Variable Nutrient Research Articles

Impact of Twig-Tip Dieback on Leaf Nutrient Status and Resorption Efficiency of Mango (Mangifera indica L.) Trees

Mineral nutrition is essential for plant growth and the interaction of plants with biotic and abiotic stresses. Mango twig-tip dieback (MTTD) is a new type of mango decline, but its impact on trees’ mineral nutrition is unknown. This study was conducted to determine the effect of MTTD infection on the nutrient status, balance, and resorption efficiency (RE) of mangoes. Leaf nutrient concentrations and deviation from the optimum percentage (DOP) indices of ‘Kensington Pride’ (KP) mango trees with low (LD) and high (HD) levels of MTTD infections were analyzed to compare the foliar nutrition status and nutrient balance between the LD and HD trees. Moreover, the nutrient resorption efficiency of MTTD-infected dried leaves (RED) was compared with the resorption efficiency of healthy (RES) leaves of KP mangoes. The concentrations of total Ca, Mg, Cu, Fe, Mn, and Zn were lower in the HD trees than in the LD trees. But the total K content was higher in the HD trees, and its DOP index was sufficient, while the total K concentration was of a low and deficient level in LD trees. Moreover, the DOP indices for total Ca, Mn, and Zn were less deficient in LD trees than in HD trees, and the overall nutrient imbalances were exacerbated in HD trees. The RED was significantly lower than RES for the total N, P, S, Cu, Fe, and Zn but significantly higher than RES for K. This study underscores the significant influence of MTTD on the mineral nutrition of KP mangoes, revealing distinct nutrient variations between trees with low and high MTTD infection levels. These findings have important implications for mango crop management, emphasizing the need for targeted nutrient interventions to address imbalances induced by MTTD and enhance the overall health and resistance of mango trees against MTTD infections.

Mesoscale variability of phosphorus stocks, hydrological and biological processes in the mixed layer in the Eastern Mediterranean Sea in autumn and during an unusually dense winter phytoplankton bloom

We investigated spatiotemporal variations of nutrients, dissolved organic pools (C, N, P), phosphomonoesterase (PME) and phosphodiesterase (PDE) activities, heterotrophic prokaryotic production and planktonic microorganisms within the mixed layer (ML) in the Eastern Mediterranean Sea. We characterized two contrasted situations: autumn 2018 (highly stratified period, deep chlorophyll maximum within 100 m depth) and winter 2019 (including a bloom period). We compared the distribution of biogeochemical variables within the mixed layer and hydrological vertical structure between the different stations using a principal component analysis. Six groups of stations were identified (one group in autumn, 5 in winter), based on variable physical descriptors but also environmental biogeochemical conditions related to i) the seasonal aspect (for instance, all stations sampled within the Ierapetra anticyclone in autumn clustered in one, single group); ii) transitions between cyclonic and anticyclonic structures with a large range of ML depths (18–269 m) and indications of intense, preceding winter convection events: iii) progression of a high phytoplankton bloom during the winter cruise inferred from a series of observations: a strong nitrate drawdown, important growth of Synechococcus, pico and nano eukaryotes, accumulation of chlorophyll a (>60 mg m−2), primary production rates up to 509 mg C m−2 d−1, changes in the pigments’ diversity, increase in biomass-specific ectoenzymatic activities and of heterotrophic prokaryotic production, all in conjunction with the vicinity of the Rhodes gyre. Here, we studied the distribution of biological and biogeochemical properties within the mixed layer, in particular by employing sensitive methods for the detection of low phosphate concentrations and of the labile dissolved organic phosphorus pool. From this data set, we demonstrate that the surface mixed layer classically considered as a P-depleted and uniform layer in the Eastern Mediterranean Sea was highly biologically dynamic, and prone to rapid spatio-temporal changes in phosphatase activities and phytoplankton dynamics. Altogether, these data reveal a strong short-term population dynamics. The results highlight the role of mixing episodes in winter, which provide pulsed supplies of phosphate and/or nitrate from the deeper layer to the euphotic zone, triggering transient blooms that often go undetected by satellites.

Diel and seasonal mixing patterns and water quality dynamics in a multipurpose tropical semiarid reservoir.

