Low Nutrient Research Articles

The Range of the Colonial Microcystis’ Biomass for Shift to Diatom Aggregates Under Aeration Mixing and Low Light

In order to investigate non-cyanobacteria dominance succession from Microcystis blooms, particularly to diatom dominance, an experiment using varying colonial Microcystis biomasses expressed as bulk concentrations of 2.0, 4.0, 6.0, 8.0, 10.0, 12.0, 14.0, 16.0, 18.0, 20.0, 22.0, and 24.0 mL L−1 was undertaken under continuous aeration mixing in a greenhouse during a hot summer where shading had reduced light level by 97%. The results showed that the algal shift process was affected by the initial biomass of the colonial Microcystis, and the algal community diversified. When the Microcystis bulk concentration was between 2.0 and 16.0 mL L−1, the bloom became dominated by diatom Nitzschia palea, which aggregated on the mucilage sheathes of the Microcystis colonies. The diatom density at bulk concentration biomass of 2.0 mL L−1 reached a maximum at 2.8 × 105 cells mL−1 on day 27. When the bulk concentration was at 18.0–24.0 mL L−1, no diatom dominance appeared. The shift from a Microcystis bloom to diatom dominance was affected by the initial Microcystis biomass, and the most suitable bulk concentration biomass for colonial Microcystis was at 2–12 mL L−1, in which the chlorophyll-a level was about from 285 to 1714 μg L−1. The mechanism underlying this algal shift may be that the low light and nutrient levels in the Microcystis bloom promoted diatom aggregation growth on the mucilage sheaths of Microcystis colonies under continuous aeration mixing.

Enzymatic Biosensors: Advanced Tools for Soil and Plant Health Monitoring

Soil health is the potential of the soil to support the productivity of organisms, preserve the environment, and improve the health of plants and animals. Healthy soil is vital for agricultural sustainability and environmental resilience. The presence of high concentrations of toxic chemicals (pollutants and contaminants) in the soil poses a significant risk to human health and the ecosystem. Plant health is influenced by various factors, including the surrounding environment. To minimize constraints such as low nutrient levels, ecosystem contamination/pollution, and pest and disease incidences in crops, and to maximize productivity and ensure agricultural sustainability, advanced detection and management strategies are urgently needed. Diagnosis, prediction, and monitoring are essential for managing agricultural practices to mitigate these harmful impacts. The development of improved biosensing devices has been driven by the demand for quick, accurate, sensitive, real-time, and fast instruments for screening and identifying contaminants. Specific enzymes are used as the biological sensing element in an enzyme-based biosensor, which is combined with a transducer to transform the signal from the enzymatic reaction into a quantifiable response proportionate to the analyte concentration. Enzymatic biosensors need to possess high specificity, selectivity, reproducibility, stability, a low limit of detection, a low limit of quantification, and a rapid response time. They have a diverse array of uses, such as soil quality monitoring, water monitoring, food quality monitoring, pathogen detection, drug discovery, disease identification, and environmental research.

Natural and Engineered Ocean Inflow Projects to Improve Water Quality Through Increased Exchange

Globally, the health of coastal water bodies continues to be threatened by climate change and mounting anthropogenic pressures related to population increase and associated development. Land use changes have increased the direct runoff of freshwater, nutrients, and other contaminants from watersheds into coastal systems. Exacerbated by increased temperatures, these changes have contributed to a worldwide decline in seagrass coverage and losses of critical habitat and ecosystem functions. For restricted estuaries and lagoons, the influx of nutrients is particularly damaging due to high water residence times and impaired flushing. The result is eutrophication and associated declines in water quality and ecosystem function. To mitigate degraded water quality, engineered ocean–estuary exchanges have been carried out and studied with examples in Australia, New Zealand, India, Denmark, the Netherlands, Portugal, and the United States of America. Based on successes including decreased nutrient concentrations, turbidity, and chlorophyll and increased faunal abundance in some past studies, this option is considered as a management tool for combatting worsening water quality in other estuaries including the Indian River Lagoon, a subtropical, lagoon-type estuary on the central east coast of Florida, USA. Decreased residence times, lower nutrients, higher dissolved oxygen (DO), higher salinity, lower temperature, and lower turbidity all combine for improved ecosystem health. In this review, the successes and failures of past projects intended to increase ocean–estuary exchanges, including biological and geochemical processes that contributed to observed outcomes, are evaluated. The primary indicators of water quality considered in this review include nutrient contents (e.g., nitrogen and phosphorus) and dissolved oxygen levels. Secondary indicators include changes in temperature and salinity pre- and post- engineering as well as turbidity, which can also impact seagrass growth and overall ecosystem health. Each of the sites investigated recorded improvements in water quality, though some were more pronounced and occurred over shorter time scales. Overall, enhanced ocean exchange in restricted, impaired water bodies resulted in system-specific response trajectories, with many experiencing a net positive outcome with respect to water quality and ecosystem health.

