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Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

AbstractMost conventional phosphorous (P) fertilizers are highly soluble, which favors P retention in the solid phase of the soil, and this condition hinders P availability to plants. Alternative P fertilizers, such as organominerals and struvite, have a slow release of nutrients into the soil, which in turn favors P uptake by plants; nevertheless, soil acidification caused by nitrogen (N) fertilizers can reduce P availability in the soil. In his study, we assessed the effect of N fertilizers on P availability for maize (Zea mays) grown in tropical soils with alternative P fertilizers. An experiment was set up in columns under greenhouse conditions with maize in two cultivation cycles in two soils with contrasting textures (medium and clayey textures), two N fertilizers (calcium nitrate - CN - and ammonium sulfate - AS), three P fertilizers (triple superphosphate - TSP -, organomineral - OM - and struvite - ST), and a control treatment (without addition of P and N fertilizers). At 45 days after emergence, we measured the biomass production and the N and P contents in plants to calculate fertilization efficiency as well as the soil P content. AS promoted the highest aboveground N accumulation, whereas the highest efficiency was obtained with CN. The alternative P sources did not differ in terms of P availability when combined with both N sources. Soil textures were sensitive to fertilizer combination. Further studies are needed to assess struvite interaction with other elements in the soil and the P release kinetics to plants. [ABSTRACT FROM AUTHOR]

Citrus decline is a significant deteriorating factor in citrus cultivation, imposing costly damages to many orchards worldwide, including in Iran. Key factors contributing to citrus decline include environmental stresses such as the physical and chemical conditions of the soil, soil nutritional status, soil moisture condition, and biotic stresses. Environmental stresses, particularly mineral deficiencies and water stress, appear to play a crucial role in citrus deterioration. The Jiroft region is one of the major agricultural centers in south of Iran. Despite its pivotal role in citrus production of the country, the region's orchards experience widespread deterioration, causing considerable annual losses. However, no research has yet explored the potential benefits of simultaneous use of management and nutritional treatments in these orchards. Therefore, this study aims to investigate the effect of management and nutritional treatments on alleviating both biotic and abiotic stresses and reducing citrus fruit deterioration. Materials and Methods The current study employed a randomized complete block design over two years in Jiroft, south of Iran, incorporating the following treatments: 1. Control: No intervention. 2. Optimal Management: This included timely irrigation, fertilization (chemical and organic amendments based on soil and leaf tests), and gardening practices (pruning, fruit thinning, and weed removal). 3. Optimal Management + Potassium Silicate: This treatment received optimal management plus potassium silicate fertilizer applied through irrigation water three times at a rate of 30 L ha-1 (as determined by soil test). 4. Optimal Management + Shading: This treatment consisted of optimal management with shading (integrated or individual) at approximately 25% during the hot season, along with plant mulch. 5. Optimal Management + Biocontrol & Fungicides/Nematicides: This treatment combined optimal management with Mycorrhizal and Trichoderma fungi, along with fungicides and nematicides. 6. Optimal Management + Calcium Nitrate Injection: Trees received calcium nitrate injection (30%) directly into the trunk twice a year. 7. Optimal Management + Calcium Nitrate Fertilizer & Foliar Spray: This treatment involved optimal management with calcium nitrate fertilizer applied three times (500 grams per tree, one-month intervals) through irrigation water supplemented by foliar sprays containing calcium chelate and micronutrients (zinc, manganese, iron, and copper) applied three times. Then, leaf samples (both 5–6-month-old leaves and new leaves) and fruits were collected and transported to the laboratory for analysis. This analysis included measurements of number of new leaves, leaf area (average surface area per tree leaf), yield, fruit length and diameter, and the concentration of specific macro- and microelements in the leaves. Results and Discussion The results revealed an inverse relationship between the average number of new leaves per tree and the severity of decay. Treatment-4 displayed a 1.5-fold increase in new leaves compared to the control (treatment-1). Additionally, the number of final shoots (spring and summer regrowth) was 191 in the treatment-4 and 76 in the control treatment. In the treatment-4, the mean leaf area was 41.8 cm2, compared to 29.4 cm2 in the control treatment, demonstrating an increase of 42.20%. Statistical comparisons of other responses also indicated a significant increase in treatment-4 compared to the others. Treatment-4 also exhibited the greatest improvements in fruit size. Fruit diameter and length increased by 35.5% and 33.9%, respectively, compared to the control. Treatment-4 resulted in the largest average leaf area (41.8 cm²) compared to the control (29.4 cm²). Fruit yield followed a similar trend, the lowest fruit yield (22.9 kg/tree) being observed in the control treatment. Conversely, treatment-4 (optimal irrigation management with shading and mulch) achieved the highest fruit yield (50.2 kg/tree), representing a significant increase of 119.2%, 45.9%, 52.5%, 2,100.0%, 95.3%, and 77.4% compared to control, treatment-2, treatment-3, treatment-5, treatment-6, and treatment-7, respectively. Treatment-4 also demonstrated the highest concentrations of zinc, manganese, and iron in the fruits. These elements increased by 1.50, 1.52, and 1.65 times, respectively, compared to the control. The results overwhelmingly favored treatment-4 compared to the control and other treatments. This superiority likely stems from the combined effects of shade mesh and mulch, which are unique to treatment-4. Shade mesh not only provides shade but also reduces radiation intensity, ultimately minimizing heat stress, sunburn, and water loss through evaporation and transpiration from the tree's foliage. Beneficial effects of Treatment-4 go beyond shade and mulch by ensuring optimal plant nutrition based on soil tests, addressing a crucial factor in citrus health. Inadequate nutrition can contribute to tree decline. By providing the necessary macro and micronutrients and adjusting environmental conditions like temperature and humidity, particularly around the roots, we can minimize disruptions in nutrient uptake and promote overall tree health. Conclusions Given the warm climatic conditions of Jiroft at Kerman's southern region, citrus decline arises from a combination of biotic and abiotic stresses. Consequently, solutions targeting either biotic or abiotic constraints are unlikely to provide a sustainable solution to the citrus decline question. An integrated approach, incorporating optimal irrigation and combined nutrient management, was found to be more effective. Therefore, implementing optimal irrigation and combined nutrition management, using plant mulch in the shaded area of the trees, and employing netting as a shade was proven to be a suitable solution to the citrus decline in the Jiroft at southern region of Kerman province, Iran. [ABSTRACT FROM AUTHOR]

This investigation presents results on the improvement of the corrosion-protective effect of consecutive sealing treatments of anodized Al 1050 (AlAnod). The treatments were performed in cerium-containing and mixed NaH2PO4 + Ca(NO3)2 solutions. The changes of the surface morphology, structure and chemical composition, chemical state of the elements, and basic corrosion parameters of the studied systems were investigated by SEM, EDXS, XRD, XPS, and a complex of electrochemical techniques (PDP, EOCP vs. timeplot, chronoamperometric transients, Rp and CR at EOCP, etc.). The results obtained show that the basic components of the obtained sealing conversion layers (before and after exposure to model Cl−-containing corrosion media) are characterized by Ca10(PO4)6(OH)2, AlO(OH), CePO4, and CeAlO3 (after the corrosion tests, they are converted to insoluble Me-PO3 and Me-P4O10). We conclude that the observed decrease in the corrosion rate of Al and the corresponding increase in the polarization resistance are accomplished by the two-step sealing treatment, which fills up the AlAnod pores with insoluble deposits. [ABSTRACT FROM AUTHOR]

The European hazelnut (Corylus avellana L.) is a self-incompatible, wind-pollinated species of significant economic-productive interest, mainly cultivated between the Mediterranean basin and the Black Sea. Hazelnut breeding programs and high cropping in commercial orchards are necessarily linked to the availability of fertile pollen with wide germinability and high viability. The objective was to develop an improved method to determine the germinability of pollen, comparing the results with those found in the literature. Pollen germinability was firstly evaluated on a wild-type accession using boric acid (H3BO3), calcium nitrate (Ca(NO3)2), magnesium sulfate (MgSO4), potassium nitrate (KNO3), casein hydrolysate and different concentrations of sugars, including sucrose (10, 15 and 25%) and two monosaccharides, glucose (15%) and fructose (15%). The optimal composition included 15% sucrose in a semi-solid medium composed of 1% animal gelatin, containing collagen. This formulation was then tested on three cultivars of commercial interest, evaluating the effect of different concentrations of sucrose. The comparison between different in vitro germination methods showed that the hanging drop technique in a semi-solid medium provides a statistically higher germination index compared to the liquid and solid/agarized techniques. This study proposes an easy-to-use medium for the in vitro germination of Corylus avellana L. pollen. [ABSTRACT FROM AUTHOR]

