Nitrogen Absorption Research Articles

Newly Established Blueberry Plants: The Role of Inorganic Nitrogen Forms in Nitrogen and Calcium Absorption

Efficient nitrogen (N) management is crucial for maximizing the growth of young blueberry plants (Vaccinium corymbosum). This study evaluates the effects of the N fertilization form (ammonium, NH4+; nitrate, or NO3−) and application timing on the blueberries’ establishment, N and Ca absorption, and N distribution. The experiment was conducted in the southern hemisphere, in Chile, from October 2023 to January 2024. Six-month-old blueberry cv. Blue Ribbon plants were cultivated in pots. NH4+ and NO3− were used as full or split-dose applications using the 15N isotopic dilution technique. Plant leaves, stems, root growth, and biomass, as well as their N and Ca contents, were measured. Our results showed that 90 days after nitrogen application, blueberry plants obtained the lowest biomass in their leaves, stems, and roots when NO3− was applied in T1 or T1T2. The same pattern was observed for N and Ca contents, hence for N recovery. During the first period (T1) of application, heavy rain (100 mm) was registered over the course of a few days and caused leaching. Therefore, applying nitrate to young blueberry plants cultivated in areas with spring rainfall and low temperatures would not be recommended because the leaching losses and lower growth conditions, such as low temperatures and high precipitation, led to reduced transpiration, resulting in lower calcium and nitrogen contents. These confirm that N fertilization management (form and timing) can ensure a better establishment for young blueberry plants, optimizing their growth and sustainable production by minimizing nitrogen losses.

A synthetic bacterial community engineered from Miscanthus floridulus roots enhances ammonia nitrogen removal in ionic rare earth mine tailings

Ammonium sulfate, as the primary leaching agent, has caused significant nitrogen pollution in rare earth elements (REEs) mining areas. Phytoremediation is a promising remediation method, relying on the synergistic relationships between plants and their root-associated microbiome. Nevertheless, harnessing the microbiome to accelerate nitrogen transformation and absorption by plants is challenging. Here, we investigated the composition, activities and culturable fraction of the root bacterial microbiome of the pioneer plant Miscanthus floridulus grown in a REEs tailing soil containing a high ammonia nitrogen (AN) concentration at 344.35 mg kg−1. Based on this, we constructed a simplified synthetic microbial community (SynCom) derived from the roots of M. floridulus, possessing nitrification and denitrification capabilities, to help REEs mine plants efficiently convert pollutant AN into nutrients, thereby enhancing plant growth and AN removal. This SynCom, consisting of 10 bacterial strains, included species of the genera Burkholderia (5) Paraburkholderia (1), Curtobacterium (1), Leifsonia (1) and Sinomonas (2). As a result, this SynCom alone achieved a significant reduction of 24.8% in AN content in tailing soil. When the SynCom inoculated with plants, the reduction in AN was even more significant (32.6%), surpassing the reduction achieved solely by plants (25.5%). Moreover, live SynCom inoculation significantly increased shoot and root biomass by 39.8% and 49.7%, respectively, compared to dead SynCom inoculation. These results indicate that the reduction in AN can be attributed to the SynCom's nitrification and denitrification capabilities, as well as its ability to enhance plant nitrogen absorption by stimulating their growth. Notably, seven nitrifying and denitrifying strains of the SynCom are particularly enriched, suggesting that plant roots selectively recruit nitrogen cycle-related bacteria to accelerate nitrogen transformation and absorption. These results provide a practical solution for harnessing the synergistic relationships between plants and their root microbiome in environmental remediation efforts.

