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Macroalgae growth depends on biologically available nitrogen, such as ammonium and nitrate, making nitrogen the most common growth-limiting factor for macroalgae. However, the role of surface microorganisms in promoting nitrogen transformation and improving nitrogen utilization by macroalgae remains unclear. In this study, 228 bacterial strains were isolated from the surface of U. fasciata , and high-throughput sequencing revealed significant shifts in the composition of surface bacterial communities under different nitrogen concentrations. Key bacterial families such as Rhodobacteraceae and Flavobacteriaceae were identified as essential for nitrogen cycling. Network analysis indicated that Rhodobacteraceae and Flavobacteriaceae were central nodes in microbial interactions. A synthetic microbial community (SynCom2), comprising four strains, significantly increased the biomass, nitrogen, and phosphorus acquisition of U. fasciata , with soluble sugar, protein, and Chlorophyll a level increasing by 23.9–49.2%. Quantitative reverse transcription polymerase chain reaction (RT-qPCR) analysis revealed that compared to untreated control plants, SynCom2 enhanced the expression of key genes associated with photosynthesis (rbcL , 1.04-fold), lipid biosynthesis (accD , 11.21-fold), and growth hormone precursor pathways (wrkY , 9.54-fold). These findings suggest that SynCom2 promotes U. fasciata growth by improving nutrient acquisition and activating growth-related genes. [ABSTRACT FROM AUTHOR]

The concentration of nitrogen fertilizer is matched with the nutrient requirements in different growth stages of plants, which coordinates their vegetative and reproductive growth. In this study, the influences of nitrogen concentration before and after initiation of flower bud differentiation (first and second stage, respectively) on pepper seedling quality were studied. The chlorophyll a content, sucrose synthase activity, and sucrose phosphate synthase activity of pepper seedlings grown under moderate nitrogen (15 mmol L−1) in the first stage combined with high nitrogen (25.61 mmol L−1) in the second stage were 15.7%, 39.3%, and 34.6% higher than those of the same nitrogen concentration (15 mmol L−1) in the first and second stages treatment, respectively. The regression model also showed that the values of flower bud diameter, shoot fresh weight, root fresh weight, and glutamine synthetase activity of pepper were high under the condition of moderate nitrogen in the first stage and higher nitrogen in the second stage. In addition, the results of comprehensive evaluation showed that moderate nitrogen (15 mmol L−1) in the first stage and high nitrogen (25.61 mmol L−1) in the second stage treatment ranked first, which improved carbon and nitrogen metabolism, increased biomass accumulation, and promoted the flower bud differentiation and flowering of pepper seedlings. [ABSTRACT FROM AUTHOR]

Kale (Brassica oleracea var. Achepala) is a leaf vegetable plants from the Brassica family that has high potential to develop. The use of nutrients in hydroponic cultivation has important role to fulfil the nutrient needs of curly kale plants. The presence of nitrogen is important for kale in growth and crop result. Cultivation with floating raft system needs to focus into the ideal population to get an optimal growth rate. This study aimed to obtain the correct amount of nitrogen concentration and plant population on the growth and yield of curly kale with floating raft hydroponic system. This research conducted in the Green house experimental field of Agriculture Faculty, University of Brawijaya on August 2022 to November 2022. The research using Factorial Randomized Block Design with 2 factors and 3 replication. The first factor is nitrogen concentration of hydroponic nutrients, and the second factor is plant population. The result implies that Nitrogen concentration 2M with 4 plants population given higher EC value. 1,5M nitrogen concentration on 4 population plants and 2M nitrogen concentration on 6 plants population given the higher leaf area. Combination of nitrogen concentration of 1M and 2M and 8 plant population gives higher fresh total weight per container. 2 M nitrogen concentration given higher number of leaves and EC value in the media, but given shorter result the root length of curly kale than nitrogen concentration of 0,5M. 8 plants population gives lower number of leaves and root length than 4 curly kale plants population. [ABSTRACT FROM AUTHOR]

Macroalgae growth depends on biologically available nitrogen, such as ammonium and nitrate, making nitrogen the most common growth-limiting factor for macroalgae. However, the role of surface microorganisms in promoting nitrogen transformation and improving nitrogen utilization by macroalgae remains unclear. In this study, 228 bacterial strains were isolated from the surface of U. fasciata, and high-throughput sequencing revealed significant shifts in the composition of surface bacterial communities under different nitrogen concentrations. Key bacterial families such as Rhodobacteraceae and Flavobacteriaceae were identified as essential for nitrogen cycling. Network analysis indicated that Rhodobacteraceae and Flavobacteriaceae were central nodes in microbial interactions. A synthetic microbial community (SynCom2), comprising four strains, significantly increased the biomass, nitrogen, and phosphorus acquisition of U. fasciata, with soluble sugar, protein, and Chlorophyll a level increasing by 23.9–49.2%. Quantitative reverse transcription polymerase chain reaction (RT-qPCR) analysis revealed that compared to untreated control plants, SynCom2 enhanced the expression of key genes associated with photosynthesis (rbcL, 1.04-fold), lipid biosynthesis (accD, 11.21-fold), and growth hormone precursor pathways (wrkY, 9.54-fold). These findings suggest that SynCom2 promotes U. fasciata growth by improving nutrient acquisition and activating growth-related genes.

