Nutrient Transfer Research Articles

Remotely characterizing photosynthetic biocrust in snowpack-fed microhabitats of Taylor Valley, Antarctica

Microbial communities are the primary drivers of carbon cycling in the McMurdo Dry Valleys of Antarctica. Dense microbial mats, consisting mainly of photosynthetic cyanobacteria, occupy aquatic areas associated with streams and lakes. Other microbial communities also occur at lower densities as patchy surface biological soil crusts (hereafter, biocrusts) across the terrestrial landscape. Multispectral satellite data have been used to model microbial mat abundance in high-density areas like stream and lake margins, but no previous studies have investigated the lower detection limits of biocrusts. Here, we describe remote sensing and field-based survey and sampling approaches to study the detectability and distribution of biocrusts in the McMurdo Dry Valleys. Using a combination of multi- and hyperspectral tools and spectral linear unmixing, we modeled the abundances of biocrust in eastern Taylor Valley. Our spectral approaches can detect low masses of biocrust material in laboratory microcosms down to biocrust concentrations of 1% by mass. These techniques also distinguish the spectra of biocrust from both surface rock and mineral signatures from orbit. We found that biocrusts are present throughout the soils of eastern Taylor Valley and are associated with diverse underlying soil communities. The densest biocrust communities identified in this study had total organic carbon 5x greater than the content of typical arid soils. The most productive biocrusts were located downslope of melting snowpacks in unique soil ecosystems that are distinct from the surrounding arid landscape. There are similarities between the snowpack and stream sediment communities (high diversity of soil invertebrates) as well as their ecosystem properties (e.g., persistence of liquid water, high transfer of available nutrients, lower salinity from flushing) compared to the typical arid terrestrial ecosystem of the dry valleys. Our approach extends the capability of orbital remote sensing of photosynthetic communities out of the aquatic margins and into the drier soils which comprise most of this landscape. This interdisciplinary work is critical for measuring and monitoring terrestrial carbon stocks and predicting future ecosystem dynamics in this currently water-limited but increasingly dynamic Antarctic landscape, which is particularly climate-sensitive and difficult to access.

To be a transit link: Similarity in the structure of colonial system of integration and communication pores in autozooids and avicularia of Terminoflustra membranaceotruncata (Bryozoa: Cheilostomata).

Bryozoan colonies consist of zooids, which can differ in structure and function. Most heteromorphic zooids are unable to feed and autozooids supply them with nutrients. The structure of the tissues providing nutrient transfer is poorly investigated. Here, I present a detailed description of the colonial system of integration (CSI) and communication pores in autozooids and avicularia of the cheilosome bryozoan Terminoflustra membranaceotruncata. The CSI is the nutrient transport and distribution system in the colony. In both autozooids and avicularia it consists of a single cell type, that is, elongated cells, and has a variable branching pattern, except for the presence of a peripheral cord. The general similarity in the CSI structure in avicularia and autozooids is probably due to the interzooidal type of the avicularium. Interzooidal avicularia are likely to consume only a part of the nutrients delivered to them by the CSI, and they transit the rest of the nutrients further. The variability and irregularity of branching pattern of the CSI may be explained by the presence of single communication pores and their varying number. The structure of communication pores is similar regardless of their location (in the transverse or lateral wall) and the type of zooid in contact. Rosette complexes include a cincture cell, a few special cells, and a few limiting cells. Along each zooidal wall, there are communication pores with both unidirectional and bidirectional polarity of special cells. However, the total number of nucleus-containing lobes of special cells is approximately the same on each side of any zooidal wall. Supposing the polarity of special cells reflects the direction of nutrient transport, the pattern of special cells polarity is probably related to the need for bidirectional transport through each zooidal wall. The possibility for such transport is important in large perennial colonies with wide zones of autozooids undergoing polypide degeneration.

