Nutrient Analysis Research Articles

Comparison of rhizobacterial communities between secondary forest and palm oil plantations in East Kalimantan, Indonesia

Abstract. Yuliatin E, Hariani N, Dharma B, Patang F, Budiman. 2025. Comparison of rhizobacterial communities between secondary forest and palm oil plantations in East Kalimantan, Indonesia. Biodiversitas 26: 490-499. The conversion of primary forests to plantations is considered a sustainable form of land management; however, its implications for soil rhizobacterial diversity remain insufficiently explored. This study compared the rhizobacterial communities associated with Palm oil Plantation (PP) and Secondary Forest (SF) in East Kalimantan using a metagenomic approach. The soil samples were collected around the Secondary Forest soil (SF) and Palm oil Plantation soil (PP) plant roots in Berambai, Samarinda. The samples were then analyzed for soil physico-chemical properties such as pH, nitrogen (N), phosphorus (P), potassium (K), organic matter, and C/N ratio. At the same time, the rhizobacterial diversity was analyzed using a metagenomic analysis through Illumina Hiseq. Soil physico-chemical assessments showed acidic conditions in both soils, with PP being more acidic (pH 4.41) than SF (pH 5.38); nutrient analysis indicated medium nitrogen levels and high organic carbon in both soils, while PP had elevated P content due to fertilization. Metagenomic analysis revealed similar rhizobacterial richness, but diversity was slightly higher in PP. Dominant phyla included Proteobacteria and Acidobacteriota, with notable orders like Rhizobiales and Acidobacteriales. The functional analysis highlighted rhizobacterial roles in organic decomposition, plant growth promotion, and nitrogen fixation, illustrating ecological adaptation to soil conditions and management practices. This study provides insights into the rhizobacterial functional diversity in distinct soil environments.

Horses with previous episodes of laminitis have altered insulin responses to seasonal oral sugar testing and grazing compared to horses with no known history of laminitis

Forage is essential for equine health and performance, but intake of elevated pasture nonstructural carbohydrates (NSC) may exacerbate metabolic disorders. This study aimed to investigate the influence of laminitis history on metabolic and morphometric responses in grazing horses. Twelve non-pregnant mares (15 ± 3.4 yrs) were selected based on previous diagnosis of laminitis (PRELAM; n=6) or not (NOLAM; n=6). Horses were maintained on 8.5-ha pasture. Weekly pasture samples were clipped at random for nutrient analysis. Monthly blood samples were collected and analyzed for glucose and insulin concentrations. Body weight (BW), body condition score (BCS), and cresty neck score (CNS) were evaluated monthly. Each month, a modified oral sugar test (OST) was used to assess basal (T0) and 75-minute (T75) insulin dynamics following 0.30 mL/kg BW Karo Light Corn Syrup. Data were analyzed using PROC MIXED with repeated measures (SAS Institute). PRELAM had greater CNS (P < 0.001), BW (P < 0.05), and BCS compared to NOLAM (P < 0.05). Non-fasted glucose was influenced by month (P < 0.001) while non-fasted insulin was affected by group by month (P = 0.004). Fasted insulin concentrations (T0) were affected by month and group (P < 0.001) where PRELAM had greater concentrations. T75 glucose and insulin concentrations were affected by month (P < 0.001 and P = 0.002, respectively) and were higher for PRELAM (P = 0.003). These data suggest horses with greater general and regional adiposity, and previous history of laminitis, often exhibit greater insulin concentrations on pasture and to OST.

Water quality within the greater Suva urban marine environment through spatial analysis of nutrients and water properties.

Coastal ecosystems in Pacific Island Countries and Territories are vital to local livelihoods, yet increasingly face pressures from urbanization. In Fiji, the Greater Suva Urban Area, where one-third of the nation's population live, exemplifies these challenges. This study examines spatial and temporal water quality variations in the coastal zone, focusing on physicochemical, nutrients, and clarity parameters. Using a Seabird Scientific SBE19 CTD and Thermo Scientific Orion™ AQUAfast™ colorimeter, coupled with hierarchical clustering and principal component analysis, six water quality clusters were identified, influenced by oceanic processes, river inputs, and anthropogenic activities. Key findings highlight nutrient enrichment near urban centers particularly at the Kinoya Sewage Treatment Plant outfall, where ammonia exceeded 17.8mg/L, and significant variation observed in nitrate (up to 0.24±0.06mg/L) and nitrite (up to 0.24±0.06mg/L) concentrations near river mouths. Seasonal runoff contributed to elevated turbidity (up to 3.5 NTU) and total suspended solids (up to 14.7mg/L) levels during wet months. Salinity, and temperature exhibited strong spatial and seasonal variability, reflecting land-ocean interactions and restricted water exchange. These findings emphasize the need for targeted action to mitigate nutrient pollution, urban runoff, and wastewater impacts. This study provides a cost-effective monitoring framework for water quality management, offering insights for sustainable coastal resource management in Fiji and other Pacific regions amidst urbanization and climate change.