Eutrophication has become a recurrent concern in reservoirs worldwide. This problem is intensified in tropical semiarid regions, where the reservoirs have high seasonal and annual variability of water level and volume. Therefore, an extensive understanding of the diel variation of water quality key-parameters can help improve management of such reservoirs. This study focuses on Castanhão reservoir with the largest multipurpose dam in the Brazilian semiarid. Its main water uses are irrigation, fish farming, and human supply. The reservoir faced a decline in water quality due to a prolonged drought period. While previous research has predominantly emphasized the seasonal dynamics of thermal and chemical stratification, our investigation provides diel assessments of multiple water quality parameters, including nutrient concentrations and phytoplankton abundance. Our primary objective is to compare seasonal and diel variations in stratification and nutrient distribution within the reservoir. Key findings reveal a diel cycle of thermal stratification, primarily during dry season, driven by higher wind speeds. This is corroborated by a significant negative correlation between wind speed and the relative water column stability index. In contrast, during the rainy season, the reservoir experiences continuous thermal stratification due to inflowing water being warmer than the reservoir's water temperature. Notably, a significant negative correlation between total phosphorus and chlorophyll-a, along with a two-fold increase of this nutrient throughout the day during the rainy season, underscores the influence of the phytoplankton community dynamics on the diel nutrient variation. Chemical stratification of dissolved oxygen occurred during dry and rainy seasons, indicating that even during the dry season, where there is no significant inflow, the internal nutrient loading can also significantly impact the water quality of a reservoir. This study advances the understanding of diel water quality dynamics in tropical semiarid reservoirs, shedding light on both climatic and anthropogenic influences on water resources.

Comparative Metabolic Profiling of Different Colored Rice Grains Reveals the Distribution of Major Active Compounds and Key Secondary Metabolites in Green Rice.

Pigmented rice grains are important resources for health and nutritional perspectives. Thus, a thorough dissection of the variation of nutrients and bioactive metabolites in different colored rice is of global interest. This study applied LC-MS-based widely targeted metabolite profiling and unraveled the variability of metabolites and nutraceuticals in long grain/non-glutinous black (BR), red (RR), green (GR), and white rice (WR) grains. We identified and classified 1292 metabolites, including five flavonoid compounds specific to BR. The metabolite profiles of the four rice grains showed significant variation, with 275-543 differentially accumulated metabolites identified. Flavonoid (flavone, flavonol, and anthocyanin) and cofactor biosynthesis were the most differentially regulated pathways among the four rice types. Most bioactive flavonoids, anthocyanidins (glycosylated cyanidins and peonidins), phenolic acids, and lignans had the highest relative content in BR, followed by RR. Most alkaloids, amino acids and derivatives, lipids, and vitamins (B6, B3, B1, nicotinamide, and isonicotinic acid) had higher relative contents in GR than others. Procyanidins (B1, B2, and B3) had the highest relative content in RR. In addition, we identified 25 potential discriminatory biomarkers, including fagomine, which could be used to authenticate GR. Our results show that BR and RR are important materials for medicinal use, while GR is an excellent source of nutrients (amino acids and vitamins) and bioactive alkaloids. Moreover, they provide data resources for the science-based use of different colored rice varieties in diverse industries.

Dams alter the control pattern of watershed land use to riverine nutrient distribution: Comparison of three major rivers under different hydropower development levels in Southwestern China

Land use plays a critical role in managing water quality in a watershed, as it governs the import and distribution of nutrients. In addition to the land use, some rivers in Southwest China are encountering a new environmental stressor of damming, which is being driven by the national strategy of hydropower development. However, the coupling effect of land use and dams on nutrients remains poorly understood, challenging the effective management of riverine water quality. Therefore, this study examined the nutrients in the Nu, Yarlung Tsangpo (YT), and Lancang (LC) Rivers, which have no dam, 1 dam, and 11 dams, respectively, during different regulatory periods (spring and fall) to identify variations in nutrient control patterns influenced by land use and dams. The findings suggested that an increase in hydropower development contributed to a notable shift in nutrient patterns from land use regulation towards dam regulation and coupling effects. Land use dominated the nutrient variations of the Nu (27.4 %–32.8 %) and low hydropower development YT (25.2 %–30.9 %) Rivers during both seasons, but the primary contributors to the nutrient variations of the high hydropower development LC River were dams (17.9 %–41.6 %) and coupling effects (16.5 %–29.0 %). Dams transform nutrient levels and compositions through internal reservoir cycling, decoupling land use and nutrients. Partial least-squares structural equation model analysis further suggested that the coupling effects of the LC River were seasonal-specific, which was primarily attributed to hydrological variations that affected their interactions. During spring, the reservoir underwent a drainage mode characterized by high-level nutrients in the bottom water. Combined with the import of riverine nutrients, it exacerbated the increase of nutrients (synergistic effect). In contrast, the reservoir transitioned into a storage mode where it intercepted nutrients from the upstream and watershed during the fall, leading to a reduction in the previously observed increasing trend and an increase in nutrient variability (antagonism effect).

