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In the Indian sector of the Southern Ocean, 80°E marks an important transition in ocean circulation between the greater Prydz Bay gyre to the west and the Australian Antarctic gyre to the east. Here, the submarine Kerguelen Plateau impedes the eastward flow of the Antarctic Circumpolar Current (ACC), topographically steering the flow. Enhanced biological productivity associated with the southern plateau supports an important marine ecosystem with many foraging marine predators. We collate ship-based hydrographic data on the vertical structure of the upper water column near 80°E from eight voyages spanning 1994 to 2021, from 58°S towards the Antarctic continent. The study aims to investigate the mixed layer oceanography, the implications for nutrient supply from deep to near-surface waters, and associated biological production. Our results show that the major oceanographic fronts are constrained within the narrow Princess Elizabeth Trough, between the southern Kerguelen Plateau and the Antarctic slope. Therefore, the Southern Boundary and the Southern ACC Front (SACCF) are often co-located, albeit with some interannual variability, with the location of the SACCF ranging from roughly 63°S to 65°S. The average depth of the seasonal mixed layer ranges from 34-49 m, typically deepening from south to north, in association with longer time since sea-ice melt. Below the mixed layer, Winter Water (WW) characteristics also vary across the observed latitudinal range; typically the temperature and thickness of the WW layer are inversely related, with warmer WW layers being thinner. Subsurface nitrate concentrations range from 20-40 µM, while silicate concentrations reach 100 µM. Nutrient drawdown is calculated based on mean concentrations in the mixed layer and WW layer, with drawdown values at individual stations reaching nearly 12 µM and 60 µM for nitrate and silicate, respectively, and a positive correlation between the two. Nutrient drawdown was higher in association with longer time since sea-ice melt and with thinner WW layers, while higher nitrate-based production was associated with deeper mixed layers. Observed relationships between upper water column characteristics and biological processes are discussed in terms of likely nutrient supply mechanisms and seasonal patterns of utilization. [ABSTRACT FROM AUTHOR]

Intermittent fasting (IF) has proven to be a feasible dietary intervention for the wider population. The recent increase in IF clinical trials highlights its potential effects on health, including changes in body composition, cardiometabolic status, and aging. Although IF may have clinical applications in different populations, studies suggest there may be sex-specific responses in parameters such as body composition or glucose and lipid metabolism. Here, the existing literature on IF clinical trials is summarized, the application of IF in both disease prevention and management is discussed, and potential disparities in response to this type of diet between men and women are assessed. Moreover, the potential mechanisms that may be contributing to the sexually dimorphic response, such as age, body composition, tissue distribution, or sex hormones are investigated. This review underscores the need to further study these sex-specific responses to IF to define the most effective time frames and length of fasting periods for men and women. Tailoring IF to specific populations with a personalized approach may help achieve its full potential as a lifestyle intervention with clinical benefits. [ABSTRACT FROM AUTHOR]

Theory and models of enzymatic stoichiometry have been typically used to assess microbial resource limitation, such as the ratios between the activities of carbon (C), nitrogen (N) and phosphorus (P) acquiring enzymes and vector characteristics (that is, vector length and angle). However, the validity of using these stoichiometry indicators to infer microbial resource limitation has been questioned by recent some studies. To test the validity of using these indicators in peatland ecosystems, we conducted a laboratory incubation experiment by adding available C, N and P individually as well as in combination to create various resource limitation scenarios. Results showed that the activity of C- (β-D-glucosidase, BDG) and P-acquiring enzymes (phosphatase, PHO) significantly decreased by 87% and 80% with the addition of C and P, respectively. However, the activity of N-acquiring enzymes (N-acetyl-β-glucosaminidase and leucine aminopeptidase, NAG + LAP) increased by 11.5% following N addition, introducing a bias when using the ratios of lnBDG:ln(NAG + LAP) and ln(NAG + LAP):lnPHO to assess microbial resource limitation. Although the ratios of lnBDG:lnPHO could better indicate C or P limitation, it was not valid to indicate C and P co-limitation. Overall, any individual enzymatic stoichiometric ratio only based on two enzymes (for example, BDG:NAG) could not validly indicate microbial resources co-limitation. However, vector characteristics provided an intuitive indication of microbial C and N co-limitation, as well as C and P co-limitation, but not N and P co-limitation. In summary, we recommend prioritizing the more intuitive vector characteristics as a basis for evaluating microbial resource limitation in peatland ecosystems. [ABSTRACT FROM AUTHOR]

Purpose: The current study aimed to investigate the trophocidal and cysticidal activities of cinnamaldehyde (Cinn), a natural compound with known antimicrobial properties, against environmental and reference strains of Acanthamoeba castellanii. Additionally, we explored the potential benefits of Cinn formulated as a nanoemulsion (Cinn-NE) in enhancing its efficacy. Methods: Cinn-NE was prepared using the ultrasonic emulsification method. The amoebicidal effect of Cinn was evaluated against both trophozoites and cysts of reference and environmental strains of Acanthamoeba, along with an assessment of whether nanotechnology enhances this effect. Results: Our results demonstrated that Cinn exhibited strong activity against both trophozoites and cysts of Acanthamoeba. Importantly, Cinn-NE showed enhanced activity compared to pure Cinn, possibly due to increased surface area and improved interaction with microbial membranes. In this study, the difference in susceptibility to Cinn and Cinn-NE between the environmental and the reference strain of A. castellanii was observed. Acanthamoeba cysts were more resistant to the effects of Cinn or Cinn-NE than trophozoites. Additionally, we found that nutrient availability in the medium influenced the susceptibility of Acanthamoeba to Cinn and Cinn-NE. A nutrient-deficient medium reduced their vulnerability to destruction, suggesting a role for nutrient availability in the response of Acanthamoeba to antimicrobial agents. Conclusion: In conclusion, our study highlights the potential of Cinn and Cinn-NE as effective agents for combating Acanthamoeba infections. Further research is needed to elucidate the specific mechanisms underlying the differential susceptibility to Cinn, optimize its use as a treatment or surface disinfectant, and explore Acanthamoeba's cellular and molecular responses to nutrient availability. [ABSTRACT FROM AUTHOR]