Digestion, faeces microbiome, and selected blood parameters in dogs fed extruded food containing Black soldier fly (Hermetia illucens) meal

The aim of this study was to determine the effects of using black soldier fly (Hermetia illucens) (HI) at 0% (HI0), 7.5% (HI75) and 15% (HI150) larva meal instead of chicken meal in extruded dog food. A total of 18 Golden Retriever were used. In the study, HI larva meal was obtained and after detailed nutrient analysis, it was extruded as a dog food formulation instead of chicken meal. The foods were first subjected to in vitro digestion. Then, in vivo feeding in dogs was performed to determine preference test, digestion, blood variables and faecal microbiome, faecal score and organic acids. The HI larva meal up to 15% in dog food linearly increased the molarities of acetic (AA) and propionic (PA) acids in faeces (p <.05), but linearly decreased the molarities of butyric (BA) and valeric (VA) acids (p < 0.05). Iso-butyric (IBA), iso-valeric (IVA) and iso-caproic (ICA) acids in faeces decreased linearly with HI larva meal (p < .05). The relative abundances of Phascolarctobacterium, Megamonas, Collinsella and Fournierella genera were higher in faeces of HI75 than those of HI0 (p <.05). The relative proportion of Ligilactobacillus increased with HI larva meal (p < .05). As a result, HI larva meal can be used up to 100% instead of chicken meal in extruded dog food without any negative effects on body weight, digestibility, faecal score, consumption preference, kidney-liver enzyme activities and immunological parameters. Besides, HI larva meal at 7.5% and 15% in extruded dog food had different effects on the faecal microbiome.

Impact of intermittent stream flow on water quality and structural composition of macroinvertebrates in a semi-arid region of South Africa

Abstract. Matita TP, Addo-Bediako A, Luus-Powell W. 2024. Impact of intermittent stream flow on water quality and structural composition of macroinvertebrates in a semi-arid region of South Africa. Biodiversitas 25: 5074-5082. This study investigated the impact of varying flow regimes on water quality and the structural composition of macroinvertebrates in the Moopitse River, South Africa. Samples were collected during three distinct flow conditions: high flow, low flow, and intermittent flow. Water quality parameters were measured in situ, and water samples were collected for nutrient analysis before macroinvertebrate sampling. A total of 4,094 individuals, representing seven orders and 22 families, were recorded. The assessment, based on water quality and macroinvertebrate structure, revealed that intermittent flow (cessation of flow) negatively affected both water quality and the distribution of macroinvertebrates. There was a decline in both taxa richness and abundance in response to flow intermittency. The observed low taxa richness and abundance, particularly during high flow and intermittent regimes, align with expectations for such hydrologically extreme habitats. Compared to the perennial rivers in the Olifants River Basin, the Moopitse River is less diverse, as the intermittent environment favors generalist and stress-tolerant taxa rather than sensitive taxa. Water parameters such as turbidity, conductivity, total dissolved solids (TDS), and nutrient levels were significantly higher during intermittent flow, while dissolved oxygen levels were notably lower. Overall, water quality was best during low flow, which also supported greater macroinvertebrate richness and abundance. These findings suggest that river discontinuity may lead to habitat degradation, thereby altering the structural distribution of macroinvertebrate communities. Understanding the effects of flow variation and habitat changes is crucial for environmental and biodiversity conservation. Therefore, conservation strategies should incorporate innovative approaches to mitigate the impacts of flow discontinuities and habitat degradation.

Exploring Predictors of Type 2 Diabetes Within Animal-Sourced and Plant-Based Dietary Patterns with the XGBoost Machine Learning Classifier: NHANES 2013-2016.