Regulatory role of sesarmid crabs in nutrient dynamics and implications for the productivity of mangroves

The ecological role of brachyuran crabs in mangroves has been extensively studied, but their role as mediators of biogeochemical processes of essential nutrients remains unclear. We hypothesized that speciose sesarmid crabs in tropical mangroves can improve nutrient transfer rate (NTR) and enhance primary productivity by reducing nutrient recycling bottlenecks. Using stable isotope labels and tidal mesocosms simulating the mangrove environment (with and without crabs), we traced the transfer of carbon (C) and nitrogen (N) across the system (from mangrove leaf litter to mangrove seedlings, the microphytobenthos (MPB), and sediment). We compared NTR between the two treatments by measuring the 13C and 15N enrichment levels (as a proxy for NTR) of mangrove seedlings, MPB, and sediment. The significantly higher enrichment level of sediment, MPB and seedlings (for N) in mesocosms with crabs indicated higher NTR driven by these animals. Such increased NTR also led to higher primary productivity, supporting our hypothesis. A consumer-driven nutrient dynamics (CND) framework was established to provide a comprehensive understanding of the role of sesarmid crabs in mediating biogeochemical processes. It is clear that the reciprocal nutrient flow between MPB and sesarmid crabs, and the biogeochemical hotspots created in surface sediment underpin this CND effect. A system picture emerges whereby nutrient flow is strongly regulated by sesarmid crabs promoting the productivity of mangroves by (1) enhancing nutrient remineralization; (2) retaining nutrients; (3) creating biogeochemical hotspots; and (4) improving overall nutrient transfer rate.

X-ray computed tomography – Measured pore characteristics and hydro-physical properties of soil profile as influenced by long-term tillage and rotation systems

Soil hydro-physical properties and pore characteristics are crucial for crop production as they determine water, air, and nutrients transfer. Long-term tillage and crop rotation studies provide valuable insights into the effects of management practices on various soil properties. Because of the inherent differences between the surface and sub-surface soils, the impact of management systems can be pronounced differently at different soil depths. Though many studies have reported the tillage and rotation effects on soil hydro-physical properties, their vertical impacts to a depth of 40 cm were less explored. This study aims to assess the impact of long-term tillage and crop rotations on soil hydro-physical properties and pore characteristics to a depth of 40 cm utilizing the X-ray Computed Tomography (XCT) technique. Intact soil cores of 7.6 cm height × 7.6 cm ∅ were collected from tillage [no-till (NT); reduced-till (RT); conventional-till (CT)] and crop rotation [continuous corn (CC) – Zea mays L. and corn-soybean (CS) – Glycine max [Merr.] L.] plots of 0–40 cm depth (each sample for 10 cm increment). The XCT scanning allowed us to investigate the soil pore size distribution, porosity, number of branches, and average branch length. Measured hydro-physical properties in the study include bulk density (ρb), plant available water content (PAW), saturated hydraulic conductivity (Ksat), and water retention. XCT image analysis revealed that NT with CC/CS rotation increased the number of macropores at surface and sub-surface depths. However, the number of mesopores was higher with NT × CS. In addition, NT lowered the ρb by 9.6 % and increased the PAW by 28 % compared to the CT. Ksat was higher under NT × CS at 0–10 cm and had a strong positive correlation with the XCT-measured number of macropores. Therefore, we conclude that NT with CS rotation can potentially improve soil pore characteristics and hydro-physical properties, leading to enhanced soil function.