Comparison study on the effect of oxygen, nitrogen and hydrogen absorption on phase transformation and mechanical properties of quenched CP Ti and Ti6Al4V alloy

Comparison study on the effect of oxygen, nitrogen and hydrogen absorption on phase transformation and mechanical properties of quenched CP Ti and Ti6Al4V alloy

Effects of the Application of Organic Fertilizers on the Yield, Quality, and Soil Properties of Open-Field Chinese Cabbage (Brassica rapa spp. pekinensis) in China: A Meta-Analysis

With the development of sustainable agriculture, trials on the benefits of the application of organic fertilizers around the world have been conducted. Herein, we investigated the impact of the pure chemical fertilizers (CFs) combined with organic fertilizers compared with the application of CFs (100% CFs) and no fertilizers (NFs) on soil properties as well as the yield and quality of Chinese cabbage through meta-analysis. Results indicate that: (1) Compared with NFs, the application of organic fertilizers can significantly improve the yield and quality of Chinese cabbage and increase soil nutrients. (2) Compared with CFs, the application of organic fertilizers can increase the fresh weight, number of leaves, transverse diameter, leaf length, and development of Chinese cabbage per plant, with increases of 8.54%, 6.6%, 9.905%, 8.42%, and 10.03%; Meanwhile, organic fertilizers can significantly increase the yield (total amount of above-ground parts produced) and commercial yield (the portion that meets the required quality standards and is intended for sale) of Chinese cabbage to increase the yield and commercial yield by 10.08% and 35.56%, respectively. However, it has no significant impact on the income from growing Chinese cabbage. (3) Compared with CFs, the application of organic fertilizers can significantly increase the content of vitamin C (11.06%), soluble sugar (19.16%), and soluble protein (8.83%) and reduce the content of nitrate and nitrite in Chinese cabbage, with a reduction of up to 19.02% and 20.9%, respectively. The application of organic fertilizers will also have a certain impact on the absorption of heavy metals in Chinese cabbage. (4) Compared with CFs, the application of organic fertilizers can significantly improve soil organic matter, soil carbon sequestration, nitrogen absorption, and potassium absorption, showing increases of 12.73%, 13.19%, 7.91%, and 7.37%, and the application of organic fertilizers reduces soil electrical conductivity and available nitrogen, showing decreases of 36.78% and 38.75%, respectively. (5) The application of organic fertilizers significantly increased the content of soil urease and soil sucrase, increasing by 9.42% and 17.16%, respectively. This study helps inform the application of organic fertilizers in Chinese cabbage production.

OsSTP1 mediates sucrose allocation to regulate rice responses to different nitrogen supply levels

Improving the nitrogen use efficiency is an effective way to increase the yield of rice, and maintaining carbon-nitrogen balance is essential for the normal growth and development of rice. To investigate the impact of the sucrose transporter protein OsSTP1 on nitrogen absorption in rice, in this study, we constructed transgenic lines overexpressing the sucrose transporter gene OsSTP1 (OsSTP1-OE1, OsSTP1-OE2) and mutant transgenic lines (osstp1-1, osstp1-2) from the wild type TB309. Further, we conducted a hydroponic experiment with four nitrogen supply levels of free nitrogen (FN, 0 mg/L), low nitrogen (LN, 10 mg/L), normal nitrogen (NN, 40 mg/L), and high nitrogen (HN, 80 mg/L) to study the responses of each line to different nitrogen supply levels during the seedling stage. The results showed that compared with the wild type and mutant lines in the LN group, the OsSTP1-overexpressing lines exhibited significantly increased biomass, root length, and plant height, decreased soluble sugar content in the leaves, and increased soluble sugar content in the roots. The results indicate that the soluble sugars produced by leaf photosynthesis are transported to the roots through the phloem to promote root growth and nitrogen uptake, thus increasing the aboveground biomass. This study has identified that OsSTP1 can affect the long-distance transport of carbohydrates from source to sink to promote root growth, ultimately influencing rice's absorption and accumulation of nitrogen, improving nitrogen use efficiency and providing reference for reducing nitrogen fertilizer application.

Prokaryotic expression and purification of inorganic nitrogen transporters in wheat