Background/Objectives: Understanding the relationship between dietary patterns, nutrient intake, and chronic disease risk is critical for public health strategies. However, confounding from lifestyle and individual factors complicates the assessment of diet-disease associations. Emerging machine learning (ML) techniques offer novel approaches to clarifying the importance of multifactorial predictors. This study investigated the associations between animal-sourced and plant-based dietary patterns and Type 2 diabetes (T2D) history, accounting for diet-lifestyle patterns employing the XGBoost algorithm. Methods: Using data from the National Health and Nutrition Examination Survey (NHANES) from 2013 to 2016, individuals consuming animal-sourced foods (ASF) and plant-based foods (PBF) were propensity score-matched on key confounders, including age, gender, body mass index, energy intake, and physical activity levels. Predictors of T2D history were analyzed using the XGBoost classifier, with feature importance derived from Shapley plots. Lifestyle and dietary patterns derived from principal component analysis (PCA) were incorporated as predictors, and high multicollinearity among predictors was examined. Results: A total of 2746 respondents were included in the analysis. Among the top predictors of T2D were age, BMI, unhealthy lifestyle, and the ω6: ω3 fatty acid ratio. Higher intakes of protein from ASFs and fats from PBFs were associated with lower T2D risk. The XGBoost model achieved an accuracy of 83.4% and an AUROC of 68%. Conclusions: This study underscores the complex interactions between diet, lifestyle, and body composition in T2D risk. Machine learning techniques like XGBoost provide valuable insights into these multifactorial relationships by mitigating confounding and identifying key predictors. Future research should focus on prospective studies incorporating detailed nutrient analyses and ML approaches to refine prevention strategies and dietary recommendations for T2D.

Photon budgets and the relative effects of CDOM and pigment absorptions on primary production along a coastal salinity gradient

The study highlights the critical role of CDOM in coastal light attenuation and its impact on primary production (PP). We investigated the spectral attenuation of light due to water, phytoplankton pigments, detritus and coloured dissolved organic matter (CDOM) along a salinity gradient in the outer Oslofjord, Norway. By examining the effects of these components across different seasons, we aimed to elucidate their relative contributions to light absorption and PP. The findings suggest that increased terrestrial CDOM inputs, driven by climate, changed atmospheric deposition and land-use changes, could significantly affect coastal ecosystems by altering light attenuation and consequently PP and potentially leading to other ecological pressures. CDOM consistently dominated light absorption across all stations and seasons, contributing 50%–80% of the total absorption of photosynthetically active radiation. The absorption by CDOM and detritus decreased with increasing salinity, while phytoplankton absorption followed a seasonal succession. PP estimates show high seasonal variability from maximums in June to minimums in November, mainly attributed to, changes in seasonal light availability and phytoplankton biomass, followed by light attenuation by CDOM and differences in quantum yields of photosystem II (PSII). Nutrient analysis showed a seasonal pattern, with the highest nitrogen concentrations in November and depletion during more productive seasons, as well as conservative mixing throughout the salinity gradient. CDOM absorption played substantial, albeit not leading, role in influencing PP estimates, derived from a bio-optical model. CDOM was the main determinant of light attenuation across most wavelegnths.

Isolation and Characterization of Major Cultivable Bacteria from Novel Natural Fertilizer with Comprehensive Nutrient Analysis

Ancient Natural Fertilizer (Jivamrit) is a traditional liquid natural mixture that undergoes fermentation and is frequently applied to enhance the soil microbiome. It is a great source of biomass with macro and micronutrients needed by crops, as well as increasing the organic carbon in the soil. With a thorough nutritional analysis that included bacterial isolation, biochemical tests, and bacterial identification by 16S rRNA sequencing, and nutrient analysis of Jivamrit, the current study concentrated on the isolation along with characterization of the major culturable bacteria from Jivamrit prepared using Gir cow native to Gujarat, India. Jivamrit yielded a total of fifteen major isolates, which were utilized for biochemical analysis and morphological evaluation. The biochemical analysis (catalase, indole synthesis, methyl red, VP test, urease, citrate, sucrose fermentation) and plant growth-promoting assays were performed on all isolated bacteria. The chemical analysis of Jivamrit revealed that it contains large amounts of macro and micronutrients and, importantly, contains Azotobacter, Zinc solubilizing bacteria, and total potash mobilizing bacteria. Molecular characterization of bacterial isolates was performed by amplifying the 16S rRNA gene using bacterial universal primers. PCR-amplified product was sequenced and was carried out, and its analysis revealed that the majority of isolates belong to the Bacillus and Priestia genera. A phylogenetic and evolutionary analysis imparts that the majority of isolates belonged to a different Bacillus species, while JW6 and JW9 belonged to Priestia megaterium. Thus, the present study revealed that major cultivable Bacillus and Priestia bacterial genus are present in Jivamrit. A literature survey revealed that the identified species immensely contribute to increasing soil fertility, plant growth, and yield. Therefore, Jivamrit acts as an alternative to chemical manure and works as a natural fertilizer, which minimises the hazardous effects of chemical farming practices on human well-being and the surroundings.