Timing of connection to mycorrhizal networks matters: Nutrition, N fixation, and transfer of fixed N in maize-bean intercropping

The mycorrhiza-mediated transfer of nutrients to plants connected through mycorrhizal networks may be managed through the timing at which plants integrate to the networks and the integrity of those networks. This is particularly relevant for intercropping agrosystems. We used soil tillage to disrupt mycorrhizal networks and sowing time treatments to manipulate the connection time of maize and bean in a field experiment. We hypothesized that 1) the benefits from connecting to mycorrhizal networks would be greater for the crop that is established first and retrieved resources from the network without competition, and 2) tillage disruption delaying colonization and connection to preserved mycorrhizal networks would reduce mycorrhizal colonization in roots and soil, crop nutrition, N fixation by beans, and transfer of fixed N to maize. Mycorrhizal network disruption with tillage reduced early mycorrhizal development in roots and soil, and N and P nutrition of both crops. In general, sowing time had no effect in maize but tillage increased plant density, growth, and the yield of maize by alleviating soil compaction. Reduced tillage and early sowing increased nutrition, development, N fixation and yield of bean. N derived from symbiotic fixation in bean and transferred to maize were higher with bean sown before maize under reduced tillage. Early connection to mycorrhizal networks favored mostly bean and made little difference to maize regardless of sowing time, contrary to our expectations. The greatest overall benefit for both crops was obtained when bean was sown before maize and connected early to preserved mycorrhizal networks under reduced tillage.

Biomolecular profiles of Arctic sea-ice diatoms highlight the role of under-ice light in cellular energy allocation.

Arctic sea-ice diatoms fuel polar marine food webs as they emerge from winter darkness into spring. Through their photosynthetic activity they manufacture the nutrients and energy that underpin secondary production. Sea-ice diatom abundance and biomolecular composition vary in space and time. With climate change causing short-term extremes and long-term shifts in environmental conditions, understanding how and in what way diatoms adjust biomolecular stores with environmental perturbation is important to gain insight into future ecosystem energy production and nutrient transfer. Using synchrotron-based Fourier transform infrared microspectroscopy, we examined the biomolecular composition of five dominant sea-ice diatom taxa from landfast ice communities covering a range of under-ice light conditions during spring, in Svalbard, Norway. In all five taxa, we saw a doubling of lipid and fatty acid content when light transmitted to the ice-water interface was >5% but <15% (85%-95% attenuation through snow and ice). We determined a threshold around 15% light transmittance after which biomolecular synthesis plateaued, likely because of photoinhibitory effects, except for Navicula spp., which continued to accumulate lipids. Increasing under-ice light availability led to increased energy allocation towards carbohydrates, but this was secondary to lipid synthesis, whereas protein content remained stable. It is predicted that under-ice light availability will change in the Arctic, increasing because of sea-ice thinning and potentially decreasing with higher snowfall. Our findings show that the nutritional content of sea-ice diatoms is taxon-specific and linked to these changes, highlighting potential implications for future energy and nutrient supply for the polar marine food web.

Enantioselective transformation of phytoplankton-derived dihydroxypropanesulfonate by marine bacteria.

Chirality, a fundamental property of matter, is often overlooked in the studies of marine organic matter cycles. Dihydroxypropanesulfonate (DHPS), a globally abundant organosulfur compound, serves as an ecologically important currency for nutrient and energy transfer from phytoplankton to bacteria in the ocean. However, the chirality of DHPS in nature and its transformation remain unclear. Here, we developed a novel approach using chiral phosphorus-reagent labeling to separate DHPS enantiomers. Our findings demonstrated that at least one enantiomer of DHPS is present in marine diatoms and coccolithophores, and that both enantiomers are widespread in marine environments. A novel chiral-selective DHPS catabolic pathway was identified in marine Roseobacteraceae strains, where HpsO and HpsP dehydrogenases at the gateway to DHPS catabolism act specifically on R-DHPS and S-DHPS, respectively. R-DHPS is also a substrate for the dehydrogenase HpsN. All three dehydrogenases generate stable hydrogen bonds between the chirality-center hydroxyls of DHPS and highly conserved residues, and HpsP also form coordinate-covalent bonds between the chirality-center hydroxyls and Zn2+, which determines the mechanistic basis of strict stereoselectivity. We further illustrated the role of enzymatic promiscuity in the evolution of DHPS metabolism in Roseobacteraceae and SAR11. This study provides the first evidence of chirality's involvement in phytoplankton-bacteria metabolic currencies, opening a new avenue for understanding the ocean organosulfur cycle.