Variations in Primary Nutrients and Sowing Dates Influence Performance of Monsoon Maize (Zea Mays L.) in Punjab, India

ABSTRACT Maize, being a nutritious and multipurpose crop requires proper nutrition (N, P, and K) and standardization of sowing time to enhance productivity and profitability under changing climate scenario. Therefore, a field experiment was conducted during monsoon season of 2021 and 2022 at agricultural farm, Lovely Professional University, Punjab, in split plot design with four fertilizer levels (125, 100, 75, and 50% recommended dose of fertilizers; RDF) in main plots and four sowing dates (15 and 30 of June and July) in subplots, replicated thrice. Maize sown on 30 June and fertilized with 125% RDF ensured higher growth attributes throughout crop growth. Besides, comparatively greater yield attributes as well as grain yield (8.22 t ha−1), stover yield (11.86 t ha−1), and harvest index (40.9%) were observed from that treatment combination, and it also recorded higher quality protein and nutrient uptakes but less residual soil fertility. Maize grown on 30 July under application of 50% RDF was the poorest yielder. Further, production economics and energy analysis showed similar trend and indicated that maize grown on 30 June under application of 125% RDF recorded maximum gross return (₹168275 ha−1), net return (₹109565 ha−1), and benefit-cost ratio (2.87) as well as energy output (269084 MJ ha−1) and net energy gain (250750.3 MJ ha−1).

Comparative analysis of mycorrhizal communities associated with Struthiopteris spicant (L.) Weiss across Europe and North America.

Ferns constitute the second largest group of vascular plants. Previous studies have shown that the diversity and composition of fern communities are influenced by resource availability and water stress, among other factors. However, little is known about the influence of these environmental factors on their biotic interactions, especially regarding the relationship between mycorrhizal fungi and ferns. The present study compares the mycorrhizal communities associated with 36 populations of Struthiopteris spicant L. Weiss across Europe and North America. This species exhibits a great tolerance to variations in light, nutrient, and pH conditions, and it can survive with and without mycorrhizae. With the aim of determining which environmental factors impact the composition and abundance of the root-associated fungal communities in this species, we used an ITS-focused metabarcoding approach to identify the mycorrhizal fungi present and analyzed the influence of climatic and edaphic variables at global and regional scales. We encountered striking differences in the relative abundance of arbuscular mycorrhizal fungi (AMF) between S. spicant populations at both spatial levels. We recorded a total of 902 fungal ASVs, but only 2- 4% of the total fungal diversity was observed in each individual, revealing that each fern had a unique fungal community. Light availability and the interactive action of pH and soil nitrogen concentration showed a positive influence on AMF relative abundance, explaining 89% of the variance. However, environmental factors could only explain 4- 8% of the variability in AMF community composition, indicating that it might be determined by stochastic processes. These results support the hypothesis that ferns may be more independent of mycorrhization than other plant groups and interact with fungi in a more opportunistic manner.

Sedimentary contamination study in the Great Chao Phraya River watershed, Thailand, using geographically weighted regression

ABSTRACT This research investigated the spatial variations of heavy metals and nutrients in the sediment of the Great Chao Phraya River network of Thailand using geographically weighted regression (GWR). The performance of GWR in explaining the spatiality of selected contaminants using single and multiple predictors was compared and discussed, and a suitable approach was recommended for sediment study. Extensive explanatory variables, including land use type and topographic, socio-economic, and meteorological indicators were utilized in the geospatial regressions of river sediment contaminants at the sub-catchment scale. In the case of simple regression, GWR outperformed the ordinary least square (OLS) regressions with global R 2 (range 0.34–0.72 for GWR and 0–0.24 for OLS, respectively), over 2-fold of which was derived by OLS. Similar observations were obtained in multiple regressions, where GWR offered global R 2 values between 0.27 and 0.6, higher than those that were provided by OLS (i.e. 0.12–0.44). Furthermore, multiple GWR model presented higher local explanatory power and performance with significantly increased local R 2 (up to 51%) compared with simple GWRs (p ≤ 0.05). It is recommended to combine the applications of simple and multiple GWR models to understand the effects of selected explanatory predictors on sediment contaminations from different perspectives.

