Nutrient Status Research Articles

Decoupled Nutrient Status: a framework to disentangle host from microbial responses to diets that vary in digestibility

Diet shapes the gut microbiome, which in turn influences host phenotype. Accordingly, there is much interest in leveraging diet to modulate gut microbial communities and host biology. However, recent approaches have not fully appreciated that hosts and gut microbes experience diet differently. Whether dietary nutrients reach the gut microbiota, which primarily resides in the colon in humans and other hindgut fermenters, depends on nutrient absorption in the small intestine. That gut microbes utilize the fraction of diet that escapes host-driven digestion creates a paradigm where host nutrient status is decoupled from, and often negatively correlated with, gut microbiota nutrient status. Here, we present a framework based on this concept of decoupled nutrient status (DNS), which can be used to understand distinct host and gut microbial phenotypes that are ultimately mediated by the small intestinal digestibility of the diet. We evaluate our framework against existing research employing diets of varying digestibility and demonstrate convergence of host phenotypes and gut microbial signatures across studies. Further, we highlight that gut microbial signatures predicted by DNS manifest most strongly in humans living industrialized lifestyles and in captive animals that habitually consume diets with high host-driven digestibility. We posit that the evolutionary decoupling of nutritional status between hosts and their gut microbiota has likely been especially pronounced in humans due to our intensified pursuit of calorie-rich, easy-to-digest diets. We conclude by proposing future research directions to better capture diet as it appears to gut microbes, a perspective likely to deliver new understanding of diet-microbiome interactions.

The Millet Scenario in India during the Last Three Decades

The nutrient rich millet crops are cultivated in marginal and poor soil as rainfed crop in India.Millets are rich in proteins, and minerals like Zinc, Iron and Phytochemicals, because of it rich nutrient status it’s called as Nutri-cereals. The market demand on millets in increasing day by day. So, this study focussed on the growth performance and instability in area, production and productivity. This study considered the period from 1990 to 2021. The secondary data like area, production and productivity were collected from various publications like APEDA, Agriculture StatisticsHandbook and India Stat. Over the entire period the area, production and productivity showed a decreasing trend. The estimated CDVI (Cuddy-Della Valle Index) value revealed that the production of millets had high instability while the area had the lowest instability. Hence the government should create awareness among the farmers and consumers.

Heightened TPD52 linked to metabolic dysfunction and associated abnormalities in zebrafish

The tumor protein D52 (TPD52) gene encodes a proto-oncogene protein associated with various medical conditions, including breast and prostate cancers. It plays a role in multiple biological pathways such as cell growth, differentiation, and apoptosis. The function of TPD52 in lipid droplet biosynthesis has been investigated in vitro. However, its precise role in lipid metabolism in animal models is not fully understood. To investigate the functions of TPD52 in vivo, we performed a conditional TPD52 protein expression analysis using a Tet-off transgenic system to establish conditionally expressed Tpd52 transgenic zebrafish. The effect of Tpd52 on lipogenesis was assessed using various methods, including whole-mount Oil Red O staining, histological examination, and measurement of inflammatory markers and potential targets using real-time quantitative polymerase chain reaction and immunoblotting in Tpd52 fish. Zebrafish with increased Tpd52 levels exhibited notable weight gain and the enlargement of fat deposits, which were mainly attributed to an increase in the volume of adipocytes. Moreover, Tpd52 overexpression was correlated with the triggering of the adipocyte differentiation signaling pathway. During adipocytic differentiation in response to nutrient status, our observations revealed adipogenesis, nonalcoholic fatty liver disease, and metabolic cardiomyopathy (MCM) in Tpd52 transgenic zebrafish. To gain a deeper understanding of the contribution of these proteins to the regulation of cellular growth, we investigated the expression of their corresponding genes and proteins in zebrafish. In the present study, the activated protein kinase pathway was identified as the primary target of TPD52. Adult Tpd52 zebrafish showed increased lipid accumulation, resulting in the development of visceral obesity, nonalcoholic fatty liver disease, and MCM. These findings strongly suggest that TPD52 actively contributes to adipose tissue expansion and its subsequent effects. This investigation provides compelling evidence that Tpd52 facilitates adipocyte development and related metabolic comorbidities in zebrafish.