Elevated CO2 and warmer temperatures represent the future environmental conditions in the context of global change. A good understanding of plant response to their combined effects is, therefore, critically important for predicting future plant performance. This study investigated the photosynthetic acclimation of Amur linden (Tilia amurensis) seedlings (current year, about 60 cm tall), a shade-tolerant tree species in the temperate broadleaf deciduous forest, to the combination of current CO2 concentration and temperature (CC) and the combination of the predicted future CO2 concentration and temperature (FC). The results show that FC promoted aboveground growth, but reduced photosynthetic capacity (V cmax: maximum rate of RuBP carboxylation and J max: maximum photosynthetic electron transport rate). However, the photosynthetic rate measured under the corresponding growth CO2 concentration was still higher under FC than under CC. FC depressed the photosynthetic limiting transition point (C i-t, A n-t) from Rubisco carboxylation to RuBP regeneration, i.e. A n-t decreased without a change in C i-t. FC did not change leaf N concentration but increased the total leaf N content per tree and photosynthetic nitrogen utilization efficiency. This suggests that N utilization, rather than photosynthetic capacity, may play an important role in the acclimation of the species to future climatic conditions. This study provides new insights into the photosynthetic acclimation of Amur linden and can be used to predict its possible performance under future climatic conditions. [ABSTRACT FROM AUTHOR]

Abstract Background It has been long thought that nitrogen (N), phosphorus (P) concentrations and their ratios (N:P) in metabolically active or functional organs (i.e., leaves) are less responsive to environmental changes. Little attention, however, has been paid to the reproductive organs—seeds, while seeds may maintain their nutrients more stable for the evolutionary fitness of next generation. Methods Here, we conducted a field experiment of N, P addition and drought in an alpine meadow, aiming to compare the difference of leaf and seed nutrients and stoichiometric ratios in response to these resource treatments and their interactions. Four dominant species were selected among grass and forb functional groups, including Elymus nutans, Deschampsia caespitosa, Artemisia roxburghiana and Polygonum viviparum. Results Under natural conditions, leaf N and P concentrations were consistently lower than seed among species. However, leaf nutrients were much more sensitive than seed nutrients to N and P addition. Specifically, N or P addition accordingly increased leaf N or P concentration by 22.20–44.24% and 85.54–93.61%, while only enhanced seed N or P concentration by 5.15–17.20% and 15.17–32.72%, respectively. Leaf N or P concentration was significantly reduced by P or N addition, but seed nutrients remained unchanged. In contrast, drought did not change both organ nutrients. Similarly, nutrient addition and drought had synergistic interactions on leaf nutrients, but not on seed nutrients. Conclusions This study highlights that seed nutrient concentrations could be more stable than metabolically active leaf organ when facing multidimensional resource changes. This complements the traditional view on the ‘Stable Leaf Nutrient Hypothesis’ with the involvement of reproductive organs. The less responsiveness of seed nutrients suggests the adaptive strategy to ensure the success of next generations and long-term plant demographic stability.

1. Root respiration is essential for nutrient acquisition. The respiration rate of absorptive roots theoretically relates to the economics of carbon‐nutrient exchange, but its empirical role remains largely unexplored in the trait space defining nutrient uptake strategies. 2. Here, we measured the respiration rates of the distal, non‐woody, absorptive roots of 252 woody and herbaceous species from subtropical and temperate climate zones, including both arbuscular mycorrhizal and ectomycorrhizal fungal hosts. 3. We found a consistent and positive correlation between root respiration rate and specific root length (root length per dry weight), irrespective of growth form, mycorrhizal type and climate zone. Root respiration rate was also positively, but less strongly and less frequently correlated with root nitrogen concentration. Root morphology strongly explained the fast‐slow gradient of root respiration in the root economics space. 4. By quantifying the ratio of arbuscular mycorrhizal fungal DNA copy number and root tissue DNA copy number using qPCR, we found that the morphology‐driven gradient did not explain the full variation in fungal collaboration; thick roots were consistently well colonised, but medium and thin roots displayed a wide range of colonisation intensity. 5. Synthesis: These results advance our understanding of the fundamental trait relationships that underpin the root economics space. Our study also provides a physiological linkage to the frequently measured root morphological traits and relates the root economics space to root‐derived carbon‐nutrient cycling processes. [ABSTRACT FROM AUTHOR]

Thermal runaway (TR) is one of the main concerns in battery application due to their hazard level for the people and environment. In this work, the thermal runaway behaviors of lithium-ion batteries (LIBs) are investigated in ambient nitrogen (N2) concentration from 78 to 100%. Several parameters are measured to assess the fire hazards of LIBs, including battery surface temperature (Tsurf), ignition time (tig), total mass loss, heat release rate, and total heat release. The experimental results show that the risk of TR increases with the increase in state of charge. For different N2 concentrations, the addition of N2 will reduce oxygen (O2) concentration and weaken internal reactions, while excessive N2 will react with lithium-ion inside the LIBs. 82% N2 concentration shows the greatest inhibition effect on TR, where the values of battery surface temperature, total mass loss, heat release rate, and the total heat release reach the minimum ones. [ABSTRACT FROM AUTHOR]