Deciphering the linkage between ecological stoichiometry and ecosystem functioning under anthropogenic nitrogen (N) deposition is critical for understanding the impact of afforestation on terrestrial carbon (C) sequestration. However, the specific changes in above‐ versus belowground stoichiometric asymmetry with stand age in response to long‐term N addition remain poorly understood. In this study, we investigated changes in stoichiometry following a decadal addition of three levels of N (control, no N addition; low N addition, 20 kg N ha−1 year−1; high N addition, 50 kg N ha−1 year−1) in young, intermediate, and mature stands in three temperate larch plantations (Larix principis‐rupprechtii) in North China. We found that low N addition had no impact on both above‐ (leaf and litter) and belowground (soil and microbe) stoichiometry. In contrast, high N addition resulted in significant asymmetry in above‐ versus belowground stoichiometry, which then diminished during stand development. Following 10 years of N inputs, the young and intermediate plantations transitioned from a state of relative N limitation to co‐limitation by both N and phosphorus (P), whereas the mature plantation continued to experience relative N limitation. Conversely, soil microorganisms exhibited relative P limitation in all three plantations. Broader niche differentiation (N limitation for trees, but P limitation for microorganisms) under long‐term N input may have been responsible for the faster attainment of stoichiometric homeostasis in mature plantations than in young plantations. Our findings provide stoichiometric‐based insight into the operating mechanisms of large C sinks in young forests, particularly above‐ versus belowground C stock asymmetry, and highlight the need to consider the role of flexible stoichiometry when forecasting future forest C sinks. [ABSTRACT FROM AUTHOR]

The major limitations of rain-fed areas in Pakistan include soil fertility loss, reduced soil productivity, and water scarcity. To address these challenges, research has investigated the potential use of biochar in low-fertility and degraded soils to increase soil fertility, nutrient uptake, and water retention, ultimately improving soil productivity and crop growth. A field study was undertaken to evaluate the impact of biochar, coupled with chemical nutrient on the availability of soil nutrient and crop growth. Six distinct experimental treatments were utilized, with each treatment being replicated thrice. The treatments included: T1(control), T2 (0.25 ton/ha biochar), T3 (0.5 ton/ha biochar), T4 (standard nitrogen nutrient dosage), T5 (0.25 ton/ha biochar along with standard nitrogen nutrient dosage), and T6 (0.5 ton/ha biochar along with standard nitrogen nutrient dosage). At maturity the test crop, mash bean was harvested. Soil samples and plant samples were obtained before sowing and after harvesting. The evaluations comprised measurements of CEC (cation exchange capacity) of soil, pH levels of soil, soil bulk density, total nitrogen (N), soil phosphorus (P), SOM, soil texture, extractable potassium (K), and total organic carbon (TOC). Nitrogen fixation by mash beans was also evaluated using xylem solute techniques. Statistical analysis was conducted on the collected data using Analysis of Variance (ANOVA), comparing means at a 5% level of significance. This study's results will contribute valuable insights into the impact of biochar on crop growth and soil health in rain-fed regions. [ABSTRACT FROM AUTHOR]

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Phosphorus (P) and potassium (K) nutrients are pivotal macro-elements influencing the growth and development of tomato plants. This research aims to compare the extraction results of P and K nutrients using 5 extraction methods and determine the optimal extraction method for tomato cultivation in Andisols and Inceptisols. Soil P and K availability analysis using 5 extraction methods (Mehlich-1, Bray-1, Morgan-Wolf, Ammonium acetate, and HCl-25%) correlated with tomato plants' relative dry biomass weight. Overall, the research findings indicate a significant and strong positive correlation between the 5 extraction methods of P and K with tomato plants in Andisols and Inceptisols (p < 0.01, r > 0.75). Based on the correlation coefficient (r), Mean Relative Error (MRE), and Root Mean Square Error (RMSE), the best extraction methods for P and K in tomatoes on Andisols are respectively Bray- 1 (YP = 0.295x + 20.53, r = 0.88, MRE = 0.10, RMSE = 4.44) and HCl-25% (YK = 0.023x + 36.46, r = 0.90, MRE = 0.05, RMSE = 2.95). The best extraction methods for P and K in tomatoes on Inceptisols are respectively Bray-1 (YP = 0.353x + 28.58, r = 0.91, MRE = 0.05, RMSE = 2.59) and Mehlich-1 (YK = 0.036x + 21.17, r = 0.95, MRE = 0.05, RMSE = 1.84). The outcomes of this study will be instrumental in determining phosphorus and potassium fertilizer dosages for tomato plants in Andisols and Inceptisols. [ABSTRACT FROM AUTHOR]

Abstract Organic agricultural practices are increasingly recognized for promoting sustainable soil–plant-environment interactions. However, the specific impact of soil additives in organic systems on nutrient and microbial dynamics, and their subsequent effects on crop performance, are still relatively unexplored. This study sought to address this gap by investigating the screening of suitable rice-legume residue combinations for biochar (BC) production and assessing the effect of incorporating BC as a soil additive in organic soil nutrient management. A two-year field experiment was conducted with six organic soil treatments comprising farmyard manure (FYM) and vermicompost (VC) as organic nutrient sources (equivalent to 100 kg N ha−1), along with BC and Jeevamrit (J-Con) as soil additives, and a non-fertilized control to evaluate their impacts on nutrient cycling and crop performance. The rice-pigeon pea crop residue combination was found to be the most suitable for BC production (BC-RP), maintaining favorable nutritional quality and conversion efficiency. Among the soil treatments, T5 (50% FYM + 50% VC + BC) emerged as the most effective for enhancing soil pH, carbon content, and nutrient and microbial dynamics, followed by 50% FYM + 50% VC + J-Con (T6). This treatment also notably improved crop (onion) parameters, including growth, yield, quality, and production economics. The incorporation of BC as soil additive in 50% FYM + 50% VC significantly enhanced nutrient and microbial transformations in the soil, resulting in improvements of 7–25% in crop parameters. The findings of the study thus may be useful for achieving sustainable onion production by enhancing synchronized soil–plant interactions within an organic production system.