This study aimed to comprehensively investigate the properties of a binder based on high-calcium fly ash and silica fume with a complex additive consisting of calcium nitrate and magnesium chloride. The strength characteristics, the characteristics of the hydration process, and the phase composition of the hydration products of the binder were investigated. Silica fume was used to suppress the expansion of fly ash during hydration. A complex additive (CA) consisting of Ca(NO3)2 and MgCl2 provided a higher strength of binder than each of these salts separately. When testing a mortar with sand, the CA additive ensured that the strength of the specimens was 43.5% higher than the strength of the mortar with the addition of Ca(NO3)2 and 7.5% higher than the strength of the mortar with the MgCl2 additive. Calcium nitrate greatly accelerated the process of heat release in the first 60 min of binder hydration, and subsequently, conversely, slowed it down. The addition of MgCl2 gave a significantly greater thermal effect than Ca(NO3)2. When the two salts acted together, even a small fraction of magnesium chloride (0.2 of CA) compensated for the retarding effect of calcium nitrate and provided heat release for the binder that was almost as good as that of MgCl2. [ABSTRACT FROM AUTHOR]

The chicken eggshell was applied as an alternative calcium source to produce calcium nitrate fertilizer. 12 g of eggshell waste was used as raw material for extraction into liquid calcium nitrate by a 100 mL of 10%(v/v) nitric acid solution. The liquid calcium nitrate fertilizer was encapsulated through the wet-extrusion process, in which calcium ions from liquid calcium nitrate as crosslinking agents and sodium alginate as an absorbent polymer. 73.57% of nitrate was absorbed by the droplet of 2%(w/v) sodium alginate, forming sphericallike gel structures. The optimal hardening time for bead gel formation was 120 min. The average size of wet bead gels was 4.29 ± 0.34 mm. The bead gels were oven-dried at 45◦C for 1 hour to maintain their shapes. Among other controlled release agents, pectin showed the slowest nitrate release from fertilizer bead gel. The chemical nature of bead gels characterized by FTIR indicated that nitrate was absorbed by alginate polymer incorporated with pectin, binding with the Ca2+ ions.

Calcium nitrate (CN: Ca(NO3)2) has been shown to mitigate alkali–silica reaction (ASR) in concrete. Such ASR mitigation has been suggested to be on account of precipitate (i.e., barrier or passivation layer) formation‐induced dissolution inhibition of reactive/dissolving aggregate surfaces. Herein, we examine the ability of CN to mitigate ASR across two cements (Type I/II and Portland Limestone Cement), for aggregates of varying reactivity, and across different types and dosages of SCMs (supplementary cementitious materials, i.e., amorphous steel slag and Class C and Class F fly ashes). Based on expansion measurements carried out as per ASTM C1260/C1567, it is observed that CN, as a function of dosage, substantively mitigates ASR in mortar formulations across aggregate types. Careful microstructural examinations, dissolution studies, and thermodynamic calculations indicate that CN induces the formation of C–S–H, portlandite (Ca(OH)2), and calcite (CaCO3) precipitate mixtures, which form on aggregate surfaces at the expense of typical ASR gels. Such precipitates create a dissolution barrier and inhibit ASR in both SCM‐free and SCM‐containing formulations. The outcomes indicate that CN is an efficient and cost‐effective ASR mitigation additive (∼$250–$600 per tonne), particularly in a time of dwindling fly ash supplies and unaffordable lithium prices (>∼$12 000 per tonne). [ABSTRACT FROM AUTHOR]

Processed manure products have the potential to substitute chemical fertilizers and the use of these products may increase resource efficiency in the food system and decrease emissions of ammonia (NH3) and greenhouse gasses (GHG). The yields of maize and grass, as well as emissions, have been determined from a processed manure product: liquid ammonium sulfate from nitrogen stripping animal manure (AS), in comparison to a regular mineral fertilizer, calcium ammonium nitrate (CAN), in a greenhouse experiment and a field demonstration using a sandy and a clay soil. NH3 emissions were determined by comparing AS with a dairy manure as a reference. The yield of both crops, their nitrogen nutrient use efficiency (NUE), and nitrous oxide (N2O) emissions were not significantly different, while NH3 emission was lower from AS compared to the dairy manure. As a side-effect, the sulfur (S) contents of the grass in the fields fertilized with AS were much higher than in the non-fertilized control. We conclude that AS, produced here with a pH < 5.5, can be used as an alternative for CAN in Dutch dairy systems, or similar other system, if S leaching losses do not pose a problem for the environment. Meanwhile, care should be taken not to exceed S in feed above toxic levels for ruminants. [ABSTRACT FROM AUTHOR]

Biodegradable scaffolds are needed to repair bone defects. To promote the resorption of scaffolds, a large surface area is required to encourage neo-osteogenesis. Herein, we describe the synthesis and freeze-drying methodologies of ferric-ion (Fe3+) doped Dicalcium Phosphate Dihydrate mineral (DCPD), also known as brushite, which has been known to favour the in situ condition for osteogenesis. In this investigation, the role of chitosan during the synthesis of DCPD was explored to enhance the antimicrobial, scaffold pore distribution, and mechanical properties post freeze-drying. During the synthesis of DCPD, the calcium nitrate solution was hydrolysed with a predetermined stoichiometric concentration of ammonium phosphate. During the hydrolysis reaction, 10 (mol)% iron (Fe3+) nitrate (Fe(NO3)3) was incorporated, and the DCPD minerals were precipitated (Fe3+-DCPD). Chitosan stir-mixed with Fe3+-DCPD minerals was freeze-dried to create scaffolds. The structural, microstructural, and mechanical properties of freeze-dried materials were characterized. [ABSTRACT FROM AUTHOR]

Porous chitosan/hydroxyapatite (Chi-HAp) composite microspheres were prepared in an aqueous solution containing chitosan, calcium nitrate, and ammonium dihydrogen phosphate by using a hydrothermal method at various temperatures. The investigation indicated that temperature significantly impacted the final product's appearance. Hydroxyapatite (HAp) coupled with dicalcium phosphate dihydrate (DCPD) flakes were obviously found at 65 and 70 °C, while the latter gradually disappeared at higher temperatures. Conversely, synthesis at 90 °C led to smaller particle sizes due to the broken chitosan chains. The microspheres synthesized at 75 °C were selected for further analysis, revealing porous structures with specific surface areas of 36.66 m2/g, pores ranging from 3 to 100 nm, and pore volumes of 0.58 cm3/g. Vancomycin (VCM), an antibiotic, was then absorbed on and released from the microspheres derived at 75 °C, with a drug entrapment efficiency of 20% and a release duration exceeding 20 days. The bacteriostatic activity of the VCM/composite microspheres against Staphylococcus aureus increased with the VCM concentration and immersion time, revealing a stable inhibition zone diameter of approximately 4.3 mm from 24 to 96 h, and this indicated the retained stability and efficacy of the VCM during the encapsulating process. [ABSTRACT FROM AUTHOR]

Fruit cracking and sunburn are two major disorders that can negatively impact pomegranate (Punica granatum L.) production. To address these problems, an experiment was conducted to evaluate the combined effects of silica (0, 100, 300, and 500 ppm) and calcium nitrate (0, 0.75%, and 1.5%) spraying on the fruit of 'Malase-Saveh' pomegranate. The treatments were applied three times during the growing season and a factorial experiment was conducted based on the completely randomized block design. The results indicate that most of the qualitative and quantitative traits were influenced by foliar spraying of these substances. Furthermore, the results demonstrated that foliar application of silica, calcium nitrate, and their interaction significantly affected fruit cracking. The lowest fruit cracking (1.06%) was obtained by spraying 500 ppm silica and 1.5% calcium nitrate, while the highest fruit cracking (21.6%) was recorded from untreated plants. The highest fruit weight (215.4 g) was observed in the treatment 1.5% calcium nitrate. Most of the treatments had a positive effect on fruit weight and increased it compared to the control. Moreover, the treatments improved some qualitative characteristics, such as an increase in fruit acidity and decrease in sunburn disorder. Ultimately, this study concluded that combined spraying of silica with calcium is more effective than individual use and results in the highest fruit yield and quality, as well as the lowest cracking and sunburn disorders. These findings suggest there are synergistic effects between these compounds. [ABSTRACT FROM AUTHOR]