为利用克里藻JNU41高效生产油脂、亚油酸和叶黄素等重要代谢产物，对其进行培养条件的优化及代谢产物积累的评估。采用改良的BG-11（mBG-11）和BBM（mBBM）培养基，设置3组光照强度〔单侧100 μmol/(m2·s)、单侧300 μmol/(m2·s)和双侧300 μmol/（m2·s）〕和6种初始氮浓度（3、6、9、12、15、18 mmol/L）对克里藻JNU41进行培养，并测定其生长曲线、生化组成、总脂产率、脂肪酸组成及叶黄素含量。结果表明：克里藻JNU41在mBBM培养基、双侧光照强度300 μmol/（m2·s）、初始氮浓度6 mmol/L条件下，生物量和总脂产率最高,分别为8.38 g/L和281.71 mg/(L·d)；在mBG-11培养基、双侧光照强度300 μmol/(m2·s)、初始氮浓度3 mmol/L条件下，总脂和总脂肪酸含量最高，分别为5512%和47.10%。克里藻JNU41主要脂肪酸组成为棕榈酸、油酸、亚油酸和亚麻酸，其中亚油酸含量最高，亚油酸最高相对含量为65.87%。此外，克里藻JNU41还积累一定量叶黄素，最高含量可达1.64 mg/g。因此，克里藻JNU41是一株可用于生产多种高附加值产物的潜力藻株。To efficient production of important metabolites such as oil, linoleic acid and lutein by Klebsormidium sp. JNU41, the culture conditions were optimized and the accumulation of metabolites in Klebsormidium sp. JNU41 was evaluated. The growth curve, biochemical composition, total lipid yield, fatty acid composition and lutein content of Klebsormidium sp. JNU41 were studied using modified BG-11 (mBG-11) and BBM (mBBM) as the media, and three sets of light intensities 〔unilateral 100 μmol/(m2·s), unilateral 300 μmol/(m2·s) and bilateral 300 μmol/(m2·s)〕 and six initial nitrogen concentrations (3, 6, 9, 12, 15, 18 mmol/L) were used for culture. The results showed that under the conditions of mBBM media, bilateral light intensity 300 μmol/(m2·s) and initial nitrogen concentration 6 mmol/L, the biomass (8.38g/L) and total lipid yield 〔281.71 mg/(L·d)〕 reached a maximum value. Under the conditions of mBG-11 media, bilateral light intensity 300 μmol/(m2·s) and initial nitrogen concentration 3 mmol/L, the highest total lipid and total fatty acid contents reached 55.12% and 47.10%, respectively. The main components of fatty acids were palmitic acid, oleic acid, linoleic acid and linolenic acid, and linoleic acid content was the highest with the highest relative content of 65.87%. In addition, Klebsormidium sp. JNU41 also accumulated a certain amount of lutein, up to 1.64 mg/g. Therefore, Klebsormidium sp. JNU41 is an algal strain that can be used to produce high value-added products.

Background: It has been long thought that nitrogen (N), phosphorus (P) concentrations and their ratios (N:P) in metabolically active or functional organs (i.e., leaves) are less responsive to environmental changes. Little attention, however, has been paid to the reproductive organs—seeds, while seeds may maintain their nutrients more stable for the evolutionary fitness of next generation. Methods: Here, we conducted a field experiment of N, P addition and drought in an alpine meadow, aiming to compare the difference of leaf and seed nutrients and stoichiometric ratios in response to these resource treatments and their interactions. Four dominant species were selected among grass and forb functional groups, including Elymus nutans, Deschampsia caespitosa, Artemisia roxburghiana and Polygonum viviparum. Results: Under natural conditions, leaf N and P concentrations were consistently lower than seed among species. However, leaf nutrients were much more sensitive than seed nutrients to N and P addition. Specifically, N or P addition accordingly increased leaf N or P concentration by 22.20–44.24% and 85.54–93.61%, while only enhanced seed N or P concentration by 5.15–17.20% and 15.17–32.72%, respectively. Leaf N or P concentration was significantly reduced by P or N addition, but seed nutrients remained unchanged. In contrast, drought did not change both organ nutrients. Similarly, nutrient addition and drought had synergistic interactions on leaf nutrients, but not on seed nutrients. Conclusions: This study highlights that seed nutrient concentrations could be more stable than metabolically active leaf organ when facing multidimensional resource changes. This complements the traditional view on the ‘Stable Leaf Nutrient Hypothesis’ with the involvement of reproductive organs. The less responsiveness of seed nutrients suggests the adaptive strategy to ensure the success of next generations and long-term plant demographic stability. [ABSTRACT FROM AUTHOR]

Water and fertilizer coupling is a high-efficiency technology for the development of facility agriculture. However, the interaction effect of nitrogen (N) and air carbon dioxide (CO2) on hydroponic purple cabbage, especially on its leaf anthocyanins under hydroponic solution systems, remains unexplored. In this study, six treatments were set as C0N0, C0N2, C0N4, C1N0, C1N2 and C1N4, with N0, N2 and N4 being 0.0 g/L, 0.2 g/L and 0.4 g/L exogenous urea-N to hydroponic solution dilution, respectively. C0 and C1 were set as with and without CO2 fertilizer (i.e., 800 g CO2 agent added one week after transplanting and 600 g CO2 agent added when the plant reached 15 cm in height), respectively. Pot experiments were conducted to investigate the interaction effect of N and air CO2 (NÃ--CO2) on the growth, photosynthesis, yield and anthocyanin content of hydroponic purple cabbage Brassica campestris ssp. chinensis. The results showed NÃ--CO2 extremely significantly influenced plant height (H), net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular oxidation concentration (Ci), transpiration rate (Tr), leaf water use efficiency (LWUE) and yield. The C1N0 treatment had the largest yield at 262.5 g/plant, with higher values for root length, root weight, plant height and leaf number than the other treatments. The Pn, Ci and Tr of C1N4 were the highest at 3.05 μmol CO2/m²·s, 352.8 μmol CO2/m²·s and 2.31 mmol H2O/m²·s, respectively. The C1N2 treatment received the largest Gs value of 0.70 mol H2O/m²·s and the largest Tr of 2.31 mmol H2O/m²·s. There was the highest LWUE for C0N2 (1.41) and the highest anthocyanin content for C1N2 (1.35 mg/kg). There was a significant negative correlation between leaf number and anthocyanin (r = -0.414, p<0.05). The findings demonstrated that adding CO2 fertilizer and 0.2 g/L exogenous urea-N to hydroponic solution dilution is a potential NÃ--CO2 coupling strategy to increase anthocyanin and the yield of purple cabbage. [ABSTRACT FROM AUTHOR]

