contents of diffuse double layer (DDL) water and free water. In addition, the EC parameter, σ, was considered as the ratio of electrical surface conductivity and electrical conductivity of water. The changes in the thickness of DDL (χ) were also assessed to obtain corresponding equations to establish a connection with clay mineralogy, water content, and specific gravity in the final prediction. Three-dimensional surface analyses were conducted to find a correlation among F, σ, and χ to identify an appropriate method to predict liquid limit and plastic limit. The study was conducted with 39 different types of samples, and the outcomes from the EC approach were validated against the conventional methods. Overall, the coefficient of determination, R2 = 0.90, and Lin’s concordance correlation coefficient, (LCCC) = 0.91, were obtained for liquid limit prediction, whereas R2 = 0.64 and LCCC = 0.80 were obtained for plastic limit determination.

Analysis of Temperature, pH, and Electrical Conductivity of Water in Response to Taheri Consciousness Field 2

Water, as the most abundant molecule on Earth's surface and a vital component of living organisms, has always been the subject of investigation and analysis in the scientific community regarding its physicochemical properties and changes resulting from environmental variables. In previous studies on the effects of T-Consciousness Fields, changes in the pH and temperature of water as a result of exposure to these fields have been investigated. In this study, in addition to these two parameters, changes in the electrical conductivity of water molecules under the influence of T-Consciousness Field 2 have been examined, with the aim of finding a parameter of water that is more sensitive and responsive to T-Consciousness Fields. According to the results of this research throughout 8, 24, and 48 hours, changes in pH in the sample and control groups showed an increase, and temperature changes showed a decrease. Furthermore, changes in the electrical conductivity of water under the influence of T-Consciousness Field 2 were significant. To complement the current study, the examination of the levels of oxygen and carbon dioxide gases in pure water under the exposure of T-Consciousness Field 2 is on the agenda of the authors.

Study of the dyeing industry pollution after mandatory installation of ETP in Madhabdi municipality, Bangladesh

ABSTRACT Madhabdi municipality of the Narsingdi district of Bangladesh, the “Manchester of the East,” is famous for its cloth market and fabric dyeing industries. The untreated effluent discharge has been mixed with the water and soil, degrading the environmental standards of this area for years. Installing an effluent treatment plant (ETP) in all textile industries in Bangladesh is mandatory. This study evaluates the soil condition, surface water quality, and heavy metal contamination in cultivated vegetables after the compulsory installation of ETP. Soil and water samples from eight locations and cultivated vegetable samples from three locations are collected and analyzed for this study. The pH, EC (electric conductivity), TDS (total dissolved solids), DO (dissolved oxygen), and heavy metal concentrations are observed. The water quality index, contamination index, metal evaluation index, pollution load index, and metal pollution index are calculated from the collected samples. The study found that the physico-chemical properties of water pH (9.19), EC (2232.38 µScm-1), and DO (0.79 mgL-1) violate the national standards. The mean TDS is below the maximum permissible level. The heavy metal concentrations of Cr and Pb in water are 1.03 and 0.13 mgL-1, crossing the permissible limit, respectively, but Mn, having 0.89 mgL-1, is within the limit. The water quality is unsuitable for domestic and agricultural use, contamination is “medium,” and metal evaluation is “medium.” The soil is alkaline, having a pH of 8.58. The soil’s Cr, Pb and Mn concentrations are 68.21 µgg-1, 52.73 µgg-1and 805.16 µgg-1, respectively. The soil contamination level is low to moderate. Cultivated leafy vegetables have a concentration of Cr, Pb and Mn; 2.61 µgg-1, 0.30 µgg-1and 288.67 µgg-1, respectively, where Cr has crossed, Pb is within, and Mn is lower than the permissible limit. Produced vegetables have high (12.10–33.09) MPI (metal pollution index) and are at a high-risk level for consumption as food.