BACKGROUND: Better utilization of rape straw can provide alternative strategies for sustainable ruminant and food production. The research reported here investigated changes in the carbohydrate composition of rape straw as a result of mixed ensiling with whole‐crop corn or inoculated with nitrate, and the consequent effects on ruminal fermentation through in vitro batch culture. The three treatments included: rape straw and corn silage (RSTC), and ensiling treatment of rape straw with whole‐crop corn (RSIC) or with calcium nitrate inoculation (RSICN). RESULTS: Ensiling treatment of rape straw and whole‐crop corn or plus nitrate enriched lactic acid bacteria and lactate. The treatments broke the fiber surface connections of rape straw, leading to higher neutral detergent soluble (NDS) content and lower fiber content. Ensiling treatments led to greater (P < 0.05) dry matter degradation (DMD), molar proportions of propionate and butyrate, relative abundance of the phylum Bacteroidetes and genus Prevotella, and lower (P < 0.05) methane production in terms of g kg−1 DMD, molar proportions of acetate, and lower acetate to propionate ratio than the RSTC treatment. The RSICN treatment led to the lowest (P < 0.05) hydrogen concentration and methane production among the three treatments. CONCLUSION: Ensiling treatments of rape straw and whole‐crop corn destroy the micro‐structure of rape straw, promote substrate degradation by enriching the phylum Bacteroidetes and the genus Prevotella, and decrease methane production by favoring propionate and butyrate production. Nitrate inoculation in the ensiling treatment of rape straw and whole‐crop corn further decreases methane production without influencing substrate degradation by providing an additional hydrogen sink. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Copyright of International Journal of Engineering Transactions B: Applications is the property of International Journal of Engineering (IJE) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In situ capping and biochemical oxidation are two of the most commonly used methods for internal phosphorus (P) control, but there are few studies on the combined use of these two methods. In this study, two lanthanum (La)-based materials, La-modified bentonite (LMB) and the La-modified attapulgite and chitosan composite (LMA&C), were combined with calcium nitrate (CN) to investigate the effect on sediment P control. Results showed that SRP removal rates by LMB+CN and LMA&C+CN were much higher than that by LMB, LMA&C and CN alone. LMB+CN and LMA&C+CN decreased DGT-labile P flux both in overlying water and surface 65 mm sediment, while LMB and LMA&C had an effect only on overlying water and surface 10~40 mm sediment, and CN was effective only on sediments. LMB and LMA&C transformed NH4Cl-P, BD-P, NaOH-SRP and NaOH-NRP in surface 20 mm sediment to HCl-P and Residual-P on day 60. CN transformed NaOH-SRP and NaOH-NRP to BD-P, resulting in the increase in NH4Cl-P. LMB+CN and LMA&C+CN sequestered P in the surface 20 mm mainly as HCl-P and Residual-P, and mainly as BD-P in −20~−60 mm. Results indicate that the combination of capping by La-based material and oxidation by CN is a promising method for sediment P control. [ABSTRACT FROM AUTHOR]

Nitrate accumulation is a common problem in most leafy vegetables and it happens when the amount of nitrate absorption exceeds the amount consumed by the plant. This study was conducted as a factorial experiment in the form of a completely randomized design and in three replications. The first factor included adding nitrate (calcium nitrate) to Hoagland's standard solution at three levels of 0, 10 and 20%, and the second factor was adding different concentrations of molybdenum from sodium molybdate salt at four levels of 0, 0.5, 1.5 and 3 µM. The measured traits included traits of some growth characteristics, total phenol and flavonoids, ascorbic acid, spinach leaf nitrate. According to the obtained results, fresh and dry weight of leaf, dry weight of root and percentage of dry matter increased by increasing calcium nitrate concentration up to 20% and molybdenum application up to 3 µM in nutrient solution. The simultaneous application of molybdenum and nitrogen had no significant effect on total phenolic, total flavonoid and ascorbic acid traits, and the highest amount of these traits was observed in 3 µM molybdenum. The highest amount of leaf nitrate (3247.4 mg kg-1 FW) was observed in the treatment of 20% additional nitrate along with molybdenum. Based on the results, the use of molybdenum in nutrient solution had a reducing effect on nitrate accumulation in spinach leaf, therefore adding 3 µM sodium molybdate to Hoagland nutrient solution in hydroponic system for spinach production is recommended to obtain the maximum amount of antioxidant compounds and the minimum amount of nitrate accumulation. Introduction Plants take nitrogen (N) either as nitrate (NO3-) or ammonium (NH4+) form for various growth and developmental processes; however, NO3- is more important for such processes. For most of the crop plants, the nitrate form is mobile, less toxic, and can be stored in vacuoles. However, Nitrate must be reduced to NH4+ before it can be utilized for the synthesis of amino acids, proteins, and other nitrogenous compounds in plant cells. Nitrate reductase (NR) and nitrite reductase (NiR), the key nitrate assimilatory enzymes, are located in cytosol and chloroplasts and catalyze nitrate reduction to NO2- followed by NO2- to NH4+, respectively, in the leaf tissues. However, NH4+ is directly assimilated to produce different amino acids by the mutual actions of glutamine synthetase (GS) and glutamate synthase (GOGAT) enzymes in a cyclic manner within the plant cells. Nitrate accumulation is a common problem in most leafy vegetables and it happens when the amount of nitrate absorption exceeds the amount consumed by the plant. Molybdenum (Mo) is an essential microelement for higher plants and also a metal component of the Mo-cofactor, (Moco) biosynthesis. Moco binds to Mo-requiring enzymes and optimizes their activities for normal functioning of plant growth and developmental processes. Molybdenum plays a significant role in N metabolism, which includes nitrate reduction, assimilation, and fixation, by regulating the NR and GS enzymes activities and expressions. During symbiotic N fixation, Mo acts as a cofactor for nitrogenase enzymes to catalyze the redox reaction to convert elemental N into ammonium ions. Materials and methods This study was conducted as a factorial experiment in the form of a completely randomized design and in three replications. The first factor included adding nitrate (calcium nitrate) to Hoagland's standard solution at three levels of 0, 10 and 20%, and the second factor was adding different concentrations of molybdenum from sodium molybdate salt at four levels of 0, 0.5, 1.5 and 3 µM. This research was conducted in the research greenhouse of Campus of Agriculture and Natural Resources Razi University. Senator spinach seeds were obtained from Fardin Kasht Alborz Institute. Spinach seeds were disinfected with 1% sodium hypochlorite for 5 minutes and then planted in seedling trays containing cocopeat and perlite with a volume ratio of 1:1. The measured traits included traits of some growth characteristics, total phenol and flavonoids, ascorbic acid, spinach leaf nitrate. Results and discussion According to the obtained results, fresh and dry weight of leaf, dry weight of root and percentage of dry matter increased by increasing calcium nitrate concentration up to 20% and molybdenum application up to 3 µM in nutrient solution. The simultaneous application of molybdenum and nitrogen had no significant effect on total phenolic, total flavonoid and ascorbic acid traits, and the highest amount of these traits was observed in 3 µM molybdenum. The highest amount of leaf nitrate (3247.4 mg kg-1 FW) was observed in the treatment of 20% additional nitrate along with molybdenum. The most important point in this research was the use of molybdenum to control nitrate accumulation, and the use of molybdenum in concentrations of 1.5 and 3 µM was able to reduce the amount of nitrate accumulation in the aerial parts to some extent, thus neutralizing the toxicity of excess nitrate. The use of sodium molybdate can be one of the recommended ways to reduce the accumulation of nitrates and at the same time enrich molybdenum in spinach and increase the nutritional value of this plant. Conclusion Nitrate and ammonium are the major forms of N that plants use for different growth and developmental processes. The present study revealed that Mo fertilizer plays a key role in N metabolism through regulating the activities and expressions of N-assimilating enzymes. In general, the results of this research showed that the increase in molybdenum concentration in hydroponic culture affected the growth and biochemical characteristics of spinach. Based on the results, the use of molybdenum in nutrient solution had a reducing effect on nitrate accumulation in spinach leaf, therefore adding 3 µM sodium molybdate to Hoagland nutrient solution in hydroponic system for spinach production is recommended to obtain the maximum amount of antioxidant compounds and the minimum amount of nitrate accumulation. [ABSTRACT FROM AUTHOR]