Impacts of long-term irrigation of municipally-treated wastewater to the soil microbial and nutrient properties.

Reusing treated wastewater (TWW) for crop irrigation has shown to provide environmental and economic benefits as well as drawbacks. This study was conducted using soils collected from a wastewater reuse facility in Tallahassee, FL, mainly to elucidate the long-term impact(s) of TWW irrigation on soil microbiome and nutrient status. Approximately 890ha of land have been spray-irrigated with TWW since the 1980's to grow fodder crops. Soil cores were collected from six irrigated and six control sites at depths of 0-15, 15-30, and 30-60cm during summer and winter, followed by nutrient analysis and assessment of bacterial, fungal, and denitrifier communities using SSU rRNA, ITS, nirK, nirS, and nosZ phylogenetic markers. TWW irrigation significantly increased soil pH, soluble salts, nitrate, phosphate, calcium, magnesium, and organic matter, alongside shifts in the prokaryotic and fungal community structures, particularly in summer. Beta-diversity analyses indicated that wastewater quality and season collectively explained 23% of prokaryotic community similarity and 9.8% of fungal community dissimilarity. Indicator species analysis, supported by random forest machine learning, identified 37 prokaryotic and 11 fungal bioindicators whose occurrences varied significantly with wastewater quality and season. Key nitrogen-cycling microbes included ammonia-oxidizing families of Nitrosomonadaceae, Nitrosopumilaceae, Nitrososphaeraceae, Nitrosotaleaceae, and comammox-performing Nitrospiraceae. The fungal community was predominated by Ascomycota (78.6%±4.2%). FUNGuild analysis showed dominant trophic levels of symbiotrophs, saprotrophs, and pathotrophs, averaging 42%±7.1%. Overall, this study points to the long-term impacts of TWW irrigation on the studied soil properties and microbial communities.

Performance Efficiency of Selected Medium Culture and Raft Systems for Waste Removal in a Small‐Scale Aquaponics Production System

Aquaponics systems integrate aquaculture and hydroponics to create a sustainable method for food production by recycling nutrients. However, nutrient waste management in aquaponics systems remains a challenge, particularly in achieving optimal growth for both fish and plants while minimizing environmental impacts. This study compared the effectiveness of raft and selected medium culture systems in removing waste from a small‐scale aquaponics production system that included leafy vegetable crops (Brassica oleracea) and Nile tilapia (Oreochromis niloticus). The aquaponics systems comprised of four hydroponics systems: three media based (charcoal, perlite, and pumice) and one raft system in a completely randomized design. The crops were cultivated in the hydroponic units, while O. niloticus fingerlings were reared in the fish tanks for 22 weeks. To compare the various hydroponics systems, growth metrics for the fish (weight and length) and plants growth parameters such as leaf index and biomass, as well as nutrient analysis were monitored and documented. Physicochemical parameters of the culture water were also monitored. Fish grown in the perlite medium had significantly higher mean final length and weight compared to other aquaponics setups in the study (p &lt; 0.05). Plants grown on pumice had significantly more total biomass than other media (p &lt; 0.05) and had the highest crude protein (CP) content, while those planted on perlite had the highest crude lipid content (p &lt; 0.05). The charcoal medium was the most effective, lowering total ammonia nitrogen (TAN) levels by up to 67.1%. Pumice showed the highest total suspended solids (TSSs) retention capacity (p &lt; 0.05), resulting in a 25.9% drop in TSS levels. The raft system was the least effective at reducing aquaculture nutrient waste. This study demonstrated that the choice of hydroponics media is important in optimizing aquaponics systems for both plant and fish growth.