Monitoring of soil EC for the prediction of soil nutrient regime under different soil water and organic matter contents

Smart farms and precision agriculture require automatic monitoring and supply of water and nutrients for crops, but sensors to monitor plant available nutrients in soil are not available. Soil electrical conductivity (EC) is related to nutrients in soil solution, which can be affected by soil organic matter, soil texture, temperature, and water content. Therefore, the objective of this study is to evaluate factors influencing soil EC sensor values by monitoring EC under different soil organic matter and water contents. Ten soil samples with various sand and clay contents, EC, pH, and organic matter contents were selected and saturated with water. Volumetric water content and EC of the soil were monitored while drying the soil. Humic acid and manure were added to soils in order to evaluate the effect of organic matter on soil EC. Soil EC values linearly increased with increasing water content at 10–25% which is favorable water content for plant growth. The EC increased when organic matter was added to soils, which was related to ions released from the organic matter. Soil EC calibration factor for soil water content increased when EC of the soil was high and organic matter was added. The sensor EC values in sandy loam and loam soils was related to the ion contents in pore water, and exchangeable ions in soil, respectively. Sensor EC values were highly correlated with organic matter and K contents in soil and can be used as an indicator for plant available nutrients in soil. Therefore, the sensor EC at optimal soil water content for plant growth can be used to monitor changes in plant available nutrients in soil.

Production and postharvest quality of <i>Passiflora edulis</i> Sims under brackish water and potassium doses

<abstract> <p>The aim of this research was to assess the yield and postharvest characteristics of 'BRS Sol do Cerrado' sour passion fruits based on irrigation with varying levels of saline water and potassium fertilization. The study was conducted under field conditions at an experimental farm in São Domingos, Paraíba, Brazil. A randomized block design was implemented in a 5 × 4 factorial arrangement, with five levels of electrical conductivity of water (ECw): 0.3, 1.1, 1.9, 2.7, and 3.5 dS m<sup>−1</sup>, and four potassium doses (KD): 60, 80,100, and 120% of the recommended amount, with 3 replications. The potassium dose equivalent to 120% of the recommended dose in combination with low-salinity water resulted in the highest fresh mass accumulation in the sour passion fruit. Water electrical conductivity up to 2.7 dS m<sup>−1</sup>, along with the lowest recommended KD, led to increased levels of soluble solids and ascorbic acid in the sour passion fruit. Irrigation with water of 3.5 dS m<sup>−1</sup> and using 80 to 100% of the recommended KD enhanced the total sugar content in the sour passion fruit. On the other hand, irrigation with water of 3.5 dS m<sup>−1</sup> combined with 60% of the recommended KD resulted in a higher pulp yield in the 'BRS Sol do Cerrado' sour passion fruit 160 days post-transplantation. Adjustments in potassium fertilization management at different irrigation water salinity levels played a crucial role in maintaining both the production and quality of the sour passion fruit.</p> </abstract>

The physiological quality of Vigna unguiculata L. seeds shows tolerance to salinity.

Salinity reduces feijão-caupi production, and the search for tolerant varieties becomes important within the agricultural context, as, in addition to being used in the field, they can be used in genetic improvement. The objective was to for a identify variety that is tolerant to salinity considering the physiological quality of seeds and seedling growth. A 2 × 4 factorial scheme was used, referring to the varieties Pingo-de-ouro and Coruja, and four electrical conductivities of water (0; 3.3; 6.6 and 9.9 dS m-1). The physiological quality of seeds and the growth of seedlings were analyzed, in addition to the cumulative germination. The Pingo-de-ouro variety showed no germination, length of the shoot and root, dry mass of the shoot and root compromised up to electrical conductivity of 6 dS m-1 in relation to 0.0 dS m-1. On the other hand, the Coruja variety showed reduced germination, increased shoot and root length. The creole variety Pingo-de-ouro proved to be tolerant to salinity.

