Nutrient Status Research Articles

Enhanced sediment microbial diversity in mangrove forests: Indicators of nutrient status in coastal ecosystems.

Coastal ecosystems are increasingly threatened by nutrient imbalances and environmental degradation, which can compromise their stability and productivity. We analyzed the sediment characteristics, microbial community structures, and nutrient cycling across three habitats: mangrove forests, seagrass beds, and bare beaches. The physicochemical properties (including pH, total nitrogen (TN), phosphorus (P), and potassium (K)) of the sediment samples were analyzed, and the microbial diversity was assessed using high-throughput sequencing. Our findings indicated that the organic matter (OM), TN, and cation exchange capacity (CEC) of mangrove sediments were significantly higher than those of seagrass beds and bare beaches. The microbial community in mangroves was positively correlated with OM content and was more complex and stable than that in seagrass beds and bare beaches. MG potentially improved the abundance of k00059 and enzyme 1.1.1.100 in sediment bacteria and further increased sediment TN, OM, and CEC. This study indicates the importance of microbial diversity as a potential indicator of sediment and plant nutrient status, emphasizing the need for conservation efforts to preserve mangrove ecosystems.

Evaluation of Statistical Models of NDVI and Agronomic Variables in a Protected Agriculture System

Vegetable production in intensive protected agriculture systems has evolved due to its intensity and economic importance. Sensors are increasingly common for decision-making in crop management and control of environmental variables, obtaining optimal yields, such as estimating vegetation indices. Innovation and technological advances in unmanned vehicle platforms have improved spatial, spectral, and temporal resolution. However, in protected agriculture systems, the use is limited due to the assumption of having controlled environmental conditions for indeterminate vegetable production. Therefore, sequential monitoring of NDVI is proposed during the 2022 and 2023 agricultural cycles using the Green Seeker® sensor and agronomic variables. This has created a database to generate predictive models of development and yield as a function of nutrient status. The results obtained indicate high significance levels for the development and NDVI curves in all phenological stages; in contrast to the yield predictive models, this is due to the maximum values (close to one) recorded for NDVI inside the greenhouse in comparison to the yield prediction obtained from the 18th week of harvest. Evaluating the models between NDVI and agronomic variables is not an index that offers certainty in predicting yield in indeterminate crops in protected agriculture production systems. This is due to the constant optimal development in response to controlled environmental conditions, nutrient status, and water supply inside the greenhouse, without the sustainability of yield, which decreases in the final stages of production until production becomes economically unprofitable.

Spatial Distribution Characteristics and Relationships of Salt-Based Ions and Nutrients in Old Protected Vegetable Fields

To achieve a scientific and objective evaluation of soil acidification, secondary salinization, and nutrient imbalance in old protected vegetable fields (OPVs) with over 30 years of cultivation history, a soil surface breeding vigorous moss was investigated. Here, quantitative laboratory analysis and mathematical statistics were employed to explore the spatial distribution of soil salinity and nutrients, as well as their relationships. The results revealed that OPVs exhibited slightly acidified values. The measured anions and cations in the soil salt composition constituted approximately 77% of the total ions. Among which, Ca2+ was the dominant cation, while SO42− and NO3− were predominant anions. The total water-soluble salt (TDS) content of the surface soil reached 4.52 g kg−1, exceeding the Chinese Saline Soils standard (1.0 g kg−1) by 350%. In the OPVs, nitrate nitrogen was significantly higher than ammonium nitrogen, and available phosphorus and available potassium were generally abundant. Despite exhibited various soil health concerns, a field visit survey presented consistently high and stable yields in OPVs. We hypothesize that this seemingly contradictory finding may be attributable to several factors, including the abundance of divalent cations (Ca2+ and Mg2+), the soil fertility and water retention capacity of unsaturated salt-based suitable soil, as well as good soil aggregate structure. These factors had the potential to reduce the stresses on the soil. This study provided a foundational understanding of the nutrient and salinity status of soils in OPVs, offering valuable data and theoretical groundwork for future research endeavors.