Study on Types of Umbilical Cord Insertion in Normal and Intrauterine Growth Restriction

Background: Intrauterine growth restriction (IUGR) is said to be in neonates whose birth weight is less thantenth percentile of the average for gestational age. IUGR is associated with short and long-term complicationswhich can severely impact quality of life. Placental size, weight and shape may vary within wide extreme values.Ability to transfer nutrients is related to placental size. Decreased placental surface area and size are associatedwith increased risk of IUGR. Umbilical cord is the key marker for intrauterine complications. It is one of the mostimportant part of fetoplacental unit that transfer vital nutrients to fetus. This current study was taken to find outthe difference in placental morphometric features and to find the correlation between placental and neonatalweight.Materials and methods: This study included 100 samples which were equally divided into cases and controls.Placenta was collected after delivery and the data is measured quantitatively.Results: Central insertion of umbilical cord observed in IUGR in our study was 40%, eccentric was 20%, marginalwas 38%, velamentous insertion was 2% while furcate insertion observed was nil in our study.Conclusion: Central and marginal insertion was prevalent in IUGR in our study. Types of cord insertion plays alsoplays role in transfer of nutrients. Vasculature being the most important factor the growth of fetus, any imbalancein it will alter the growth.

Sustained use of marine subsidies promotes niche expansion in a wild felid

The use of marine subsidies by terrestrial predators can facilitate substantial transfer of nutrients between marine and terrestrial ecosystems. Marine resource subsidies may have profound effects on predator ecology, influencing population and niche dynamics. Expanding niches of top consumers can impact ecosystem resilience and interspecific interactions, affecting predator-prey dynamics and competition. We investigate the occurrence, importance, and impact of marine resources on trophic ecology and niche dynamics in a highly generalist predator, the caracal (Caracal caracal), on the Cape Peninsula, South Africa. Caracals have flexible diets, feeding across a wide range of terrestrial and aquatic prey. We use carbon and nitrogen stable isotope analysis of fur samples (n = 75) to understand trophic position and niche shifts in coastal and inland foragers, as well as the implications of a diet rich in marine resources. We found significant differences in isotope signatures between these groups, with higher δ13C (P < 0.05) and δ15N values (P < 0.01) in coastal foragers. Isotope mixing models reveal that these elevated signatures were due to non-terrestrial food subsidies, where approximately a third of coastal foraging caracal diet comprised marine prey. The addition of marine prey species to diet increased both the trophic level and isotope niche size of coastal foraging caracals, with potential impacts on prey populations and competition. Our results suggest that marine prey are an important dietary resource for coastal foraging caracals, where seabirds, including two endangered species, are a major component of their diet. However, there are likely risks associated with these resource benefits, as routine consumption of seabirds is linked with higher pollutant burdens, particularly metals. Increased encounters between this terrestrial predator and seabirds may be a result of increased mainland colonies due to changes in habitat availability and the highly opportunistic and generalist foraging behaviour of a native predator.

One-carbon metabolite supplementation to nutrient-restricted beef heifers affects placental vascularity during early pregnancy.