Analysis of Physicochemical Properties, Enzyme Activity, Microbial Diversity in Rhizosphere Soil of Coconut (Cocos nucifera L.) Under Organic and Chemical Fertilizers, Irrigation Conditions

The application of chemical fertilizers and organic fertilizers, as well as irrigation, is an important agricultural practice that can increase crop yields and affect soil biogeochemical cycles. This study conducted coconut field experiments to investigate the effects of conventional fertilization (NCF), optimized fertilization (MCF), conventional fertilization + organic fertilizer (NOF), optimized fertilization + organic fertilizer (MOF), conventional fertilization + organic fertilizer + irrigation (NOFW), and optimized fertilization + organic fertilizer + irrigation (MOFW) treatments on soil physicochemical properties, soil enzyme activity, bacterial and fungal community structure and diversity, and compared the controls (CK, non-fertilizer and non-irrigation). The results showed that MOFW significantly increased soil electrical conductivity (EC), organic matter (OM), alkaline nitrogen (AN), available phosphorus (AP), available potassium (AK), available calcium (ACa), and available magnesium (AMg) levels. At the same time, it also significantly enhanced the activities of soil catalase (CE), polyphenol oxidase (POE), sucrase (SE), urease (UE), acid protease (APE), and acid phosphatase (APPE) (p < 0.05). The PCA analysis of soil microorganisms in the coconut rhizosphere soil showed indicated significant changes in bacteria and fungi community structure under fertilization treatments. The fertilization application leaded to an increase in the relative abundance and diversity of bacteria, but a decrease in fungi. Acidobacteriota, Proteobacteria, and Actinobacterota were the dominant bacterial phyla, and Ascomycota, Basidiomycota, Rozellomycota, and Mortierellomycota were the significant fungal phyla. Compared with CK, MOFW significantly increased the abundance of Acidobacteriota, Proteobacteria, Basidiomycota, and Mortierellomycota. Redundancy analysis (CCA) and Mantel test further revealed that pH, EC, OM, and AP were the main soil fertility factors driving changes in microbial communities. CE, SE, UE, APE, APPE were significantly correlated with microbial communities. Compared with NOFW, MOFW has a lower proportion of N, P, and K fertilizers in its fertilizer composition. The results indicated that MOFW can better improve the nutrient and enzyme status of the soil, which is a promising method for maintaining the balance of soil microorganisms in coconut orchards, and accordingly, reducing chemical fertilizers within a certain range can not only ensure consistency with conventional fertilizers, but also effectively improve soil conditions.

Evaluation and risk assessment of heavy metals in wetland soil in the University of Lagos