Effects of Long-Term Rice–Crayfish Coculture Systems on Soil Nutrients, Carbon Pools, and Rice Yields in Northern Zhejiang Province, China

This research was to examine the impacts of long-term integrated rice–crayfish farming on soil nutrients, carbon pools, and rice yields in paddy fields. The aim was to establish a scientific basis for the sustainable development of RS in the northern region of Zhejiang. The results showed that the change from rice monoculture (CK) to rice–crayfish coculture systems (RS) led to a 24.99% increase in the 5-year average of soil ammonium nitrogen (AN), while the soil nitrate nitrogen (NN), available potassium (AK), and available phosphorus content (AP) decreased by 28.02%, 16.05%, and 28.76%, respectively. Moreover, the total organic carbon (TOC), easily oxidizable organic carbon (EOC), dissolved organic carbon (DOC), and microbial biomass carbon (MBC) exhibited a reduction of 2.45%, 8.82%, 35.31%, and 65.84%, respectively. Correlation analysis revealed a significant positive correlation between NN, EOC, and MBC in the RS mode. In terms of rice yield, the 5-year average of rice yield in RS decreased by 8.40% compared to CK. The mean yield of early-maturing rice varieties was reduced by 13.16%, while that of late-maturing rice varieties was reduced by 6.00%. These results shed light on the annual variation in soil nutrients, carbon pools, and rice yield in the RS mode, providing insights for the sustainable development of RS in northern Zhejiang.

Available nitrogen and enzyme activity in rhizosphere soil dominate the changes in fine-root nutrient foraging strategies during plantation development

The variation in fine-root traits in response to soil resources (i.e., fine-root nutrient foraging strategy) is critical for plants to adapt to environmental changes and even win in intra- or interspecific resource competition. However, the patterns and driving mechanisms that change in fine-root traits and nutrient foraging strategies during the development of plantations remain unclear. We analyzed the relationships among fine-root traits, rhizosphere soil nutrient variables, and enzyme activities at four stages of Pinus massoniana plantations: 18 years (young), 30 years (middle-aged), 43 years (mature), and 63 years (overmature). We found that specific root area (SRA) and specific root length (SRL), which represent the speed of nutrient acquisition, decreased with stand development. Root tissue density (RTD) and specific root tip number (SRT), which represent the cost of nutrient foraging, decreased with stand development after peaking in the mature and middle-aged forests, respectively. Compared with young stands, fine-root organic carbon and total phosphorus contents decreased by 23 % in the overmature forest, but total nitrogen increased by nearly 50 %. Principal component analysis (PCA) showed that those fine-root traits significantly varied from young to overmature stands on PC1, and such a shift was consistent with changes in the growth period from fast (in the young forest) to slow (in the overmature forest) for P. massoniana. We suggest that those changes in fine-root traits along the PC1 represents a change in the fine-root foraging strategy of P. massoniana. This strategy (i.e., PC1) was negatively correlated with rhizosphere soil total nutrients (i.e., soil organic carbon and total nitrogen) and carbon (C)-nitrogen (N)-phosphorus (P) stoichiometry but positively correlated with available carbon, nitrogen, and C and N cycling-related enzyme activities. Specifically, the variation in rhizosphere soil NH4+ had the highest amount of explication (72 %) for the variation in the root nutrient foraging strategy. These results demonstrate that the intensity of the fine-root response to soil resources is related to the structure of rhizosphere soil available nutrients (especially soil available nitrogen) as well as carbon and nitrogen conversion enzyme activities during plantation development. Such relationships can reshape fine-root traits and change the fine-root nutrient foraging strategies during the development of plantations.