Thermo-amplifier circuit in probiotic E. coli for stringently temperature-controlled release of a novel antibiotic.

Peptide drugs have seen rapid advancement in biopharmaceutical development, with over 80 candidates approved globally. Despite their therapeutic potential, the clinical translation of peptide drugs is hampered by challenges in production yields and stability. Engineered bacterial therapeutics is a unique approach being explored to overcome these issues by using bacteria to produce and deliver therapeutic compounds at the body site of use. A key advantage of this technology is the possibility to control drug delivery within the body in real time using genetic switches. However, the performance of such genetic switches suffers when used to control drugs that require post-translational modifications or are toxic to the host. In this study, these challenges were experienced when attempting to establish a thermal switch for the production of a ribosomally synthesized and post-translationally modified peptide antibiotic, darobactin, in probiotic E. coli. These challenges were overcome by developing a thermo-amplifier circuit that combined the thermal switch with a T7 RNA Polymerase. Due to the orthogonality of the Polymerase, this strategy overcame limitations imposed by the host transcriptional machinery. This circuit enabled production of pathogen-inhibitory levels of darobactin at 40°C while maintaining leakiness below the detection limit at 37°C. Furthermore, the thermo-amplifier circuit sustained gene expression beyond the thermal induction duration such that with only 2h of induction, the bacteria were able to produce pathogen-inhibitory levels of darobactin. This performance was maintained even in physiologically relevant simulated conditions of the intestines that include bile salts and low nutrient levels.

Effect of FYM and Inorganic Fertilizers on Growth, Yield of Wheat (Triticum aestivum L.) and Soil Properties of Red Alfisol

The soil multi-nutrient deficiency is not only a problem for soil quality, but also for crop productivity. In problematic soils, in particular acid soils, where low nutrient availability is a concern for general soil use, organic fertilizers are important. The importance of FYM is not limited to their role as accessibility, cost-effectiveness, soil nutrient reservoirs, moisture and ameliorating soil properties that determine soil fertility and productivity status. A pot experiment was conducted on wheat crop at Banaras Hindu University, India, to investigate the effect of FYM and inorganic fertilizers on growth, yield of wheat (Triticum aestivum L.) and soil properties of red Alfisol. The results revealed that maximum number of tiller pot-1 (17.0), plant height (78.0 cm), grain yield (27.4 g pot-1), straw yield (9.98 g pot-1), biological yield (67.5 g pot-1), harvest index (40.6%), were recorded in 1.5RF+FYM1applied pots. The correlation study revealed a significant positive correlation of soil organic carbon with biological yield, and soil available N, P and K. The integration of FYM along with 1.5 times RF significantly enhanced wheat productivity, quality, and soil nutrient availability, indicating the potential of this integrated approach for restoring soil fertility in degraded soils to sustainable crop production in red Alfisol.