A study was conducted to evaluate the concentration of heavy metals, and the physicochemical and microbiological properties of wetland soils at the University of Lagos. Soil samples were randomly collected from the Faculty of Science (FSC), Lagoon Front, and Distance Learning Institute areas at depths of 5 cm, 10 cm, 15 cm, and 20 cm using a soil auger. The samples were stored in sterile nylon bags, appropriately labelled, and transported to the University of Lagos Central Research Laboratory for chemical analysis. The physicochemical characteristics measured included soil pH, determined using a pH meter, and moisture content, assessed through the oven-drying method. Heavy metal concentrations were analyzed using an Atomic Absorption Spectrophotometer. Microbial population diversity was examined using the disc diffusion method. Statistical analysis was performed using SPSS version 20, and mean values were evaluated using Tukey’s multiple comparison test at a probability level of P < 0.05. The results revealed that soil pH ranged from 7.20 to 8.81, with the highest value (8.81) recorded near the Faculty of Science (FSC-3). Eight heavy metals, including Pb, Ni, Cr, Cd, Fe, Cu, Mn, and Zn, were analyzed. Lead concentrations ranged from 0.02 to 0.29 ppm, followed by nickel, which ranged from 0.01 to 0.13 ppm. Chromium ranged from 0.0 to 0.25 ppm, cadmium from 0.03 to 0.08 ppm, iron from 1.02 to 2.96 ppm, copper from 3.31 to 4.60 ppm, manganese from 3.31 to 5.16 ppm, and zinc from 1.67 to 9.17 ppm. Lead and zinc concentrations were found to be below the permissible limit at all locations, while chromium and cadmium were within permissible limits. However, Zn, Mn, Cu, Fe, and Ni exceeded the permissible limits. Correlation analysis revealed a significant correlation (P < 0.05) between Pb and Zn, likely due to effluents from human waste and seepage from nearby dumpsites into the lagoon, streams, or beaches. The isolated microbial flora included three bacterial genera, Bacillus megaterium, Bacillus spp, and Enterobacter spp, as well as four fungal genera, Aspergillus, Penicillium, Aspergillus flavus, and Fusarium. Bacterial counts were lower than fungal counts in polluted soils, likely due to the nutrient status of the soil. The isolates were found to be tolerant to slightly alkaline pH and heavy metal pollutants, with microbial variation attributed to the impact of pH and heavy metals on the microbial population.

Potassium Fertilizer Application Rates for Fertigated Edamame Grown on Low-K Soils

Edamame, a legume consumed fresh as a vegetable, is highly nutritious, particularly protein-rich, and holds significant economic value. However, its cultivation faces challenges, especially on dry land, due to water scarcity and limited nutrient availability, particularly potassium (K). This study, which investigated the impact of potassium fertilization rate on edamame cultivation, underscores the need for further research. The study utilized a single factor, potassium fertilization rate, arranged in a completely randomized block design. Potassium rates consist of 0% X, 50% X, 100% X, 150% X, and 200% X, where X represents the recommended potassium fertilization rate according to the dry soil test device (DSTD) guidelines. Each treatment was replicated five times. Data were analyzed using ANOVA at a 5% significance level, and any significant effects were further examined using orthogonal polynomial and regression analysis. The results indicated that potassium fertilizer rates did not significantly affect edamame height, pod weight per plot, and marketable yield. However, the study identified the optimal potassium fertilizer rate, which was between 83%X and 119%X, equivalent to 83–119 kg.ha⁻¹ of KCl (50–72 kg.ha⁻¹ of K₂O). This range positively increased total branch yield, productive branches, number of flowers, pod weight per plant, number of pods per plant, and plant dry weight, producing a quadratic response pattern. The study recommends further research to optimize potassium fertilizer doses based on DSTD recommendations, particularly at a low K nutrient status, to maximize marketable yields through fertigation.

Remote Sensing Evaluation of Trophic Status in the Daihai Lake Based on Fuzzy Classification

Trophic state index (TSI) is a critical ecological and environmental issue in water resource management that has garnered significant attention. Given the complexity of optical characteristics in aquatic environments, this study employs fuzzy classification methods (FCM) and composite nutrient status indices to meticulously classify in-situ remote sensing reflectance data, aiming to develop evaluation models for different nutrient status categories to facilitate the assessment of the Daihai River in Inner Mongolia, China. Subsequently, we applied this model to MSI data to analyze the nutrient status of Daihai Lake from 2016 to 2021. Furthermore, a structural equation model (SEM) was utilized to explore the primary driving factors influencing nutrient status. The results indicated that the water bodies in Daihai Lake can be broadly classified into three categories, with the nutrient status models demonstrating robust performance for each category (R2 = 0.80, R2 = 0.83, and R2 = 0.74). Comparisons were made between nutrient status accuracies obtained through the NCM and FCM based on measured data, yielding R2 values of 0.74 and 0.85, respectively. Furthermore, the TSI results derived from MSI inversion were validated, with NCM achieving an R2 of 0.49, RMSE of 6.88, and MAPE of 10.36%, while FCM exhibited an R2 of 0.55, RMSE of 8.89, and MAPE of 13.18%. An SEM–based analysis revealed that over the long term, human activities exerted a more substantial impact on eutrophication in Daihai Lake, while climatic factors played an accelerating and reinforcing role. These results are consistent with prior research in the Daihai area, indicating a state of mild eutrophication and the potential of the fuzzy classification method and comprehensive trophic status index method in eutrophication assessment.