Undisturbed soil columns were used to study the effect of sterile rice spikelets-derived biochar (SRSB) on NH4+-N, available P, and available K leaching and nutrients availability in a paddy soil under continuous standing water (CSW) condition. The experiment was conducted for two crop cycles and comprised of three treatments: recommended dose of sole chemical fertilizers (CF), CF+SRSB (2 t ha−1), and control. In both crop cycles, incorporation of SRSB reduced the leachate NH4+-N and available K concentrations, while increased the available P concentration compared to sole CF. The SRSB amendment reduced the cumulative losses of NH4+-N by 35–38% and available K by 23–25% than CF only. However, there was no significant variation in cumulative available P loss between SRSB and CF only. The reduced leaching loss of NH4+-N and available K could be attributed to the better nutrient adsorption capacity of SRSB. After completion of two crop cycles, the soil pH, soil organic carbon, soil total N, available P, and available K increased with SRSB amended soils than sole CF. This study showed positive effects of SRSB on retaining nutrients and increasing their availability in the soil which could benefit efficient fertilizer management in paddy soil under CSW.

This study evaluated the effectiveness of zeolite, both alone and in combination with mineral fertilizers, in improving the yield and quality of table beets (Beta vulgaris L.) grown in dark chestnut soils of southeast Kazakhstan. The research was conducted at the Kazakh Research Institute of Horticulture during the 2022-2023 growing seasons using a randomized complete block design with six treatments: control (no fertilizers), zeolite 2 t/ha, N45P45K45 (single dose of mineral fertilizers), N90P90K90 (double dose of mineral fertilizers), zeolite 2 t/ha + N45P45K45, and zeolite 2 t/ha + N90P90K90, replicated three times. The application of zeolite significantly improved soil physical properties, such as water permeability and soil density, enhancing root development and water retention. Nutrient availability, particularly nitrate nitrogen and mobile phosphorus, increased significantly in zeolite-treated plots. The combination of zeolite and mineral fertilizers resulted in the highest improvements, with nitrate nitrogen content reaching 40.5 mg/kg and mobile phosphorus 89.2 mg/kg. Moreover, zeolite reduced heavy metal concentrations, particularly cadmium, by 50% compared to the control. Table beet yield significantly increased with zeolite application, with the highest yield of 62.7 t/ha achieved with 2 t/ha zeolite combined with double dose N90P90K90 fertilizers, compared to 42.8 t/ha in the control. Marketable yield also improved, indicating better crop quality. Nutrient composition of the beets improved, with increased dry matter content (21.9%) and reduced nitrate content (240 mg/kg) in zeolite-treated variants. In conclusion, zeolite, especially when combined with mineral fertilizers, effectively enhances soil health, nutrient availability, and table beet yield and quality.

Abstract Sessile drying droplets in various bio-related systems attracted attention due to the complex interactions between convective flows, droplet pinning, mechanical stress, wettability, and the emergence of unique patterns. This study focuses on the drying dynamics of Chlamydomonas reinhardtii (chlamys), a versatile model algae used in molecular biology and biotechnology. The experimental findings shed light on how motility and nutrient availability influence morphological patterns– a fusion of macroscopic fluid dynamics and microbiology. This paper further discusses the interplay of two competing stressors during drying– nutrient scarcity (quantitative analysis) and mechanical stress (qualitative analysis), where the global mechanical stress does not induce cracks. Interestingly, motile chlamys form clusters under nutrient scarcity due to metabolic stress, indicating the onset of flocculation, a common feature observed in microbial systems. Moreover, non-motile chlamys exhibit an “anomalous coffee-ring effect” in the presence of nutrients, with an inward movement observed near the droplet edge despite sufficient water in the droplet. The quantitative image processing techniques provide fundamental insights into these behaviors in classifying the patterns into four categories (motile+with nutrients, motile+without nutrients, non-motile+with nutrients, and non-motile+without nutrients) across five distinct drying stages– Droplet Deposition, Capillary Flow, Dynamic Droplet Phase, Aggregation Phase, and Dried Morphology.

Although herbivory and allelopathy play important roles in plant invasions, their roles in mediating the effect of plant diversity on invasion resistance remain unknown. In a 2‐year field experiment, we constructed native plant communities with four levels of species richness (one, two, four, and eight species) and used a factorial combination of insecticide and activated carbon applications to reduce herbivory and allelopathy, respectively. We then invaded the communities with the introduced plant Solidago canadensis L. One year after the start of the experiment, there was no statistically significant net effect of species richness on biomass of the invader. However, a structural equation model showed that species richness had a positive direct effect on invader biomass that was partially balanced out by a negative indirect effect of species richness via increased light interception. In the second year, the relationship between invader biomass and species richness was negative when we analyzed the treatment combination with herbivory and allelopathy separately. Therefore, we conclude that joint effects of herbivory and allelopathy may play major roles in driving the diversity–invasibility relationship and should be considered in future studies. [ABSTRACT FROM AUTHOR]

Conventional agricultural practices viz; usage of pesticides and chemical fertilizers, often translate into a surge in soil infertility and plant susceptibility to various biotic and abiotic stresses. Incorporation of organic manure in traditional agricultural practices offers the advantages of enhancing soil texture, aeration, structure, and water retention while aiding in the growth of a healthy plant system via the easy availability of nutrients. Microbial-based techniques like biofertilizers are being encouraged as an alternative to chemical fertilizers to increase crop productivity. They have proven to have a substantial impact on plant development by viable sustainable strategies to increase plant biomass. Under the integrated plant nutrition system (IPNS), organic amendments in addition to synthetic fertilizers are more efficient in increasing and maintaining crop output and soil fertility. The objective of this review is to revisit the impact of the combined application of organic manures and beneficial bacterial populations on soil health, agricultural productivity, and sustainability in field crops. [ABSTRACT FROM AUTHOR]