Impact of Subsurface Drainage System Design on Nitrate Loss and Crop Production

Subsurface (or tile) drainage offers a valuable solution for enhancing crop productivity in poorly drained soils. However, this practice is also associated with significant nutrient leaching, which can contribute to water quality problems at the regional scale. This research presents the findings from a 4-year tile depth and spacing study in central Illinois that included three drain spacings (12.2, 18.3, and 24.4 m) and two drain depths (0.8 and 1.1 m) implemented in six plots under the corn and soybean rotation system (plots CS-1 and CS-3: 12.2 m spacing and 1.1 m depth, plots CS-2 and CS-4: 24.4 m spacing and 1.1 m depth, and plots CS-5 and CS-6 18.3 m spacing and 0.8 m depth). Our observations indicate that drain flow and NO3-N losses were higher in plots with narrower drain spacings, while plots with wider drain spacing showed reduced drain flow and NO3-N losses. Specifically, plots set up with drain spacings of 18.3 m and 24.4 m showed significant reductions in drain flow compared to plots featuring a 12.2 m drain spacing. Likewise, plots characterized by 18.3 m and 24.4 m drain spacings (except CS-4) showed better NO3-N retention and lower leaching losses than those with 12.2 m spacing (CS-1 and CS-3). Crop yield results over a 3-year period indicated that CS-2 (wider spacing plot) showed the highest productivity, with up to 13.6% higher yield compared to other plots. Furthermore, when comparing plots with the same drainage designs, CS-2 and CS-4 showed 5.1% to 2.6% higher corn yield (3-year average) compared to CS-1 and CS-3, and CS-5 and CS-6, respectively. Overall, a wider drainage system showed the capacity to export lower nutrient levels while concurrently enhancing productivity. These findings represent that optimizing tile drainage systems can effectively reduce nitrate losses while increasing crop productivity.

Effect of Nano-fertilizers in Wheat Crop Nutrition: A Review

The use of nano - fertilizers in wheat cultivation represents a promising approach to overcoming some of the inefficiencies and environmental challenges associated with conventional fertilizer practices. Traditional fertilizers often suffer from low nutrient use efficiency, leading to excessive application, nutrient runoff, and environmental harm. Nano fertilizers, due to their nano-scale size and enhanced reactivity, improve nutrient uptake by plants, leading to better growth, higher yields, and reduced nutrient wastage. Studies show that Nano formulations of both macronutrients (such as nitrogen, phosphorus, and potassium) and micronutrients (like zinc and iron) can significantly enhance wheat productivity. Nano fertilizers not only increase crop yield but also reduce the overall cost of fertilizer application by minimizing nutrient loss and improving absorption by the plants.

Assessment of Spatial Variability of Major and Micro Nutrients in Soils of Satara District, Maharashtra, India

Georeferenced surface soil samples from eleven (11) tehsils were delineated using stratified random soil sampling method investigation was carried out at All India Co-ordinated Research Project on Micro and Secondary Nutrients and Pollutant Elements in Soils and Plant under Department of Soil Science, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola, Maharashtra to assess the chemical properties, major and micronutrients status in soils of Satara district in the year 2022-2023 of three hundred and thirty soil (330) samples at the depth of (0-20 cm) were collected across the Satara district of Maharashtra and analysed in the laboratory. The results revealed that pH, EC, CaCO3 and OC of soils collected across different tehsils of Satara district varied from 6.00 to 9.43,0.10 to 0.98 dS m-1, 1.50 to 29.25 % and 0.72 to 7.80 g kg-1. The DTPA -Zn, Fe, Cu and Mn in soil of Satara district ranged from 0.18 to 1.85 mg Kg-1, 1.89 to 12.50 mg Kg-1, 0.36 to 2.15 mg Kg-1 and 3.91 to 38.44 mg Kg-1 respectively. The CaCl2-B in soils of all the tehsils ranged from 0.18 to 1.69 mg Kg-1. The results obtained clearly showed a large variability in physio-chemical properties of soil across the Satara district with low nutrient indices were in nitrogen (1.12) and iron (1.51), medium for phosphorus (1.99), Sulphur (2.08) and zinc (1.88), high for potassium (2.92), copper (2.96), manganese (2.77) and boron (2.47).