Improving maize yield and drought tolerance in field conditions through activated biochar application

Amidst depleting water resources, rising crop water needs, changing climates, and soil fertility decline from inorganic modifications of soil, the need for sustainable agricultural solutions has been more pressing. The experimental work aimed to inspect the potential of organically activated biochar in improving soil physicochemical and nutrient status as well as improving biochemical and physiological processes, and optimizing yield-related attributes under optimal and deficit irrigation conditions. Biochar enhances soil structure, water retention, and nutrient availability, while improving plant nutrient uptake and drought resilience. The field experiment with maize crop was conducted in Hardaas Pur (32°38.37’N, 74°9.00’E), Gujrat, Pakistan. The experiment involved the use of DK-9108, DK-6321, and Sarhaab maize hybrid seeds, with five moisture levels of evapotranspiration (100% ETC, 80% ETC, 70% ETC, 60% ETC, and 50% ETC) maintained throughout the crop seasons. Furthermore, activated biochar was applied at three levels: 0 tons/ha (no biochar), 5 tons per hectare, and 10 tons per hectare. The study’s findings revealed significant improvements in soil organic matter, bulk density, nutrient profile and total porosity with biochar supplementation in soil. Maize plants grown under lower levels of ETC in biochar supplemented soil had enhanced membrane stability index (1.6 times higher) increased protein content (1.4 times higher), reduced malondialdehyde levels (0.7 times lower), improved antioxidant enzyme activity (1.3 times more SOD and POD activity, and 1.2 times more CAT activity), improved relative growth (1.05 times more) and enhanced yield parameters (26% more grain and stover yield, 16% more 1000-seed weight, 29% more total seed weight, 33% more apparent water productivity) than control. Additionally, among the two biochar application levels tested, the 5 tons/ha dose demonstrated superior efficiency compared to the 10 tons/ha biochar dose.

Application of SWAT to assess peatland forestry impacts on water quality

ABSTRACT Peatland drainage can affect the natural state of hydrological conditions and nutrient loading but is rarely included in catchment-scale models. To understand the gap, we aimed to use the soil and water assessment tool (SWAT) model to observe drained peatlands and their properties to predict nutrients and suspended solids (SS) in the peatland-dominated Simojoki catchment. We integrated drainage networks in SWAT to (i) identify the parameters for the drainage; (ii) determine annual loads and mean concentrations of SS, organic phosphorus (Org-P), total phosphorus (TP), organic nitrogen (Org-N), and total nitrogen (TN); (iii) understand spatial variation of nutrients and SS; and (iv) investigate the uncertainty ranges for the estimates. The calibrated SWAT model showed a 9.6% PBIAS between the simulated flow and the observations with low to medium loading variations for the water quality parameters. For Org-N and TN, the highest loading per year was at the downstream outlet, whereas for SS, Org-P, and TP, it was higher at the upstream outlet of the catchment. This approach of representing the drained peatland in SWAT indicated a maximum spatial distributed load in the peat soil in the clear-cut area and it can be beneficial in future hydrological modelling efforts in identifying the status of nutrients or SS.

Potassium limits productivity in intensive cereal cropping systems in Southeast Asia.

Potassium (K) has received little attention as a potential yield-limiting factor in cropping systems. Here we investigated the K status in intensive cereal cropping systems in Indonesia, which are representative of many other Southeast Asian countries. Our analysis included nutrient input-output balance, leaf nutrient status, long- and short-term fertilizer trials, and farmer surveys. We revealed that soil K levels alone are insufficient to meet plant requirements, and current fertilizer applications are inadequate to prevent K deficiencies and large negative annual soil K balances in farmer fields (average -62 kgK ha-1). On-farm fertilizer trials indicated that nearly 80% of rice crops and 70% of maize crops achieved higher yields with the application of K fertilizer. Addressing K limitations will require an enhanced capacity to predict crop responses to K fertilizer, together with long-term, flexible fertilizer and crop residue management strategies. Furthermore, similar K limitations have probably emerged in other regions globally due to intensive cropping with insufficient K replenishment, which must be addressed to close yield gaps on existing farmland.