Altitudinal variation of dragon fruit metabolite profiles as revealed by UPLC-MS/MS-based widely targeted metabolomics analysis

BackgroundGeographical factors affect the nutritional, therapeutic and commercial values of fruits. Dragon fruit (Hylocereus spp) is a popular fruit in Asia and a potential functional food with diverse pharmacological attributes. Although it is produced in various localities, the information related to the altitudinal variation of dragon fruit nutrients and active compounds is scarce. Hence, this study aimed to investigate the variations in metabolite profiles of H. polyrhizus (variety Jindu1) fruit pulps from three different altitudes of China, including Wangmo (WM, 650 m), Luodian (LD, 420 m), and Zhenning (ZN, 356 m). Jindu1 is the main cultivated pitaya variety in Guizhou province, China.ResultsThe LC-MS (liquid chromatography-mass spectroscopy)-based widely targeted metabolic profiling identified 645 metabolites, of which flavonoids (22.64%), lipids (13.80%), phenolic acids (12.40%), amino acids and derivatives (10.39%), alkaloids (8.84%), and organic acids (8.37%) were dominant. Multivariate analyses unveiled that the metabolite profiles of the fruit differed regarding the altitude. Fruits from WM (highest altitude) were prime in quality, with higher levels of flavonoids, alkaloids, nucleotides and derivatives, amino acids and derivatives, and vitamins. Fruits from LD and ZN had the highest relative content of phenolic acids and terpenoids, respectively. We identified 69 significantly differentially accumulated metabolites across the pulps of the fruits from the three locations. KEGG analysis revealed that flavone and flavonol biosynthesis and isoflavonoid biosynthesis were the most differentially regulated. It was noteworthy that most active flavonoid compounds exhibited an increasing accumulation pattern along with the increase in altitude. Vitexin and isovitexin were the major differentially accumulated flavonoids. Furthermore, we identified two potential metabolic biomarkers (vitexin and kaempferol 3-O-[2-O-β-D-galactose-6-O-a-L-rhamnose]-β-D-glucoside) to discriminate between dragon fruits from different geographical origins.ConclusionOur findings provide insights into metabolic changes in dragon fruits grown at different altitudes. Furthermore, they show that growing pitaya at high altitudes can produce fruit with higher levels of bioactive compounds, particularly flavonoids.

The transition from diet to blood: Exploring homeostasis in the insect haemolymph nutrient pool

AbstractNutrition is vital to health, but while the link between diet and body nutritional composition is well explored in humans and other vertebrates, this information is not well understood in insects, despite the vital roles they play in ecosystems, and their increasing use as experimental models. Here we used Nutritional Geometry to explore the rapid physiological response to ingested nutrients in the haemolymph nutritional profile of Spodoptera littoralis caterpillars. We ask whether blood nutrients are maintained homeostatically in the face of variable nutritional intake, or if regulation is more flexible for some nutrients than others (allostasis), which allows animals to adapt to stress by responding in a way that prioritises efficiency of responses in the face of trade‐offs. Caterpillars were placed on 1 of 20 diets, systematically varying in their nutrient ratios (protein: carbohydrate) and density (calorie content), and their consumption was measured. After 48 h, caterpillars were bled, and the macronutrient (protein, carbohydrates and lipids) and nutrient metabolite (amino acids and simple sugars) content of the haemolymph was measured. Proteins comprised 93% of the haemolymph macronutrient pool on average and their concentration increased with protein eaten. The amino acid (AA) pool was dominated by five AAs, and the total pool increased with total nutrient intake. However, the ratio of essential to non‐essential AAs increased as the proportion of protein consumed increased. Carbohydrates were tightly controlled, increasing only on the most extreme carbohydrate intakes. Simple sugars were dominated by glucose and trehalose, and overall, the simple sugar pool showed high levels of homeostasis. Rather than strict homeostasis of blood nutritional properties, an allostatic model seemed to be a better fit for blood nutrient regulation in this generalist herbivore. This flexibility in response to the nutritional composition of the diet may, in part, explain how this species has evolved to extreme dietary generalism and may play a role in its worldwide pest status. Given the range of fitness‐related processes affected by the haemolymph, future studies should examine the physiological impacts of blood nutrient variation on reproduction, growth and response to infection and the trade‐offs between them.

Determination and prediction of standardized ileal amino acid digestibility of wheat bran in broiler chickens.