The nitrate transporter (NRT) and ammonium transporter (AMT) are crucial transmembrane proteins involved in the absorption, transport, and distribution of inorganic nitrogen in wheat. Obtaining NRT/AMT and preparing corresponding antibodies are conducive to probing into their tissue localization and comprehending the nitrogen utilization process in wheat. In this study, four genes (TaNPF4.5, TaNPF8.3, TaNRT3.1, TaAMT1.2) with high expression levels were chosen and cloned from 405 genes of the TaNRT/TaNPF family and 23 genes of the TaAMT family identified previously. The transmembrane domains of the four transporters were predicted by HMMER to determine the putative expression segments, followed by prokaryotic expression and purification. Under the induction with 1 mmol/L IPTG at 37 ℃, the non-transmembrane segments of TaNPF4.5, TaNPF8.3, and TaNRT3.1 reached the highest expression levels (as inclusion bodies) after 4 h, while TaAMT1.2 was expressed at the highest level (as a soluble protein) after 3 h. TaNPF4.5, TaNPF8.3, and TaNRT3.1 were purified by a pH gradient. The purity of TaNPF4.5 and TaNPF8.3 reached about 87% and 85% at pH 2.0 and pH 3.0, respectively, both of which were suitable for antibody preparation. However, the purity of TaNRT3.1 did not reach 85%. TaAMT1.2 was purified by an imidazole gradient, reaching the purity of about 95% at 20 mmol/L imidazole, and the antibody was prepared successfully. The expression, purification, and antibody preparation of TaAMT1.2 not only provides insights into the expression, purification, and antibody preparation of membrane proteins including TaNPF4.5 and TaNPF8.3 but also lays a foundation for studying the expression and localization of membrane proteins in wheat.

Optimal Water and Nitrogen Regimes Increased Fruit Yield and Water Use Efficiency by Improving Root Characteristics of Drip-Fertigated Greenhouse Tomato (Solanum lycopersicum L.)

The growth of root system directly affects the absorption and utilization of soil water and nitrogen, and understanding the responses of root characteristics to water and nitrogen regimes is thus crucial for optimizing water and nitrogen management. The root characteristics of each soil layer, i.e., root length, root surface area, and root volume, as well as fruit yield and water use efficiency of greenhouse tomato under drip fertigation in response to different irrigation levels and nitrogen rates were explored in northwest China. There were four irrigation levels, i.e., 50% ETC (W1), 75% ETC (W2), 100% ETC (W3), and 125% ETC (W4), where ETC is the crop evapotranspiration, and four nitrogen rates, i.e., 0 kg ha−1 (N1), 150 kg ha−1 (N2), 250 kg ha−1 (N3), and 350 kg ha−1 (N4). The results showed that reasonable irrigation and nitrogen regimes (W3N3) significantly increased fruit yield by 31.64% and root length, root surface area, and root volume by 45.03%, 61.24%, and 148.21% compare to W3N1, respectively. The promoting effect of increasing irrigation level on root characteristics increased with soil depth and had the greatest increases in root volume by 27.07%, 123.43%, and 211.47% for the 0–10, 10–20, and 20–30 cm soil layers, respectively. In addition, reducing irrigation level significantly increased the percentages of roots in the top soil by 29.71%, 26.77%, and 18.53% for root length, root surface area, and root volume, respectively. The reasonable nitrogen rate (N3) significantly increased fruit yield by 41.11%, water use efficiency by 34.42%, and root length, root surface area, and root volume by 40.42%, 41.44%, and 112.76%, respectively. The over-application of nitrogen (N4) reduced root characteristics of all soil layers, fruit yield, and water use efficiency. The promoting effect of increasing nitrogen rate on root length of each soil layer decreased with soil depth, by 71.01%, 48.96%, and 15.71% for 0–10, 10–20, and 20–30 cm soil layers, respectively. Irrigation level was the main factor dominating the root growth of each soil layer. The correlation analysis showed that fruit yield had significantly positive correlations with root characteristics in all soil layers, while water use efficiency had significantly positive correlations with the percentages of root length and root surface area in the 0–10 cm soil layer. In conclusion, rational water and nitrogen regimes achieved better fruit yield by promoting root growth of greenhouse tomato, and the water use efficiency of greenhouse tomato was improved by increasing the root percentage in the topsoil layer to alleviate the adverse effects under water stress conditions. This study reveals how irrigation volume and nitrogen application can enhance tomato yield and water use efficiency by regulating root characteristics and vertical root distribution, providing support for understanding the response of root systems to changes in soil water and nitrogen conditions.