We hypothesized that restricted maternal nutrition and supplementation of one-carbon metabolites (OCM; methionine, folate, choline, and vitamin B12) would affect placental vascular development during early pregnancy. A total of 43 cows were bred, and 32 heifers successfully became pregnant with female calves, leading to the formation of four treatment groups: CON-OCM (n = 8), CON + OCM (n = 7), RES-OCM (n = 9), and RES + OCM (n = 8). The experimental design was a 2 × 2 factorial, with main factors of dietary intake affecting average daily gain: control (CON; 0.6kg/d ADG) and restricted (RES; -0.23kg/d ADG); and OCM supplementation (+OCM) in which the heifers were supplemented with rumen-protected methionine (7.4g/d) and choline (44.4g/d) and received weekly injections of 320mg of folate and 20mg of vitamin B12, or received no supplementation (-OCM; corn carrier and saline injections). Heifers were individually fed and randomly assigned to treatment at breeding (day 0). Placentomes were collected on day 63 of gestation (0.225 of gestation). Fluorescent staining with CD31 and CD34 combined with image analysis was used to determine the vascularity of the placenta. Images were analyzed for capillary area density (CAD) and capillary number density (CND). Areas evaluated included fetal placental cotyledon(COT), maternal placental caruncle (CAR), whole placentome (CAR + COT), intercotyledonary fetal membranes (ICOT, or chorioallantois), intercaruncular endometrium (ICAR), and endometrial glands (EG). Data were analyzed with the GLM procedure of SAS, with heifer as the experimental unit and significance at P ≤ 0.05 and a tendency at P > 0.05 and P < 0.10. Though no gain × OCM interactions existed (P ≥ 0.10), OCM supplementation increased (P = 0.01) CAD of EG, whereas nutrient restriction tended (P < 0.10) to increase CAD of ICOT and CND of COT. Additionally, there was a gain × OCM interaction (P < 0.05) for CAD within the placentome and ICAR, such that RES reduced and supplementation of RES with OCM restored CAD. These results indicate that maternal rate of gain and OCM supplementation affected placental vascularization (capillary area and number density), which could affect placental function and thus the efficiency of nutrient transfer to the fetus during early gestation.

Analyzing the effect of mycorrhizal fungi on plant communication of nutrients

The goal of our experiment was to determine if phosphate transfer occurred between plants, using mycorrhizal fungi. We hypothesized that a “communication” network existed between plants when the mycorrhizal fungi were present and that there would be no transfer of nutrients if the mycorrhizal fungi were not present. This study extended the analysis of Suzanne Simard who studied Paper Birch, Douglas Fir, and Western Red Cedar in Canada. She was able to confirm that there is a massive underground communication where different plants cooperate with resources using mycorrhizal fungi. The purpose of our experiment was to see if plants with nutrients would transfer their excess levels of phosphate to the plant that had a limited amount of nutrients. Overall, no definitive conclusion could be drawn from the treatments conducted. The measurements greatly deviated from the hypothesized results and demonstrated a more complicated relationship than originally thought. Further study will need to be conducted to determine if there are further conditions that must be met, such as a minimum amount of phosphate concentration or a minimum differential between the resources (in terms of this study, phosphate concentration) of the two plants, for this transfer to occur. The results of this study, if replicated and shown to be conclusive at long distances, could be used to aid forest management.

STABLE ISOTOPES AND MERCURY AS TOOLS TO DEPICT AQUATIC FOOD WEBS

The structure of food webs is a fundamental attribute of ecosystems, and their characterization provides an intrinsic knowledge of the trophic interactions among organisms and of nutrient and energy transfer within ecosystems. Over the last few decades, several chemical and biogeochemical approaches have been proposed to explore different aspects of food webs. In this sense, this study reviews the application of stable isotopes and mercury as main auxiliary tools to the characterization and modeling of aquatic food webs, including analytical and modeling advances, strengths and limitations. The metanalysis performed showed that the most used tools for trophic ecology studies are stable isotopes, and that they can provide better results when combined with mercury and specific chemical molecules such as amino and fatty acids. In addition, the statistical methods applied in the interpretation of results, such as isotope mixing models, have witnessed significant advances in the last two decades. All approaches have premises and limitations when applied to aquatic ecosystems, which must be well understood prior to results interpretation. The use of multiple tracers in trophic studies provides complementary information and in many cases is an appropriate alternative to overcome some limitations, allowing to expand the knowledge of the food webs.