The objective of this experiment was to determine the standard ileal digestibility (SID) of amino acid (AA) in 10 different sources of wheat bran fed to broilers and establish the SID AA prediction based on the chemical composition. A total of 660 1-day-old broilers were randomly divided into 11 treatments with 6 replicates of 10 chickens each. Diets included 10 semi-purified mash diets and 1 nitrogenfree diet. Titanium dioxide (TiO2) 0.50% was used as an indigestible index. On day 13, 6 chickens from each replicate were selected for slaughter to collect ileal contents. On day 28, 4 chickens from each replicate were selected for slaughter to collect ileal contents. Results showed that the coefficient of variation of the conventional nutrients (except for gross energy, and dry matter) and all AAs was greater than 8.00%. The average SID of essential AA in wheat bran for 13-day-old broilers was 37.24% and the average SID of nonessential AA was 42.02%; the average SID of essential AA for 28-day-old broilers was 67.13% and the average SID of nonessential AA was 69.51%. A correlation was observed (p<0.05) between most SID AA and crude protein (CP), crude fiber (CF), acid detergent fiber (ADF), and ash at day 13. A correlation was observed (p<0.05) between most SID AA and CF, and ADF at day 28. The R2 value of stepwise regression equations for predicting the SID AA at day 13 and day 28 was best for glutamic acid (R2 = 0.97 using CP, ash, CF, ether extract (EE), and neutral detergent fiber [NDF]) and lysine (R2 = 0.74 using ash, ADF, EE, and NDF), respectively. In conclusion, broiler age had a significant effect on the SID AA values of wheat bran. The chemical composition of wheat bran varied widely between sources, and CP, CF, ADF, NDF, and ash were reasonable predictors of the SID AA of wheat bran.

Seasonal variation in pore water nutrients and their fluxes from the bottom sediments in Harima Nada, Seto Inland Sea

Seasonal variation in pore water nutrients and their fluxes from the bottom sediments in Harima Nada, Seto Inland Sea

Estimation of the nutrient variation in feed delivery and impacts on lactating dairy cattle

Diets formulated for dairy cattle are designed to supply nutrients, but rations delivered to the animal may deviate from original formulations resulting in implications on milk production, composition, and even pregnancy rate. The objective of this study is to evaluate retrospective feed mixing records collected from 8 commercial dairy farms over 52 weeks. Farms ranged from 2,982 – 29,783 animals, producing 31.8 ± 5.93 kg milk with 4.14 ± 0.461% fat and 3.26 ± 0.218% protein. Data collected included daily TMR nutrient deviation; calculated as diet nutrient content minus the observed divided by the formulated diet concentrations of CP, fat, NDF, and starch. Data were analyzed with fixed effects of time (modeled as 28-d periods) and days of positive nutrient deviation in fat, CP, NDF and starch with each nutrient alone and in combination with the other nutrients, random effects of herd, and repeated measure of time within herd. The nutrient deviation by farm averaged (±SD) 1.68 ± 2.655, 2.28 ± 4.473, 1.75 ± 2.621, and 1.47 ± 2.147% for CP, fat, NDF, and starch. Days of positive nutrient deviation per period averaged (±SD) 25.5 ± 3.47, 25.5 ± 3.72, 25.6 ± 3.49, and 25.9 ± 2.61. Dry matter intake (DMI; 17.2 ± 1.78 kg/d) decreased with increasing positive deviation days in starch (−0.0483 ± 0.01265; P < 0.01) and increased with increasing positive deviation days in CP (0.0211 ± 0.00942; P = 0.03). Milk yield (31.4 ± 2.50 kg/d) increased with positive deviation days in starch (0.0486 ± 0.02110; P = 0.02) and decreased with increased positive deviation days in NDF (−0.0298 ± 0.02202; P = 0.18). Finally, pregnancy rate (21.7 ± 4.34) increased with increasing positive deviation days in fat (0.385 ± 0.1635; P = 0.02) and decreased with increasing positive deviation days in CP (−0.420 ± 0.1879; P = 0.03). For these models, period significantly affected milk yield (P < 0.01) and but was not observed to affect pregnancy rate and DMI (P ≥ 0.12). Results suggest farm and nutrient type were significant sources of variation and overall, farms overfeed nutrients CP, fat, NDF, and starch 92% of the days of a 28-d period.