Differential gliding motility responses of Chryseobacterium sp. strain PMSZPI isolated from uranium ore deposit on hard and soft substrates

The Bacteroidota bacterium, Chryseobacterium sp. strain PMSZPI isolated from sub-surface soil of uranium ore deposit was shown to move on solid surfaces via gliding motility resulting in the formation of thin spreading colonies. In this study, we attempted to understand the influence of the surfaces, soft or hard/rigid, on the motility behaviour of PMSZPI cells. The computational tool T9GPred in combination with LC-MS/MS analysis established the presence of orthologs of vital gliding motility proteins in PMSZPI. We analyzed the single cell or population motility phenotypes of PMSZPI under spreading and non-spreading conditions. A low percentage of agar or soft agar (0.35%) with low nutrient levels induced more active gliding motility in individual cells leading to increased colony spreading. Microscopic analyses indicated the self-assembly of the gliding cells into irregular edged or spherical microcolonies based on the agar concentration. Cells moved at a speed of 0.2 to 0.6 µm s-1 on low-percentage gliding permissive agar (0.35%) surface in contrast to significant inhibition of motility on rigid or hard agar (1.5%) surface. RNA sequencing and real-time quantitative PCR (qPCR) analysis revealed increased expression of gliding motility genes under low agar conditions consistent with increased spreading behaviour. These findings provide the first glimpse into the gliding motility behaviour of a Bacteroidota bacterium from metal enriched environment that apparently could have implications on bacterial adaptation to changing surface environments.

Effect of Black Soldier Fly Larvae Frass as Organic Fertilizer on Postharvest Quality and Shelf Life of Open-field-grown Tomato (Solanum lycopersicon L.)

Open-field-grown tomatoes in Saudi Arabia are stressed by poor soil fertility because of the low organic matter content, low nutrient availability, and high pH. Thus, high chemical fertilizer inputs are crucial for commercial production; however, they cause economic loss as well as negatively affect environmental sustainability. The use of efficient organic fertilizers would be useful for developing more cost-effective, environmentally friendly, and sustainable agriculture. The current study evaluated the impact of Black soldier fly (Hermetia illucens L.) frass (BSFF) fertilizer applications as organic fertilizer on postharvest fruit quality and shelf life of open-field-grown F1 hybrid ‘Sinag Tala’ tomatoes compared with those grown under control treatment (received recommended doses of chemical fertilizers for tomato production under open field conditions). The experiment was conducted using a randomized complete block design with four replicates. The results showed that the application of BSFF fertilizer, especially at the higher rate (5 ton/ha; BSFF3), improved the overall quality of tomato fruit. The BSFF fertilizer treatments reduced weight loss, maintained higher firmness, antioxidants [vitamin C, total phenol content (TPC) and total flavinoid (TFC)], total soluble solids (TSS), and titratable acidity (TA) contents, and lowered the TSS/TA ratio of fruits during shelf life compared with those of the control. The decay incidence was only detected after 9 days of shelf life and was significantly lower in all the BSFF fertilizer treatments (range, 8.40%-12.05%) than in the control (15.9%). In addition, BSFF fertilizer treatments reduced both disease incidence and severity of gray mold following pathogen inoculation during shelf life compared with those of the control. These results might be attributable to the higher antioxidants content (vitamin C, TPC, and TFC) and higher polyphenol oxidase activity in BSFF-fertilized tomatoes. In conclusion, BSFF fertilizer could be used as a potential eco-friendly alternative to chemical fertilizers to improve tomato fruit quality during shelf life.

Nano-Fe3O4/FeCO3 modified red soil-based biofilter for simultaneous removal of nitrate, phosphate and heavy metals: Optimization, microbial community and possible mechanism