Assessment and Delineation of GPS-GIS Based Soil Fertility Maps of Instructional Farm, Malegaon Tehsil Baramati

The present investigation was conducted in the year 2023-24 at division of Soil Science, Dr. Sharadchandra Pawar College of Agriculture, Baramati with an objectives to assess the soil available nutrient status and delineation of GIS based maps of soil available nutrients. Using Arc-GIS 10, Version 10.8, fertility maps of the available macro nutrients were created. The area under the Instructional Farm had soil pH ranged from 7.11 to 8.32, categorized into the slightly alkaline to moderately alkaline categories while the EC varied from 0.21 to 1.99 dSm-1, indicating that most of the soils were non-saline. The soil's organic carbon and calcium carbonate contents ranged from 0.21 to 0.97 per cent and 1.50 to 19.75 per cent and they were classified into low to high and low to very high categories respectively. In the Instructional Farm, the ranges of available nitrogen, phosphorus and potassium content were 85.50 to 360.75, 23.29 to 80.08 and 202.5 to 968.68 kg ha-1 respectively. The Instructional Farm soils had very low to moderate levels of available nitrogen, moderately high to very high levels of available phosphorus and moderately high to very high levels of available potassium. The implementation of GPS-GIS-based techniques for soil sampling represents a significant advancement that will allow researchers and institute officials to track changes in soil fertility over the years. The soil fertility maps created for the Instructional Farm will be invaluable for establishing a scientifically sound fertilization schedule.

Input optimization in short duration red gram [Cajanus cajan (L.) Millsp.] for the agri-food systems in southern Kerala

In the present study, a field experiment was laid out to assess the suitability of two short-duration varieties of red gram and standardize the agronomic management practices. The treatments included combinations of two varieties, two spacings, and three nutrient levels. Individual effects of the variety, APK 1, narrow spacing, and the highest nutrient level were found superior for yield and its contributing attributes. The pooled analysis registered the highest seed yield (1.38 t ha-1) in the combination APK 1 + 40 cm × 20 cm + 40:80:40 kg NPK ha-1. The net returns and benefit-cost ratio were also the highest. Soil available nutrient status was found to be augmented with the cultivation, with wider spacing and the highest nutrient dose recording maximum postharvest soil NPK contents. The results proved that the variety APK 1 and the agronomic management of 40 cm × 20 cm spacing with 40:80:40 kg NPK ha-1 are most suitable for red gram cultivation in southern Kerala.

Transferability of models for predicting potato plant nitrogen content from remote sensing data and environmental variables across years and regions

The use of remote sensing technologies to monitor the nitrogen nutrient status of crops is gradually becoming a more sensible choice, as traditional methods are time-consuming, labor-intensive, and destructive. However, most predictive models utilizing remote sensing data are statistical rather than mechanistic, making them difficult to extend at interannual and regional scales. This study explored the interannual and regional transferability of the potato plant nitrogen content (PNC) prediction models, which combined environmental variables (EVs, e.g. temperature, precipitation, etc.) with proximal hyperspectral vegetation indices (VIs). Two methodologies were implemented to fuse EVs and VIs. The first involved a multiple regression analysis utilizing a multivariate linear model and a random forest approach, with VIs and EVs treated as independent variables, respectively. The second, a hierarchical linear model (HLM), employed EVs to dynamically adjust the relationship between VIs and PNC for different experimental sites. The predictive outcomes demonstrated that (i) the conventional method relying solely on optical VIs exhibited limited accuracy and stability in interannual and regional PNC forecasting; (ii) albeit the multivariate regression approach significantly enhanced model accuracy within the calibration set, its scalability across years and regions remained suboptimal; (iii) the HLM method exhibited high precision and scalability across years and regions, with R2, RMSE, and NRMSE values of 0.68, 0.50 %, and 19.68 % in the validation set, respectively. Those findings corroborate that using a two-tier HLM method can automatically adjust for discrepancies in VIs response to PNC through EVs, thereby enhancing the model's stability. Provided that remote sensing data and EVs are sustainably acquired over the potato growth cycle, it will provide a particularly promising approach to potato nitrogen diagnostics as a decision-making tool for regional application of nitrogen fertilizer.