Mannitol Induces Mercury Tolerance in Lettuce (Lactuca sativa) Through Improved Growth, Photosynthetic Efficiency, and Antioxidant Activity

ABSTRACTMercury (Hg) is a hazardous heavy metal that disrupts plant growth and metabolism, posing significant risks to agriculture and human health. The widespread use of Hg in industrial activities and agricultural chemicals has exacerbated Hg contamination in soil and water, resulting in severe phytotoxic effects on crops, including lettuce (Lactuca sativa L.). This study explores the potential of mannitol, an osmolyte known for its protective properties, to mitigate Hg‐induced stress in lettuce. Lettuce plants were exposed to Hg stress (10 mg L−1) and treated with foliar applications of mannitol (15 mM) to assess its impact on growth, photosynthetic performance, and oxidative stress responses. Under Hg stress, lettuce exhibited a significant reduction in relative growth rate (RGR) by 31% and relative water content (RWC) by 20%. However, mannitol treatment enhanced RGR by 18% and improved RWC by 13% in Hg‐stressed plants. Nutrient analysis revealed that mannitol treatment restored K, Fe, Mn, and Zn levels, which were otherwise depleted by Hg exposure. Photosynthetic parameters were adversely affected by Hg, with a 62% reduction in carbon assimilation rate (A). Mannitol treatment partially recovered A by 55% and improved PSII photochemistry, including Fv/Fm and Fv/Fo. Mannitol also moderated oxidative stress indicators, evidenced by decreased H2O2 and lipid peroxidation levels, and enhanced the activities of key antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POX), and catalase (CAT). The results indicate that mannitol treatment significantly alleviates Hg‐induced phytotoxicity in lettuce by improving growth, enhancing photosynthetic efficiency, and modulating oxidative stress responses. This study highlights the potential of mannitol as a viable strategy for mitigating Hg pollution effects, offering new insights into its application for improving crop resilience under heavy metal stress.

Land survey assistance and its potential for the provision of sustainable agricultural land in East Barito District [Pendampingan survei lahan dan potensinya untuk penyediaan lahan pertanian berkelanjutan di Kabupaten Barito Timur

The conversion of rice paddy fields into oil palm plantations and mining sites in East Barito Regency, Central Kalimantan, poses a significant threat to the sustainability of agriculture. If this trend continues, the availability of land suitable for farming will decline. This study aims to assist local communities in the identification and management of sustainable agricultural land. The activities were conducted in Wuran Village, Karusen District, East Barito Regency, Central Kalimantan, from July to August 2024. The methods employed in this community service include interviews and assistance in soil suitability surveys as well as analysis of nutrient content at the site. Interview results indicate that 90% of respondents found the program beneficial. Soil surveys, analyzed with pH as a primary indicator, revealed a low pH of 4.5, necessitating interventions to raise it closer to the neutral pH of 6. Efforts undertaken include improving water management through the construction of bunds and the application of lime. Nutrient analysis showed that nitrogen (N), phosphorus (P), and potassium (K) levels were categorized as moderate to low. To enhance land productivity, it is recommended to increase doses of urea, SP-36, and KCl according to guidelines, along with the application of organic amendments such as straw. In conclusion, the enthusiasm of the community for the assistance provided indicates the potential for sustainable agricultural practices on their land. The findings of this study are expected to serve as a reference for the development of more sustainable agricultural strategies in the region.

Handling of Ion-Selective Field-Effect Transistors (ISFETs) on Automatic Measurements in Agricultural Applications Under Real-Field Conditions

The use of ion-selective field-effect transistors (ISFETs) facilitates real-time nutrient analysis in agricultural applications, including soil analysis and hydroponics. The rapid digital availability of analysis results allows for the implementation of ion-specific fertilisation control. The success, accuracy, and robustness of measurements using ISFET technology strongly depend on the handling of the process. This article presents a detailed overview of the sub-process steps required for the implementation of a stable automated application-specific ISFET-based measurement. This article provides experience-based recommendations for handling the conditioning, full calibration, and single-point calibration of the ISFET sensors. The hypotheses were empirically tested under authentic conditions and subsequently integrated into an overall process optimisation strategy. A comprehensive investigation has been conducted with the objective of gaining a deeper understanding of the ISFET baseline drift and implementing corrective measures. The results show that the baseline drift can be quantified and taken into account in the evaluation of the ISFET measurements. The efficacy of these measures was validated using standard laboratory analyses.

Unravelling the role of Black Soldier Fly Frass (BSFF) in nutrient enrichment and growth promotion of groundnut (Arachis hypogaea L.)