From Practice to Science: Assessment Soil Nutrient Status Using “Minus One Element Technique (MOET)” for Early Growth of Maize

Soil nutrient deficiency will influence maize growth, so it is necessary to add nutrients based on the fertility status of the soil. One way to find out the nutrient soil status using a simple method is using the minus one element technique (MOET). The minus one element technique (MOET) determines which element is the limiting factor. This study was carried out to confirm the nutrient soil status using the minus one element technique (MOET) with the early growth of maize as the indicator. The research was conducted in greenhouse, Polytechnic of Lamandau, Central Borneo, Indonesia, at an altitude of 50 m above sea level. The research used a non-factorial design arranged in a completely randomized block design and five fertilizer treatments based on the minus one element technique consisting of control (without fertilization), PK, NP, NK, and NPK with three replications. The results showed that the deficiency of nitrogen, potassium, and phosphorus reduced the growth of maize, leaf greenness, photosynthetic rate, and especially the total dry weight of the plant. The dry weight of maize roots decreased by 18.85% - 75.47% when N, P, and K fertilizer were not applied. Then the decrease in photosynthesis rate ranged from 18.23% to 46.21% when N, P, and K fertilizer were not applied. The low of photosynthesis rates resulted in the accumulation of plant dry weight was hampered, and there was a decrease of 8.00% -74.43%. The results of the evaluation of fertility status are based on the results of the relative dry weight of the plant, which was

Enhancing Growth and Yield of Tulsi (Ocimum sanctum L.): Influence of Organic Manure and Inorganic Fertilizer Applications

The indiscriminate use of inorganic fertilizers depletes soil fertility and reduces crop yields. Limited information exists on nutrient management for Tulsi (Ocimum sanctum L.). A field experiment conducted from 2016-17 to 2019-20 at Rahuri (MS) evaluated the effects of organic manure and inorganic fertilizer levels on Tulsi yield. The randomized block design (RBD) experiment included 12 treatments combining chemical fertilizers (N:P2O5:K2O) at three levels (30:20:10, 40:30:20, and 50:40:30 kg ha⁻¹) with or without farmyard manure (FYM) at 5 or 10 t ha⁻¹, alongside FYM-only and control treatments. The results showed that, the treatment T9 (50:40:30 kg ha⁻¹ + FYM 10 t ha⁻¹) significantly improved plant height, branches per plant, fresh and dry herbage yield, and soil nutrient status (N, P, and K) over the control. T9 also achieved the highest economic returns with a superior B:C ratio, closely followed by T8 (40:30:20 kg ha⁻¹ + FYM 10 t ha⁻¹). This study concludes that combining higher inorganic fertilizer levels with FYM (10 t ha⁻¹) optimizes growth, yield, and soil fertility in Tulsi cultivation.

Regional variations in the soil characteristics of the Ghiror block in Uttar Pradesh's Mainpuri District

Soil serves as the basis for plant growth and is essential for agricultural output. Soil testing is decisive in modern agriculture for assessing fertility, nutrient status, and crop suitability. In the current study an attempt has been made to ascertain currents spatial variability of soils from seven different villages of Ghiror Block three different soil samples of each village were gathered from 0-15 cm depth section, and it was examined using the help of standard laboratory techniques. Therefore, the effectiveness of the material showed that the pH values were found in the-neutral to alkaline (Mean=7.98), electrical conductivity of the soils was salinity-free (Mean=0.44 dS m-1) and aadditionally, the soils' carbon content quality was low (mean = 0.27 per cent). having a mean score of 299.45 kg per ha, the amount of available potassium was noted to be relatively more, followed by available phosphorus with a mean score of 36.09 kg per ha, and usable nitrogen with a mean of 132.10 kg per ha. Similarly, the nutrient index values of the Ghiror block were high for nitrogen, phosphorus, potassium and low for sulphur. These outcomes indicate that maintaining a balanced fertilization program that accounts for crop demand, soil availability, efficiency of fertilizers, and the contribution of animal manure enhances yield and promotes soil health.