Determination of nutritional sufficiency ranges for pomelo (Citrus grandis Osbeck) grown on alluvial soils using DRIS.

Pomelo is an important tropical fruit with a high nutrient content and economic value in the Vietnamese Mekong Delta (VMD). The Diagnosis and Recommendation Integrated System (DRIS) helps determine the leaf nutrient status of various plants worldwide. However, the DRIS-based nutritional balance in pomelo leaves remains to be established. Therefore, in this study, we aimed to (i) construct the DRIS norms and indices for nutrients, including macronutrients (N, P, K, Ca, and Mg) and trace elements (Cu, Fe, Zn, and Mn) in pomelo leaves, and (ii) establish nutrient sufficiency value ranges for sustainable pomelo cultivation in the VMD. We collected 270 leaf samples at three stages of pomelo growth, i.e., flowering, fruit development, and postharvest, and calculated DRIS indices for various nutrients. The DRIS indices established for various nutrients in pomelo leaves were accurate and reliable, as indicated by the high coefficient of determination (R2 = 0.43-0.93, p < 0.05) between nutrient concentrations and their DRIS indices. We observed that pomelo leaves were deficient in N (IN = -6.82), P (IP = -24.0), and Fe (IFe = -0.40) at the flowering stage and most deficient in P (IP = -15.6), K (IK = -11.7), Fe (IFe = -0.50), and Mn (IMn = -2.31) at the fruit development stage. However, only N (IN = -2.64) and P (IP = -13.4) shortages were observed at the postharvest stage. Thus, in this study, we evaluated nutrient value ranges (deficient, balanced, and excess) in pomelo leaves at their different growth stages and established DRIS indices for various nutrients. The results contribute to our understanding of the nutritional status of pomelo leaves, which can help growers improve plant health for sustainable pomelo production.

Growth, physiological and N, P, K accumulation responses of Erythropalum scandens Bl. Seedlings under different substrates

Erythropalum scandens Bl. is a medicinal woody vegetable found in southern China and parts of Southeast Asia. Studies have shown improper substrate hindered E. scandens seedling growth, causing water accumulation and nutrient deficiency. In pursuit of an ideal growth medium for E. scandens seedlings during the early stages, this study conducted a pot experiment to identify a mixed substrate with optimal water permeability and fertility. In this study, pure Alfisols soil treatment as the control (CK), and two soilless substrates (peat soil and perlite) were combined with Alfisols soil into different volume ratios, in order to better use soil resources from understory space and balance the texture of mixed substrates. The growth, physiological characteristics and nutrient status of 24-month-old E. scandens seedlings were determined after planting in different mixed ratios. The results showed that as the proportion of peat soil increased in the mix, most indexes exhibited an initial increase followed by a decline, while soluble protein content decreased consistently. Conversely, an increasing perlite ratio resulted in a general decline in most growth and physiological indexes. Root growth, biomass accumulation and chlorophyll content, peaked in the 66.67% Alfisols soil + 33.33% perlite (T4) treatment. Notably, T3 (66.67% Alfisols soil + 33.33% peat soil) showcased the best above-ground growth, while T1 (50.00% Alfisols soil + 50.00% peat soil) excelled in element content accumulation. In conclusion, the cultivation substrate should primarily consist of Alfisols soil, constituting at least 50%. The addition of peat soil enhances above-ground growth and nutrients accumulation, while perlite contributes to robust root development. One third of peat soil and a small amount of perlite can be added to the substrate during E. scandens seedling cultivation, and proper fertilization should also be used in order to increase nutrient accumulation in aboveground and underground parts. This research provides valuable insights into maximizing the potential of E. scandens seedlings through precise cultivation methods.