The decomposition of organic waste by Black Soldier Fly (BSF) plays a potential role in plant growth promotion and soil nutrient enrichment. This study investigated the effect of different compost from food waste, vegetable &amp; fruit waste, cow manure, pig manure, poultry manure, TNPL (Tamil Nadu Newsprint and Papers Limited) bio sludge and combinations of these materials induced varied growth promotion on groundnut. A pot culture experiment evaluated shoot length, root length, germination percentage, plant biomass and vigour index. The best results were observed in the treatment combining hostel food waste and vegetable waste (50 %) with poultry manure (50 %) (T7), showing a shoot length of 20.34 cm, vigour index of 3629, plant biomass of 24.3 g, and germination percentage of 93.33%. Other treatments, such as food waste (T1) and vegetable and fruit waste (T2), showed vigour indices of 2561.6 and 2692.9, respectively, while the untreated control had the lowest vigour index of 900.4. Nutrient analysis of T7 compost revealed high levels of nitrogen (462 kg/ha), phosphorus (375 kg/ha), potassium (320 kg/ha) and micronutrients like iron (29.04 ppm) and zinc (7.58 ppm). GC-MS analysis identified growth-promoting compounds like Cyclohexanol (64.3 %), Glycerol (3.9 %) and Dibutyl phthalate (1.49 %). Metabolite set enrichment analysis (MSEA) highlighted pathways like fatty acid biosynthesis and glycerolipid metabolism, which support root development and stress tolerance. The results indicated that BSF compost, especially from food and vegetable waste with poultry manure, significantly enhances soil fertility and plant growth, providing a sustainable solution for organic waste management.

Drivers of consumption of plant-based meat alternatives and their nutritional contributions: A mixed methods approach.

Plant-based meat alternatives (PBMA) are considered an alternative to animal products. We aimed to understand the patterns and drivers of consumption of PBMA and their nutritional contributions using dietary modelling, whilst also considering the relevance of processing. This study used a mixed methods exploratory sequential approach. Semistructured online interviews (n = 19) with consumers and nonconsumers of PBMA were conducted. Thematic analysis of interviews considered drivers of PBMA consumption, with content used to develop personas to represent key concepts driving incorporation (or lack of intake) into dietary patterns. Diets were modelled for personas, based on recommended and typical population intake and with variations in processed foods based on the Nova food classification system, including PBMA. Diets were analysed against nutrient reference values. The main drivers of PBMA consumption were animal welfare, health improvement and environmental concerns. Convenience, cost, taste, processing and thoughts that the nutritional value of PBMA was lesser than meats were all described. Six personas were identified from the interview content. The three most disparate personas (age, dietary pattern and nutrient requirements) were used for dietary modelling. Nutrient analyses showed diets predominantly meeting reference values, with deficiencies more likely when modelled on food choices typical of population intake and diets excluding processed foods. This study found that PBMA may have beneficial nutritional qualities such as lower saturated fat and higher dietary fibre when compared to their meat equivalents. PBMA may have a place in a healthy diet, whilst alleviating animal welfare and environmental concerns which were identified as key drivers of consumption.

Study of Seasonal Variability of Ground Water Quality in Sarguja District (C.G.), India

Water is the vital essence, miracle of nature and the great sustainer of life. It is extremely essential for survival of all living organism. Ground water serves as a major source for drinking, irrigation and industrial purpose all over the world. Many factors affect the quality of groundwater and cause major health issues. Therefore regular monitoring of ground water quality is necessary. Present paper has formulated on the basis of assessment of impact of geological features and agricultural runoff in ground water sources of Sarguja district (C.G.) India. Water samples were collected from ten environmentally significant spots for analysis of physical, minerals, nutrients, agricultural qualities and toxic metallic and non metallic elements. The procured experimental values were subjected for the statistical evaluation and compared with the standard values prescribed by the water monitoring agencies BIS (2012) and WHO (2011). The result for pH recorded up to 10.0, turbidity (15.67 NTU), TS (720 mg/L), F- (15.67 mg/L), Fe (2.366 mg/L), Na (115 mg/L), in maximum concentration. The statistical parameter such as mean, standard deviation, standard error, % CV, correlation matrix and water quality index (WQI) were systematically calculated for pre monsoon, monsoon and post monsoon session. The obtained results are far away from the standard values which showed the investigated water samples are not suitable for drinking and agricultural purpose without prior treatment.