Calcium silicate is widely used in endodontics because its bioactivity precedes tissue regeneration. The synthesis of pure compounds is challenging, especially for the C 3 S phase (3CaO·SiO 2) because, despite the use of pure phases to understand the phenomena involved in the fresh and hardened states, its isolated production requires specific conditions. Synthesis by combustion is an alternative method for obtaining improved endodontic cements. This study presents an alternative method for obtaining C3S-based nanostructured cements with the smallest possible amounts of polymorphs and CaO. To obtain the powders, citric acid was used as the fuel, and tetraethylorthosilicate was used as the silica precursor. In addition, two calcium precursors—calcium carbonate and calcium nitrate—were evaluated as oxidizers. Different parameters were investigated, including combustion temperatures (400 and 600 °C), equivalence ratios (χ) (citrate/nitrate) of 3, 5, and 7, type of oxidizer, and heat treatment temperatures (800, 1000, and 1200 °C). The thermal and structural properties, functional groups, and surface area were evaluated. The results indicate that at the combustion temperature of 600 °C, followed by heat treatment at 1000 °C with an equivalence ratio (χ) of 7, it is possible to obtain a nanostructured cement based on the M3 polymorph of C3S with 23.62 nm. The obtained material shows potential for application in endodontics because of its highly reactive and bioactive behavior. [ABSTRACT FROM AUTHOR]

Rising global energy prices have led to increased costs of nitrogen (N) fertilisers for farmers, but N pollution (losses) from agricultural activities can account for over 50% of the nitrogen applied. This study assesses the feasibility of a low-cost and low-tech method of NH3 emission capture from an agricultural point source (chicken manure) using a water column bubbling technique, and its application as a fertiliser to several plant types. Solutions of i) nitric acid (HNO3), ii) calcium nitrate (Ca(NO3)2), iii) a mixture of Ca(NO3)2 and HNO3 and iv) deionised H2O were used to scrub NH3 from air pumped from a storage container containing chicken manure. We conclude that NH3 can be captured from manure using low-tech methods, and that solutions of common fertiliser compounds such as ammonium nitrate and calcium ammonium nitrate can be replicated by binding captured NH3 to solutions of nitrate. Our results suggest that dissolved calcium nitrate is just as effective at scrubbing NH3 from the atmosphere as nitric acid at low concentrations, but could do so at a near neutral pH. For use on common silage grass for livestock feed, all of the captured ammonium solutions significantly increased yields, including the ammonium only solution. However, the aquatic plants (Taxiphyllum Barbieri and Salvinia auriculata) did not respond favourably to a high ratio of NH4+ in solution, and in the case of Salvinia auriculata, the plant was significantly damaged by the ammonium only solution. In conclusion, we highlight that the capture and utilisation of NH3 emissions from point sources is possible using very basic apparatus and that if used correctly, this captured nitrogen can be stored and applied to crops in a variety of forms which could reduce reliance and cost of mineral fertiliser use. [ABSTRACT FROM AUTHOR]

Introduction Increasing the shelf life of oranges after harvesting while maintaining its quality is very important. In addition, preventing waste production and increase the shelf life of this fruit along with maintaining its quality is very important. Citrus fruits in Iran have the highest production of tree products with the production of more than 4 million tons, in the country. Mazandaran province (North of Iran), contains about 50% of orange orchards of Iran, which first ranks in orange production and the cultivated area of this product in the country. Plant nutrition is very important and the use of potassium nitrate, potassium phosphide and calcium nitrate can increase the quantitative and qualitative yield of oranges. The use of wax coating increased the shelf life of oranges in the warehouse, on the other hand, it improved their appearance quality. Material and Methods This two year research (2019-2021) was carried out as factorial based on randomized complete block design with three replications in Mazandaran province, Iran, on orange fruits cv. Thomson Novel. Experimental factors were consisted of four levels of spraying ( 1. control, 2. calcium nitrate foliar spraying (2 mg.l-1 ), 3. potassium nitrate foliar spraying (3 mg.l-1 ), and 4. potassium phosphide foliar spraying (3 mg.l-1 ), and 9 storage coating levels (control, Nylon, Deco wax (based on petroleum polyethylene), Xeda wax (with natural carnauba gum base), Poshan Emulsion Wax (with paraffin base), Deco wax+ Rural TS fungicide (2 mg.l-1 ), wax remover + Rural TS fungicide (2 mg.l-1 ), Poshan emulsion wax + Rural TS fungicide (2 mg.l-1 ), and nylon + Rural TS fungicide (2 mg.l-1 )). Results and Discussion The results showed that the nutritional treatments as well as the coating treatments increased the yield and quality of oranges. The highest fruit weight in 45 days and 90 days after storage was seen in the interaction of Rural TS fungicide + nylon + potassium nitrate which was the same statistic group with interaction of Rural TS fungicide treatments + nylon + potassium phosphide, interaction of Xeda wax + potassium nitrate, interaction of Xeda wax + potassium phosphide and also interaction of nylon + potassium phosphide. Rural TS fungicide + nylon as well as Xeda wax increased the traits studied in this research and also improved the quantitative and qualitative yield of oranges compared to other treatments. Therefore, it is recommended to apply potassium phosphide and potassium nitrate treatments along with nylon and Xeda wax. In addition, the application of rural TS 2 fungicide in thousand decreased the diseases and the percentage of decay along with the wax coating treatments compared to the control. The increase of fruit yield and quality can be attributed to the effect of potassium on the entry of carbohydrates or the synthesis of plant regulators in young fruits. Fruit coatings with wax can effectively maintain the quality of these perishable materials after harvesting and increase their useful life. In another research on Valencia oranges, using different commercial wax coatings, it was observed that the coating Wax-containing helped preserve the appearance of fruits compared to other coatings. Conclusion The application of coatings treatments by caused to reducing the amount of decay and diseases, and kept the consumer's acceptance of orange fruits in storage for a longer period of time and increased the appearance quality of oranges in storage conditions, but among the applied treatments, rural fungicide treatment TS 2 ppm + Xeda wax increased the traits studied in this research and also improved the quantitative and qualitative yield of oranges compared to other treatments. Therefore, it is recommended to apply potassium phosphide and potassium nitrate treatments along with Xeda wax. [ABSTRACT FROM AUTHOR]

As an important economic plant, Lycopersicon esculentum (Mill.) faces salinity stress from germination to all growth stages. The aim of this study is to ride salt-induced agriculture difficulties of tomato by applying different chemical seed priming: ascorbic acid (ASA), potassium nitrate (KNO3) and calcium nitrate (CaNO3) during two time periods which are 24 and 48 hours. In the current case, the seeds were pre-treated with previously mentioned chemicals for varying periods of time before germination in a salt solution (100 mM NaCl). The treatments were replicated three times. For no primed seeds, salt treatment decreased germination parameters as well as seedling growth parameters (fresh weight, epicotyl and root length and chlorophyll content). Different chemical seed priming alleviated the salt harmful effect on germination and growth parameters. In saline conditions, the priming agents, had more significant effect in comparison with normal conditions. Significantly, the treatment including CaNO3-48-h priming, had high efficacy in promoting germination and plant growth and is associated with reduced levels of leaf proline and malondialdehyde (MDA) content. [ABSTRACT FROM AUTHOR]

The post-harvest management of oranges is critical in Iran, given their importance as an agricultural commodity and a significant source of income for farmers. The study aimed to evaluate the effects of nutritional treatments and storage coatings on the yield and quality of Thomson Novel oranges in post-harvest conditions. A two-year factorial experiment was conducted in Sari, Mazandaran, Iran, to evaluate the effects of four nutritional treatments and nine storage coatings on the quality parameters of Thomson Novel oranges during post-harvest storage. The quality traits were monitored at 45-day intervals over the course of the study. Based on the results of ANOVA, both the individual effects of nutritional treatments and storage coatings were found to be statistically significant for all measured parameters, including fruit texture firmness, fruit peel thickness, vitamin C, titratable acidity, fruit sugar, fruit pH, and fresh weight. However, the interaction effects of nutritional treatments and storage coatings were only significant for fresh weight. The study found that the foliar application of potassium had a positive effect on post-harvest orange quality, while nylon and Xeda wax were the most effective storage coatings for improving various fruit quality parameters. These findings highlight the importance of using appropriate nutritional treatments and storage coatings to enhance the quality and prolong the shelf life of oranges during storage. [ABSTRACT FROM AUTHOR]