Effect of mixed planting on soil nutrient availability and microbial diversity in the rhizosphere of Parashorea chinensis plantations.

Parashorea chinensis Wang Hsie (Pc) is an endangered tree species endemic to tropical and subtropical China. However, the acidic red soil areas where it is distributed generally face nutrient limitation. The study of the effects of mixed planting on soil biogeochemical processes contributes to the sustainable management and conservation of Pc. We selected pure and mixed stands of Pc and collected its rhizosphere and bulk soil samples to clarify the effect of mixed planting on the soil microbial community and the nutrient status. The results showed that (1) All stands were strongly acidic phosphorus-deficient soils (pH < 4.0, available phosphorus <10.0 mg·kg-1). There was a significant rhizosphere aggregation effect for soil organic C, total and available N and K, microbial biomass, and inorganic P fraction. (2) The mixed planting significantly increased the soil water content, organic C, available nutrients, the activities of β-1,4-glucosidase and urease, and microbial biomass. The inorganic P fractions are more influenced by rhizosphere, while organic P fractions are more influenced by tree species composition. (3) Fungi and their ecological functions are more susceptible to tree species than bacteria are, and have higher community compositional complexity and α-diversity in mixed plantations. And mixed planting can improve network complexity among key microorganisms. (4) The correlation between soil microorganisms and environmental factors was significantly higher in mixed forests than in pure forests. Soil organic C, available N and P, microbial biomass C and N, β-1,4-glucosidase, and stable P fractions were the key environmental factors driving changes in fungal and bacterial communities. In conclusion, the mixed planting patterns are more advantageous than pure plantations in improving soil physicochemical properties, enhancing nutrient effectiveness, and promoting microbial activities and diversity, especially Pc mixed with Eucalyptus grandis × E. urophylla is more conducive to soil improvement and sustainable management, which provides practical references for relocation protection of endangered tree species and species selection and soil fertility management in mixed planting. In addition, the study highlighted the key role of rhizosphere microenvironment in soil nutrient cycling and microbial community structure, which provides new perspectives for a deeper understanding of soil-microbe-plant interaction mechanisms.

The Different Concentrations of Applied Exogenous Sugars Widely Influence the Specificity, Significance and Physiological Relevance of Study Outcomings.

Plant growth and development are governed via signal networks that connect inputs from nutrient status, hormone signals, and environmental cues. Substantial researches have indicated a pivotal role of sugars as signalling molecules in plants that integrate external environmental cues and other nutrients with intrinsic developmental programmes regulated via multiple plant hormones. Therefore, plant growth and development are controlled through complication signalling networks. However, in many studies, to obtain more obviously experimental findings, excess concentrations of applied exogenous sugars have aggravated the complexity of this signalling networks. Once researchers underestimate this complexity, a series of contradictory or contrasting findings will be generated. More importantly, in terms of these contradictory findings, more contradictory study outcomings are derived. In this review, we carefully analyze some reports, and find that these reports have confused or neglected that the sugar-antagonism of ethylene signalling is specific or conditional. As a result, many contradictory conclusions are generated, which will in turn misdirect the scientific community.

Water volumes and mulches affect plant growth, leaf nutrient status and orchard soil mineral content of sweet orange cv. Mosambi