Organic agricultural practices are increasingly recognized for promoting sustainable soil–plant-environment interactions. However, the specific impact of soil additives in organic systems on nutrient and microbial dynamics, and their subsequent effects on crop performance, are still relatively unexplored. This study sought to address this gap by investigating the screening of suitable rice-legume residue combinations for biochar (BC) production and assessing the effect of incorporating BC as a soil additive in organic soil nutrient management. A two-year field experiment was conducted with six organic soil treatments comprising farmyard manure (FYM) and vermicompost (VC) as organic nutrient sources (equivalent to 100 kg N ha−1), along with BC and Jeevamrit (J-Con) as soil additives, and a non-fertilized control to evaluate their impacts on nutrient cycling and crop performance. The rice-pigeon pea crop residue combination was found to be the most suitable for BC production (BC-RP), maintaining favorable nutritional quality and conversion efficiency. Among the soil treatments, T5 (50% FYM + 50% VC + BC) emerged as the most effective for enhancing soil pH, carbon content, and nutrient and microbial dynamics, followed by 50% FYM + 50% VC + J-Con (T6). This treatment also notably improved crop (onion) parameters, including growth, yield, quality, and production economics. The incorporation of BC as soil additive in 50% FYM + 50% VC significantly enhanced nutrient and microbial transformations in the soil, resulting in improvements of 7–25% in crop parameters. The findings of the study thus may be useful for achieving sustainable onion production by enhancing synchronized soil–plant interactions within an organic production system. [ABSTRACT FROM AUTHOR]

Background and aims: Increased N deposition can break the coupled associations among chemical elements in soil, many of which are essential plant nutrients. We evaluated the effects of four years of N deposition (0, 10, 20, 50 kg N ha−1 yr−1) on the temporal dynamics of the spatial co-variation (i.e., coupling) among ten chemical elements in soils from a semiarid shrubland in central Spain. Methods: Soil element coupling was calculated as the mean of Spearman rank correlation coefficients of all possible pairwise interactions among elemental cycles, in absolute value. We also investigated the role of atomic properties of elements as regulators of coupling. Results: While N deposition impacts on nutrient bioavailability were variable, soil elemental coupling consistently increased in response to N. Coupling responses also varied among elements and N treatments, and four out of ten elemental cycles also responded to N in a season-dependent manner. Atomic properties of elements such as mass, valence orbitals, and electronegativity contributed to explain the spatial coupling of soil elements, most likely due their role on the capacity of elements to interact with one another. Conclusions: The cumulative effects of N deposition can alter the spatial associations among chemical elements in soils, while not having evident consequences on the bioavailability of single elments. These results indicate that considering how multiple elements co-vary in topsoils may provide a useful framework to better understand the simultaneous response of multiple elemental cycles to global change. [ABSTRACT FROM AUTHOR]

The Cerrado, South America's largest savanna, has acidic, nutrient‐poor soils and its native plants thrive under these conditions. However, abandoned pastures historically undergo changes in chemical properties due to interventions like liming and fertilizer use. This favors invasive African grasses and hinders native plants, impacting restoration efforts. In a Cerrado grassland undergoing restoration study, we tested whether soil acidification could restore native soil conditions and control invasives using 56 plots across 14 blocks. We hypothesized that decreased soil pH and nutrient availability would reduce invasive biomass and enhance diversity. We show that acidification reduced invasive biomass by 71%, with acidification negatively affecting invasives while sparing natives. Maintaining nutrient‐poor soil conditions can help to control invasive grasses in restoration projects, as fertilizer application can favor invasive species establishment. Soil acidification effectiveness depends on local nutrient levels. Areas with high soil cation content may require larger amendment quantities. Restoration strategies in nutrient‐poor ecosystems should aim recovering historical soil conditions to control invasives growth and support slow‐growing native plants. [ABSTRACT FROM AUTHOR]

The low rice production level in Africa is attributed to poor soil fertility despite the potential for rice cultivation in the inland valleys. This study was conducted to evaluate soil characteristics in some lowlands that have been continuously and intensively used for rice production for over two decades in southwestern Nigeria. Soil physical, chemical, and mineralogical properties, as well as phosphorus sorption characteristics, were assessed in soil samples collected from diagnostic horizons of profiles in six benchmark soils. The results show kaolinite, quartz, potassium(K)-feldspars, and mixed-layered smectite as the predominant minerals. The iron oxide fractions indicate that the soils are at varying degrees of development where the soils at the advanced stage of development are predominantly rich in kaolinite and quartz with a high concentration of total pedogenic iron oxide and generally low in soil fertility. Soil phosphorus buffering capacity is low and varies inversely with pH, confirming the deficiency of phosphorus at low pH. Short-range-order (SRO) iron (Fe) oxides show a strong affinity for phosphorus and this is stronger at lower soil horizons and mediated by some redoxomorphic reactions. The SRO iron oxide concentration has more influence on phosphorus retention in soils rather than the absolute concentration of iron oxides. The study concludes that SRO Fe oxides and soil pH are the major edaphic factors playing a prominent role in phosphorus retention and availability in the wetland soils rather than the clay minerals. [ABSTRACT FROM AUTHOR]