Thermochemical Corrosion of Furnace Materials in Atmospheres Containing Ammonia

ABSTRACTFurnace components are made from heat‐resistant materials that must withstand the long‐term effects of the atmospheres used during heat treatment. In a nitriding furnace, the atmosphere usually consists of various gaseous media that react not only with the treated parts but also with the furnace equipment. This leads to thermochemical corrosion, even with carefully selected heat‐resistant and stainless steels or nickel‐based alloys. The present research focuses on determining the long‐term effects of ammonia‐containing atmospheres on the metallic furnace materials AISI 309, AISI 314, Alloy 600, and Alloy 601. The materials studied were exposed to numerous nitriding or nitrocarburizing treatments for more than 10 years to investigate the long‐term effects of repeated contact with ammonia‐containing atmospheres. The surface layers of the samples were characterized by several methods to determine the microstructural changes due to nitrogen absorption. A different nitrogen absorption of the metallic furnace materials from the heat treatment atmosphere, depending on the material properties, could be proven by the investigations.

Intercropping of tobacco and maize at seedling stage promotes crop growth through manipulating rhizosphere microenvironment.

Changes in the rhizosphere microbiome and metabolites resulting from crop intercropping can significantly enhance crop growth. While there has been an increasing number of studies on various crop combinations, research on the intercropping of tobacco and maize at seedling stage remains limited. This study is the first to explore rhizosphere effects of intercropping between tobacco and maize seedling stages, we analyzed the nitrogen, phosphorus and potassium nutrients in the soil, and revealed the important effects on soil microbial community composition and metabolite profiles, thereby regulating crop growth and improving soil balance. Compared with mono-cropping, intercropping increased the biomass of the two crops and promoted the nutrient absorption of nitrogen, phosphorus and potassium. Under intercropping conditions, the activities of sucrase, catalase and nitrate reductase in tobacco rhizosphere soil and the content of available potassium, the activities of nitrate reductase and acid phosphatase in maize rhizosphere soil were significantly increasing. Rhizosphere soil bacterial and fungal communities such as Sphingomonas, Massilia, Humicola and Penicillium respond differently to crop planting patterns, and soil dominant microbial communities are regulated by environmental factors such as pH, Organic Matter, Available Potassium, Nitrate Reductase, and Urease Enzyme. Network analysis showed that soil microbial communities were more complex after intercropping, and the reciprocal relationship between bacteria and fungi was enhanced. The difference of metabolites in soil between intercropping and monocropping system was mainly concentrated in galactose metabolism, starch and sucrose metabolism pathway, and the content of carbohydrate metabolites was significantly higher than that of monocropping soil. Key metabolites such as D-Sucrose, D-Fructose-6-Phosphate, D-Glucose-1-Phosphatel significantly influence the composition of dominant microbial communities such as Sphingomonas and Penicillium. This study explained the effects of intercropping between flue-cured tobacco and maize on the content of soil metabolites and soil microbial composition in rhizosphere soil, and deepened the understanding that intercropping system can improve the growth of flue-cured crops seedlings through rhizosphere effects.

Pipe experiment elucidates biochar application depth affects nitrogen leaching under crop present condition

Nitrogen leaching, resulting from the inefficient use of fertilizers, pollutes the environment, such as groundwater. Biochar can be applied to farmlands to mitigate nitrogen leaching. The effect depends on the application depth. However, the effect has not been examined under crop-farming conditions. Evaluating the interactions between biochar application depth and crop growth is indispensable for considering depth in the actual field. To address this, we conducted a pipe experiment with four treatments, no biochar (control), surface (0–5 cm), plow layer (0–30 cm), and subsurface (25–30 cm) applications, and compared the results with no-crop conditions from a previous study. Biochar application depth affected soil NO3−−N and NH4+−N absorption ability and also influenced soil-water stress conditions, affecting crop growth. Surface biochar application improved nitrogen absorption and reduced soil-water stress, improving crop growth. The NO3−−N leaching was reduced to 87.7%. Plow layer application worsened nitrogen absorption and resulted in frequent dry stress in the shallow-soil layer, preventing root growth in this layer. The NO3−−N and NH4+−N leaching increased 106.4% and 264.1%, respectively. The effects of subsurface application were similar to those in the control. Selecting an appropriate application depth can simultaneously improve crop growth and reduce nitrogen leaching.