A field experiment was conducted to investigate the effect of calcium nitrate and magnesium sulfate on the growth and tuber yield in potato (Solanum tuberosum L). Experiment was carried out in split-plot design comprising of nine calcium nitrate and magnesium sulfate treatments i.e. T1- Ca(NO3)2 @0.5%, T2- Ca(NO3)2 @ 1%, T3- Ca(NO3)2 @ 2%, T4- MgSO4 @ 0.5%, T5- MgSO4 @ 1%, T6- MgSO4 @ 2%, T7- Ca(NO3)2 @ 1% + MgSO4 @ 1%, T8- Ca(NO3)2 @ 2% + MgSO4 @ 2%, T9- Control on two potato varieties i.e. Kufri Jyoti and Kufri Chandramukhi. Data collected on different parameters were analyzed using CPCS1 software. Among all the calcium nitrate and magnesium sulfate treatments, application of Ca(NO3)2 @ 2% + MgSO4 @ 2% was found to be the best for most of the parameters studied and between the varieties Kufri Jyoti was found highly significant for the different parameters under study. Hence it can be concluded that commercial cultivation of potato in the central region of Punjab can be successfully supplemented with application of Ca (NO3)2 + MgSO4 and variety Kufri Jyoti. [ABSTRACT FROM AUTHOR]

This study aimed to comprehensively investigate the properties of a binder based on high-calcium fly ash and silica fume with a complex additive consisting of calcium nitrate and magnesium chloride. The strength characteristics, the characteristics of the hydration process, and the phase composition of the hydration products of the binder were investigated. Silica fume was used to suppress the expansion of fly ash during hydration. A complex additive (CA) consisting of Ca(NO3)2 and MgCl2 provided a higher strength of binder than each of these salts separately. When testing a mortar with sand, the CA additive ensured that the strength of the specimens was 43.5% higher than the strength of the mortar with the addition of Ca(NO3)2 and 7.5% higher than the strength of the mortar with the MgCl2 additive. Calcium nitrate greatly accelerated the process of heat release in the first 60 min of binder hydration, and subsequently, conversely, slowed it down. The addition of MgCl2 gave a significantly greater thermal effect than Ca(NO3)2. When the two salts acted together, even a small fraction of magnesium chloride (0.2 of CA) compensated for the retarding effect of calcium nitrate and provided heat release for the binder that was almost as good as that of MgCl2.

In this work, radioactivity levels and distributions of natural radionuclides in selected fertilizer samples from Tiruvannamalai locality, Tamil Nadu, India were investigated. Various types of chemical fertilizer samples such as calcium nitrate (CN), Urea (U), Sulphur (S), Complex Fertilizer (CF) and Spic Surabi (SS) were collected from the manufacturers and suppliers of Tiruvannamalai locality, Tamil Nadu, India. Activity concentration of natural radionuclides in different fertilizer samples were measured by gamma counting system. Hazard parameters have been calculated for different studied samples. The following parameters were studied: Radium Equivalent Activity (Raeq), Absorbed dose rate (DR), Annual Effective Dose Rate (AEDR), Gamma Index (Iγ), External Hazard Index (Hex), Activity utilisation index (AUI), and Cancer risk (CR). The mean activity concentrations of uranium, thorium and potassium were 188.56, 27.06 and 579.0 Bq.kg−1 respectively. Obtained activity concentrations as well as hazard parameters were compared with world recommended values. Results shown that hazard parameters for studied samples were less than the international recommended values except AUI and CR. [ABSTRACT FROM AUTHOR]

Chilo partellus is a serious pest of agricultural crops. The present investigation was carried out to characterize the gut α-amylase from C. partellus and to explore its inhibition kinetics with various α-amylase inhibitors. α-amylase eluted at ve/vo of 1.38–1.48 on sephadex G-100 column chromatography with 15.58 folds purification. It had a single isoform of 65 KDa with an optimum pH of 8.0. It was thermally stable up to 50 °C and showed the highest activity with starch. A critical analysis of Lineweaver–Burk plot showed that the Michaelis constant, Km, of α-amylase for starch was 0.32 mg/ml while Vmax was observed to be 1.47 nmoles of reducing sugars formed/min/ml of enzyme. Among the various chemicals studied, citric acid, salicylic acid, oxalic acid, zinc chloride and calcium nitrate were found to be the potent inhibitors of α-amylase activity. Through a concerted study of the primary and secondary plots of Lineweaver–Burk, fractional velocity and combination plots, it was revealed that citric acid, salicylic acid, oxalic acid, zinc chloride and calcium nitrate caused complete inhibition of α-amylase activity by mixed- non-competitive-uncompetitive mode. [ABSTRACT FROM AUTHOR]

Effects of Calcium Ammonium Nitrate (CAN) and Stabilized Urea (SU) fertilizers were compared for herbage yield and composition and silage composition of perennial ryegrass (Lolium perenne L.) swards over a two‐year study. The aim of this experiment was to establish the likely impacts of farmers transitioning to using SU fertilizers in order to reduce the nitrogenous emissions associated with silage production as the agriculture industry moves to address the challenges of climate change. Experimental plots of 7.5 m2 area were established in a randomized block experiment comprising 4 replicates of 18 treatments in a 3 × 6 factorial design (4 × 3 × 6 = 72 plots) for each of 3 silage harvest periods in 2018, and repeated in 2019. Herbage samples and yield measurements were collected weekly for weeks 2–7 post fertilizer application, and herbage harvested after seven weeks regrowth was ensiled and silage was analysed after 100 days. There were no significance differences overall between responses of CAN and SU fertilized plots in terms of grass dry matter (DM) yield and quality parameters (acid detergent fibre (ADF), ash, buffering capacity (BC), metabolisable Energy (ME), nitrate (NO32−), nitrogen (N), or water soluble carbohydrate (WSC) or silage quality parameters (DM, volatile corrected organic dry matter (VCODM), ammonia nitrogen as a fraction of total nitrogen (NH3‐N/ Total N), pH, crude protein (CP), lactic acid (LA), acetic acid (AA), propionic acid (PA), butyric acid (BA), ethanol, propanol, ADF, ash, WSC or dry matter digestibility (DMD). Numerous significant differences between week and between cut were identified for grass quality, silage quality and grass ensilability parameters, and in the grass DM yields recorded. However, in many instances there was no associated treatment effect identified. There were no significant interactions between CAN and SU treatments and either cut, or week for nitrate concentration or yield. Variance of nitrate concentration was highest at the third cut and indicates a reduction in the nitrogen use efficiency of the 3rd cut silage harvest, potentially demonstrating a need to reduce fertilizer application recommendations for late‐season silage harvests. Overall, the results of this study support the hypothesis that replacing the currently favoured CAN fertilizer products with SU will not impact production of grass silage in Northern Ireland, meaning SU can be confidently adopted by farmers as a mitigation strategy to reduce farm nitrogenous emissions without reducing levels of sward productivity. This study recorded average annual grass silage DM yields of 15.5 and 16.1 t DM/ha from the CAN and SU fertilizer treatments respectively, which were not significantly different. In addition, the yield gain response to the application of each fertilizer type were not significantly different at 21.51 and 23.24 kg of DM produced for every kg of N applied as SU or CAN respectively, relative to control plots receiving 0 nitrogen. [ABSTRACT FROM AUTHOR]

Continuous cropping can lead to an excessive accumulation of nitrate in facility-cultured soil. Excessive accumulation of nitrate gradually becomes the main reason for crop failure in vegetables and endangers human health. Therefore, the exploration of effective measures to decrease abundant nitrate accumulation in Chinese flowering cabbage is indispensable. In this study, a kind of plant growth regulator, fulvic acid (FA), was used to study its positive effect on alleviating the growth inhibition induced by excessive Ca(NO3)2 in Chinese flowering cabbage. Meanwhile, we conducted hydroponic cultivation and measured the growth indices, photosynthetic and oxidation-reduction characteristics of Chinese flowering cabbage with different treatments. After determining the optimal treatment concentration, we mainly designed four treatment groups, including Con, FA, Ca(NO3)2 and FA + Ca(NO3)2 cotreatment, to explore the regulatory mechanism by which FA alleviates Ca(NO3)2 stress in Chinese flowering cabbage. The results showed that FA can effectively alleviate the inhibitory effect of excessive Ca(NO3)2 on the growth of Chinese flowering cabbage seedlings. FA recovered the photosynthetic capacity of seedlings under Ca(NO3)2 stress. In addition, FA depressed the accumulation of O2·−, H2O2, malondialdehyde (MDA) and relative electrical conductivity, but increased the activity of antioxidant enzymes, including SOD, POD, CAT and APX, which finally enhanced the stress resistance of Chinese flowering cabbage to Ca(NO3)2. The expression of nitrate-related transporters, BcNRT1.1 and BcNRT1.5, was depressed by FA, which inhibited redundant nitrate absorption and restricted more nitrate from being stored in the roots instead of being transferred to the shoot. Ultimately, nitrate accumulation in the edible part was reduced in Chinese flowering cabbage seedlings. In general, exogenous FA may alleviate nitrate stress by improving oxidation resistance, photosynthetic capacity and redundant Ca(NO3)2 accumulation in Chinese flowering cabbage. [ABSTRACT FROM AUTHOR]