The pollution of nitrogen, phosphorus and heavy metals in surface water is becoming more and more serious, affecting the safety of water quality. In this study, three biofilters were constructed using iron-modified red soil-based filler carriers (RSC, nano-Fe3O4@RSC, and FeCO3@RSC) combined with strain Zoogloea sp. ZP7 to simultaneously remove nitrate (NO3--N), phosphate (PO43--P), copper (Cu2+), and zinc (Zn2+). The long-term operation results showed that the three groups of biofilters could remove 85.0, 90.0, and 89.8% of NO3--N, respectively. Furthermore, the addition of iron compounds enhanced the removal of PO43--P and the resistance to the stress of Cu2+ and Zn2+ in the biofilter. The analysis illustrated that iron modification improved the redox activity and zeta potential of RSC surface. The secondary structure analysis of the protein showed that the microbial secreted proteins were more compact on the surface of the iron-modified RSC, which facilitated the formation of biofilm on the carrier surface. In addition, the iron-modified RSC-based biofilter also showed excellent NO3--N and PO43--P removal efficiency in the treatment of actual surface water. The microbial community analysis results showed that Zoogloea became the dominant species in the biofilter. On the other hand, the presence of iron-reducing bacteria and the expression iron cycle-related genes may contribute to denitrification under low nutrient conditions.

Changes in Nutrient Surpluses and Contents in Soils of Cereals and Kiwifruit Fields

Knowledge of nutrient surpluses in soils is critical to optimize nutrient management and minimize adverse environmental effects. We investigated the nutrient surpluses in soils in two regions over 25 years (1992 to 2017) in the south Loess Plateau, China. One region has cereals as the main crop, whereas in the other region, the main cereal crops was changed to kiwi orchards. The inputs of nitrogen (N), phosphorus (P), and potassium (K) increased rapidly (by 74%, 77%, and 103% from 1992 to 2017 in the cereal region; and by 91%, 204%, and 368% in the kiwifruit region), while the nutrient outputs were relatively stable, which resulted in increasing nutrient surpluses (the annual averaged surpluses of N, P, and K were 178, 62, and 12 kg ha−1 y−1 for the cereal region; and 486, 96, and 153 kg ha−1 y−1 for the kiwifruit region) and lower nutrient use efficiency (NUE). The higher N surplus in the orchard-dominated region caused high nitrate N accumulation (3071 kg N ha−1 of 0–5 m in 11–20 y in the kiwifruit orchard) in deeper soil profiles. Similarly, high P and K surpluses in the orchard-dominated region increased soil available P and K. This highlights that comprehensive measures should be taken to control nutrient surpluses, which will help balance nutrient inputs and outputs and minimize nutrient losses in intensive horticultural crop systems.

Biomass Productivity and Photosynthetic Activity in Ulva compressa (Chlorophyta) in Raceway Photobioreactors Under Stress Conditions.

Research in seaweed cultivation technologies aims to increase production and reduce costs, leading to more efficient and sustainable processes. In this study, we analyzed the outdoor production of Ulva compressa cultured in summertime at different stocking densities of 0.6, 0.8 and 1.0 kg Fresh weight (FW) m-2 in a raceway photobioreactor with 30 m2 surface (3000 L), and its relation to photosynthetic activity. Under the experimental conditions of high temperature (>28-30 °C) and pH > 9 in culture water, higher seaweed density resulted in lower specific growth rate. The biomass production has been related to photosynthetic activity by using in vivo chlorophyll a fluorescence. Dynamic photoinhibition was observed at noon, which was less severe in cultures with higher algal densities. However, photosynthesis recovered in the afternoon. Seaweeds that were acclimatized for a week to the conditions of 1.0 kg FW m-2 stocking density showed an increase in biomass growth and absence of photoinhibition compared to non-acclimatized thalli. In conclusion, the cultivation of U. compressa in a mid-scale raceway photobiorreactor under conditions of high irradiance and temperature and low nutrient input, exhibited the best photosynthetic performance and hence the highest growth rates for the highest culture density assayed (1.0 kg FW m-2).

Optimizing Irrigation Scheduling to Enhance Nutrient Uptake and Soil Microbial Activity in Linseed Cultivation (Linum usitatissimum L.)