Effect of replacing Tifton 85 hay with Moringa hay (Moringa oleifera L.) on the nutrient metabolism, metabolic profile, and water balance of sheep.

This study aimed to evaluate the effect of replacing Tifton 85 hay (TH) with Moringa hay (MH) on the intake, apparent digestibility, ingestive behaviour, rumen parameters, serum attributes, nitrogen balance, water balance, and urinary attributes of sheep. Thus, 5 rams, ½ Dorper + ½ Santa Inês, that were 12 ± 4 months of age with an initial body weight of 32.8 ± 2.6kg were distributed in metabolic cages in a Latin square design. The experiment lasted 85 days and was divided into five 17-day periods. The animals received rations with increasing replacement (0, 100, 200, 300, or 400g/kg of dry matter in the total diet) of TH for MH. The forage: concentrate ratio of the diets was 40:60. Replacing TH with MH reduced (P < 0.05) the intake of organic matter, crude protein, neutral detergent fibre (NDFap), and total digestible nutrients by sheep. The apparent digestibility of NDFap and the feeding and rumination efficiencies of NDFap were reduced (P < 0.05) when MH replaced TH in the animals' diet. This replacement did not influence (P > 0.05) serum urea, total protein, creatinine, or aspartate aminotransferase in sheep. Replacing TH with MH decreased water intake and excretion (P < 0.05). In addition, nitrogen excretion via urine, urinary creatinine, and nitrogen absorption decreased (P < 0.05) when TH was replaced with MH. However, there was an increase in the sheep's nitrogen retention and urine pH. We recommend replacing 30% TH with MH in the diet of lambs because it does not compromise nutrient metabolism.

Effect of Delayed Irrigation at the Jointing Stage on Nitrogen, Silicon Nutrition and Grain Yield of Winter Wheat in the North China Plain.

Water scarcity is a key limitation to winter wheat production in the North China Plain, and it is essential to explore the optimal timing of spring irrigation to optimize N and Si uptake as well as to safeguard yields. The aim of this study was to systematically study the effect mechanism of nitrogen and silicon absorption of winter wheat on yield under spring irrigation and to provide a scientific basis for optimizing irrigation strategy during the growth period of winter wheat. In this experiment, the winter wheat 'Heng 4399' was used. Five irrigation periods, i.e., 0 d (CK), 5 d (AJ5), 10 d (AJ10), 15 d (AJ15), and 20 d (AJ20) after the jointing stage, were set up to evaluate the nitrogen (N) and silicon (Si) absorption and grain yield (GY). The results showed that delayed irrigation for 5-10 days at the jointing stage had increased the GY. With the delay of irrigation time, the N/Si content of the entire plant at the maturity period increased first and then decreased; among that, the maximum N contents appeared in AJ15 and AJ5 in 2015 and 2020, respectively, while the Si concentrations appeared in AJ5 and AJ10 in sequence. Compared with AJ15 and AJ20, the N accumulation of vegetative organs in AJ5 increased by 3.05~23.13% at the flowering stage, 14.12~40.12% after the flowering stage, and a 1.76~6.45% increase in the N distribution rate at maturity stage. A correlation analysis revealed that the GY was significantly and positively correlated with the N/Si accumulation at the anthesis and N translocation after the anthesis stage. In conclusion, under limited irrigation conditions, delaying watering for 5 to 10 days at the jointing stage can improve the nitrogen and silicon absorption and nutrient status of wheat plants and increase wheat yield.

Mechanism of microbial action of the inoculated nitrogen-fixing bacterium for growth promotion and yield enhancement in rice (Oryza sativa L.)