Nitrogen (N) fertilization effectiveness in onion depends on N source, as well as on soil type and management system. The aim of the study is to investigate the effect of N sources and doses applied as top-dressing on bulb yield, leaf N contents and on the postharvest conservation of onion bulbs grown under no-tillage (NTS) and conventional tillage (CTS) systems. Three experiments were carried out: two in Lebon Régis County-SC, under NTS; and one in Caçador County-SC, under CTS. The herein tested N sources comprised urea, ammonium nitrate, calcium nitrate and ammonium sulfate, in combination to N doses applied as top-dressing (70, 140, 210, 280 and 350 kg N ha-1) in addition to the control, without N. The N sources did not affect yield parameters, leaf N content and post-harvest onion losses. The maximum technical efficiency in bulb yield was observed at N doses of 195.8 and 258.4 kg ha-1 in the no-tillage system (NTS) and at 270.7 kg N ha-1 in the CTS. The NTS enabled maximum yield at N dose 47% lower than the officially recommended one. Maximum relative commercial yield was associated with 31.1 g kg-1 of leaf N. [ABSTRACT FROM AUTHOR]

A field experiment was conducted to investigate the effect of calcium nitrate and magnesium sulfate on the growth and tuber yield in potato (Solanum tuberosum L). Experiment was carried out in split-plot design comprising of nine calcium nitrate and magnesium sulfate treatments i.e.T1- Ca(NO3)2 @ 0.5%, T2- Ca(NO3)2 @ 1%, T3- Ca(NO3)2 @ 2%, T4- MgSO4 @ 0.5%, T5- MgSO4 @ 1%, T6- MgSO4 @ 2%, T7- Ca(NO3)2 @ 1% + MgSO4 @ 1%, T8- Ca(NO3)2 @ 2% + MgSO4 @ 2%, T9- Control on two potato varieties i.e. Kufri Jyoti and Kufri Chandramukhi. Data collected on different parameters were analyzed using CPCS1 software. Among all the calcium nitrate and magnesium sulfate treatments, application of Ca(NO3)2 @ 2% + MgSO4 @ 2% was found to be the best for most of the parameters studied and between the varieties Kufri Jyoti was found highly significant for the different parameters under study. Hence it can be concluded that commercial cultivation of potato in the central region of Punjab can be successfully supplemented with application of Ca (NO3)2 + MgSO4 and variety Kufri Jyoti.

The objective of this work to study the influence of foliar application of boric acid (0, 125, 250 and 500 ppm) and calcium nitrate (0, 1%, 2% and 3%) on fruit set and yield as well as fruit quality of Seewy date palm cultivar growing in El Dakhla Oasis, New Valley governorate during two successive seasons (2021, 2022), palms were treated with different rates of boric acid (zero, 125, 250 and 500 ppm) and sprayed with calcium nitrate at rates (zero, 1%, 2% and 4%). Results showed that all studied treatments had significant effect on fruit set and total yield compared with the control treatment in both experimental seasons. Spraying boric acid at 500 ppm with calcium nitrate at 2% in both seasons gave the best results of fruit set and total yield. In addition, this combination gave the highest T.S.S content, total sugars and reducing sugars; in contrast, the lowest values of total acidity in two studied seasons.

Fly ash from Berezovskaya Thermal Power Plant, containing a lot of CaO, in combination with silica fume does not expand and exhibits the properties of a binder. However, the strength of this binder is low. The addition of Ca(NO3)2 significantly increases the strength of the binder. The work aims to study the effect of Ca(NO3)2 additive on the strength, heat of hydration, and phase composition of hydration products of the binder based on high-calcium fly ash and silica fume. The results of X-ray diffraction and Differential Thermal Analysis show that the main phases formed during the hydration of binder with the calcium nitrate additive in various dosages are lime, calcium hydroxide, ettringite, CSH(II) type silicates and calcium aluminosilicates, corresponding to such minerals as gismondine, yugavaralite, goosecreekite. When hardening in water, the residual amount of lime after 7 days is sharply reduced. An increase in the dosage of Ca(NO3)2 from 1.5 to 11.8 % leads to a decrease in the CaO content by almost 2 times. With an increase in the dosage of calcium nitrate, the content of portlandite noticeably decreases, and a significant increase in the amount of calcium hydroaluminosilicates, especially the composition of CAS2H4, is observed. A study of the heat release process showed that calcium nitrate greatly accelerates the process in the first 60 minutes of hydration. However, then the composition with the addition of Ca(NO3)2 is inferior in the rate of heat release to binder without the additive. When testing a mortar with polyfractional sand, the addition of Ca(NO3)2 more than doubled the compressive strength of the mortar.

ABSTRACT Nitrogen (N) fertilization effectiveness in onion depends on N source, as well as on soil type and management system. The aim of the study is to investigate the effect of N sources and doses applied as top-dressing on bulb yield, leaf N contents and on the postharvest conservation of onion bulbs grown under no-tillage (NTS) and conventional tillage (CTS) systems. Three experiments were carried out: two in Lebon Régis County-SC, under NTS; and one in Caçador County-SC, under CTS. The herein tested N sources comprised urea, ammonium nitrate, calcium nitrate and ammonium sulfate, in combination to N doses applied as top-dressing (70, 140, 210, 280 and 350 kg N ha-1) in addition to the control, without N. The N sources did not affect yield parameters, leaf N content and post-harvest onion losses. The maximum technical efficiency in bulb yield was observed at N doses of 195.8 and 258.4 kg ha-1 in the no-tillage system (NTS) and at 270.7 kg N ha-1 in the CTS. The NTS enabled maximum yield at N dose 47% lower than the officially recommended one. Maximum relative commercial yield was associated with 31.1 g kg-1 of leaf N.

This research paper presents the results and analysis obtained via the evaluation of calcium nitrate as an effective stabilizer to alter the thermal properties as well as improve the compressive strength of frost-susceptible soil. Two silty sand soils with 15% and 25% fines content that are categorized as high to very high frost-susceptible soil were considered and treated with varying dosages of calcium nitrate contents (1.5%, 3.0%, 4.5%, 10%, 15%, and 20% of soil weight). The thermal properties, including thermal hysteresis, thermal conductivity, specific heat capacity, freezing point depression, and phase changes (freezing and thawing point) were determined for the untreated and treated soil samples. It was observed that the treated samples' thermal properties were significantly altered with respect to untreated soils. The effects of fines content on the thermal properties were evaluated using a stabilizer–silt content ratio. The threshold calcium nitrate dosage content was established, and a new correlation was established to evaluate the freezing point and thawing point. The unconfined compressive strength (UCS) tests performed on the treated soils depicted a significant increase in compressive strength compared to the untreated soil. Further analysis showed that fines content has a significant role to play on the compressive strength of treated silty sand. A qualitative analysis performed on images from a scanning electron microscope (SEM) showed that increasing the calcium nitrate dosage reduced the pore size and improved the cementation between the sand and silt grains. [ABSTRACT FROM AUTHOR]

Nitrate addition is reported as a cost-effective method for remediating black-odorous water, which is mainly induced by the deficiency of electron acceptor. However, excessive release of nitrate and lack of long-term effectiveness significantly limited the application of direct nitrate dosing technology. Herein, for remediating black-odorous water, we constructed a nitrate sustained-release ecological concrete (ecoN-concrete), in which calcium nitrate (Ca(NO3)2) was dosed into concrete block to regulate the release of nitrate. The results showed that chemical oxygen demand (COD), turbidity, ammonia, phosphate, and sulfate were significantly removed in an ecoN-concrete-contained reactor fed with black-odorous water, and its removal efficiency was largely dependent on Ca(NO3)2 dosage. Meanwhile, the released nitrate was lower than 25% of its total dosage and nitrite was lower than 1.5 mg/L during 14 days remediation. After three recycles, the removal efficiencies of COD and turbidity by using ecoN-concrete were still more than 85%, indicating an excellent nitrate sustained-release performance of ecoN-concrete, which can be applied for preventing water re-blackening and re-stinking. Further investigation illustrated that the ecoN-concrete (1) decreased the abundance of Desulfovibrio, Desulfomonile, and Desulforhabdus in the phylum of Desulfobacterota to alleviate the odorous gas production and (2) significantly increased the abundance of Bacillus and Thermomonas, which utilized the released-nitrate for consuming organic matters and ammonia. This study provided an artful Ca(NO3)2 dosing strategy and long-term effective method for black-odorous water remediation. [ABSTRACT FROM AUTHOR]