Linseed crop cultivated under residual moisture and water scarcity conditions in rabi season. To improve the productivity of linseed irrigation water is applied at different stages of crop. So, to optimize the irrigation scheduling and enhance the nutrient uptake and soil microbial activity, this experiment was conducted at Main Agriculture Research Station, University of Agricultural Sciences, Raichur (which comes under North Eastern Dry zone of Karnataka) (India) during rabi 2023-24. The experiment was carried out with Randomized Complete Block Design (RCBD) with five treatments and four replications. The results revealed that, pre sowing irrigation fb three irrigations at vegetative stage (30-35 DAS), flowering stage (40-45 DAS) and capsule development stage (60-65 DAS) (T4) recorded significantly higher nutrient uptake by linseed crop (46.07, 19.87 and 39.83 NPK kg ha-1). The rainfed condition treatment (T5) recorded significantly lower nutrient uptake by the crop (19.35, 8.15 and 18.40 NPK kg ha-1). Among the different treatments, pre sowing irrigation fb three irrigations at vegetative stage (30-35 DAS), flowering stage (40-45 DAS) and capsule development stage (60-65 DAS) recorded significantly higher soil microbial population of bacteria (16.1 X 106 cfu g-1 of soil), fungi (13.8 X 104 cfu g-1 of soil) and actinomycetes (6.8 X 103 cfu g-1 of soil) as compared to other treatments. The soil enzymatic activity was significantly influenced by scheduling of irrigation at different growth stages in linseed. At harvest among the different treatments, pre sowing irrigation fb three irrigations at vegetative stage (30-35 DAS), flowering stage (40-45 DAS) and capsule development stage (60-65 DAS) recorded significantly higher dehydrogenase, urease and alkaline phosphatase activity (18.63 μg TPF g-1 soil day-1, 22.5 μg NH4-N g-1 soil hr-1 and 14.4 µg PNP g-1 soil hr-1, respectively).

Metagenomic analysis of deep-sea bacterial communities in the Makassar and Lombok Straits

The extreme conditions of the deep-sea environment, including limited light, low oxygen levels, high pressure, and nutrient scarcity, create a natural habitat for deep-sea bacteria. These remarkable microorganisms have developed unique strategies to survive and adapt to their surroundings. However, research on the diversity of deep-sea bacteria, both culture-dependent and culture-independent, in Indonesian waters remains insufficient. This study focused on exploring the biodiversity of deep-sea bacteria, specifically in the Makassar and Lombok Strait, the main Indonesian throughflow pathway characterized by relatively fertile water, which serves as an important deep-sea region. High-throughput DNA sequencing of full-length 16S rRNA was employed to construct a genomic database. The results of the bioinformatic analysis revealed that two stations, 48 and 50 (Makassar Strait), exhibited a more similar community structure of deep-sea bacteria than did station 33 (Lombok Strait). Among the predominant phyla found at a depth of 1000 m, the top ten were Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria, Planctomycetes, Acidobacteria, Nitrospinae, Verrucomicrobia, Candidatus Melainabacteria, and Cyanobacteria. Furthermore, the genera Colwellia, Moritella, Candidatus Pelagibacter, Alteromonas, and Psychrobacter consistently appeared at all three stations, albeit with varying relative abundance values. These bacterial genera share common characteristics, such as psychrophilic, halophilic, and piezophilic tendencies, and are commonly found in deep-sea ecosystem. The environmental conditions at a depth of 1000 m were relatively stable, with an average pressure 10 MPa, temperature 4.68 °C, salinity 34.58 PSU, pH 8.06, chlorophyll-a 0.29 µg/L, nitrate 3.19 µmol/L, phosphate 6.32 µmol/L and dissolved oxygen (DO) 2.90 mg/L. The bacterial community structures at the three sampling stations located at the same depth (1000 m) exhibited similarities, as indicated by the closely aligned similarity index values.

Effects of Soil Properties on the Accumulation and Bioavailability of Copper in the Orange Growing Soil in Cao Phong, Hoa Binh

