Improving irrigation efficiency is essential for sustaining vegetable production in water-limited environments, yet field-scale evaluations of practical time-based automated drip irrigation systems remain limited. This study compared an Automated Drip Irrigation Treatment (ADIT) employing scheduled time-based irrigation with a Manually Operated Drip Irrigation Treatment (MDIT) under polythene mulch for brinjal ( Solanum melongena L. ) cultivation in sandy loam soil during the 2025 Yala season in Sri Lanka. Soil moisture dynamics, irrigation uniformity, root distribution, wetting patterns, crop water requirement, yield, and irrigation water-use efficiency (IWUE) were evaluated using field measurements together with CropWat and HYDRUS-1D simulations. ADIT achieved consistently higher irrigation performance, with Christiansen’s coefficient of uniformity (CU) of 91–93%, emission uniformity (EU) of 90–92%, and distribution uniformity (DU) of 88%, compared with 75–80%, 78–82%, and 72%, respectively, under MDIT. Improved water distribution resulted in more stable root-zone soil moisture conditions, while HYDRUS-1D simulations predicted substantially lower deep percolation losses under ADIT than MDIT during crop development. Field observations also showed greater lateral root spread (40.7 cm vs 33.0 cm), higher irrigation water-use efficiency (4.91 vs 3.37 kg m -3 ), and greater marketable yield (22.3 vs 16.7 t ha -1 ; 2.35 vs 1.62 kg plant -1 ) under ADIT. Because the evaluated irrigation configurations differed in hydraulic characteristics as well as irrigation control strategy, and the study was conducted as a single-season field-scale pilot without replicated treatment plots, the findings should be interpreted as comparative evidence of system-level performance rather than effects attributable solely to automation. Nevertheless, the evaluated ADIT configuration demonstrated considerable potential for improving irrigation performance and water productivity under sandy loam, semi-arid conditions, warranting validation through replicated experiments using hydraulically identical irrigation systems.
Background Brevibacillus , a spore-forming and resilient bacterium, thrives in diverse environments. This study investigated the plastic-degrading potential of three Brevibacillus spp. (SM1, SM2, and SM3) isolated from landfill soil near Dhaka, Bangladesh. Method The isolated strains were first characterized based on their optimal growth conditions, morphology, and biochemical properties. 16S rRNA gene sequencing and phylogenetic analysis were conducted to identify the isolates. Results All three isolates exhibited optimal growth at an alkaline pH of 8-8.5 and tolerated extreme conditions up to pH 11.5 and temperature 55 °C. SM1 and SM3 grew best at 30-37 °C, while SM2 favored 40-45 °C. Microscopy confirmed all isolates as Gram-positive, rod-shaped, and motile. Biochemical tests yielded positive results for oxidase, catalase, and citrate in all strains. SM1 exhibited the highest lipase activity, while esterase activity was higher in SM2 and SM3. A halo around SM2 on polyethylene glycol plates indicated potential degradation. All strains demonstrated the ability to utilize PET, LDPE, and LLDPE as sole carbon sources in degradation assays. The weight-loss analysis indicated greater LLDPE degradation efficiency over time in SM1 and SM3 compared to SM2. The DCPIP assay confirmed degradation of PET and LDPE by SM2. Molecular identification (16S rRNA and BLASTn) revealed 97% similarity to Brevibacillus species ( B. parabrevis , B. reuszeri , and B. brevis ). MSA and phylogenetic analyses confirmed their taxonomic placement within the Brevibacillus genus. Conclusion These findings highlight the potential of wild-type Brevibacillus spp . isolated from Bangladeshi landfill soil for application in plastic bioremediation.