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In this study, polyvinylidene fluoride (PVDF) fibers doped with hydrated calcium nitrate were prepared using electrospinning. The samples were analyzed using scanning electron microscopy (SEM), X-ray diffraction (XRD), optical spectroscopy, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR), Raman, and photoluminescence (PL) spectroscopy. The results are complementary and confirm the presence of chemical hydrogen bonding between the polymer and the dopant. Additionally, there was a significant increase in the proportion of the electroactive polar beta phase from 72 to 86%. It was shown that hydrogen bonds acted as a transport pathway for electron capture by the conjugated salt, leading to more than a three-fold quenching of photoluminescence. Furthermore, the optical bandgap of the composite material narrowed to the range of visible light energies. For the first time, it the addition of the salt reduced the energy of the PVDF exciton by a factor of 17.3, initiating photocatalytic activity. The calcium nitrate-doped PVDF exhibited high photocatalytic activity in the degradation of methylene blue (MB) under both UV and visible light (89 and 44%, respectively). The reaction rate increased by a factor of 2.4 under UV and 3.3 under visible light during piezophotocatalysis. The catalysis experiments proved the efficiency of the membrane design and mechanisms of catalysis are suggested. This study offers insight into the nature of chemical bonds in piezopolymer composites and potential opportunities for their use. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to investigate the effects of growth-promoting chemical regulations on internode elongation and its sugar accumulation in sugarcane internode, and to analyze the relationship between cane yield and important agronomic traits. The results will provide reference for the directional chemical regulation of sugarcane agronomic characters and the improvement of cultivation techniques of high yield and high sugar content. [Method] In the study, sugarcane excellent cultivar GT58 was used as planting material in a 2-year field plot trials, water spraying on leaves was used as control group ( CK), and different growth-promoting chemical regulators were used as chemical regulators treated groups. They were respectively calcium nitrate(A),boric acid(B),potassium dihydrogen phosphate(C),compound sodium nitrophenolate(D),gibberellin(E),composed of gibberellin and compound sodium nitrophenolate(F),composed of gibberellin,calcium nitrate, boric acid, potassium dihydrogen phosphate, compound sodium nitrophenolate ( G) . The plant height, intemode elongation rate, sugar content and yield of sugarcane were measured at different growth stages after chemical regulator was applied in intemode elongation period. [ Result] The intemode elongation rate treated with different growth-promoting chemical regulators was 1. 22 - 1. 67 cm/ d. The average internode number was 21. 30 -23. 90,and the average intemode length was 11. 41 -12. 41 cm, and those of E and G treatments containing gibberellin were extremely significantly higher than CK ( P < 0. 01, the same as below) . The plant height with gibberellin E and G treatments were significantly higher than CK ( P < 0. 05, the same as below), the stem diameter was significantly lower than CK, the effective stem number was lower than CK but the difference was not significant( P > 0. 05), and the final yield was higher than CK. In the process of sugar accumulation in sugarcane intemode, the treatment groups containing gibberellin-containing regulator( E, F and G treatments) could promote the accumulation of sugar in the middle and upper intemode of cane stem, and promote the sugar content in different parts of intemode to reach the level of process maturity, and reduce the reducing sugar content to the level below CK. Correlation analysis showed that there was a weak negative correlation between stem diameter and yield in treated group, and their Pearson's coefficient was only - 0. 082. There was extremely significant positive correlation between millable canes number and yield,as well as plant height. [ Conclusion]The growth-promoting chemical regulators promoted the formation of sugarcane plant height by regulating intemode elongation, thus affecting the correlation between yield, plant height, millable canes number and stem diameter, and realized the improvement of sugarcane yield formation at last. Among them, containing gibberellin chemical regulators could promote intemode elongation and accelerate the rapid accumulation of sugar from the middle intemode to the upper intemode in sugarcane, which had great potential for increasing yield and its sugar content in sugarcane. These can be used in the directional chemical control of agronomic traits and the improvement of high-yield and high-sugar cultivation technology in sugarcane. [ABSTRACT FROM AUTHOR]

As an environmentally friendly cemental material, supersulfate cement has the defect of low strength in early stage. In order to explore a way to improve its early strength, the effect of calcium nitrate content on the strength was studied, and the mechanism was analyzed by methods of ion concentration, XRD, pore structure and SEM. The results show that the strength of supersulfate cement is significantly improved with calcium nitrate content from 0 to 2.0% at 3 d age, and the strength is still greatly improved later. The optimum content of calcium nitrate is 1.5% at 3 d age, and it is 1.0% at the age of 7 d, 28 d and 90 d. It is the main enhancement mechanism that calcium nitrate improves the hydration rate of cement, reduces the alkalinity of hydration system, promotes the transformation of ettringite from acicular to columnar, and reduces the porosity of cement harden paste. Adding an appropriate amount of calcium nitrate is an effective way to improve the strength of supersulfate cement. [ABSTRACT FROM AUTHOR]

In this study, a high-performance concrete based on calcium oxide-activated materials (HPC-CAM) was developed and studied. Calcium chloride and calcium nitrate additives were used to improve the microstructure of such concrete. In addition, different fibers including steel, recycled PET, basalt, glass, and modified synthetic macro fibers were used to overcome the brittleness of the HPC-CAM geopolymer matrix. Compressive, flexural, water absorption, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) tests were performed to evaluate the overall characteristics of the specimens thus prepared. The results showed that adding calcium chloride and calcium nitrate increased the compressive strength of HPC-CAM by 69% and 29%, respectively. All samples containing calcium chloride had flexural strengths that were 20% higher than those with calcium nitrate. HPC-CAM samples reinforced with recycled PET fibers and modified synthetic macro-fibers recorded flexural toughness values that were 8- and 6-fold greater than those for steel fibers. The highest calcium silicate hydrate gel (C–S–H) and Si–O-T (T = Si or Al) peaks were obtained in HPC-CAM containing calcium chloride.

Calcium is one of the most limiting factors for the growth and reproduction of peanut, which ultimately affects pod and seed yields. A two-year field experiment was carried out to assess the impact of five calcium applications, including nano-calcium and conventional forms, on growth, leaf nutrient content, yield traits, and quality parameters of three diverse peanut cultivars (Ismailia-1, Giza-5, and Giza-6). The applied calcium applications were calcium sulfate, which is recommended for commercial peanut cultivation and commonly referred to as gypsum (coded as Ca-1), calcium nitrate (Ca-2), nano-calcium nitrate (Ca-3), 50% calcium nitrate + 50% nano-calcium (Ca-4), and 50% calcium sulfate + 50% nano-calcium (Ca-5). Calcium sulfate (gypsum, Ca-1) was soil-supplied during the seedbed preparation as recommended, while the other calcium applications (Ca-2, Ca-3, Ca-4, and Ca-5) were exogenously sprayed three times at 30, 45, and 60 days after sowing. The soil of the experimental site was alkaline, with a high pH of 8.6. The results revealed significant differences among cultivars, calcium applications, and their interactions. The soil-supplied gypsum Ca-1 displayed lower agronomic performance on all recorded growth, leaf nutrient content, yield traits, and quality parameters. On the other hand, the foliar-supplied calcium, particularly Ca-4 and Ca-5, displayed superior effects compared to the other simple calcium forms. Ca-4 and Ca-5 produced significantly higher seed yield (3.58 and 3.38 t/ha) than the simple recommended form (Ca-1, 2.34 t/ha). This could be due to the difficulty of calcium uptake from soil-supplied calcium under high soil pH compared to the exogenously sprayed nano-calcium form. Moreover, the superior performance of Ca-4 and Ca-5 could be caused by the mixture of fertilizers from the synergistic effect of calcium and nitrate or sulfate. Furthermore, the effect of nitrate was applied in nano form in the Ca4 and Ca-5 treatments, which contributed to improving nutrient uptake efficiency and plant growth compared to the other treatments. The peanut cultivar Giza-6 showed superiority for most measured traits over the other two cultivars. The interaction effect between the assessed cultivars and calcium applications was significant for various traits. The cultivar Giza-6 showed a significant advantage for most measured traits with the mixture of 50% calcium nitrate + 50% nano-calcium (Ca-4). Conclusively, the results pointed out the advantage of the exogenously sprayed nano-calcium form combined with calcium nitrate or calcium sulfate for promoting growth, leaf nutrient content, yield, and quality traits of peanut, particularly with high-yielding cultivars under sandy soil with high pH. [ABSTRACT FROM AUTHOR]