【Objective】 Precision agriculture needs a rapid diagnosis of water and nutrient deficits, which is challenging at large scales in the field. Taking maize as an example, this paper proposes to estimate nitrogen content in maize canopy using remote sensing data. 【Method】 The study was carried out at Hetao Irrigation District using UAV multi-spectral imagery data measured in 2020. A variety of vegetation indices extracted from the imageries were used to calculate nitrogen content in the canopy when the crop grew to different stages. The model was validated against ground-truth data and was then used to evaluate critical nitrogen concentration and potential nitrogen pollution at different growth stages. 【Result】 The planted area of maize in Hetao Irrigated District in 2020 was 275 000 hm2. The suitable vegetation indices for calculating canopy nitrogen varied with growing stages; the canopy nitrogen at elongation, early and late tasseling stage and flowering stage was best estimated by GBNDVI, RVI, NRI, and NDVI, respectively. It was found that nitrogen concentration in the canopy was low at the flowering stage, and high at the elongation and later tasseling stage, during which nitrogen pollution could occur. Analysis showed that the risk of nitrogen pollution was Grade 4 in early tasseling stage and zero in flowering stage. 【Conclusion】 The UAV multispectral image data can be used to estimate nitrogen content in plant and assess the potential of nitrogen pollution at different growing stages at large scales in the field. It can help improve fertilization and reduce the potential of non-point source pollution.

Moisture stress is one of the most important constraints for crop production in arid regions. Cowpea is a vital food legume that has been cultivated in tropical and sub-tropical regions where water is scarce. Rhizobia inoculation confers resistance to water stress legumes. Two-year field experiments were conducted to assess the carbon assimilation and water use efficiencies of inoculated cowpea varieties at three sites. The treatments consist of four varieties and three levels of Bradyrhizobium inoculation arranged in a factorial randomized complete block design with four replications. The nitrogen (% N) and carbon (% C) concentrations in plant shoots were obtained directly from the mass spectrometric analysis. The results revealed considerable variation for shoot % N and % C, shoot growth, and δ13C among the varieties. Similarly, Bradyrhizobium significantly affected plant growth, % C, C and N contents, C/N ratio, and carbon isotope discrimination of the shoot. For instance, C and N contents and the C/N ratio increased by 28, 24, and 31%, respectively, due to Bradyrhizobium inoculation. In general, these results indicated that physiological performances such as carbon assimilation and water use efficiency of the crop could be, significantly improved when effective Bradyrhizobium strains and the best performing varieties are selected.

Nitrogen is one of the most important nutrients affecting the growth and fruit quality of walnut trees. Rapid and accurate monitoring of nitrogen concentration in the walnut canopy can provide a digital basis for its nutritional diagnosis and precision fertilization. Consequently, the main purpose of this study was to use Unmanned Aerial Vehicle (UAV) remote sensing technology to monitor the nitrogen concentration of walnut canopies. In this study, UAV multispectral images of the canopies of nine walnut orchards with different management levels in Wensu County, South Xinjiang, China, were collected during the fast-growing (20 May), sclerotization (25 June), and near-maturity (27 August) periods of walnut fruit, and canopy nitrogen concentration data for 180 individual plants were collected during the same periods. The validity of the information extracted via the outline canopy and simulated canopy methods was compared. The accuracy of nitrogen concentration inversion for three modeling methods, partial least squares regression (PLSR), support vector machine (SVM), and random forest (RF), was analyzed; the effects of different combinations of variables on model accuracy were compared; and the spatial distribution of the nitrogen concentration in the walnut canopy was numerically mapped using the optimal model. The results showed that the accuracy of the model created using the single plant information extracted from the outlined canopy was better than that of the simulated canopy method, but the simulated canopy method was more efficient in extracting effective information from the single plant canopy than the outlined canopy. The simulated canopy method overcame the difficulty of mismatching the spectral information of individual plants extracted, by outlining the canopy in the original image for nitrogen distribution mapping with the spectral information of image elements in the original resolution image. The prediction accuracy of the RF model was better than that of the SVM and PLSR models; the prediction accuracy of the model using a combination of waveband texture information and vegetation index texture information was better than that of the single-source model. The coefficients of determination (R2) values of the RF prediction model built using the band texture information extracted via the simulated canopy method with the vegetation index texture information were in the range of 0.61–0.84, the root mean square error (RMSE) values were in the range of 0.27–0.43 g kg−1, and the relative analysis error (RPD) values were in the range of 1.58–2.20. This study shows that it is feasible to monitor the nitrogen concentration of walnut tree canopies using UAV multispectral remote sensing. This study provides a theoretical basis and methodological reference for the rapid monitoring of nutrients in fruit trees in southern Xinjiang. [ABSTRACT FROM AUTHOR]