Association Between Physical Fitness and Cardiovascular Health in Chilean Schoolchildren from the Metropolitan Region.

Background: Cardiovascular diseases increasingly impact youth, with early development of risk factors such as obesity, hypertension, and inadequate nutrient intake. Proper nutrient intake and physical fitness are vital for reducing these risks, especially in pediatric populations. This study explores the connection between physical fitness, metabolic risk, and nutrient status among 1656 Chilean schoolchildren from diverse socio-economic backgrounds. Methods: Anthropometric measures included weight, height, skinfold thickness, waist circumference, and blood pressure. Physical fitness was assessed via handgrip strength, standing long jump, and a six-minute walk test. Nutrient intake was also evaluated, and a composite metabolic risk score was calculated based on waist circumference, skinfolds, and blood pressure. Results: Boys consistently outperformed girls in physical fitness tests, including grip strength and horizontal jump, with differences becoming more pronounced in higher grades and Tanner stages. Girls exhibited higher subcutaneous fat levels and obesity prevalence during later grades, highlighting gender-specific patterns in body composition. Better physical fitness was associated with lower waist circumference, skinfold thickness, and metabolic risk scores. A moderate correlation between aerobic fitness (distance/height) and blood pressure (r = 0.27, p = 0.01) was observed. Z-Score MR analysis revealed that students in the lowest fitness tertile exhibited significantly higher cardiovascular risk profiles compared to their fitter peers. Conclusions: Physical fitness plays a critical role in reducing cardiovascular risk in children. The findings underscore the importance of promoting gender- and age-specific interventions that include both aerobic and strength-based physical activities. Comprehensive school programs focusing on nutrition and physical activity are essential to mitigating cardiovascular risk and promoting long-term health outcomes. Future longitudinal studies are recommended to establish causal relationships and evaluate the impact of targeted interventions.

Impacts of long-term irrigation of municipally-treated wastewater to the soil microbial and nutrient properties.

Reusing treated wastewater (TWW) for crop irrigation has shown to provide environmental and economic benefits as well as drawbacks. This study was conducted using soils collected from a wastewater reuse facility in Tallahassee, FL, mainly to elucidate the long-term impact(s) of TWW irrigation on soil microbiome and nutrient status. Approximately 890ha of land have been spray-irrigated with TWW since the 1980's to grow fodder crops. Soil cores were collected from six irrigated and six control sites at depths of 0-15, 15-30, and 30-60cm during summer and winter, followed by nutrient analysis and assessment of bacterial, fungal, and denitrifier communities using SSU rRNA, ITS, nirK, nirS, and nosZ phylogenetic markers. TWW irrigation significantly increased soil pH, soluble salts, nitrate, phosphate, calcium, magnesium, and organic matter, alongside shifts in the prokaryotic and fungal community structures, particularly in summer. Beta-diversity analyses indicated that wastewater quality and season collectively explained 23% of prokaryotic community similarity and 9.8% of fungal community dissimilarity. Indicator species analysis, supported by random forest machine learning, identified 37 prokaryotic and 11 fungal bioindicators whose occurrences varied significantly with wastewater quality and season. Key nitrogen-cycling microbes included ammonia-oxidizing families of Nitrosomonadaceae, Nitrosopumilaceae, Nitrososphaeraceae, Nitrosotaleaceae, and comammox-performing Nitrospiraceae. The fungal community was predominated by Ascomycota (78.6%±4.2%). FUNGuild analysis showed dominant trophic levels of symbiotrophs, saprotrophs, and pathotrophs, averaging 42%±7.1%. Overall, this study points to the long-term impacts of TWW irrigation on the studied soil properties and microbial communities.