This study focuses on investigating the crucial influence of some soil properties on the adsorption capacity and fractions of Cu in the citrus-growing soil in Cao Phong district, Hoa Binh province. Batch experiments were conducted by adding 0, 100, 500, and 1000 mgCu/L to soil samples with different characteristics. In the 100 mgCu/L added experiment, we found the highest Cu adsorption rate (> 93.76%) in soil samples with loamy texture, high pHKCl, %OC, and low nutrients. Conversely, the lowest Cu adsorption rates (78.32-79.23%) were observed in soil samples with lower pH, and higher %OC and nutrient availability. Noting that the total adsorbed Cu has a negative correlation with the amount of Cu added to the soil, gradually decreasing from (78.32-95.67%) to (26.67-34.19%) and the lowest (22.48-28.56%) in soil samples with the added levels of 100, 500, and 1000 mgCu/L, respectively. In soil samples with total Cu > 200 mg/kg, pHKCl 4.79-5.32, and OC 1.34-2.06%, the bioavailable Cu ranged from 2.29-4.29 mg/kg, which is safe for the soil environment and ecosystem, and sufficient as a micronutrient for citrus plants. It is necessary to find the best solutions for managing Cu-polluted soils.

Evaluating water quality of rock glacier outflows in the Western Alps, Italy: a regional perspective.

Intact rock glaciers (RG) are considered valuable water storage because containing permafrost ice volumes. The hydrological relevance of RG is forecasted to increase with respect to glaciers under climate change scenarios, as well as RG's role as water resources in alpine basins for multiple uses. Besides the assessment of water amount stored in intact rock glaciers, the evaluation of water quality is of primary importance. Here, we present the results of a chemical survey performed on five outflows from intact RG in 2020-2023 in the Piedmont region, Western Alps, Italy, along a latitudinal gradient and in different geological settings. The survey aimed to assess the water quality of RG outflows based on chemical indicators (major ions, nutrients, trace metals). Sampling and analyses were performed according to standard methods for freshwater samples, paying specific attention to the analytical quality and consistency of the data. We considered seasonal and interannual variability of the main chemical variables and the possible effects of RG outflows on the chemistry of lakes and ponds located in proximity to the RG. All the investigated sites were characterized by low to moderate ion content, low nutrients, and trace metals close to or below the detection limit, indicating a good water quality status. Results suggested lithology as the main factor affecting the chemical composition of RG outflows. The results of this study indicate it is advisable to develop shared protocols and joint monitoring programs for data collecting at RG outflow sites all over the Alps, possibly integrating chemical and biological indicators, with the final aim of monitoring the water quality of these valuable resources and its temporal evolution under climate change.

Effects of Recommended Fertilizer Application Strategies Based on Yield Goal and Nutrient Requirements on Drip-Irrigated Spring Wheat Yield and Nutrient Uptake

Excessive application of fertilizers in drip-irrigated wheat production can suppress yields, lower nutrient utilization efficiency, and lead to economic and environmental issues such as nitrogen residues in the soil. Based on a recommended fertilizer application (RF) strategy that takes into account target yield and nutrient requirements, this study explores the responses of wheat plant traits, changes in topsoil and subsoil nutrients, fertilizer utilization, and economic benefits under this strategy. From 2022 to 2023, a field experiment was conducted in a typical oasis spring wheat production area at the northern foot of the Tianshan Mountains in Xinjiang. The treatments included no fertilizer control (CK), the farmer’s conventional practice (FP), recommended fertilizer (RF), RF with nitrogen omission (RF-N), phosphorus omission (RF-P), and potassium omission (RF-K). The results showed that compared with FP, the RF reduced 91 kg N ha−1 (30.3%) and 33 kg P2O5 ha−1 (24.8%) in 2022, and 69 kg N ha−1 (23.0%) and 2 kg P2O5 ha−1 (1.5%) in 2023. The effect in 2023 was better; RF also decreased the NO3−1-N residue in the 0–100 cm soil layer by 40.1 kg N ha−1 compared with FP, with no significant difference in wheat grain yield (RF: 5382.9 kg ha−1) or economic benefit (RF: USD 1613.1 ha−1). Furthermore, there were no significant differences between RF and FP in pre-anthesis NP transport or post-anthesis NP accumulation; however, RF significantly increased pre-anthesis potassium transport volume (15.8%) and transport rate (12.5%). RF led to a 16.3% increase in nitrogen utilization efficiency (NUE), while there was no significant difference in phosphorus utilization efficiency (PUE) compared with FP. The fertilizer yield effect for RF was evaluated as N > P > K. Correlation analysis indicated that grain yield was significantly positively correlated with pre-anthesis NPK transport and post-anthesis NP accumulation. It was also positively correlated with organic matter, alkali-hydrolyzed nitrogen, and Olsen-P content in both the topsoil (0–20 cm) and subsoil (20–40 cm), but not with available potassium in the soil. Therefore, conducting soil tests and determining fertilizer recommendations based on the proposed RF method at harvest can reduce fertilizer usage and achieve a balance between the conflicting objectives of environmental protection, increased crop yields, nutrient utilization efficiency, and improved economic benefits in oasis agricultural areas facing excessive fertilizer application.