The dynamic of pH and EC in the Katingan tidal irrigation system, under influences of acid water, brackish water, and tidal movement

The Katingan tidal irrigation area frequently experiences high salinity due to its coastal position and acidity due to the acid sulphate soil type and water discharge from the neighboring peat forests. This study aims to investigate the dynamic of pH and Electrical Conductivity (EC) caused by the interaction of peat water and brackish water, which is impacted by tides in an acid sulphate soil environment. Field measurements were conducted to collect data on water level, pH, and EC in both channels and fields. The dynamic of acid water from peat forests and acid sulphate soils with brackish water in the irrigation network was investigated using HEC-RAS simulations. The simulation incorporates water level, EC, and pH recorded at the Katingan River from December 22, 2022, to January 5, 2023. The results of simulations are calibrated with observed data at the main channel. The influence of brackish water on increasing pH and EC (pH = 5–7, EC = 0∼5.94 dS/m) is more significant in hydrotopography Type A, but it is less significant (pH = 4∼5.5, EC = 0∼2.25 dS/m) in hydrotopography Type B, which is less affected by brackish water. The water pH is more acidic in hydrotopography Type C, which is not impacted by tides. These simulation results may serve as a foundation for developing and operating sluice gates to improve water quality by allowing or preventing the entry of water into the irrigation network.

ЭКОЛОГИЧЕСКОЕ СОСТОЯНИЕ ВОДОЕМОВ ГОРОДСКОЙ ЧЕРТЫ КАЛИНИНГРАДА НА РАЗНЫХ ЭТАПАХ БЛАГОУСТРОЙСТВА

In this paper, we describe the hydrological-hydrochemical and hydrobiological conditions in 3 ponds from Kaliningrad city as registered in the summer of 2021–2022. The list of analyzed indicators included transparency, water temperature, pH value, TDS, water electrical conductivity, dissolved oxygen, permanganate value, nutrients, water hardness. The state of algae and zooplankton within the study period was described and assessed. Based on the survey results, the obtained values were identified pursuant to the scale of hydrochemical transformation. The well-maintained Poplavok pond, where supporting measures are regularly held, as well as the Lesnoye pond, a reservoir in the park area, are in a relatively favorable ecological condition. The ecological situation of the Letniy pond, according to the cumulative assessment, requires rehabilitation of the water body. This is confirmed by both hydrochemical and hydrobiological indicators.

Population dynamics of pelagic rotifers in Marala Headworks (Pakistan).

Research work was designed to investigate the density and diversity of pelagic rotifers in a Lake near Marala Headworks. The physico-chemical parameters of water such as pH, dissolved oxygen, temperature, electrical conductivity, transparency and turbidity were evaluated. Correlation between rotifers and these parameters was also studied. Plankton sampling was done on monthly basis in order to check the population density of rotifers. In total, 18 species of rotifers were identified which belonged to 11 genera. The highest number of rotifers and their diversity was shown by genera namely Brachionus, Keratella, and Filinia. The Brachionus calyciflorus was dominant species in all the samples with mean population density (41%). Analysis of variance of physico-chemical parameters presented that the air and water temperature, electrical conductivity, transparency, dissolved oxygen and oxygen saturation were statistically significant in all the months. While pH was statistically non-significant (p≥0.05. Pearson correlation showed that oxygen and transparency were negatively correlated with rotifers density and diversity. Air and water temperature, concentration of hydrogen ions (pH), electrical conductivity and salinity showed positive relationship with density and diversity of rotifers.

EC conversion for 1:5 extracts and standard saturated soil–water pastes in the assessment of arid land salinization: Classical methodologies revisited

The common assessment of soil salinity posits a linear function, which transfers the electrical conductivity (EC) of highly diluted extracts to the standard state of soil paste. Our study examines this assumption and explains its limitations in a wide range of EC for highly saline soils of the Aral region in Uzbekistan. For a comparative EC assessment in the liquid phase from standard soil pastes and 1:5 aqueous extracts we used portable EC–meters. The dependences of EC, total dissolved solids (TDS), and soil–water potential on the pore water content were evaluated using centrifugation to separate the liquid phase from the soil matrix. The non-linearity of the relationship between the EC of water from soil pastes and 1:5 water extracts for both average and median data over a broad (0.4–160 dS/m) range of their variation is detected. A strong retention and concentration of electrolytes in fine pores and water films resistant to vacuum extraction, as well as the nonlinear EC versus TDS relationship in highly saline soils are attributed to this nonlinearity. A comprehensive statistical analysis showed that despite the general non-linearity, in the EC range from 0 to 30–35 dS/m, the results for 1:5 extract can be reliably converted to the standard state using the dilution model for the liquid phase of the soil with one basic parameter of soil bulk density. For hypersaline soils (EC > 30–35 dS/m), conversion based on the dilution theory is unacceptable due to a strong underestimation of TDS.