Hydromulch Maintains Strawberry Yield, Fruit Quality, and Plant Nutrition across Two Contrasting Environments

Plastic mulches made from nonbiodegradable polyethylene (i.e., “PE mulch”) are an integral tool for organic and conventional strawberry (Fragaria ×ananassa) production due to their ability to optimize soil and crop microclimates, suppress weeds, and promote overall yield and fruit quality. Unfortunately, PE mulch is primarily single-use and seldom recycled, leading to large volumes of plastic waste, with some of the plastic mulch fragments residing in the soil or polluting the surrounding agroecosystem. Although soil-biodegradable plastic mulches are a promising mulch technology that aims to reduce waste generation, no commercial products are available that meet the National Organic Program’s requirements. Hydromulches are an alternative mulch technology that is sprayable and can be formulated to meet organic requirements, but they have undergone limited testing. The objective of this study was to evaluate the effects of various hydromulch formulations on yield, fruit quality, and tissue nutrient status of day-neutral strawberries grown in two diverse environments. Hydromulches made with various formulations of paper, guar gum, or psyllium tackifiers were compared with PE mulch in Northwest Washington and North Dakota in 2022. Few treatment effects were observed throughout the experiment, and both strawberry yield and fruit quality were maintained. Slight variations in tissue nutrient concentrations were observed but not attributed to hydromulch treatments. Information resulting from this project demonstrates hydromulches maintain crop productivity and quality. Future research should evaluate the ability of hydromulches to suppress a spectrum of weed species, impacts on soil health, and economic viability.

Effect of potassium solubilizing bacteria and foliar application of potassium on soil nutrient status and soil biological properties in paddy (Oryza sativa) in coastal acid soils of Karnataka

Effect of potassium solubilizing bacteria and foliar application of potassium on soil nutrient status and soil biological properties in paddy (Oryza sativa) in coastal acid soils of Karnataka

Influence of plant growth promoting rhizobacteria And organic manures on yield of okra (abelmoschus esculentus (l.) Moench)

The investigation revealed that different growth and yield parameters viz., minimum days to first flowering, earliest first flowering node, minimum days to first fruit harvest and maximum plant height, average fruit weight, fruit length, fruit breadth, fruit yield per plant, fruit yield per plot and harvest duration were recorded in treatment combination of FYM + Vermicompost + Jeevamrit + Pseudomonas fluorescens. Therefore, supply of plant nutrients through organic sources like vermicompost, FYM, jeevamrit and Pseudomonas fluorescens enhance plant growth and development, increase soil nutrient status and maintain sustainable crop production. Bangladesh J. Bot. 53(4): 1021-1025, 2024 (December)

Nutrient status, water consumption and productivity of grain sorghum in the southern part of the Rostov region depending on sowing dates and seeding rates

Sorghum is a drought-resistant, heat-loving crop, the grain of which is highly nutritious and widely used in animal husbandry. In the Russian Federation, the Rostov Region ranks first in terms of sowing areas for this crop. The purpose of the current study was to determine the effect of seeding rates and sowing dates of grain sorghum on productivity, water consumption and nutrient status in the southern part of the Rostov Region. The study was conducted at the FSBSI “ARC “Donskoy” in 2022–2023. As a result of the study, there has been found a decrease of grain nitrogen available to sorghum plants to 4.1–4.7; 4.1-4.9 and 4.2–4.7 mg/kg of soil for the varieties ‘Zernogradskoye 88’, ‘Ataman’ and ‘Esaul’, respectively. By the complete maturity stage, the mobile phosphorus content in soil decreased to 15.3–17.0; 16.0–17.0; 14.1–15.7 mg/kg of soil, respectively, for the varieties ‘Zernogradskoe 88’, ‘Ataman’, and ‘Esaul’. At the end of grain sorghum vegetation period, the exchangeable potassium content was at the level of 271–306; 275–295; 261–290 mg/kg of soil, respectively, for the varieties ‘Zernogradskoe 88’, ‘Ataman’, and ‘Esaul’. Water consumption was at the level of 227.4–277.9 mm/ha for the variety ‘Zernogradskoye 88’, 219.6–272.1 mm/ha for the variety ‘Ataman’ and 222.8–271.5 mm/ha for the variety ‘Esaul’. At the same time, moisture consumption for the formation of grain productivity was 48.42–70.41; 42.92–69.85; 47.15–83.70 mm/t, respectively, for the varieties ‘Zernogradskoye 88’, ‘Ataman’, and ‘Esaul’. Over the years of study, the mean grain productivity was 4.51 t/ha for the variety ‘Zernogradskoye 88’, 4.66 t/ha for the variety ‘Ataman’, 4.11 t/ha for the variety ‘Esaul’. The largest productivity was identified in the third sowing date (4.66 t/ha on average according to a sowing date) and at a seeding rate of 0.4 million germ. pcs. per ha (4.94 t/ha on average according to a seeding rate).