Nitrogen Fate of Chemical Fertilizer and Green Manure-Wheat Rotation Using 15N Tracer Technique

To investigate the accumulation, distribution, and translocation of nitrogen (N) from chemical fertilizers and green manure in wheat plants, we conducted an experiment using leguminous green manure crop hairy vetch and wheat as test materials. During the anthesis and maturity stages of wheat, the 15N enrichment and Nitrogen content of wheat plant samples were determined in different organs, and 15N enrichment and nitrogen content of soil samples were measured at maturity. The accumulation and distribution characteristics of nitrogen from different sources during the wheat growth stages were investigated to explore the impacts of green manure and chemical fertilizers on wheat growth and nitrogen uptake. The results showed that nitrogen from chemical fertilizers in the soil-plant system exhibited the following pattern: plant absorption &gt; soil residue &gt; loss, while nitrogen from green manure showed: soil residue &gt; loss &gt; plant absorption. Wheat had higher absorption of nitrogen from chemical fertilizers compared to green manure. The absorption of nitrogen from chemical fertilizers by wheat ranged from 46.00% to 54.08%, while the absorption of nitrogen from green manure ranged from 20.71% to 28.21%. The residual nitrogen from green manure in the soil (38.47% to 58.22%) was higher than that from chemical fertilizers (31.44% to 40.69%), and the nitrogen loss from green manure (21.07% to 33.31%) was higher than that from chemical fertilizers (5.22% to 22.56%). Supply of nitrogen from the two sources could coordinate the distribution of nitrogen in various organs and increase the proportion of nitrogen allocation in grains. This was beneficial for facilitating nutrient transfer to reproductive organs.

Understanding the mechanisms of nutrient transfer between Arbuscular Mycorrhizal Fungi (AMF) and Host Plants

Understanding the mechanisms of nutrient transfer between AMF and host plants is essential for enhancing our knowledge of plant nutrition and improving agricultural practices. Transporters are protein substances that enable the movement of nutritional elements between the host plant and AMF. They ensure even and adequate distribution and uptake of micronutrients, phosphorus, and nitrogen. Apart from transporters, AMF also have a crucial role in the distribution of nutrients within the host plants. These beneficial microbes establish an intricate system of hyphae that spreads in soil, assimilating limited nutrients that would otherwise be inaccessible to the host plant. These fungal networks augment the plant's ability to obtain nourishment, particularly in environments where some elements are limited. The mechanisms underlying the transporter network involved in nutrient exchange between AMF and host plants remain to be fully deciphered. Examining the connections of this network can bring to light the coordination between incongruent transporters and the entire process of nutrient interchange. Future studies should prioritize investigating the particular molecules and genes engaged in nutrient exchange to understand this essential mutual relationship better. Furthermore, assessing the impact of environmental factors on AMF associations can help devise strategies to optimize nutrient absorption in agricultural systems. By manipulating ecological factors such as soil nutrients or pH levels, it may be possible to increase the efficiency of nutrient transfer, thus improving plant growth and productivity.

The sensitivity of the equatorial pacific ODZ to particulate organic matter remineralization in a climate model under pre-industrial conditions