The use of nitrogen-fixing bacteria in agriculture is increasingly recognized as a sustainable method to boost crop yields, reduce chemical fertilizer use, and improve soil health. However, the microbial mechanisms by which inoculation with nitrogen-fixing bacteria enhance rice production remain unclear. In this study, rice seedlings were inoculated with the nitrogen-fixing bacterium R3 (Herbaspirillum) at the rhizosphere during the seedling stage in a pot experiment using paddy soil. We investigated the effects of such inoculation on nutrient content in the rhizosphere soil, plant growth, and the nitrogen-fixing microbial communities within the rhizosphere and endorhizosphere. The findings showed that inoculation with the R3 strain considerably increased the amounts of nitrate nitrogen, ammonium nitrogen, and available phosphorus in the rhizosphere by 14.77%, 27.83%, and 22.67%, respectively, in comparison to the control (CK). Additionally, the theoretical yield of rice was enhanced by 8.81% due to this inoculation, primarily through a 10.24% increase in the effective number of rice panicles and a 4.14% increase in the seed setting rate. Further analysis revealed that the structure of the native nitrogen-fixing microbial communities within the rhizosphere and endorhizosphere were altered by inoculation with the R3 strain, significantly increasing the α-diversity of the communities. The relative abundance of key nitrogen-fixing genera such as Ralstonia, Azotobacter, Geobacter, Streptomyces, and Pseudomonas were increased, enhancing the quantity and community stability of the nitrogen-fixing community. Consequently, the nitrogen-fixing capacity and sustained activity of the microbial community in the rhizosphere soil were strengthened. Additionally, the expression levels of the nitrogen absorption and transport-related genes OsNRT1 and OsPTR9 in rice roots were upregulated by inoculation with the R3 strain, potentially contributing to the increased rice yield. Our study has revealed the potential microbial mechanisms through which inoculation with nitrogen-fixing bacteria enhances rice yield. This finding provides a scientific basis for subsequent agricultural practices and is of critical importance for increasing rice production and enhancing the ecosystem services of rice fields.

Responses of Water and Fertilizer Utilization Efficiency and Yield of Cotton to Foliar Biostimulant under Irrigation with Magnetic–Electric-Activated Water

The foliar application of biostimulants at specific concentrations under magnetic–electric water irrigation has a positive effect on water and fertilizer use efficiency and yield of cotton, which is crucial for green and sustainable agricultural development. As a new type of fertilizer, biostimulants have demonstrated remarkable effects in improving crop yield and quality by enhancing nutrient uptake, promoting plant growth, and increasing resilience to environmental stress. In this study, the effects of magnetic–electric-activated water irrigation and foliar biostimulant application on cotton growth and yield were investigated, with the aim of understanding the underlying mechanisms. The field experiment included various irrigation treatments (brackish water, fresh water, magnetic–electric brackish water, and magnetic–electric fresh water) and biostimulant concentrations (1600, 1200, 800, 400 times dilution, and no spraying). SEM analysis indicated that under magnetoelectric water irrigation, the foliar application of biostimulants enhances physiological growth of cotton, improving the water and nutrient uptake efficiency, and thereby increasing yield. Specifically, the effective boll number and single boll weight under magnetic–electric fresh water irrigation with an 800 times biostimulant concentration increased by 21.84–48.78% and 5.50–18.91%, respectively, compared to the no-spraying treatment. The seed cotton yield rose by 16.61–38.63%, water-use efficiency improved by 24.35%, the harvest index reached 0.33, and nitrogen absorption increased by 76.21%. Thus, integrating magnetic–electric water irrigation with foliar biostimulants offers a theoretical and technical foundation for advancing green, high-quality agriculture and sustainable production.

Distribusi Nitrogen pada Budidaya Ikan Koi (Cyprinus Rubrosfuscus) dalam Sistem Vertiqua Menggunakan Biofikal Filter Atas

Vertiqua is an innovation in vertical cultivation on limited land and water. Vertiqua continues to be developed to be effective in cultivating fish. This research aims to examine the effectiveness of nitrogen distribution in vertiqua using biofical top filters. The analysis used is quantitative analysis by calculating and testing the data that has been collected. Total nitrogen feed input, total nitrogen wasted, and percentage of nitrogen absorption were calculated using existing formulas. Comparative testing using the T – test on the Mini Tab application was carried out to test the effectiveness of nitrogen absorption. The research results showed that nitrogen absorption in the vertiqua using the top biofical filter was effective, ranging from 198,12 – 200,89 mg/l. Nitrogen absorption in the vertiqua without using a biofical top filter ranges from 42,75 – 43,35 mg/l. The distribution value of effective nitrogen absorption in vertiqua using the top biofical filter is shown by a P value &lt;0,05. Vertiqua with a biofical top filter is also able to reduce nitrogen levels so that fish survival is good.