Effects of oligotrophication and Dreissena littoral-pelagic coupling on littoral invertebrate and fish communities: insights from stable isotopes of archived samples

Changing nutrient concentrations and introduction of non-native species affect the energy and nutrient fluxes in aquatic ecosystems. As a response, invertebrate communities could be altered, and ‘novel’ trophic communities could develop. Lake Constance (Europe) experienced pronounced nutrient variation caused by cultural eutrophication (prior 1980s) and oligotrophication (post-1980) and experienced many neobiota invasions. We used archived samples to investigate the impact of oligotrophication and invasive species on carbon and nitrogen isotope signatures of littoral macroinvertebrates during spring and autumn periods from 2000 to 2015 and of littoral fish species in 2018. Isotopic signatures of invertebrate and fish species were in the same range and showed similar seasonal differences and clear patterns in respect to littoral vs pelagic food sources and trophic level. Oligotrophication did not strongly alter isotopic values and only δ15N values of invertebrates declined weakly with oligotrophication. In contrast, interannual variability of stable isotope signatures was related to abundances of the invasive Dreissena polymorpha suggesting interannual differences in the importance of benthic-pelagic coupling due to Dreissena pseudofaeces for the nutrition of littoral invertebrates. This study illustrates how stored samples can be used to detect the importance of oligotrophication and benthic-pelagic coupling on the stable isotope signatures of a benthic community.

Status Gizi, Tingkat Konsumsi Zat Gizi Besi (Fe) dan Siklus Menstruasi Dengan Kejadian Anemia Remaja Putri

Background: There are many factors that can cause anemia, including nutritional status, low consumption levels (fe) and abnormal menstrual cycles. Aims: To determine the relationship between nutritional status, levels of consumption of Fe iron nutrients and menstrual cycles with the incidence of anemia in female adolescents at SMPN 18, Merangin Regency. Methods : This type of research is a quantitative study with a cross-sectional design and data collection by means of interviews, checking Hb and distributing questionnaires. The number of samples is 48 teenagers. Data analysis in this study used Univariate and Bivariate analysis using the chi square test to determine the relationship between the dependent variable (Nutritional Status, Consumption Level of iron (fe) nutrients and Menstrual Cycle) with the dependent variable (The incidence of anemia in young women) Results: The results showed that the percentage of under/over nutritional status was 29 respondents (60.4%), the level of iron (fe) consumption was lacking by 35 respondents (72.9%), the menstrual cycle was abnormal by 30 (62.5%). %), the incidence of anemia was 43 (89.6%). There is a relationship between nutritional status and the incidence of anemia (p = 0.041), there is a relationship between the consumption level of iron (fe) and the incidence of anemia (p = 0.006) and there is a relationship between the menstrual cycle and the incidence of anemia (p = 0.022). Conclusion: In this study it can be concluded that the incidence of anemia is quite high in SMPN 18 Merangin District. It is recommended for adolescents to maintain their food intake, because it affects health.

Nutrient content in olive leaves through sustained irrigation with treated wastewater

Water scarcity is posing a major challenge to sustainable development. This issue will become more pressing as the global population grows, living standards rise, food habits evolve, and the effects of climate change intensify, resulting in rising temperatures globally. Reusing treated wastewater reduces effluent discharge into natural water bodies while also providing a reliable water source for applications that do not require high-quality water. A field trial was conducted on plots where olive trees grow. Two water treatment scenarios were investigated: one with a conventional water source as the control and one with treated wastewater as an alternative.Soil and irrigation water were characterized in the study regions, and chlorophyll, macro and micronutrients in olive leaves were analyzed. Soils treated to long-term wastewater irrigation had considerably higher electrical conductivity, total nitrogen, potassium, sodium, magnesium, zinc, and cation exchange capacity values than control. Notably, control soils had much greater levels of zinc and phosphorus than treated wastewater-irrigated soils. Except for phosphorous content (greater in plants from treated wastewater irrigated plots) and zinc content (lower in plants from treated wastewater irrigated plots), no significant variations in nutrients evaluated occurred for crops. In general, when comparing irrigation with reclaimed wastewater to irrigation with fresh water, no negative influence on tree performance was detected over time. Nevertheless, it's crucial to consider the potential risk of soil salinization associated with the consistent use of this water for irrigation.