A Simplified Approach for Estimating Ionic Concentrations from Specific Conductance Data in the San Francisco Estuary

This work presents a simplified approach for estimating ionic concentrations from specific electrical conductance (EC) data in the San Francisco Estuary. Monitoring the EC of water through electrodes is simple and inexpensive. As a result, a wealth of high-resolution time-series data is available to indirectly estimate salinity concentrations and, by extension, seawater intrusion throughout the study domain. However, scientists and managers are also interested in quantifying ionic (e.g., bromide, chloride) and total dissolved solids (TDS) concentrations to meet water-quality regulations, protect beneficial uses, support environmental analyses, and track source-water dominance. These constituent concentrations, reported with lower spatial and temporal resolution than EC, are typically measured in the laboratory from discrete (grab) water samples. We divided the study domain into four unique regions to estimate concentrations of major ions and TDS as mathematical functions of measured or model-simulated EC. Salinity relationships in three of the four regions—regions that represent Sacramento-San Joaquin Delta (Delta) inflow and seawater-dominated boundaries—reflect ionic make-ups that are either independent of or weakly dependent on season and hydrologic condition, and are highly correlated with EC. The fourth region—represented by the interior Delta—exhibits salinity characteristics associated with complex-boundary source-water mixing that varies by season and hydrologic condition. We introduce a novel method to estimate ionic and dissolved solids concentrations within this fourth region, given month, water year type, and (optionally) X2 isohaline position, which allows for more accurate EC-based estimates than previously available. The resulting approach, while not a substitute for hydrodynamic modeling, can provide useful information under constrained schedules and budgets.

Multidimensional trait variability in a widespread, Paleoarctic macrophyte: functional, spectral and genetic drivers

Understanding how environmental conditions and plant functional variation are mutually related is critical to improving our comprehension of plant adaptations. In this context, our knowledge of the interlinks between plant functional, spectral and genetic traits and environmental filters is still very limited, especially for wetland species. To gain new insights on this topic, a multidimensional dataset, centred on the widespread macrophyte species Nuphar lutea, was assembled by collecting data on functional traits (including spectral traits), genetic metrics and environmental determinants from 28 plots spanning north‐central Italy. A strong environmental filter acts on all traits (morphological, biochemical, spectral and the genetic diversity metrics) resulting in significant local control over trait patterns, exemplified by the discrimination value of water electrical conductivity. This is further reinforced by the key contribution of sediment variables in explaining traits variation. Site‐specific environmental conditions were reflected in different patterns of genetic diversity, suggesting a long‐term effect of environmental filters on genotypes as well. High water conductivity – in our study sites indicative of long‐term hydrogeological settings – is linked to more acquisitive behaviour in N. lutea and a progressive reduction in its genetic diversity, while high nutrients availability in sediments promotes higher leaf traits performance. This study better explores how high variability in leaf traits reinforces current genetic and mechanistic knowledge about competitive strategies in the key aquatic plant N. lutea, by testing the effectiveness of a novel integrative approach to assess multiple sources of plant functional variation.

Morfofisiologia de gravioleira sob estresse salino e aplicação de H2O2 na fase de pré-floração

ABSTRACT In the semi-arid region of the Brazilian Northeast, water sources generally have high levels of salts, standing out as one of the abiotic stresses that restrict the growth and development of plants. In this context, the objective of the present study was to evaluate the effects of foliar applications of hydrogen peroxide on the morphophysiology of soursop under salt stress in the pre-flowering phase. The experiment was carried out in a greenhouse, using a randomized block design and a 4 × 4 factorial arrangement, with four values of electrical conductivity of the irrigation water - ECw (0.8, 1.6, 2.4, and 3.2 dS m-1) and four concentrations of hydrogen peroxide - H2O2 (0, 10, 20, and 30 μM), with three replicates. An increase in water electrical conductivity from 0.8 dS m-1 reduced stomatal conductance, CO2 assimilation rate, instantaneous carboxylation efficiency, and leaf water saturation deficit. It inhibited the growth of soursop plants at 370 days after transplanting. Hydrogen peroxide at concentrations of up to 10 μM increased leaf transpiration and water use efficiency of soursop plants irrigated with 1.8 dS m-1 water in the pre-flowering phase.