Absorption of liquid nitrogen into porous materials used in the cryogenic cold chain

A dry-shipper is a dewar used to transport frozen biomedical samples at cryogenic temperature. The inside of the dewar is lined with a porous material that absorbs and prevents the spillage of liquid nitrogen during transportation. In these porous materials vapor might be trapped during filling of the dry-shipper leading to a lower transport and storage time. The conditions under which the vapor is formed and the relationship with the porous material properties is not well understood. We studied the impact of the pore size distribution on the vapor retention in the porous materials by comparing liquid nitrogen absorption in aluminosilicate material with relatively large pores (1-100 μm) and calciumsilicate with small pores (∼0.45 μm). Both samples were immersed into saturated liquid nitrogen and a comparison of the absorbed liquid volume fraction with the porosity showed the calciumsilicate sample was completely filled with liquid, whereas the aluminosilicate contained a vapor fraction of about twenty percent. As a further investigation, we studied the absorption characteristics in subcooled liquid nitrogen. In this case, both materials absorbed liquid equivalent to their respective void fraction indicating no vapor pockets in the material. From these results, we propose a design property window for potential new porous materials for use in the dry-shippers.

The effects of polypropylene microplastics on the removal of nitrogen and phosphorus from water by Acorus calamus, Iris tectorum and functional microorganisms

Polypropylene microplastics (PP-MPs), an emerging pollutant, adversely affect the ability of aquatic plants to restore water bodies, thereby compromising the functionality and integrity of wetland ecosystems. This study examines the effects of microplastic stress on the nitrogen and phosphorus removal capacities of Acorus calamus and Iris tectorum, as well as on functional microorganisms within the aquatic system. The findings indicate that under PP-MP stress, the nitrogen and phosphorus absorption capabilities of both plants were diminished. Additionally, there was a significant reduction in the metabolic enzyme activities related to nitrogen and phosphorus in the plants, alongside a notable decrease in leaf nitrogen content. PP-MPs hinder the nutrient uptake of plants, affecting their growth and indirectly reducing their ability to utilize nitrogen and phosphorus. Specifically, in the 10 mg L−1 treatment group, A. calamus and I. tectorum showed reductions in leaf nitrogen content by 23.1% and 31.0%, respectively, and by 14.8% and 27.7% in the 200 mg L−1 treatment group. Furthermore, I. tectorum had higher leaf nitrogen levels than A. calamus. Using fluorescent tagging, the distribution of PP-MPs was traced in the roots, stems, and leaves of the plants, revealing significant growth impairment in both species. This included a considerable decline in photosynthetic pigment synthesis, enhanced oxidative stress responses, and increased lipid peroxidation in cell membranes. PP-MP exposure also significantly reduced the abundance of functional microorganisms involved in denitrification and phosphorus removal at the genus level in aquatic systems. Ecological function predictions revealed a notable decrease in nitrogen cycling functions such as nitrogen respiration and nitrite denitrification among water microorganisms in both treatment groups, with a higher ecological risk potential in the A. calamus treatment group. This study provides new insights into the potential stress mechanisms of PP-MPs on aquatic plants involved in water body remediation and their impacts on wetland ecosystems.

Root symbiotic fungi improve nitrogen transfer and morpho-physiological performance in Chenopodium quinoa.