Marine oxygen plays a fundamental role in regulating the transfer of organic carbon and nutrients to their dissolved inorganic forms, serving as the terminal electron acceptor for heterotrophic respiration. Oxygen can become limiting to these processes in coastal and open-ocean oxygen deficient zones (ODZs). The maintenance of ODZs depends on the balance between physical processes such as ventilation and biogeochemical processes such as remineralization. These two processes act in opposing directions on ODZs, with ventilation responsible for transporting oxygen from the surface, where it is near saturation with the partial pressure of O2 in the atmosphere, to deeper oxygen-depleted layers, and remineralization acting to consume oxygen through biogeochemical processes such as microbial degradation throughout the water column. Remineralization is represented in all CMIP6 models, but the actual parameterizations, as well as their magnitude, are widely varying.In this study, we examine the sensitivity to remineralization of the equatorial Pacific ODZ (O2<60μmol/kg) in a model; the NASA GISS Ocean Biogeochemical Model (NOBM-G) embedded in the NASA-GISS coupled atmosphere-ocean model. We find that increasing the remineralization rate shoals the ODZ onset depth (i.e. the regionally averaged upper bound of the ODZ), and decreases ODZ volume and regional-averaged thickness. Changes in biological consumption and vertical convergence of oxygen are identified as the primary contributors to changes in ODZ onset depth. ODZ thickness is mainly influenced by the shoaling of the bottom boundary of the ODZ, which decreases with maximum remineralization rate due to decreasing oxygen consumption and increasing horizontal oxygen convergence in deep waters. On the other hand, vertically-averaged ODZ area has a more complex, non-monotonic relationship with maximum remineralization rate. While these findings suggest an important role for remineralization in determining the shape of the ODZ in our model, the relative importance of remineralization vs. other physical parameterizations remains to be established. While our results reflect the structure of our ocean biogeochemical model, the relationship of remineralization to ODZ characteristics in other models should be examined to better inform model inter-comparisons.

JANUS: an open-source 3D printable perfusion bioreactor and numerical model-based design strategy for tissue engineering.

Bioreactors have been employed in tissue engineering to sustain longer and larger cell cultures, managing nutrient transfer and waste removal. Multiple designs have been developed, integrating sensor and stimulation technologies to improve cellular responses, such as proliferation and differentiation. The variability in bioreactor design, stimulation protocols, and cell culture conditions hampered comparison and replicability, possibly hiding biological evidence. This work proposes an open-source 3D printable design for a perfusion bioreactor and a numerical model-driven protocol development strategy for improved cell culture control. This bioreactor can simultaneously deliver capacitive-coupled electric field and fluid-induced shear stress stimulation, both stimulation systems were validated experimentally and in agreement with numerical predictions. A preliminary in vitro validation confirmed the suitability of the developed bioreactor to sustain viable cell cultures. The outputs from this strategy, physical and virtual, are openly available and can be used to improve comparison, replicability, and control in tissue engineering applications.

Recent innovations in fertilization with treated digestate from food waste to recover nutrients for arid agricultural fields

This study aims to explore the development of sustainable fertilizers from waste materials of a biogas plant and a brewery. These wastes, rich in organic carbon and nitrogen, were processed with sulfuric(VI) and phosphoric(V) acid mixture, facilitating the production of free amino acids and achieving waste sanitization. This treatment produced by-products, which extended the range of possible applications. The highest concentration of free amino acids (360 mg/l) was achieved through hydrolyzing with a 40% concentration medium over 24 h. In this case, the maximum levels were recorded for beta-alanine (69.3 mg/l), glycine (46.8 mg/l), isoleucine (43.5 mg/l), proline (36.2 mg/l), and valine (31.5 mg/l). The study presents two fertilizer technologies, with and without micronutrients, that satisfy European Parliament Regulation 2019/1009 (Ntot > 2%, Norg > 0.5%, Corg > 3%). Bioavailability of nutrients in the formulations ranged from 60 to 100%. The efficacies of these fertilizers were evaluated in 30-day pot trials with various plant species, with both single application and fertigation tested. Multielement analysis confirmed high nutrient transfer in the soil-plant system, and the inclusion of micronutrients led to biofortification of plant biomass in Cu (48.3 ± 7.2 mg/kg), Mn (249 ± 37 mg/kg), Zn (164 ± 25 mg/kg), and Fe (211 ± 32 mg/kg). These sustainable fertilizers present an alternative to traditional, non-renewable fertilizers and offer promising solutions for precision agriculture and environmentally conscious production.Graphical abstract

Dust storms increase the tolerance of phytoplankton to thermal and pH changes.