IntroductionAmong the various nutrients, nitrogen (N) is the limiting element for crop yield, which application of the optimum doses of this fertilizer in addition to increasing the yield components and grain yield in paddy fields, enhances the profits of rice cultivation in the region. One of the sustainable soil management techniques in paddy fields is the application of rice husk biochar. Biochar improves rice yield by improving soil chemical properties, increasing nutrient storage capacity, and also reducing soil acidity. Zinc deficiency can be the most important limiting factor of rice yield after N, P, and K. Therefore, the application of zinc fertilizer in the form of nanoparticles can be an effective technique to increase the quantitative and qualitative characteristics of rice. Therefore, the present study was conducted to investigate the effects of nitrogen doses along with the application of biochar and also zinc fertilizer in the form of nanoparticles on the quantitative and qualitative characteristics of rice.Materials and MethodsThe field experiment was carried out as a split-plot based on a randomized complete block design with three replications at the farmer's field located in Amol (North of Iran) in cropping season of 2019-2020. In this study, the doses of nitrogen applied at four levels of 0, 25, 50, and 75 kg.ha-1 as the main factor and application of fertilizers at four levels of control or no application of biochar and zinc nanoparticles, application of biochar, foliar application of zinc nanoparticles and combined application of biochar and zinc nanoparticles as the sub-factor were considered. The fertilizers of biochar and zinc nanoparticles at 40 ton.ha-1 and 50 mg.l-1 were used in this experiment, respectively. At harvest time, the yield components, yield, and N and Zn concentrations in grain were measured. Analysis of variance was performed using SAS software (ver. 9.2) and mean comparisons based on the least significant difference (LSD) test at the level of 5% probability.Results and DiscussionThe results showed that the simple effects of experimental treatments were significant on all morphological traits, yield components, and grain yield except the number of filled grains per panicle. The grain N concentration was not affected by biochar and zinc, while grain Zn concentration was significant under this treatment. Also, the impact of N application was significant on N and Zn concentrations in grain. The interaction between experimental treatments was not significant on the studied traits except for the number of fertile tillers per hill. The maximum fertile tillers number per hill (17.66 tillers) was obtained by using a combination of biochar + zinc nanoparticles + 50 kg N ha-1, which indicates the positive impacts of simultaneous application of these fertilizers. The application of N fertilizer at the amounts of 50 and 75 kg.ha-1, respectively, resulted in maximum grain yield (4340 kg.ha-1) and production of the highest grain N concentration (1.30%). Although the use of each of the biochar and zinc oxide nanoparticles improved the yield components, yield, and nutrient concentrations in rice grain, the combined application of biochar and zinc nanoparticles significantly increased the quantitative and qualitative characteristics of rice, so that the highest grain yield (4062 kg.ha-1) and greatest Zn concentration in grain (28.5 mg.kg-1) was observed under the simultaneous application of biochar + nanoparticles.ConclusionAccording to the results of the present study, N application at the rate of 50 kg.ha-1 and simultaneous application of rice husk biochar + zinc nanoparticles are introduced as the optimal dose of N and the ideal fertilizer option to increase crop yield and enrich rice grains.

The studies of rice nitrogen concentration on the expression of miRNA so far are mostly limited to the exogenous nitrogen, leaving the effect of endogenous nitrogen largely unexplored. OsNAR2.1 is a high-affinity nitrate transporter partner protein which plays a central role in nitrate absorption and translocation in rice. The expression of OsNAR2.1 could influence the concentration of the endogenous nitrogen in rice. We showed that the expression and production of miRNA in rice can be influenced by manipulating the endogenous nitrogen concentration via OsNAR2.1 transgenic lines. The small RNA content, particularly 24 nucleotides small RNA, expressed differently in two transgenic rice lines (nitrogen efficient line with overexpression of OsNAR2.1 (Ov199), nitrogen-inefficient line with knockdown OsNAR2.1 by RNAi (RNAi)) compared to the wild-type (NP). Comparative hierarchical clustering expression pattern analysis revealed that the expression profiles of mature miRNA in both transgenic lines were different from NP. Several previously unidentified miRNAs were identified to be differentially expressed under different nitrogen concentrations, namely miR1874, miR5150, chr3-36147, chr4-27017 and chr5-21745. In conclusion, our findings suggest that the level of endogenous nitrogen concentration variation by overexpression or knockdown OsNAR2.1 could mediate the expression pattern and intensity of miRNA in rice, which is of high potential to be used in molecular breeding to improve the rice responses towards nitrogen utilization. [ABSTRACT FROM AUTHOR]

Fucoxanthin and fatty acids are active substances that are beneficial to the growth and immunity of humans and aquatic animals. However, relatively few species have been exploited for fucoxanthin and fatty acids in the industry. At the same time, due to its low extract content, poor stability, high production cost, and serious seasonal and regional limitations, the industry cannot normally meet the greater demand of the international market. Therefore, this experiment seeks to improve the fucoxanthin and fatty acid content of C. weissflogii by adjusting the nitrogen concentration in the culture medium. It was found that when the nitrogen concentration was 150 mg L−1, the cell number was 1.5 × 106 cell mL−1, and the average biomass was 0.75 g L−1. The mean value of carotenoid concentration was 2.179 mg L−1. The average concentration of fucoxanthin was 1.547 mg g−1. When the nitrogen concentration was 75 mg L−1, the fatty acid content reached its highest. By adjusting the concentration of nitrogen, the contents of fucoxanthin and fatty acids were increased. The results provided a theoretical basis for commercial extraction of fucoxanthin and fatty acids and further promoted the industrialization of fucoxanthin and fatty acids. [ABSTRACT FROM AUTHOR]

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A computational model is developed to predict the nitrogen concentration profile within Nb utilized in superconducting radio-frequency (SRF) accelerators. This model incorporates variations in the sticking coefficient of nitrogen during the adsorption process on the Nb surface, along with the impact of nitride formation resulting from the reaction between Nb and nitrogen. The conclusions drawn from this model are compared with the outcomes of vertical test experiments. The computed results indicate that exhibiting a significant nitrogen doping effect is achieved when the nitrogen concentration is approximately 1E25 atom/m 3 under various nitrogen doping recipes. This study enhances the understanding of the nitrogen doping process and enables the rapid determination of the optimal subsequent material removal thickness for various experimental recipes. [Display omitted] • Calculation of nitrogen depth profile in nitrogen-doped Nb with a new theoretical model. • Correction of the nitrogen sticking coefficient on the surface of Nb was considered. • Reveal that the optimal nitrogen concentration of different doping recipes falls within the same range. • Enables rapid determination of the material removal thickness required for various recipes. [ABSTRACT FROM AUTHOR]