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In situ capping and biochemical oxidation are two of the most commonly used methods for internal phosphorus (P) control, but there are few studies on the combined use of these two methods. In this study, two lanthanum (La)-based materials, La-modified bentonite (LMB) and the La-modified attapulgite and chitosan composite (LMA&C), were combined with calcium nitrate (CN) to investigate the effect on sediment P control. Results showed that SRP removal rates by LMB+CN and LMA&C+CN were much higher than that by LMB, LMA&C and CN alone. LMB+CN and LMA&C+CN decreased DGT-labile P flux both in overlying water and surface 65 mm sediment, while LMB and LMA&C had an effect only on overlying water and surface 10~40 mm sediment, and CN was effective only on sediments. LMB and LMA&C transformed NH4Cl-P, BD-P, NaOH-SRP and NaOH-NRP in surface 20 mm sediment to HCl-P and Residual-P on day 60. CN transformed NaOH-SRP and NaOH-NRP to BD-P, resulting in the increase in NH4Cl-P. LMB+CN and LMA&C+CN sequestered P in the surface 20 mm mainly as HCl-P and Residual-P, and mainly as BD-P in −20~−60 mm. Results indicate that the combination of capping by La-based material and oxidation by CN is a promising method for sediment P control.

Soil ammonium toxicity can decrease plant growth, and many crop species have low resistance to ammonium, including canola, an economically important crop. Different genotypes may differ in their resistance to ammonium toxicity, and therefore determining if there are genotypes that exhibit variation in their ability to tolerate soil ammonium is a research priority. Here, we evaluate how soil ammonium impacts canola root and shoot growth and characterise differences among canola genotypes in regard to resistance to ammonium toxicity. In the first experiment, eight ammonium chloride treatments and five calcium nitrate treatments were tested for their impact on the canola genotype Crusher TT, where high application (60 mg N/kg soil) significantly decreased the dry weight of canola shoots and roots and acidified the soil from pHCaCl2 5.9 to 5.6. In the second experiment, 30 canola genotypes were screened at selected concentrations of NH4+-N, using nitrate as the control. There was wide variation among genotypes in sensitivity to high NH4+-N application. Genotypes G16, G26, and G29 had greater shoot dry weights and the highest shoot N concentration of all genotypes, and G16, G26, and G28 had root dry weight up to 35% higher at high soil NH4+-N compared with other genotypes. In contrast, genotypes G3, G13, and G30 showed the largest reduction in shoot weight, and genotypes G13, G23, and G30 showed the largest reduction in root weight at high NH4+-N application. Residual NH4+-N/kg soil in soil was higher for sensitive than resistant genotypes, suggesting lower NH4+-N use in the former. These results reveal the potential for selecting canola genotypes that are resistant to high NH4+-N concentrations in soil. [ABSTRACT FROM AUTHOR]

An experiment was carried out to study the effect of pre-harvest management in carnation (Dianthus caryophyllus L) cv Malaga to improve the flower yield, quality and vase life by the foliar application of biostimulants. In the preharvest treatments, Panchagavya @ 2 per cent + Manchurian mushroom tea 4 per cent with RDF (NPK 19:19:19 @ 8 g, calcium nitrate 1.5 g, potassium nitrate 1.0 g, monopotassium phosphate 1.5 g, borax 0.5 g, magnesium sulphate 2.5 g) proved superior in respect of flower yield parameters viz lesser days taken to bud opening (157.8), maximum flower diameter (6.54 cm), highest stem length (84.90 cm), maximum number of petals per flower (73.83), maximum number of flowers per plant (11.53), maximum number of flowers per m2 (415.20) and longest duration of flowering (80.87 days). This treatment also resulted in lowest disease incidence (2.42%). [ABSTRACT FROM AUTHOR]

Salinity is one of the critical environmental factors that decreases the water availability and induces nutritional imbalance in crops. In order to study the effect of calcium nitrate [(Ca(NO3)2] in the nutrient solution under salinity conditions, an experiment was designed with different salinity (0, 50, and 100 mM) and Ca(NO3)2 (2, 3, and 4 mM) levels on Cucurbita pepo (zucchini). Based on the results, an increase in the salinity from 0 to 100 mM caused a decrease in the leaf potassium and calcium concentration, whereas the iron, magnesium and zinc concentrations increased. The most effective Ca(NO3)2 level in increasing the nutritional quality and yield of zucchini was 3 and 4 mM. Salinity at 50 and 100 mM significantly increased the leaf sodium concentration and leaf area as well as the leaf number per plant, while the application of both Ca(NO3)2 levels modulated the harmful effects of salinity. The amount of malondialdehyde (MDA), proline and hydrogen peroxide (H2O2) as well as the catalase (CAT) activity increased under the severe salinity conditions, whereas the application of 4 mM Ca(NO3)2 had the potential of removing the negative effects of severe salinity. The catalase activity increased along with the increase in the Ca(NO3)2 concentration, which was independent from the salinity level. However, the amount of proline, MDA and H2O2 decreased in plants fed with 3 and 4 mM Ca(NO3)2 compared to the control in the presence of salinity. These findings suggest that both the 3 and 4 mM concentrations of Ca(NO3)2 under 50 mM salinity could be used to improve the zucchini performance by maintaining the ion homeostasis and inducing the antioxidant defence system. [ABSTRACT FROM AUTHOR]

The article presents the results of research on the processing of such wastes of titanium-magnesium production as sludge from sludge dumps and fine dump dusts from the electric smelting of ilmenite concentrates. The results of nitric acid leaching of sludge with the transfer of calcium into solution and the production of calcium nitrate are given. Titanium-containing cake after nitric acid leaching of sludge and electric smelting dust cannot be returned to the technological process due to its high silica content, so the silicon impurity was removed from their composition. Silicon removal was performed by fluoroammonium processing with sublimation of hexafluorosilicate compounds. An amorphous silicon dioxide product was obtained, after ammonia hydrolysis of silicon-containing sublimations and appropriate treatment of the sediment. The residue from the sublimation of silicon fluorides consists mainly of titanium-containing phases and can be suitable for return for electrofusion after ammonia treatment.

Mango (Mangifera indica L.) is a highly perishable fruit with a short shelf life at ambient conditions, which may lead to post-harvest losses approximated to be 40-45%. This reduces returns to farmers significantly. The problem is compounded by the fact that most farmers do not have access to cold storage facilities. Nutrient management has been shown to affect postharvest characteristics of fruits. Calcium particularly plays a critical role in cell membrane integrity, tissue firmness and delays lipid catabolism. Previous studies have indicated a deficiency of calcium in some mango growing regions in Kenya. A field study was carried out to determine the effect of varied calcium formulations applied at various stages of growth on mango fruits post-harvest quality and organoleptic acceptability. The study was carried out in Embu County Eastern Kenya during seasons 2017/2018 and 2018/2019 using "Van Dyke" cultivar, aged approximately 10 years. The experiment was set up in a randomized complete block design with a split-split plot arrangement, three trees per replication, replicated thrice. Three calcium formulations: calcium chloride, calcium nitrate and Easygro™ were applied at rates of 0%,1.0%, 1.5% and 2.0% at fruit set, 30 days after fruit set and 30 days to physiological maturity. The calcium sources formed the main plots, the timing of application formed the subplots while the rates of application formed the sub-sub plots. Total soluble solids (TSS) and percentage titratable acidity (TA) were assessed at harvest and after 12 days of storage under ambient conditions (25±2°C, 70±5% relative humidity) using standard procedures. Selected fruits' sensory attributes were also evaluated after storage using a hedonic scale. Analysis of data was done using the 14th Edition of the Genstat software. The differences among the means of the treatments were compared using Fisher's Protected LSD test at 5% probability level. Fruits sprayed with calcium chloride, 2.0% at fruit set had higher TSS (6.8 ° brix and 6.3° brix) (10.47 ° brix and 9.10 ° brix), TA (1.29% and 1.27%), (0.77% and 0.675%) than other treatments at maturity and after storage in both seasons, respectively. Calcium chloride at 2.0% level of application led to a superior peel color appearance contrary to calcium nitrate and Easygro™ also applied at 2.0%, which led to an inferior peel color appearance and an inferior taste of fruits. Therefore, calcium nitrate and easy gro should be sprayed at concentration of 1.5% for good taste and peel colour appearance. [ABSTRACT FROM AUTHOR]