Establishing optimal nutrient level of magnesium and boron in black pepper for optimization of productivity in Western Ghats of Kerala

Critical nutrient level of magnesium and boron in soil and plant biomass of black pepper (Piper nigrum) have been estimated in Western Ghats of Kerala by conducting field experiments in three seasons (2018-2020) by magnesium and boron fertilization. Nutrient management in black pepper plantations wins important value due to its wider use as spice all over the world. As black pepper plants are easily prone to Mg and B deficiency, its response to Mg in the form of magnesium sulphate and B as borax was evaluated in terms of yield, plant nutrient content and nutrient status in soil. Effect of Mg as well as B application on the other available nutrients and leaf nutrient content were also determined in the study. Response curves were fitted by plotting relative yield of black pepper with Mg and B in soil and index leaf. The graphical method of Cate and Nelson was used to derive the optimal concentrations of nutrients. The critical levels of magnesium in soil and black pepper leaves were established as 140 mg kg-1 and 0.44 % respectively. Optimum dose of magnesium sulphate for getting highest yield of black pepper was found as 120 kg ha-1 followed by MgSO4 @ 80 kg ha-1. Similarly critical limit of B in the soil and index leaf of black pepper were 0.58 and 21 mg kg-1 respectively. The maximum potential yield was obtained by applying boron as borax at 0.2% via foliar application and at a higher dosage of 2 kg per hectare through soil application.

A review on co-composting of biosolids and its use in crops cultivation for agriculture sustainability

Generation and disposal of biosolids (solid and semisolid materials left after the wastewater treatment) has becoming a challenge globally. A large number of objectionable components like heavy metals, pesticides, detergents and pathogens restricts the direct application of biosolids in the cultivation of agricultural crops as it contaminates the soil as well as the cultivated crops and causes health issues. Co-composting of biosolids can be a viable option to utilize the biosolids in a definite proportion along with different types of biodegradable materials (co-substrate) such as, kitchen waste, agricultural residues, forestry waste and waste from the animal husbandry etc. Co-composting improves the nutrients status of the composted biosolids and reduce the risk of accumulation of toxic heavy metals and pathogens in the soil and cultivated crops. The application of biosolids compost in to the soils significantly improve the physical structure, nutrients composition and microbial profile of the soils and subsequently enhance the crops productivity. It also reduces the risk of contamination of the soils and cultivated agricultural crops in comparison to the direct use of biosolids in soil amendment. In this paper we discussed the use of biosolids in agriculture, co-composting of biosolids with different co-substrates and their application in the cultivation of different agricultural crops for sustainable agriculture production.

The Ameliorative Effect of Coumarin on Copper Toxicity in Citrus sinensis: Insights from Growth, Nutrient Uptake, Oxidative Damage, and Photosynthetic Performance.