Aquatic communities are increasingly subjected to multiple stressors through global change, including warming, pH shifts, and elevated nutrient concentrations. These stressors often surpass species tolerance range, leading to unpredictable consequences for aquatic communities and ecosystem functioning. Phytoplankton, as the foundation of the aquatic food web, play a crucial role in controlling water quality and the transfer of nutrients and energy to higher trophic levels. Despite the significance in understanding the effect of multiple stressors, further research is required to explore the combined impact of multiple stressors on phytoplankton. In this study, we used a combination of crossed experiment and mechanistic model to analyze the ecological and biogeochemical effects of global change on aquatic ecosystems and to forecast phytoplankton dynamics. We examined the effect of dust (0-75 mg L-1 ), temperature (19-27°C), and pH (6.3-7.3) on the growth rate of the algal species Scenedesmus obliquus. Furthermore, we carried out a geospatial analysis to identify regions of the planet where aquatic systems could be most affected by atmospheric dust deposition. Our mechanistic model and our empirical data show that dust exerts a positive effect on phytoplankton growth rate, broadening its thermal and pH tolerance range. Finally, our geospatial analysis identifies several high-risk areas including the highlands of the Tibetan Plateau, western United States, South America, central and southern Africa, central Australia as well as the Mediterranean region where dust-induced changes are expected to have the greatest impacts. Overall, our study shows that increasing dust storms associated with a more arid climate and land degradation can reverse the negative effects of high temperatures and low pH on phytoplankton growth, affecting the biogeochemistry of aquatic ecosystems and their role in the cycles of the elements and tolerance to global change.

Reviewing ecological implications of mycorrhizal fungal interactions in the Brassicaceae

Mycorrhizal associations are plant-fungal mutualisms that are fairly ubiquitous and likely evolved multiple times in phylogenic history; however, some plant families have consistently been identified as non-mycorrhizal, including the Brassicaceae. In this paper, we reviewed the literature and DNA databases for potential mechanisms that preclude mycorrhizal symbioses in the Brassicaceae and for exceptions to the general observation of non-mycorrhizal status within this plant family. In instances of association between members of the Brassicaceae and arbuscular mycorrhizal fungi we posed hypotheses for why these interactions occur in the species and sites observed. Instances of inconsistent association with mycorrhizal fungi were attributed to inter- and intraspecific variations in plant biology, disagreements in vernacular, methodology contradicting historical mycorrhizal surveys, and association being a facultative, variable trait that is determined by species-site interactions. We propose further research on a) the extent of mycorrhizal association in the Brassicaceae, b) the molecular mechanisms dictating association, and c) whether Brassicaceae-mycorrhizal fungal interactions result in nutrient transfer, and their particular roles in the family’s distribution across heterogeneous and harsh environments.

Soil Quality Indicators: A Comprehensive Review

Soil health is a critical determinant of ecosystem sustainability and agricultural productivity. This review article examines the significance of soil indicators, microbial community dynamics, soil enzymes, and their relationship with essential soil properties, including organic carbon content, bulk density, soil penetration resistance, water holding capacity, temperature, and pH. Traditional agricultural practices, such as conventional tillage, have been shown to significantly alter soil structure and physical properties. Bulk density, a key parameter, is used to gauge the compaction and porosity of soil, which directly influences water and nutrient transfer, as well as aeration. Conservation tillage practices, including the incorporation of crop residues into the soil, play a pivotal role in reducing bulk density. Soil temperature is a significant factor influencing the physical, chemical, and biological processes in soil, ultimately impacting plant growth. Soil pH, often referred to as the 'master soil variable,' has a far-reaching impact on various biological, chemical, and physical characteristics within the soil. It significantly influences biogeochemical processes and the activity of enzymes involved in the degradation of organic materials. Alterations in soil pH can directly affect microbial activity, microbial diversity, and the efficiency of enzyme-driven processes. This comprehensive review synthesizes the current knowledge of these biological indicators, emphasizing their interconnections and implications for soil health and sustainable land management practices. Understanding the multifaceted relationships between these indicators is crucial for the development of effective strategies to enhance soil health and ecosystem resilience.