Application of biosolids can be beneficial for low carbon (C) and erosion‐prone soils of the dryland region of inland Pacific Northwest (iPNW). Biosolids have been proven to improve wheat yields and soil health in the iPNW. Although direct agronomic and environmental influences of biosolids with frequent applications have been extensively studied, research‐based information on persistence and long‐term residual or 'legacy' effects of biosolids applications have only rarely been reported. Therefore, this study was conducted to understand the longevity of the impacts of biosolids 7 years after the last application. The study included tillage (tandem disk vs. undercutter tillage) as the main‐plot factor and fertilizer type (biosolids vs. synthetic N + S) as the subplot factor in a split‐block experimental design. Biosolids were applied at the rate of 6.5 mt/ha (on dry weight basis to meet N requirements for two wheat crops) in 2012 and 2016. Soil samples were collected from the 0–10 cm depth in 2023 and analysed for an array of soil properties. Results showed that 7 years after the last application of biosolids, compared to the synthetic fertilizer plots, the biosolids plots had increased total C, total N, extractable P, S, Zn, Fe, Mn, and Cu and decreased soil pH, Mg, and Ca. Grain protein, soil EC, NO3−N, NH4−N, Na and B were not affected by fertilizer type. Conservation undercutter tillage showed increased soil K, Mg, OM, Zn, TN, and TC compared to traditional disk tillage. In addition, biosolids legacy showed 42% higher grain yield, 47% greater straw production, and increases in most grain yield components but 8% lower 1000‐grain weight compared to synthetic fertilizer treatments. Overall, biosolids showed improved nutrient availability, wheat grain yield, and grain yield components in a dryland region 7 years after the last application. Our data show that periodic application of biosolids improves soil health and increases grain yield in dryland wheat systems. [ABSTRACT FROM AUTHOR]

This study evaluated the effectiveness of zeolite, both alone and in combination with mineral fertilizers, in improving the yield and quality of table beets (Beta vulgaris L.) grown in dark chestnut soils of southeast Kazakhstan. The research was conducted at the Kazakh Research Institute of Horticulture during the 2022-2023 growing seasons using a randomized complete block design with six treatments: control (no fertilizers), zeolite 2 t/ha, N45P45K45 (single dose of mineral fertilizers), N90P90K90 (double dose of mineral fertilizers), zeolite 2 t/ha + N45P45K45, and zeolite 2 t/ha + N90P90K90, replicated three times. The application of zeolite significantly improved soil physical properties, such as water permeability and soil density, enhancing root development and water retention. Nutrient availability, particularly nitrate nitrogen and mobile phosphorus, increased significantly in zeolite-treated plots. The combination of zeolite and mineral fertilizers resulted in the highest improvements, with nitrate nitrogen content reaching 40.5 mg/kg and mobile phosphorus 89.2 mg/kg. Moreover, zeolite reduced heavy metal concentrations, particularly cadmium, by 50% compared to the control. Table beet yield significantly increased with zeolite application, with the highest yield of 62.7 t/ha achieved with 2 t/ha zeolite combined with double dose N90P90K90 fertilizers, compared to 42.8 t/ha in the control. Marketable yield also improved, indicating better crop quality. Nutrient composition of the beets improved, with increased dry matter content (21.9%) and reduced nitrate content (240 mg/kg) in zeolite-treated variants. In conclusion, zeolite, especially when combined with mineral fertilizers, effectively enhances soil health, nutrient availability, and table beet yield and quality. [ABSTRACT FROM AUTHOR]

Wheat (Triticum aestivum) is a globally significant cereal crop with vital roles in human civilization and the agricultural revolution. The present study aimed to investigate the impact of Integrated Nutrient Management (INM) strategies on vegetative growth and yield parameters such as plant height, spike length, grains per spike, spike m-2, grain yield, biological yield, straw yield leaf area index, harvest index, and soil nutrient availability of wheat genotype PBW 590 (Triticum aestivum). The experiment was set up in randomised block design (RBD) with nine treatments in triplicates using different ratios of NPK, farm yard manure, vermicompost etc. The results indicated significant variations in plant height among the treatments (T1, T2, T3, T4, T5, T6, T7, T8 and T9) with the maximum (95.1 cm) in T4 (70% recommended dose of fertilizer + 2.5% Azospirillum + 2.5% phosphate solubilizing bacteria + 20% Farm yard manure + 5% Vermicompost), surpassing the recommended dose of fertilizer by 6.17%. Leaf Area Index positively responded to INM treatments, with T4 displaying the highest LAI (4.55), suggesting enhanced photosynthetic efficiency. Harvest Index (HI) indicated resource allocation towards edible yield, with T4 exhibiting the highest HI (50.7%) which was 34% higher than RDF. T4 consistently showed positive effects on the parameters, such as spike length (14.1 cm) and grains per spike (33), demonstrating variations among the treatments. Nutrient availability (N, P, and K) in the soil significantly improved under INM treatments, particularly T4, showcasing the potential for nutrient management in enhancing wheat growth and improving soil health. [ABSTRACT FROM AUTHOR]

The soil solution is the compartment where plants uptake nutrients and this phase is in equilibrium with the soil solid phase. Changes in nutrient content and availability in the soil solution can vary among soil types in response to humic acid concentrations, thereby affecting Brachiaria growth. However, there are no studies demonstrating these effects of humic acid application on different soil types and how they affect Brachiaria growth. Thus, the aim of this study was to evaluate the effects of humic acid concentrations (0, 5, 10, 25, and 60 mg kg−1 carbon-humic acid) on Brachiaria brizantha growth and soil solution properties of contrasting tropical soils. Plants were grown for 35 days in greenhouse conditions in pots containing Sandy Entisol, Clayey (Red Oxisol), and Medium Texture (Red-Yellow Oxisol). Soil solution was assessed for pH, electrical conductivity (EC), carbon, and nutrient content. Shoot and root dry matter, as well as macro and micronutrients accumulation in the shoot, were determined. In a soil type-dependent effect, pH, EC, and concentrations of nutrients in solutions changed in response to carbon-humic acid concentration. In the less-buffered soils, Sandy Entisol and Red-Yellow Oxisol, the addition of 30–40 mg kg−1 carbon-humic acid increased root proliferation by 76–89%, while Brachiaria biomass produced in all soils increased by approximately 30%. Levels of carbon in solution were high (>580 mg L−1) and varied depending on the investigated soil type. Though solution carbon contents did not appear to be a driving factor controlling the positive effects of humic acid concentrations on Brachiaria dry matter, there was a direct relationship between other properties and nutrient content in the soil solution, and Brachiaria dry matter production. [ABSTRACT FROM AUTHOR]