Excessive copper (Cu) has become a common physiological disorder restricting the sustainable production of citrus. Coumarin (COU) is a hydroxycinnamic acid that can protect plants from heavy metal toxicity. No data to date are available on the ameliorative effect of COU on plant Cu toxicity. 'Xuegan' (Citrus sinensis (L.) Osbeck) seedlings were treated for 24 weeks with nutrient solution containing two Cu levels (0.5 (Cu0.5) and 400 (Cu400) μM CuCl2) × four COU levels (0 (COU0), 10 (COU10), 50 (COU50), and 100 (COU100) μM COU). There were eight treatments in total. COU supply alleviated Cu400-induced increase in Cu absorption and oxidative injury in roots and leaves, decrease in growth, nutrient uptake, and leaf pigment concentrations and CO2 assimilation (ACO2), and photo-inhibitory impairment to the whole photosynthetic electron transport chain (PETC) in leaves, as revealed by chlorophyll a fluorescence (OJIP) transient. Further analysis suggested that the COU-mediated improvement of nutrient status (decreased competition of Cu2+ with Mg2+ and Fe2+, increased uptake of nutrients, and elevated ability to maintain nutrient balance) and mitigation of oxidative damage (decreased formation of reactive oxygen species and efficient detoxification system in leaves and roots) might lower the damage of Cu400 to roots and leaves (chloroplast ultrastructure and PETC), thereby improving the leaf pigment levels, ACO2, and growth of Cu400-treated seedlings.

Exploring Microelement Fertilization and Visible-Near-Infrared Spectroscopy for Enhanced Productivity in Capsicum annuum and Cyprinus carpio Aquaponic Systems.

This study explores the effects of varying exposure times of microelement fertilization on hydrochemical parameters, plant growth, and nutrient content in an aquaponic system cultivating Capsicum annuum L. (pepper) with Cyprinus carpio (Common carp L.). It also investigates the potential of visible-near-infrared (VIS-NIR) spectroscopy to differentiate between treated plants based on their spectral characteristics. The findings aim to enhance the understanding of microelement dynamics in aquaponics and optimize the use of VIS-NIR spectroscopy for nutrient and stress detection in crops. The effects of microelement exposure on the growth and health of Cyprinus carpio (Common carp L.) in an aquaponic system are investigated, demonstrating a 100% survival rate and optimal growth performance. The findings suggest that microelement treatments, when applied within safe limits, can enhance system productivity without compromising fish health. Concerning hydrochemical parameters, conductivity remained stable, with values ranging from 271.66 to 297.66 μS/cm, while pH and dissolved oxygen levels were within optimal ranges for aquaponic systems. Ammonia nitrogen levels decreased significantly in treated variants, suggesting improved water quality, while nitrate and orthophosphate reductions indicated an enhanced plant nutrient uptake. The findings underscore the importance of managing water chemistry to maintain a balanced and productive aquaponic system. The increase in root length observed in treatments 2 and 6 suggests that certain microelement exposure times may enhance root development, with treatment 6 showing the longest roots (58.33 cm). Despite this, treatment 2 had a lower biomass (61.2 g), indicating that root growth did not necessarily translate into increased plant weight, possibly due to energy being directed towards root development over fruit production. In contrast, treatment 6 showed both the greatest root length and the highest weight (133.4 g), suggesting a positive correlation between root development and fruit biomass. Yield data revealed that treatment 4 produced the highest yield (0.144 g), suggesting an optimal exposure time before nutrient imbalances negatively impact growth. These results highlight the complexity of microelement exposure in aquaponic systems, emphasizing the importance of fine-tuning exposure times to balance root growth, biomass, and yield for optimal plant development. The spectral characteristics of the visible-near-infrared region of pepper plants treated with microelements revealed subtle differences, particularly in the green (534-555 nm) and red edge (680-750 nm) regions. SIMCA models successfully classified control and treated plants with a misclassification rate of only 1.6%, highlighting the effectiveness of the spectral data for plant differentiation. Key wavelengths for distinguishing plant classes were 468 nm, 537 nm, 687 nm, 728 nm, and 969 nm, which were closely related to plant pigment content and nutrient status. These findings suggest that spectral analysis can be a valuable tool for the non-destructive assessment of plant health and nutrient status.