Root-associated fungal endophytes may facilitate nitrogen (N) absorption in plants, leading to benefits in photosynthesis and growth. Here, we investigated whether endophytic insect pathogenic fungi (EIPF) are capable of transferring soil N to the crop species Chenopodium quinoa. We evaluated nutrient uptake, carbon allocation, and morpho-physiological performance in C. quinoa in symbiosis with two different EIPF (Beauveria and Metarhizium) under contrasting soil N supply. A controlled experiment was conducted using two plant groups: (1) plants subjected to low N level (5 mM urea) and (2) plants subjected to high N level (15 mM urea). Plants from each group were then inoculated with different EIPF strains, either Beauveria (EIPF1+), Metarhizium (EIPF2+) or without fungus (EIPF-). Differences in N and C content, amino acids, proteins, soluble sugars, starch, glutamine synthetase, glutamate dehydrogenase, and physiological (photosynthesis, stomatal conductance, transpiration), and morphological performance between plant groups under each treatment were examined. We found that both Beauveria and Metarhizium translocated N from the soil to the roots of C. quinoa, with positive effects on photosynthesis and plant growth. These effects, however, were differentially affected by fungal strain as well as by N level. Additionally, an improvement in root C and sugar content was observed in presence of EIPF, suggesting translocation of carbohydrates from leaves to roots. Whereas both strains were equally effective in N transfer to roots, Beauveria seemed to exert less demand in C. quinoa for photosynthesis-derived carbohydrates compared to Metarhizium. Our study revealed positive effects of EIPF on N transfer and morpho-physiological performance in crops, highlighting the potential of these fungi as an alternative to chemical fertilizers in agriculture systems.

Continuum absorption in pure N[formula omitted] gas and in its mixture with Ar

The N2−N2and N2−Arcontinuum absorption spectra are calculated using the classical trajectory-based simulation (CTS). The spectra obtained are validated by new measurements in the subTHz spectral range along with the previously reported data in the far infrared. A novelty of our approach consists in the use of the CTS method to simulate both the fundamental nitrogen absorption band and the rototranslational band in N2−Ar, i.e., we succeeded to step beyond the conventionally used approximation of the only rigid monomers. This extension of the theory made it possible, in particular, to demonstrate the validity of the rigid monomer assumption for the CTS simulation of the rototranslational N2−Arband. The broadband spectra within 77–354 GHz were measured using the resonator spectrometer at temperatures of 278–333 K and pressures of 900–1600 Torr. A minor underestimation of the calculated absorption by 3.7% and 5% is shown for the N2−N2and N2−Arsystem, respectively. On the basis of the obtained data, a new analytical model is developed for the N2−N2absorption in the subTHz range, which can be used in radiation propagation codes for the Earth, Titan, or other nitrogen-rich atmospheres. The advantage of the model proposed here over those previously published is discussed.

Impact of fertilization depth on sunflower yield and nitrogen utilization: a perspective on soil nutrient and root system compatibility.

The depth of fertilizer application significantly influences soil nitrate concentration (SNC), sunflower root length density (RLD), sunflower nitrogen uptake (SNU), and yield. However, current studies cannot precisely capture subtle nutrient variations between soil layers and their complex relationships with root growth. They also struggle to assess the impact of different fertilizer application depths on sunflower root development and distribution as well as their response to the spatial and temporal distribution of nutrients. The Agricultural Production Systems sIMulator (APSIM) model was employed to explore the spatial and temporal patterns of nitrogen distribution in the soil at three controlled-release fertilizer (CRF) placement depths: 5, 15, and 25 cm. This study investigated the characteristics of the root system regarding nitrogen absorption and utilization and analyzed their correlation with sunflower yield formation. Furthermore, this study introduced the modified Jaccard index (considering the compatibility between soil nitrate and root length density) to analyze soil-root interactions, providing a deeper insight into how changes in CRF placement depth affect crop growth and nitrogen uptake efficiency. The results indicated that a fertilization depth of 15 cm improved the modified Jaccard index by 6.60% and 7.34% compared to 5 cm and 25 cm depths, respectively, maximizing sunflower yield (an increase of 9.44%) and nitrogen absorption rate (an increase of 5.40%). This depth promoted a greater Root Length Density (RLD), with an increases of 11.95% and 16.42% compared those at 5 cm and 25 cm, respectively, enhancing deeper root growth and improving nitrogen uptake. In contrast, shallow fertilization led to higher nitrate concentrations in the topsoil, whereas deeper fertilization increased the nitrate concentrations in the deeper soil layers. These results provide valuable insights for precision agriculture and sustainable soil management, highlighting the importance of optimizing root nitrogen absorption through tailored fertilization strategies to enhance crop production efficiency and minimize environmental impact.