Priming effects of soil organic matter decomposition are critical to determine carbon budget and turnover in soil. Yet, the overall direction and intensity of soil priming remains under debate. A second‐order meta‐analysis was performed with 9296‐paired observations from 363 primary studies to determine the intensity and general direction of priming effects depending on the compound type, nutrient availability, and ecosystem type. We found that fresh carbon inputs induced positive priming effects (+37%) in 97% of paired observations. Labile compounds induced larger priming effects (+73%) than complex organic compounds (+33%). Nutrients (e.g., N, P) added with organic compounds reduced the intensity of priming effects compared to compounds without N and P, reflecting "nutrient mining from soil organic matter" as one of the main mechanisms of priming effects. Notably, tundra, lakebeds, wetlands, and volcanic soils showed much larger priming effects (+125%) compared to soils under forests, croplands, and grasslands (+24...+32%). Our findings highlight that positive priming effects are predominant in most soils at a global scale. Optimizing strategies to incorporate fresh organic matter and nutrients is urgently needed to offset the priming‐induced accelerated organic carbon turnover and possible losses. [ABSTRACT FROM AUTHOR]

In the Indian sector of the Southern Ocean, 80°E marks an important transition in ocean circulation between the greater Prydz Bay gyre to the west and the Australian Antarctic gyre to the east. Here, the submarine Kerguelen Plateau impedes the eastward flow of the Antarctic Circumpolar Current (ACC), topographically steering the flow. Enhanced biological productivity associated with the southern plateau supports an important marine ecosystem with many foraging marine predators. We collate ship-based hydrographic data on the vertical structure of the upper water column near 80°E from eight voyages spanning 1994 to 2021, from 58°S towards the Antarctic continent. The study aims to investigate the mixed layer oceanography, the implications for nutrient supply from deep to near-surface waters, and associated biological production. Our results show that the major oceanographic fronts are constrained within the narrow Princess Elizabeth Trough, between the southern Kerguelen Plateau and the Antarctic slope. Therefore, the Southern Boundary and the Southern ACC Front (SACCF) are often co-located, albeit with some interannual variability, with the location of the SACCF ranging from roughly 63°S to 65°S. The average depth of the seasonal mixed layer ranges from 34-49 m, typically deepening from south to north, in association with longer time since sea-ice melt. Below the mixed layer, Winter Water (WW) characteristics also vary across the observed latitudinal range; typically the temperature and thickness of the WW layer are inversely related, with warmer WW layers being thinner. Subsurface nitrate concentrations range from 20-40 µM, while silicate concentrations reach 100 µM. Nutrient drawdown is calculated based on mean concentrations in the mixed layer and WW layer, with drawdown values at individual stations reaching nearly 12 µM and 60 µM for nitrate and silicate, respectively, and a positive correlation between the two. Nutrient drawdown was higher in association with longer time since sea-ice melt and with thinner WW layers, while higher nitrate-based production was associated with deeper mixed layers. Observed relationships between upper water column characteristics and biological processes are discussed in terms of likely nutrient supply mechanisms and seasonal patterns of utilization.

The editorial discusses the impact of environmental conditions on chloroplast functioning and development in plant cells. Factors such as light intensity and quality, temperature, water availability, salt and osmotic stress, nutrient availability, and atmospheric CO2 concentration can significantly influence chloroplast performance. Understanding these mechanisms is crucial for improving plant health and productivity, especially in changing environmental conditions. The editorial highlights the importance of studying these factors to enhance our understanding of chloroplast functioning in response to environmental changes. [Extracted from the article]

Environmental conditions profoundly influence microbial diversity and activity in soil. For optimal growth, soil microbes face limiting factors such as temperature, moisture, pH, and salinity levels. This study aims to find types of functional bacteria that are able to live in saline soils. The study was conducted in the Soil Biology Laboratory at Universitas Sumatera Utara (USU), Indonesia. Soil samples were collected around the Sialang Buah Coast, Serdang Bedagai Regency, North Sumatra, Indonesia. The method employed in this research was random composite sampling taken from three vegetation types: mangrove forests, grasslands, and oil palm plantations, with sample collection locations influenced by tidal fluctuations. Ten sampling points were taken at each location and then composited for each vegetation type. The results of the study showed that there were ten species of bacteria that were able to live in saline soil, namely Pseudomonas aeruginosa, Burkholderia gladioli, Enterobacter cloacae, Brucella ciceri, Ochrobactrum oryzae, Achromobacter xylosoxidans, Priestia flexa, Enterobacter quasiroggenkampii, Bacillus cereus and Ochrobactrum oryzae. All bacteria found were able to grow on Pikovskaya, Alexandrov, and Jensen media and only seven species of bacteria were able to form biofilms, namely P. aeruginosa, B. gladioli, E. cloacae, B. ciceri, A. xylosoxidans, P. flexa, and E. quasiroggenkampii

Abstract Background Both increasing native species diversity and reducing nutrient availability can increase the ability of native plant communities to resist alien plant invasions. Furthermore, native species diversity and nutrient availability may interact to influence alien plant invasions. So far, however, little is known about the interactive effect of species diversity and nutrient availability on reproduction of alien invasive plants. We constructed native plant communities with one, four or eight species under low and high nutrient supply and then let them be invaded by the invasive alien plant Bidens pilosa. Results At both high and low nutrient supply, increasing native species richness significantly increased aboveground biomass of the native plant community and decreased aboveground biomass and biomass proportion of the invader B. pilosa. Reproductive biomass of B. pilosa decreased significantly with increasing native species richness under high nutrient supply, but this effect was not observed under low nutrient supply. Net biodiversity effect on seed mass of B. pilosa decreased significantly with increasing native species diversity under high nutrient supply, but not under low nutrient supply. This was mainly because the selection effect became dominant with increasing species richness under high nutrient supply. Conclusions Our study suggest that native species richness and nutrient supply can interact to influence reproduction of invasive alien plant species and that measures to help maintain a high level of native species richness and to reduce nutrient supply could be useful for efficient invasive plant control.