Nutrients and Ecological Stoichiometry Characteristics of Typical Wetland Soils in the Lower Yellow River

Carbon, nitrogen, phosphorus, and potassium in the soil are the necessary nutrient elements for plant growth, and their contents and ecological stoichiometry can reflect the status of soil quality and nutrient limitation. The Huayuankou Yellow River Floating Bridge Wetland in the lower Yellow River was selected as the research object. The methods of ANOVA, redundancy analysis, and linear regression fitting were used to study the contents of organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), total potassium (TK), alkaline nitrogen (AN), available phosphorus (AP), available potassium (AK), and their ecological stoichiometric ratios as well as the limiting elements of soil nutrients, and the key physicochemical properties that affect soil nutrients and their ecological stoichiometry in the wetland were revealed. The results showed that the mean values of ω(SOC), ω(TN), ω(TP), ω(TK), ω(AN), ω(AP), and ω(AK) in wetland soil were 5.46 g·kg-1, 0.60 g·kg-1, 0.28 g·kg-1, 17.06 g·kg-1, 13.75 mg·kg-1, 6.54 mg·kg-1, and 158.56 mg·kg-1, respectively, which showed an increasing trend from the river bank to the shoaly land and were generally higher at the high vegetation coverage areas than at the low vegetation coverage areas. There were significant correlations among SOC, TN, TP, and TK. Soil C/P, C/K, N/P, and N/K showed a consistent trend with soil nutrients, whereas C/N showed the opposite. The coefficients of variation of SOC, TN, AN, N/P, and N/K in the soil exceeded 50.00%, with significant spatial differences. The average value of C/N in wetland soil was 11.882, which was close to the average level of soils in China, whereas the average values of C/P and N/P were 49.119 and 4.516, respectively, both of which were lower than the average level of soils in China, and the N/P of soil was far less than 14, which indicated that N was limited in the soil. The proportion of clay and electrical conductivity combined to explain 61.4% and 43.9% of the variation in the soil nutrients and their ecological stoichiometry, respectively, which were the dominant soil physicochemical properties affecting the soil nutrients and their ecological stoichiometry of Huayuankou Yellow River Floating Bridge Wetland. The research results are helpful to improve our knowledge of nutrients and their influencing factors in the wetland soil of the lower Yellow River and provide an important scientific basis for the ecological restoration and management of the wetland in the lower Yellow River.

Partitioning of nutrient variation in alfalfa and corn silage by source on New York dairy farms

Variation in feed components contributes to variation and uncertainty of diets delivered to dairy cows. Forages often have a high inclusion rate (50 to 70% of DM fed) and variable composition, thus are an important contributor to nutrient variability of delivered diets. Our objective was to quantify the variation and identify the main sources of variability in corn silage and alfalfa-grass haylage composition at harvest (fresh forage) and feed-out (fermented forage) on NY dairy farms. Corn silage and alfalfa-grass haylage were sampled on 8 NY commercial dairy farms during harvest in the summer and fall of 2020 and during their subsequent feed-out in the winter and spring of 2021. At harvest, a composite sample of fresh chopped forage of every 8-ha section of individual fields was collected from piles delivered for silo filling. During a 16-week feed-out period, 2 independent samples of each forage were collected 3 times per week. The fields-of-origin of each forage sample during feed-out were identified and recorded using silo maps created at filling. A mixed-model analysis quantified the variance of corn silage DM, NDF, and starch and haylage DM, NDF, and CP content. Fixed effects included soil type, weather conditions, and management practices during harvest and feed-out while random effects were farm, silo unit, field, and day. At harvest, between-farm variability was the largest source of variation for both corn silage and haylage, but within-farm sources of variation exceeded farm-to-farm variation for haylage at feed-out. At feed-out, haylage DM and NDF content had higher within-farm variability than corn silage. In contrast, corn silage starch showed higher within-farm variation at feed-out than haylage CP content. For DM content at feed-out, day-to-day variation was the most relevant source of within-farm variation for both forages. However, for the nutrient components at feed-out (NDF and CP for haylage; NDF and starch for corn silage) silo-to-silo variation was the largest source of variability. Weather conditions systematically explained a proportion of the farm-to-farm variability for both forages at harvest and feed-out. We concluded that because of the high farm-to-farm variation, corn silage and haylage must be sampled on individual farms. We also concluded that due to the high silo-to-silo variability, and the still significant day-to-day and field-to-field variability within-farm, corn silage and haylage should be sampled within individual silos to better capture changes in forage components at feed-out.