Background Brevibacillus , a spore-forming and resilient bacterium, thrives in diverse environments. This study investigated the plastic-degrading potential of three Brevibacillus spp. (SM1, SM2, and SM3) isolated from landfill soil near Dhaka, Bangladesh. Method The isolated strains were first characterized based on their optimal growth conditions, morphology, and biochemical properties. 16S rRNA gene sequencing and phylogenetic analysis were conducted to identify the isolates. Results All three isolates exhibited optimal growth at an alkaline pH of 8-8.5 and tolerated extreme conditions up to pH 11.5 and temperature 55 °C. SM1 and SM3 grew best at 30-37 °C, while SM2 favored 40-45 °C. Microscopy confirmed all isolates as Gram-positive, rod-shaped, and motile. Biochemical tests yielded positive results for oxidase, catalase, and citrate in all strains. SM1 exhibited the highest lipase activity, while esterase activity was higher in SM2 and SM3. A halo around SM2 on polyethylene glycol plates indicated potential degradation. All strains demonstrated the ability to utilize PET, LDPE, and LLDPE as sole carbon sources in degradation assays. The weight-loss analysis indicated greater LLDPE degradation efficiency over time in SM1 and SM3 compared to SM2. The DCPIP assay confirmed degradation of PET and LDPE by SM2. Molecular identification (16S rRNA and BLASTn) revealed 97% similarity to Brevibacillus species ( B. parabrevis , B. reuszeri , and B. brevis ). MSA and phylogenetic analyses confirmed their taxonomic placement within the Brevibacillus genus. Conclusion These findings highlight the potential of wild-type Brevibacillus spp . isolated from Bangladeshi landfill soil for application in plastic bioremediation.
Toxic metals and metalloids (TMs) are inorganic chemical contaminants that cause adverse health outcomes. Drinking water is an important exposure route for TMs such as arsenic (As), cadmium (Cd), lead (Pb), and manganese (Mn). Arsenic and manganese are geogenic contaminants that can also arise from localized anthropogenic and industrial sources. Lead leaching from Pb-containing pipes and fittings is of particular concern. Occurrence of these and other TMs has been reported in drinking water in Mexico, but the evidence has not been synthesized. Following PRISMA Guidelines, we conducted a systematic review to understand the distribution of TM occurrence in Mexican drinking water. We searched PubMed, EBSCO Global Health, and Web of Science to identify studies published in English after 1968 that measured any TM in drinking water globally, identifying a set of 20,052 papers for screening, last searched in March 2025. A total of 134 papers were included that report quantitative data on TMs in Mexican drinking water. We found that 62%, 20%, 14%, and 18% of Mexican drinking water samples exceeded the World Health Organization’s Guideline Values for As, Pb, Mn, and Cd, respectively. Overall, there is sufficient evidence to recommend preventive measures to reduce TM exposures from drinking water in Mexico, but there is insufficient data to inform targeted remediation efforts. Across Pb, Mn, and Cd, we found that sample sites were overwhelmingly in urban settings, leaving rural populations underrepresented. While arsenic is well characterized across the country and should certainly be addressed, we found that Pb, Mn, and Cd are understudied outside of the region surrounding Mexico City. We have developed a GIS layer for researchers to identify areas where research has not been conducted. This study can inform the efforts of public health practitioners, policy-makers, and researchers to identify understudied regions for further monitoring, surveillance, and review.
Summer savory ( Satureja hortensis L.) is a valuable annual herb sensitive to drought stress. This greenhouse study investigated whether amending soil with natural bentonite clay (0, 50, or 100 g kg -1 ) could mitigate the effects of three irrigation regimes (100, 75 and 50% of field capacity, FC). Growth, physiological and biochemical parameters were measured using a factorial based on completely randomized design to assess plant respons. Results showed that severe drought (50% FC) reduced shoot biomass by 25.8% and leaf relative water content (RWC) by 37.2%, while increasing root growth and oxidative stress markers (malondialdehyde by 50.8%). Bentonite amendment at 50 g kg -1 significantly alleviated these stress symptoms: it restored leaf RWC by 42.4% in stressed plants, increased the activity of key antioxidant enzymes (guaiacol peroxidase and polyphenol oxidase) by up to 45.5% and enhanced the uptake of essential nutrients (e.g., N, K, Zn). Consequently, this optimal bentonite rate improved the biomass of drought-stressed plants by up to 19.0%. The higher application rate (100 g kg -1 ) was less effective or even detrimental, likely due to reduced soil aeration. Our findings demonstrate that moderate bentonite application (50 g kg -1 ) effectively enhances drought tolerance in summer savory by improving soil water retention, nutrient availability and the plant’s antioxidant capacity. This strategy offers a practical and sustainable approach to cultivate this high-value medicinal herb under water-limited conditions.