Limestone substrates cover 20–30% of the continents and are the habitat of many calcareous fern species, which grow preferably or exclusively on this substrate. In this review, we resume the limestone properties and their implications for calcareous ferns. Additionally, we investigate the taxonomic distribution of limestone ferns by comparing five limestone regions and six mainly lithophytic genera to understand what proportion of ferns and which genera primarily colonise limestone in each region. Mexico is presented as a more detailed case study. Calcareous ferns have to deal with higher soil alkalinity, increased levels of Ca, Mg, and carbonates, lower P, Fe, and Zn availability, and often shallow, dry soils. Limestone ferns comprised 8-13% of the regional floras (except for South Africa) and were most diverse in Pteridaceae, Aspeniaceae, and Dryopteridaceae. However, the relative proportion of calcareous ferns in each of the six genera varied from region to region. The highest proportions of limestone species were detected in Ctenitis (73% in Jamaica), Adiantum and Asplenium (50% in Thailand), Anemia (40% in Jamaica), and Polystichum (35% in Jamaica and 33% in China). These results indicate a regionally independent evolution of limestone specialisation in ferns. Gypsum and serpentine ferns have to cope with even more extreme substrate conditions, are even rarer and may have evolved from limestone ferns. [ABSTRACT FROM AUTHOR]

Ocean stratification on Arctic shelves critically influences nutrient availability, essential for primary production. However, discerning the changes in stratification and their drivers is challenging. Through the use of a highresolution ocean-sea-ice model, this study investigates the variability in stratification within the northeastern Chukchi Sea over the period from 1987 to 2016. Our analysis, validated against available observations, reveals that summers with weak stratification are marked by a warmer water column that features a saltier upper layer and a fresher lower layer, thereby diminishing the vertical density gradient. In contrast, summers with strong stratification are characterized by a cooler column with a fresher upper layer and a saltier lower layer, resulting in an increased density gradient. This variability is primarily driven by the timing of sea-ice retreat and the consequent variations in meltwater flux, with early retreat leading to less meltwater and saltier surface conditions. This factor significantly outweighs the influence of changes in circulation and associated lateral freshwater transport driven by the Bering Strait inflow. We also find that the synchronization of sea-ice retreat and Bering Strait inflow intensity is linked to the timing and strength of the Aleutian Low's westward shift from the Gulf of Alaska to the Aleutian Basin in the early winter. These insights are crucial for understanding nutrient dynamics and primary production in the region. Furthermore, monitoring sea-ice retreat timing could serve as a useful proxy for predicting subsequent summer stratification changes. [ABSTRACT FROM AUTHOR]

Employing elevated CO2 (eCO2), similar to increasing atmospheric CO2 in a greenhouse, is a common practice used to increase vegetable crop yields. However, the responses of nutrient availability, nutrient uptake and use efficiency in leafy vegetables to eCO2 remain largely unknown. The plant biomass production, nitrogen (N), phosphorus (P) and potassium (K) contents, nutrient uptake, and soil enzymatic activities of three Brassica chinensis varieties of 'Longpangqing', 'Heimeiren' and 'Qingjiangbai' were thus assessed under ambient CO2 (C0, 420/470 ppm, day/night) and eCO2 (C1, C0 + 33.3%C0; C2, C0 + 66.7%C0; and C3, C0 + 100%C0) for 4 months. Biomass production was significantly enhanced in these three tested B. chinensis varieties along with eCO2 gradients, with the highest biomass production under C3. Moreover, the eCO2 significantly increased plant N and K uptake, P and K use efficiency, soil saccharase, urease, and phosphatase activities, but decreased plant P content, soil available N and K, and catalase activity. Under eCO2, 'Qingjiangbai' exhibited higher biomass production and P and K uptake, without a decrease in soil available N and P. Consequently, more external fertilizer supplementation (especially N, followed by K) is required to maintain or promote Brassica chinensis yield under eCO2, while these management strategies must be carefully considered for different crop varieties. [ABSTRACT FROM AUTHOR]

Continuous addition of inorganic fertilizer and farm yard manure (FYM) alone or in combination is necessary to assess the changes in yield and soil properties. Therefore, a study was conducted for consecutive two years on nutrient management with nine treatments viz. T1- control, T2-100% FYM (N equivalent basis), T3-100% N, T4-NP, T5-NK, T6-PK, T7-NPK, T8-100% NPK+ FYM (recommended Practice) and T9- 150% NPK+ FYM to assess the influence of different treatments on yield, sustainable yield index, soil physic-chemical properties and soil carbon stock and sequestration rate in cauliflower and capsicum cropping sequence. Results showed that the addition of farm yard manure alone or in a combination with chemical fertilizers contributed to higher soil organic stock and soil carbon sequestration rate. Application of 150% NPK + FYM improved the SYI of system by 49.4% over a control. This treatment increases soil carbon stock by 12.5% from 25.9 Mg ha−1 to 29.6 Mg ha−1 and recorded with maximum soil carbon sequestration rate, i.e. 2.21 Mg C m−3 year−1 over the 2 years. Thus, balanced fertilization of NPK and FYM is beneficial for the maintenance of soil physical health, improving CEC and macro and micronutrient levels. [ABSTRACT FROM AUTHOR]