A multiscale accuracy assessment of moisture content predictions using time-lapse electrical resistivity tomography in mine tailings

Accurate and large-scale assessment of volumetric water content (VWC) plays a critical role in mining waste monitoring to mitigate potential geotechnical and environmental risks. In recent years, time-lapse electrical resistivity tomography (TL-ERT) has emerged as a promising monitoring approach that can be used in combination with traditional invasive and point-measurements techniques to estimate VWC in mine tailings. Moreover, the bulk electrical conductivity (EC) imaged using TL-ERT can be converted into VWC in the field using petrophysical relationships calibrated in the laboratory. This study is the first to assess the scale effect on the accuracy of ERT-predicted VWC in tailings. Simultaneous and co-located monitoring of bulk EC and VWC are carried out in tailings at five different scales, in the laboratory and in the field. The hydrogeophysical datasets are used to calibrate a petrophysical model used to predict VWC from TL-ERT data. Overall, the accuracy of ERT-predicted VWC is pm 0.03~textrm{m}^3/textrm{m}^3, and the petrophysical models determined at sample-scale in the laboratory remain valid at larger scales. Notably, the impact of temperature and pore water EC evolution plays a major role in VWC predictions at the field scale (tenfold reduction of accuracy) and, therefore, must be properly taken into account during the TL-ERT data processing using complementary hydrogeological sensors. Based on these results, we suggest that future studies using TL-ERT to predict VWC in mine tailings could use sample-scale laboratory apparatus similar to the electrical resistivity Tempe cell presented here to calibrate petrophysical models and carefully upscale them to field applications.

Application of Benthic Microbial Fuel Cells in Systems of Year-Round Monitoring of Water Environment Parameters

The bioelectrogenic activity of sediments of natural microbial association of the Peter’s Bay of Japanese sea research was performed in a year-round experiment with parallel temperature, illumination and water electrical conductivity monitoring by means of benthic microbial fuel cell (MFC) and automatic online-monitoring. Several variants of underwater devices, including benthic microbial fuel cells, monitoring water environment sensor,information collection and transmission systems, have been developed. This device make electrical voltage up to 216 mV, specific power up to 239 mW/m2. Electrogenic activity of natural microflora depends on water temperature and reach maximum on summer with temperature about 20–25°C. The introduction of toxicants in form as hydrocarbons and cadmium into the sluge led to the suppression of microbial electrogenesis. However the introduction of inductor substances of microbial sulfidogenesis led to the stimulation of microbial electrogenesis. The possibility of functioning of the benthic MFC in the field of the Peter’s Great Bay in various climatic periods is shown. It is shown that such experimental devices serve as a basis for autonomous stations monitoring the state of the aquatic environment for a long time and in a wide range of conditions change. Thus, automatic registration of temperature, illumination and salinity of water with a frequency of 48 times a day was carried out for 13 months (11/28/2019–12/31/2020). The electrogenic activity of this microbiota upon MFC scaling can potentially become a new renewable energy source for low-power marine electronics, including those used in mariculture.

Irrigation Water Source Matters: Saline Groundwater Irrigation Lowers Date Palm Root-Associated Fungal Richness and Alters Their Community Structural Patterns