Spatiotemporal differences induced changes in the structure and function of the gut microbiota in an endangered ungulate

The composition and function of animal gut microbiota are shaped by various factors, among which diet is one of the major factors. Diet is affected by seasonal shifts and geographical differences, which in turn impact the host’s nutritional levels. To adapt to these environmental changes, the gut microbiome often produces matching responses. Understanding the relationships among the environment, diet, host and the gut microbiome is helpful for exploring the environmental adaptation of wildlife. Here, we chose wild sika deer (Cervus nippon), which is composed natural allopatric populations, to explore how the environment shapes the gut microbiome and affects the relationship between microbiota composition and function and the mutual adaptation of the seasonal living environment to seasonal dietary changes. To this purpose we used DNA metabarcoding, 16S RNA gene amplification sequencing, metagenomic shotgun sequencing and nutritional analyses to comprehensively examine the relationships among the forage plant, nutrient status and host gut microbiome. Our analyses showed spatiotemporal differences in diet between the Tiebu and Hunchun regions, which ultimately led to varying intakes of protein, cellulose, and soluble sugar. The microbiome composition and function showed unique characteristics in each group, and significant differences were detected at the gene level for the protein absorption and metabolism pathway, the carbohydrate metabolic absorption pathway, and cellulase enzyme function, which are related to nutrition. We also found differences in the pathogenic bacteria and resistance mechanisms genes of the gut microbiota in different groups. Our results showed that the gut microbiome of allopatric populations adapts to changes in food composition and nutrition in different seasons and areas to help the host cope with spatiotemporal changes in the living environment. At the same time, varying levels of human activity can have potential health impacts on wild animals.

Rhamnolipid Modified Silica Nanoparticles Control Rice Blast Disease by Enhancing Antifungal Activity In Vivo and Antioxidant Defense System of Rice (Oryza sativa L.).

Blast disease caused by Magnaporthe oryzae is a devastating disease that limits rice grain production. Here, we synthesized rhamnolipid (RL) modified silica nanoparticles (SiO2NPs) based on the excellent antimicrobial activity of RL against various phytopathogens and the role of SiO2NPs in alleviating plant diseases and investigated the roles and mechanisms of RL@SiO2NPs application in controlling rice blast disease. Two-week-old rice seedlings were sprayed with 100 mL/L of different materials before pathogen inoculation, and blast incidence was investigated 5 days after inoculation. The results showed that RL0.1@SiO2NPs were the most suitable mixture ratio in suppressing blast and enhanced plant resistance. Compared with the control, application of RL0.1@SiO2NPs significantly reduced rice blast disease incidence by 10.80% and the relative growth of fungus by 97.05% and increased the shoot dry biomass by 13.33%, which alleviated the infection pressure of rice blast fungus. Additionally, after RL0.1@SiO2NPs treatment, peroxidase, ascorbate peroxidase, and polyphenol oxidase activities in rice leaves were significantly increased by 47.02%, 34.26%, and 44.36%, respectively, the total phenolics content was significantly increased by 24.14%, and the malondialdehyde and hydrogen peroxide content was decreased by 5.28% and 14.58%, respectively. RL0.1@SiO2NPs also improved plant nutrient status and enhanced disease resistance of infected plants by restoring nutrient balance or ion homeostasis, including increased potassium concentration (23.84%) in leaves and Si concentration (60.34%) in roots and decreased magnesium (11.89%) and iron concentrations (30.55%) in rice leaves. In summary, our results suggest that RL0.1@SiO2NPs enhance rice plant resistance against blast by enhancing the antifungal activity in vivo, activating the antioxidant defense system, and affecting nutrient acquisition in rice seedlings. RL@SiO2NPs have shown potential application as green and efficient agricultural chemical substitutes in plant disease management.