Association of ultra-processed food consumption with cardiovascular risk factors among patients with type-2 diabetes mellitus

BackgroundUltra-processed foods mainly have high energy content and density and low nutrients. Unhealthy lifestyles mainly develop cardiovascular diseases and, as a result, unhealthy food patterns.ObjectiveThis study aimed to investigate the relationship between the consumption of ultra-processed foods (UPFs) and the risk of novel cardiovascular disease (CVDs) in type-2 diabetes mellitus patients (T2DM).MethodThis is a cross-sectional study that was conducted on 490 type-2 diabetes mellitus patients. A validated 168-item food frequency questionnaire evaluated food intake. Ultra-processed foods were assessed according to NOVA classification. Cardiovascular risk factors such as Castelli risk index 1 and 2 (CRI-I and II), atherogenic index of plasma (AIP), lipid accumulation product (LAP), and cholesterol index (CI) were assessed by traditional CVD risk factors. The anthropometric indices predicting CVD, such as a body shape index (ABSI), body roundness index (BRI), and abdominal volume index (AVI), were assessed.ResultsEach 20-gram increase in UPF consumption was associated with a significant elevation in serum level of TC [B (SE): 1.214 (0.537); 95% CI: 0.159–2.269] and lower HDL serum concentration [B (SE): −0.371 (0.155); 95% CI: −0.675 to −0.067]. The crude model for CRI 1 [B (SE): 0.032 (0.012); 95% CI: 0.009–0.056], CRI 2 [B (SE): 0.022 (0.009); 95% CI: 0.004–0.040], and AIP [B (SE): 0.006 (0.003); 95% CI: 0.000–0.012] showed significant adverse effects.ConclusionsOur study showed that higher consumption of UPFs is associated with higher chances of developing cardiovascular diseases in T2DM patients.

Environmental impacts and nitrogen-carbon-energy nexus of vegetable production in subtropical plateau lake basins.

Vegetables are important economic crops globally, and their production has approximately doubled over the past 20 years. Globally, vegetables account for 13% of the harvested area but consume 25% of the fertilizer, leading to serious environmental impacts. However, the quantitative evaluation of vegetable production systems in subtropical plateau lake basins and the establishment of optimal management practices to further reduce environmental risks are still lacking. Using the life cycle assessment method, this study quantified the global warming, eutrophication, acidification, and energy depletion potential of vegetable production in a subtropical plateau lake basin in China based on data from 183 farmer surveys. Our results indicated that vegetable production in the study area, the Erhai Lake Basin, was high but came at a high environmental cost, mainly due to low fertilizer efficiency and high nutrient loss. Root vegetables have relatively high environmental costs due to the significant environmental impacts of fertilizer production, transportation, and application. A comprehensive analysis showed that the vegetable production in this region exhibited low economic and net ecosystem economic benefits, with ranges of 7.88-8.91 × 103 and 7.35-8.69 × 103 $ ha-1, respectively. Scenario analysis showed that adopting strategies that comprehensively consider soil, crop, and nutrient conditions for vegetable production can reduce environmental costs (with reductions in global warming potential (GWP), eutrophication potential (EP), acidification potential (AP), and energy depletion potential (EDP) by 10.6-28.2%, 65.1-73.5%, 64.5-71.9%, 47.8-70.4%, respectively) compared with the current practices of farmers. This study highlighted the importance of optimizing nutrient management in vegetable production based on farmers' practices, which can achieve more yield with less environmental impacts and thereby avoid the "trade-off" effect between productivity and environmental sustainability.