The extent to which soil enzyme activity in assessing soil nutrient availability is useful has been controversial. In this review, we discuss the utility of ecoenzymatic stoichiometry (i.e. the ratio of nutrient- to carbon (C)-acquiring enzyme activities) on the basis of the resource allocation model for ecoenzyme synthesis. Both the selection of appropriate enzymes and the balance between relative amounts of substrates and enzymes in the soil are decisive factors in utilizing the ecoenzymatic stoichiometry. Ecoenzymatic stoichiometry can evaluate the availability of nitrogen (N), phosphorus, and sulfur in many soils in which the enzyme catalytic reactions are substrate-limited but not enzyme-limited. However, the ecoenzymatic stoichiometry approach does not seem to be applicable in soils where microbes are limited by factors other than nutrient availability, such as low temperature, where the enzyme catalytic reactions are enzyme-limited. Certain enzymes, such as N-acetyl-β-glucosaminidase and protease, appear to be insensitive to soil N availability, because they release compounds containing both N and C which serve as sources for both N and C/energy. We propose the use of enzymes such as L-asparaginase and urease as N-acquiring enzymes that release a compound containing N but not C (i.e. NH4+) as the hydrolysis product. Ecoenzymatic stoichiometry can be considered as an indicator of long-term (weeks) temporally integrated soil nutrient availability, rather than instantaneous availability, for plants as well as microbes, because of (i) the long-term persistence of extracellular enzymes in soils; (ii) a significant correlation between ecoenzymatic stoichiometry and the measurements reflecting the quantity of long-term available nutrients in soil; and (iii) a significant correlation between ecoenzymatic stoichiometry and plant nutrient uptake. This review also identifies challenges in assessing microbial nutrient limitation using ecoenzymatic stoichiometry. With a comprehensive understanding of underlying mechanisms and limitations, ecoenzymatic stoichiometry can be used as a biologically relevant indicator of nutrient availability in combination with other approaches such as conventional chemical extraction methods and the nutrient addition approach. [ABSTRACT FROM AUTHOR]

An in vivo trial was conducted to determine the apparent digestibility coefficients (ADCs) of insect meals for rainbow trout, Oncorhynchus mykiss. Rainbow trout (approximately 370 g ± 23 g, mean ± SD initial weight) were stocked 25 per tank into 400-liter tanks. Fish were fed a reference diet, or 1 of 5 test diets created by blending the reference diet in a 70:30 ratio (dry-weight basis) with menhaden fish meal (MFM), 2 house cricket (Acheta domesticus) meals (cricket A and cricket B), Galleria mellonella meal, and yellow mealworm (Tenebrio molitor) meal. Diets were assigned to 3 replicate tanks of fish and fed twice daily for 14 days prior to fecal collection. Ingredients, diets, and fecal matter were analyzed in duplicate for proximate, mineral, and amino acid composition. House cricket meals were 67.3% and 69.0% protein (CP) and 16.6% and 17.1% lipid (CL), for house cricket A and B, respectively. Yellow mealworm meal contained 56.5% CP and 27.7% CL, and G. mellonella larvae meal contained 32.5% CP and 54.2% CL. Protein ADCs were 78.9 for G. mellonella larvae meal, 78.0 for yellow mealworm meal, and 76.5 for house cricket A and not different from the MFM protein ADC of 76.6, while house cricket B protein ADC was 65.8 and was significantly lower than the MFM protein ADC (F  = 7.39; df = 4,14; P  = 0.0049). Together, these nutritional values suggest house crickets, and yellow mealworms show promise as alternative protein sources in salmonid feeds, with the potential of G. mellonella as an alternative lipid source. [ABSTRACT FROM AUTHOR]

Anthropogenic activities have raised nitrogen (N) input worldwide with profound implications for soil carbon (C) cycling in ecosystems. The specific impacts of N input on soil organic matter (SOM) pools differing in microbial availability remain debatable. For the first time, we used a much‐improved approach by effectively combining the 13C natural abundance in SOM with 21 years of C3–C4 vegetation conversion and long‐term incubation. This allows to distinguish the impact of N input on SOM pools with various turnover times. We found that N input reduced the mineralization of all SOM pools, with labile pools having greater sensitivity to N than stable ones. The suppression in SOM mineralization was notably higher in the very labile pool (18%–52%) than the labile and stable (11%–47%) and the very stable pool (3%–21%) compared to that in the unfertilized control soil. The very labile C pool made a strong contribution (up to 60%) to total CO2 release and also contributed to 74%–96% of suppressed CO2 with N input. This suppression of SOM mineralization by N was initially attributed to the decreased microbial biomass and soil functions. Over the long‐term, the shift in bacterial community toward Proteobacteria and reduction in functional genes for labile C degradation were the primary drivers. In conclusion, the higher the availability of the SOM pools, the stronger the suppression of their mineralization by N input. Labile SOM pools are highly sensitive to N availability and may hold a greater potential for C sequestration under N input at global scale. [ABSTRACT FROM AUTHOR]

Phosphorus (P) and potassium (K) are essential nutrients for plant growth and development. Plants will achieve optimum biomass and production if phosphorus and potassium needs are met through fertilization. Determining the availability of phosphorus and potassium in the soil is essential because it is related to deciding phosphorus and potassium fertilizer rate recommendations. In this study, we evaluated five common phosphorus and potassium extraction methods by correlating the indicated soil nutrient levels to the relative dry-weight biomass of chili plants. The phosphorus and potassium extraction methods were Mehlich-1, Bray-1, Morgan-Wolf, Ammonium acetate, and HCl-25%. Mean Root Error (MRE) and Root Mean Square Error (RMSE) were used to determine the precision of the linear regression equation model in predicting the relationship between phosphorus and potassium soil extraction methods and the relative dry-weight biomass of chili plants. The correlation of the soil extraction methods of Cambisols with relative dry-weight biomass of chili was highly significant and very strong (r > 0.75), suggesting that the best soil-phosphorus extraction method for determining concentrations for optimal growth of chili was Morgan-Wolf (r = 0.96) with MRE = 0.21 and RMSE = 6.87. The Mehlich-1 with r = 0.91, MRE = 0.91, and RMSE = 5.60 was the best Cambisols potassium-extraction method. [ABSTRACT FROM AUTHOR]