Soil-test-crop-response based nutrient scheduling can improve soybean-wheat productivity and system sustainability

Soybean-wheat sequence, one of the most vital cropping systems for farmers, has been suffering for productivity stagnation and decline due to several factors. Strategic management of the inputs particularly the nutrients could aid the crops achieve optimum growth and yield. Keeping this in mind, four years of field experiment was conducted to study the effect of combining inorganic as well as organic nutrient sources using soil-test-crop-response (STCR) approach in a randomized block design having ten treatments including control, 100% Recommended Dose of Fertilizers (RDF), 50% RDF, 100% RDF + 5 kg Zn ha−1 (100% RDF + Zn), 100% RDF + 5 t farmyard manure ha−1 (100% RDF + FYM), 50% RDF + 5 t farmyard manure ha−1 (50% RDF + FYM), STCR inorganic with target yield-I (STCRI TY-I), STCR inorganic with TY-II, STCR integrated with TY-I (STCRO TY-I) and STCR integrated with TY-II (STCRO TY-II) with each treatment replicated thrice. The STCR equations were tailored for the experimental location and used to calculate the fertilizer requirements. Plant growth, yield, system yield, sustainability and economics, changes in soil parameters were analyzed during the study. The STCRO TY-II treatment showed 122.4 and 73.3% increase in yield of soybean and wheat over control, respectively and those were at par with the highest values recorded from 100% RDF + FYM treatment. Despite having low gross and net returns, decrease in benefit cost ratio was marginal (0.86%) in STCRO TY-II as compared to 100% RDF + FYM which indicated better utilization of resources with comparatively lower investment. In addition to that, it also performed reasonably well in improving soil available nutrient status (positive balance in available N, P, K and organic carbon), partial factor productivity of nutrients and sustainable yield index (2.43 times over control). The study elucidated significance of integrated nutrient management specially STCRO TY-II in improving soil health, optimizing yield and assuring economic sustainability in soybean-wheat cropping system.

Effects of Integrated Nutrient Management on Growth, Nodulation, and Yield of Soybean [Glycine max (L.) Merr. var. Puja

Inefficient fertilizer management is a major reason for the low soybean productivity in Nepal. This study conducted at an altitude of 811 meters in Baitadi, Nepal, examined the effects of integrated nutrient management on soybean growth, nodulation, and yield. Employing an RCBD experimental layout with 3 replications, the study evaluated 9 treatments, namely: Control, Rhizobium+100% PK, Rhizobium+50% RDF, Rhizobium+75% RDF, Vermicompost+50% RDF, Vermicompost+75% RDF, FYM+50% RDF, FYM+75% RDF, RDF (NPK @ 10:40:30 kg/ha). The results revealed that ‘Rhizobium+100% PK’ produced maximum plant height (140.8 cm), dry weight growth rate (2.89 gram/plant/day), nodule count (11.33), and nodule mass (0.55 gram). ‘Rhizobium+75% RDF’ produced the highest number of trifoliate leaves (62.78) and leaf area index (15.30). Furthermore, ‘Vermicompost+50% RDF’ resulted in a maximum fresh weight growth rate (7.86 gram/plant/day), ‘RDF’ resulted in the highest root diameter (12.89 mm), and ‘FYM+75% NPK’ produced highest 1000-grain weight (145.9 g). The treatments ‘VC+75 % RDF’ and ‘Rhizobium+50 % RDF’ stood out with a remarkable grain yield of 3.659 tons/ha and 3.642 tons/ha respectively. These two treatments were statistically indistinguishable regarding grain yield. The application of ‘VC+75 % RDF’ or ‘Rhizobium+50 % RDF’ can prove to be an effective way to enhance the productivity of soybean. However, the performance of soybean can vary depending on the variety, intercultural operations, environmental conditions, and residual nutrient status of the soil. Therefore, we recommend further research to solidify these findings.