Saline groundwater irrigation is commonly used in arid regions of the Middle East and North Africa for date palm ( Phoenix dactylifera) cultivation, yet little is known about its impact on communities of root-associated fungi (RAF). We investigated the impact of irrigation water sources (freshwater versus saline groundwater) on date palm RAF diversity, communities, and their assembly processes. RAF richness was lower in roots under saline groundwater irrigation and was significantly related to soil and water electrical conductivity (EC), and only 25.3% of the total operational taxonomic units (OTUs) were strictly found in roots under saline groundwater irrigation. Overall, the RAF communities were distinct among irrigation water sources, wherein water pH and EC were the major structuring factors. The relative importance of drift assembly was higher for RAF distribution under saline groundwater irrigation. Saprotrophic and pathotrophic communities were also distinct between irrigation water sources and shaped by irrigation water pH. In addition, we found higher abundance of saprotrophic OTUs Acrocalymma vagum, Coprinopsis sp., and Myrothecium sp. in roots under saline groundwater irrigation. In summary, we show that saline groundwater irrigation lowers RAF richness and alters overall and guild level RAF communities (saprotroph and pathotroph), which assemble mainly through drift process, wherein overall communities are shaped by irrigation water pH and EC, while saprotrophic and pathotrophic communities are structured by water pH. The high abundance of specific saprotrophs under saline groundwater irrigation indicates their potential role in nutrient cycling and plant growth promotion in arid agroecosystems.

Empowering People With Disabilities: Designing An Innovative And Sustainable Hydroponics System

Science has rendered its blessings to human kind in numerous ways. The sector of agriculture demands workers with great physical strength, rendering it difficult for the disabled to contribute productively. The solution lies in a hydroponic garden. A large variety of plants, such as tomatoes, lady’s finger, brinjal, chillies, several types of leafy vegetables, pineapples, etc. can be grown hydroponically. Combining sustainable technology and modern farming techniques opens up new big business opportunities. All it requires is a small piece of land and a few sensors to control and monitor the growth of plants, which could be done with very little physical effort. This will generate a supportive environment for PwDs, creating employment opportunities and enabling them to participate in mainstream economy of their nation. Smart farming, hydroponic gardening, with no soil and a controlled environment is rapidly becoming a favourite and has a promising market. The Indian hydroponic market is expected to grow at a CAGR (Compound Annual Growth Rate) of 13.53 per cent between 2020-2027, with the corresponding growth in the global market estimated at just half at ~6.8 percent. In addition, lab tests have shown that hydroponic produce is nutritionally either as good or even better than organic in many cases. The methodology involves using a microcontroller namely Arduino and simulating circuits using online software called Tinkercad. Arduino helps to keep track of physical parameters like temperature, electrical conductivity of water and distance of water surface from a reference point for a hydroponics system. All the physical parameters can be reflected on a computer screen and easily controlled and handled, even by people with disabilities. Use of technology in this manner can be applied for empowering workers with disabilities in field of agriculture.

Jackfruit (Artocarpus heterophyllus Lam.) grafting as affected by nitrogen fertilizer application to irrigation water

Selection of superior jackfruit (Artocarpus heterophyllus Lam.) strains has been seen in recent years in various tropical and subtropical areas, and vegetative propagation by grafting has become widely practiced. However, jackfruit is still a relatively difficult species to propagate through cleft grafting, in which scion is detached from the mother tree. Sufficient callus formation at the grafting joint is critical for grafting success; therefore, I hypothesized that application of fertilizers to the rootstocks before and after grafting operations would promote callus formation. Nitrogen (N) is known as the most important nutrient for plant growth and callus formation. Therefore, in this study, I focused on the effect of different types, concentrations, and frequencies of N fertilizer application to jackfruit rootstocks, before and after grafting, by mixing it with irrigation water. Effect of N fertilizer application on grafting success and callus formation at the joint was investigated, and rootstock management was optimized to improve grafting success. Application of KNO3 (1.6–9.2 mM) to post-grafted rootstocks, via irrigation water, resulted in a two-fold increase in grafting success (60 %) at 1.6 mM concentration, compared to that without N fertilizer. Grafting success gradually decreased at higher concentrations of KNO3; at 5.6 mM, success percentage was similar to that without N fertilizer; at 9.2 mM, it was less than 20 %. Callus formation at the joint was enhanced at higher concentrations of N fertilizer; however, leaf burns occurred on the rootstock when KNO3 > 5.6 mM. When KNO3 was replaced with (NH4)2SO4 (1.5 mM), the success percentage remained low and was similar to that without N fertilizer. Regardless the type of N fertilizer, the success percentage was significantly higher when low concentrations (3.6 mM) of N fertilizer were applied three times a week (smaller fluctuations in soil water electrical conductivity [EC]), compared to applying high concentrations (10.7 mM) once a week (larger fluctuations). The success percentage were higher for younger rootstocks (less than one-year old) than for those over one-year old. Our findings demonstrated that jackfruit grafting success can be improved by adding low concentrations of KNO3 to daily irrigation water, for about one month after grafting operations, to maintain a stable EC of 40 mS m−1 in the soil water.