Researches of the electrophysical characteristics of gate dielectrics obtained by the rapid thermal processing (RTP) method by two-stage and three-stage processes have been carried out. Each photonic processing (stage) was carried out for 12 s at a constant power of halogen lamps and heating the wafers to a maximum temperature of 1250 °C. The first two stages of the process were carried out in an oxygen atmosphere, the third - in nitrogen or a forming gas. It was found that for dielectrics obtained by the process with final processing in a nitrogen atmosphere, the absolute value of the voltage of flat zones is 0.42 V less, than for insulators, formed by a two-stage process. This is the consequence of the elimination of a significant part of the defects, responsible for the presence of Coulomb centers in the dielectric layer. Carrying out photonic processing in anitrogen atmosphere at high temperatures of procedures for proceeding of the restructuring of the structure of the dielectric layer. For insulators obtained by a three-stage process with final processing in N2, an increase in dielectric strength and breakdown voltage by 1 V and 3.3 MV/cm, respectively, is observed in comparison with dielectrics, obtained by a two-stage process. An increase in dielectric strength indicates relaxation of elastic stresses of deformed bonds and compensation for dangling bonds both in the dielectric and at its interface with Si during high-temperature photonic treatment. Passivation by nitrogen atoms of deformations at the dielectric/semiconductor interface will also have a positive effect on the strength of the insulator.

Indicators of nitrogen economy in winter wheat during vegetative development are a reliable tool for yield prognosis. This hypothesis was verified in a field experiment, carried out in the 2013/2014, 2014/2015, and 2015/2016 seasons. The field experiment, in a two-factor split-plot design, included the following systems of wheat protection (CFP): (i) N + micronutrients, (ii) N + fungicides, (iii) N + micronutrients + fungicides; and N rates: 0, 40, 80, 120, 160, 200, 240 kg N ha−1. The content and accumulation of N in wheat at the beginning of stem elongation and at heading were used for grain density and yield prediction. In the grain-filling phase, the stem N acted as a buffer, stabilizing yield at a high level. The condition for such action was the stem N equilibrium with the ear N at flowering. The N depletion from the leaves during the grain-filling period significantly depended on the grain density. The post-flowering uptake of N by wheat was affected by the grain density, which was affected by the N reserves in the stem. Yield forecast based on pre-flowering indices of nitrogen economy in cereals affects both agronomic decisions aimed at correcting the nutritional status of plants, and farm economics. [ABSTRACT FROM AUTHOR]

Grassland production is sensitive to both precipitation and plant N accumulation and utilization, such that change in one variable influences grassland response to the second variable. We investigated effects of interannual variation in precipitation on the response of 'community'-scale values of relative growth rate (RGR) to two multiplicative components of RGR, nitrogen productivity (NP; rate of change in biomass/plant N), an index of N utilization efficiency, and plant N concentration ([N]), in two grasslands in Texas, USA. Grasslands included a planted mixture of perennial grass and forb species and monoculture of the perennial C4 grass Panicum virgatum that was invaded by multiple plant species. RGR and its N components were measured at the spatial scale of 7-m diameter circular patches near the spring peak in mixture biomass during each of 5 years. We found that RGR varied substantially among patches and years and between the planted mixture and monoculture. RGR variation was strongly correlated with variation in NP. Precipitation during the 3 months prior to RGR measurement mediated the RGR response to NP by altering the correlation between NP and [N] in both grasslands. Reduced precipitation led to more negative NP-[N] correlation coefficients, which reduced proportional change in RGR per change in NP by as much as 30% even in the absence of a precipitation effect on means of RGR and NP. Our results highlight an under-appreciated aspect of the pervasive role of precipitation in grassland growth that was mediated via change in the growth benefit derived from plant N. [ABSTRACT FROM AUTHOR]

Moisture stress is one of the most important constraints for crop production in arid regions. Cowpea is a vital food legume that has been cultivated in tropical and sub-tropical regions where water is scarce. Rhizobia inoculation confers resistance to water stress legumes. Two-year field experiments were conducted to assess the carbon assimilation and water use efficiencies of inoculated cowpea varieties at three sites. The treatments consist of four varieties and three levels of Bradyrhizobium inoculation arranged in a factorial randomized complete block design with four replications. The nitrogen (% N) and carbon (% C) concentrations in plant shoots were obtained directly from the mass spectrometric analysis. The results revealed considerable variation for shoot % N and % C, shoot growth, and δ13C among the varieties. Similarly, Bradyrhizobium significantly affected plant growth, % C, C and N contents, C/N ratio, and carbon isotope discrimination of the shoot. For instance, C and N contents and the C/N ratio increased by 28, 24, and 31%, respectively, due to Bradyrhizobium inoculation. In general, these results indicated that physiological performances such as carbon assimilation and water use efficiency of the crop could be, significantly improved when effective Bradyrhizobium strains and the best performing varieties are selected. [ABSTRACT FROM AUTHOR]

【Objective】 The objective of this paper is to investigate the influence of nitrogen concentration in nutrient solution on physiological traits of lettuce grown in hydroponic culture. 【Method】 The experiment was conducted in a greenhouse, with the Flandria cultivar used as the model plant. We compared five nitrogen concentrations: 12.25, 24.5, 49, 98 and 196 mg/L, each having two replicates. In the experiment, we measured the leaf area index (LAI), accumulated water consumption and the change in meteorologic factors in the greenhouse, from which we derived the relationship between water consumption of the crop and nitrogen concentrations in the solution. 【Result】 The accumulated water consumption and LAI both increased first followed by a decline as the nitrogen concentration increased. The relationships between LAI and the nitrogen concentration can be fitted to a quadratic function, and comparison with measured data showed fitting of the model was accurate. The model describing the change in water consumption with nitrogen concentrations also agreed well with experimental data. 【Conclusion】 Accumulative water consumption and LAI of the hydroponic-cultured lettuce both increased with nitrogen concentration in the nutrient solution, and the models describing their relationships agreed well with experimental data.