Assessment of faecal sludge quality, heavy metal contamination, and ecological risk: implications for sustainable agriculture

Pit latrines represent the predominant form of on-site sanitation in Botswana, posing unique challenges in faecal sludge (FS) management. The key concerns revolve around FS extraction, treatment, and safe disposal. Currently, co-treatment with wastewater is the primary approach, but it strains wastewater treatment plants (WWTPs) and compromises effluent quality. This study comprehensively assesses FS quality from pit latrines and evaluates the potential health risks when used in agriculture for soil improvement/amendment. Systematic sampling of soils at various depth intervals, approximately 30 cm apart, was conducted, followed by extensive laboratory analysis, including determination of heavy metals (copper, iron, lead, cadmium, zinc, manganese, and arsenic) using inductively coupled plasma atomic emission spectroscopy (ICP-OES) and nutrient analysis using ion chromatography (IC). The findings unequivocally demonstrate that FS from VIP (ventilated improved pit) latrines poses no significant health risks due to heavy metal content. Specifically, Geo-accumulation Index (Igeo) values for nickel (Ni), chromium (Cr), and arsenic (As) were consistently negative, indicating negligible risk of environmental contamination. Copper (Cu) concentrations averaged 40.36 mg/kg in samples collected from Mogoditshane and 591.61 mg/kg in those collected from Broadhurst (Gaborone, Botswana) with Igeo values indicating a moderate pollution risk. Nutrient analysis showed high levels of nitrogen (NO3−), with concentrations reaching 4.47 × 103 mg/kg in some samples, and phosphorus (PO43−) levels as high as 3.9 × 104 mg/kg. These findings highlight its agricultural potential for soil amendment, though prudent management is needed to mitigate eutrophication. The study advocates for separate FS treatment, resolving co-treatment operational challenges and enhancing sustainability. Implementing these recommendations promises to address FS management issues, bolster food security, and enhance Botswana’s ecological well-being.

Review of the Innovations and Challenges in Developing Rapid Colorimetry and Turbidity NPK Soil Test Kits for Commercial Soil Nutrient Analysis

Review of the Innovations and Challenges in Developing Rapid Colorimetry and Turbidity NPK Soil Test Kits for Commercial Soil Nutrient Analysis

Influence of Continuous and Short-Term Direct Current Stimulation on the Growth and Nutrient Composition of Nitzschia closterium f. minutissima with Prospects for Large-Scale Production

This study investigates the effects of continuous and short-term direct current (DC) stimulation on the growth and nutrient composition of Nitzschia closterium f. minutissima, a marine diatom with significant potential in aquaculture feed. We explored the optimal conditions of DC stimulation by applying both short-term and continuous treatments at varying voltages (0 V, 1 V, 3 V, 5 V, 10 V for short-term; 0 V, 0.05 V, 0.5 V, 1 V for continuous). The results demonstrated that short-term DC stimulation significantly enhanced cell density and lipid accumulation, with maximum cell density increasing by 13.14% under 1 V stimulation compared to the control. However, continuous stimulation was less effective and showed growth inhibition in several cases. Nutrient analysis revealed that short-term stimulation, particularly at 3 V, led to a 67.66% increase in lipid content, while moderate continuous stimulation (0.5 V) showed a 39.47% increase in biomass dry weight. These findings suggest that short-term DC stimulation is a promising approach to optimize microalgal growth and nutrient accumulation for large-scale aquaculture production.

Proximal Absorbance Calibration Method Using an Embedded Blank Reference RGB Sensor for Determination of Ion Concentrations

Accurate analyses and management of ion concentrations are crucial in precision agriculture. Modern technology-based methods are non-destructive and do not require sample preparation, enabling fast and accurate analysis; however, they have limitations when processing multiple samples. In this study, a multi-ion analysis system was developed for the prompt and accurate analysis of concentrations of important ions such as NO3−, HnPO4−, K+, Ca2+, and Mg2+. The RGB sensitivity control was automated through calibrations by applying a reference slot-based error rate across six slots between sample measurements, facilitating sample-to-sample comparisons and enabling accurate concentration analysis. By analyzing the correlation between each ion concentration and the proximal absorbance-based concentration prediction in the simultaneous analysis system, the accuracy was verified by achieving a coefficient of determination exceeding 0.99 for most ions. This system minimizes possible deviations between slots by using an automatic calibration algorithm, thereby facilitating the simultaneous analysis of multiple samples. This is important for saving time and cost and can help in real-time nutrient analysis and monitoring in agriculture.