Application of solid phase adsorption toxin tracking technology (SPATT) for monitoring microcystins in farm dams in Levubu farming area, South Africa

South Africa has scarce freshwater resources most of which are being affected by eutrophication and the resultant harmful algal blooms (HABs). Irrigation of edible plants with cyanobacteria-infested water poses an indirect threat to humans since cyanotoxins can be bioaccumulated in the irrigated plant tissues. The study assessed the applicability of the solid phase adsorption toxin tracking technology (SPATT) as an early warning tool for the passive sampling of microcystins (MCs) in farm dams around Levubu area and determine the physicochemical parameters that correlate to toxin loads in the farm dams.Three farm dams were selected and sampled monthly from June to November 2021. Physicochemical parameters monitored included electrical conductivity (EC), pH, Temperature, total dissolved solids (TDS), turbidity, chlorophyll-a and total dissolved nitrates and phosphates.Findings showed that the water temperature, pH, EC and TDS were all within optimal range for the growth of cyanobacteria. Nutrients (phosphates and nitrates) were below the detection limit. Chlorophyll-a ranged from 0.355 to 14.07 μg L−1, indicating oligotrophic to mesotrophic eutrophic status of the rivers. Among cyanoHABs identified were the Microcystis and Lyngbya genus.Both grab and SPATT samplers detected MCs in all the farm dams throughout the sampling period but there was no correlation between the MCs detected by the two methods. None of the physicochemical parameters correlated with phytoplankton biomass nor with MC levels in the water. The use of SPATT increased the likelihood of detecting MCs thus indicating the applicability of SPATT as a useful early warning tool for the presence of MCs to the water users.

Optimizing Sugarcane Growth, Yield, and Quality in Different Ecological Zones and Irrigation Sources Amidst Environmental Stressors.

The imbalanced use of fertilizers and irrigation water, particularly supplied from groundwater, has adversely affected crop yield and harvest quality in sugarcane (Saccharum officinarum L.). In this experiment, we evaluated the impact of potassium (K) and micronutrients [viz. Zinc (Zn), Iron (Fe), and Boron (B)] application and irrigation water from two sources, viz. canal, and tube well water on sugarcane growth, yield, and cane quality under field trails. Water samples from Mardan (canal water) and Rahim Yar Khan (tube well water) were analyzed for chemical and nutritional attributes. The results revealed that tube well water's electrical conductivity (EC) was three-fold that of canal water. Based on the EC and total dissolved salts (TDS), 83.33% of the samples were suitable for irrigation, while the sodium adsorption ratio (SAR) indicated only a 4.76% fit and a 35.71% marginal fit compared with canal water. Furthermore, the application of K along with B, Fe, and Zn had led to a significant increase in cane height (12.8%, 9.8%, and 10.6%), cane girth (15.8%, 15.6%, and 11.6%), cane yield (13.7%, 12.3%, and 11.5%), brix contents (14%, 12.2%, and 13%), polarity (15.4%, 1.4%, and 14%), and sugar recovery (7.3%, 5.9%, and 6%) in the tube well irrigation system. For the canal water system, B, Fe, and Zn increased cane height by 15.3%, 13.42%, and 11.6%, cane girth by 13.9%, 9.9%, and 6.5%, cane yield by 42.9%, 43.5%, and 42%, brix content by 10.9%, 7.7%, and 8%, polarity by 33.4%, 28%, and 30%, and sugar recovery by 4.0%, 3.9%, and 2.0%, respectively, compared with sole NPK application. In conclusion, the utilization of tube well water in combination with canal water has shown better results in terms of yield and quality compared with the sole application of canal water. In addition, the combined application of K and B significantly improved sugarcane yields compared with Zn and Fe, even with marginally suitable irrigation water.