By studying the spectral information of cotton leaf nitrogen content, sensitive feature bands and spectral indices for leaf nitrogen content were screened, and different methods were used to model the screened feature bands and indices to find a method with higher accuracy and stability of the inversion model, which provides a theoretical basis and technical support for remote sensing estimation of cotton nitrogen content in Xinjiang. The experiment was conducted in 2019–2020 at the Second Company of Shihezi University Teaching Experimental Farm in Xinjiang, China, with six fertilization treatments (0, 120, 240, 360, 480 kg/hm pure N), sampled at five key fertility stages of cotton (squaring stage, full budding stage, flowering, boll stage, and boll opening stage), and the obtained data were used in two modeling approaches (eigenbands and spectral indices) to establish a cotton nitrogen estimation model and estimate the cotton leaf N content. The results showed that the nonlinear model using SVR was validated with an R2 of 0.71 and an RMSE of 3.91. The linear models of MLR and PLS were developed for the feature bands screened by SPA and RF, respectively, and the best modeling result was achieved by SPA-PLS with a validated R2 of 0.722 and an RMSE of 3.83. The existing spectral indices were optimized by screening the central wavelength and the simple linear regression model was constructed. The inversion effect of the SVR model with the characteristic spectral modeling was better than the index results. However, compared with the direct use of the characteristic wavelengths and the SVR way of modeling, the accuracy of leaf N content estimation by the model built by optimizing the spectral indices was reduced but the stability was greatly improved, and it can be used as a hyperspectral model for leaf N content at full fertility. The hyperspectral estimation of leaf N content in cotton can be used as a hyperspectral estimation method for the whole fertility period. [ABSTRACT FROM AUTHOR]

Nitrogen (N) supply and harvest timing through 'reaping and re-growth' method are critical determinants of yield and quality in hydroponically grown leafy vegetables. Lettuce (Lactuca sativa L.) was chosen as a test crop for evaluating the effect of nitrogen applications and harvesting times. In India, farmers often apply N without guidance and improperly harvest leafy vegetables. Therefore, it is essential to determine the optimum N supply and harvesting time for yield and quality enhancement of hydroponically grown lettuce. We studied the effect of different levels of N (4, 6, 8 and 10 mmolL−1) and two harvest timings on the growth attributes and quality of lettuce. The higher N levels (10 and 8 mmolL−1) showed pronounced positive effects on growth, yield, and quality of lettuce. However, the dry matter yield and ascorbic acid content decreased with the increase in N levels. For a continuous supply of fresh cut leaves of lettuce and to optimize leaf nitrate content, the plants has to be harvested by adapting cut and come again method during winter season. The average growth rate, showed significant positive response to N. The present study demonstrates that optimum levels of N (10 mmolL−1) and harvest through cutting (after 45 days of harvesting) significantly increase the leaf yield and quality of the lettuce. [ABSTRACT FROM AUTHOR]

Numerous growth and physiological variables of 3-week-old Populus simonii × P. nigra seedlings were assessed after treatment with either nitrate nitrogen (NO3−–N) (0.1, 0.5, 1, 5, or 10 mmol·L−1) or ammonium nitrogen (NH4+–N) (0.1, 0.5, 1, 5, or 10 mmol·L−1) to determine the best nitrogen form and concentration to optimize growth, biomass allocation, pigment content, and photosynthetic capacity. The results of combining membership function and an evaluation index suggested that, 5 mmol·L−1 nitrogen, regardless of the form, yielded the highest comprehensive evaluation index and good growth. In addition, a Pearson correlation analysis and network visualization revealed that the total mass, shoot mass, root mass, leaf dry mass, plant height, leaf area, chlorophyll a and total chlorophyll had a physiological index connectivity degree ≥ 15 for both nitrogen forms. Net photosynthetic rate, stomatal conductance, transpiration rate, maximum photochemical efficiency of PSII, total nitrogen content, ground diameter, chlorophyll b, and carotenoid were unique indices for evaluating NH4+–N-based nutrition, which could provide a theoretical basis for evaluating the effects of nitrogen fertilizer on seedlings, cultivation periods, and stress tolerance in P. simonii × P. nigra. [ABSTRACT FROM AUTHOR]

In this research, we study a dynamical system of total nitrogen transformation in a mangrove-filled constructed wetland. The system's variables are the mangrove biomass concentration and total nitrogen concentration in wastewater and in soil solution. We investigate the system's dynamics by examining the local stability of the equilibriums, simulating the phase portrait and solutions and providing time-dependent parameter sensitivity analyses. The analysis shows that the level of garbage acts as the parameter for when mangrove biomass will disappear. Both the graphs of the system solutions and the sensitivity function in the case of biomass concentration and total nitrogen concentration in soil solution versus time show symmetrical features at specific time intervals. According to the sensitivity index when reaching equilibrium, the level of garbage is the most sensitive parameter to the system. In addition, we explore the model's discrete form by investigating the conditions for the equilibrium's local stability and presenting bifurcation diagrams for each parameter. The symmetrical aspects are visible in the visualization of the bifurcation diagram and the solutions' chaotic behavior. [ABSTRACT FROM AUTHOR]

Investigations of the thickness and optical characteristics of thin SiO2 films obtained by one-, two-, or three-stage rapid thermal processing (RTP) at atmospheric pressure, pulses of 6, 12, and 20 s duration have been carried out. To obtain thin SiO2 films by the RTP method, N-type:Ph 4.5 Оhm/□ (100) silicon wafers were used as initial samples. The samples were preliminarily oxidized at 1000 °C of the obtained wet oxygen (SiO2 d = 100 nm), then the silicon oxide was completely removed in a solution of hydrofluoric acid, after which the wafers were subjected to chemical cleaning using the Radio Corporation of America (RCA) technology. Oxidation in a stationary oxygen atmosphere was carried out in one or two stages by heating the plates with a light pulse of different power up to maximum temperatures of 1035 – 1250 °C, as well as a three-stage process, where the final stage was annealing in a nitrogen atmosphere or in a forming gas (N2 97% + H2 3%). The characteristics of SiO2-Si barrier structures nitrided in N2, obtained by the RTP process by light fluxes with pulses of a second duration, were studied to improve the electrophysical parameters of gate oxides by the RTP method. It is of interest for integrated circuits (ICS) with a high density of the active regions of devices.