Day-by-day increasing irrigation water scarcity requires the application of water-saving irrigation techniques to sustain agriculture production. A two-year field investigation was conducted during 2018 to 2020 to determine the effects of various mulches and irrigation volumes on the growth, leaf chemicals and soil properties of one-year-old sweet oranges (Citrus sinensis) cv. Mosambi. The study included three irrigation schedules, viz.100% ETc (I1), 80% ETc (I2), and 60% ETc (I3), and five different mulches were used, viz. without mulch, white polythene, coriander straw, dry grass and black polythene mulches, replicated thrice. Results demonstrated that drip irrigation with 100% ETc and mulching with black polythene mulch significantly increase the plant growth attributes like height of the plant (28.64%) (30.31%), rootstock girth (36.61%) (37.90%), plant canopy spread (E-W and N-S) (EW- 63.82%, NS- 63.87%) (EW- 67.56%, NS- 67.90%) and leaf area (2.4%) (2.34%). Furthermore, plant leaf chlorophyll content (2.41 mg g-1) (2.41 mg g-1) and leaf mineral content such as N (2.39%) (2.40%), P (0.16%) (0.165%), K (1.57%) (1.59%), Ca (47.34 g kg-1) (47.80 g kg-1), Mg (4.54 g kg-1) (4.57 g kg-1), Fe (120.51 g kg-1) (123.15 g kg-1) and Zn (39.00 g kg-1) (37.84 g kg-1) were noted to be significantly (p ≤ 0.05) higher in plants that received 100% (were ETc (I1) and mulching with black polythene mulch (M1) treatment. Taken together, the results suggested that treatments I1 and M1 have the potential to maximize plant growth, leaf chemicals and soil nutrients of sweet orange (Citrus sinensis) cv. Mosambi plants.

Trait-specific groups of aquatic macrophytes respond differently to eutrophication of unshaded lowland streams

Understanding eutrophication effects on stream macrophytes is key to meaningful environmental management and governance. However, the response of macrophyte communities to eutrophication is complex and often the effect of eutrophication is obscured by other factors related to habitat variability including flow regime and light availability.In this study macrophyte community composition and abundance was quantified along a eutrophication gradient in 30 lowland streams. Slow flowing, medium sized streams with minimal shading were selected, to focus on examining water quality effects. The internal nutrient status of the plants and the bioavailable nutrient fraction of the sediment was measured and a national database of modelled stream descriptors was used to obtain information about land use and water quality variables. Statistical relationships between macrophyte community composition and clogginess and nutrient, underwater light, and carbon availability and flow disturbance were examined along the eutrophication gradient.Macrophytes with different growth strategies were related to different aspects of eutrophication and non-native taxa were found to dominate eutrophic streams.There was no relationship between nutrient concentrations and nutrient content of the macrophytes but sediment P was correlated with P concentrations in streams.Our results showed that 1) non-native species were common and clogginess was high in unshaded lowland streams with low water clarity and high nutrient and bicarbonate availability; 2) emergent species were associated with high nitrate availability and sediment phosphorus and low disturbance; 3) submerged species prevailed where water column total phosphorus and bicarbonate availability were high; and 4) nutrient concentrations that limit the development of clogginess are expected to be low where bicarbonate is high and flow or other physical disturbance is low. Our findings improve understanding of how stream macrophyte communities respond to changes in water quality related to eutrophication and anthropogenic changes in catchments and will contribute to informed management of macrophytes in streams.

Comparative analysis of spectroradiometric and chemical methods for nutrient detection in black gram leaves

This study evaluated the nutrient content in Vigna mungo leaves using a visible near-infrared spectroradiometer (VNIR 650–900 nm) and compared it with traditional chemical analysis. Nutrient deficiencies were induced in a controlled environment, focusing on Nitrogen (N), Phosphorus (P), and Potassium (K). The VNIR spectroradiometer measured the spectral reflectance of the leaves at different intervals. Peak reflectance for N, P, and K deficiencies occurred at 716 nm, 737 nm, and 720 nm, respectively. A 30 % deficiency in N, P, and K resulted in reflectance values of 45 %, 42 %, and 41 %, respectively, while a 40 % deficiency increased these values to 48 %, 46 %, and 43 %. Results showed a strong correlation between nutrient deficiency and spectral reflectance, providing a quicker, more economical method than traditional chemical analysis. The study concludes that VNIR spectroradiometry is an effective tool for non-destructive, real-time assessment of nutrient status in Vigna mungo, which could lead to optimized fertilizer application and improved crop management.