It is essential to understand the ecological role and importance of allelochemicals on the growth of native plants. Our study hypothesized that nitrogen (N) intimidation would influence the secretion of allelochemicals in invasive plants, impacting native plants. In the experiment, the root and aboveground aqueous extracts of three invasive compositae (Soildago Canadensis L., Erigeron Canadensis L. and Erigeron annuus) were used to treat the native compositae (Lactuca sativa) seeds under different N concentrations 0 mgL-1, 50 mgL-1, 100 mgL-1, 200 mgL-1 and distilled water added as an additional control (CK). The results showed that the Lettuce seeds (germination rate, germination potential, germination index, and vigor index) and seedlings (root height, plant height, fresh weight, and Malondialdehyde (MDA)) had different responses to different aqueous extracts. Allelochemicals were also varied with different exotic invasive plants and different parts of the plants. At the same time, N addition elevated the allelopathy effects of three Compositae invasive species and affected the growth of the seedling of native Lettuce. This approach offered the opportunity to study the influence of allelochemicals of exotic plants with an additional N source and explain the mechanism of a successful invasion. [ABSTRACT FROM AUTHOR]

Agricultural grasslands are globally important for food production, biodiversity, and greenhouse gas mitigation. Effective strategies to monitor grass sward properties, such as dry matter yield (DMY) and nitrogen concentration, are crucial when aiming to improve the sustainable use of grasslands in the context of food production. UAV-borne spectral imaging and traditional machine learning methods have already shown the potential to estimate DMY and nitrogen concentration for the grass swards. In this study, convolutional neural networks (CNN) were trained using low-cost RGB images, captured from a UAV, and agricultural reference measurements collected in an experimental grass field in Finland. Four different deep regression network architectures and three different optimizers were assessed. The best average results of the cross-validation were achieved by the VGG16 architecture with optimizer Adadelta: r 2 of 0.79 for DMY and r 2 of 0.73 for nitrogen concentration. The results demonstrate that this is a promising and effective tool for practical applications since the sensor is low-cost and the computational processing is not time-consuming in comparison to more complex sensors. [ABSTRACT FROM AUTHOR]

Copyright of Xinjiang Agricultural Sciences is the property of Xinjiang Agricultural Sciences Editorial Department 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.)

Effective water and nitrogen (N) management strategies are critical for sustainable agricultural development. Lysimeter experiments with two deep percolation rates (low percolation and high percolation, i.e., LP and HP: 3 mm d−1 and 5 mm d−1) and five N application levels (N0~N4: 0, 60, 135, 210 and 285 kg N ha−1) were conducted to investigate the effects of controlled drainage on water productivity (WP) and N use efficiency (NUE) in water-saving irrigated paddy fields. The results demonstrated that NH4+-N and NO3−-N were the major components of total nitrogen (TN) in ponded water and leachate, accounting for more than 77.1% and 83.6% of TN, respectively. The risk of N leaching loss increased significantly under treatment of high percolation rates or high N application levels. High percolation loss required greater irrigation input, thus reducing WP. In addition, N uptake increased with increasing N application, but fertilization applied in excess of crop demand had a negative effect on grain yield. NUE was affected by the amount of N applied and increased with decreasing N levels. Water and N application levels had a significant effect on N uptake of rice, but their interaction on N uptake or NUE was not significant. For the LP and HP regimes, the highest N uptake and WP were obtained with N application levels of 285 kg ha−1 and 210 kg ha−1, respectively. Our overall results suggested that the combination of controlled drainage and water-saving irrigation was a feasible mitigation strategy to reduce N losses through subdrainage percolation and to provide more nutrients available for rice to improve NUE, thus reducing diffuse agricultural pollution. Long-term field trials are necessary to validate the lysimeter results. [ABSTRACT FROM AUTHOR]

Nitrogen availability and light quality affect plant resource allocation, but their interaction is poorly understood. Herein, we analyzed the growth and allocation of dry matter and nitrogen using lettuce (Lactuca sativa L.) as a plant model in a factorial experiment combining three light regimes (100% red light, R; 50% red light + 50% blue light, RB; 100% blue light, B) and two nitrogen rates (low, 0.1 mM N; high, 10 mM N). Red light increased shoot dry weight in relation to both B and RB irrespective of nitrogen supply. Blue light favored root growth under low nitrogen. Allometric analysis showed lower allocation to leaf in response to blue light under low nitrogen and similar leaf allocation under high nitrogen. A difference in allometric slopes between low nitrogen and high nitrogen in treatments with blue light reflected a strong interaction effect on root-to-shoot biomass allocation. Shoot nitrate concentration increased with light exposure up to 14 h in both nitrogen treatments, was higher under blue light with high nitrogen, and varied little with light quality under low nitrogen. Shoot nitrogen concentration, nitrogen nutrition index, and shoot NR activity increased in response to blue light. We conclude that the interaction between blue light and nitrogen supply modulates dry mass and nitrogen allocation between the shoot and root. [ABSTRACT FROM AUTHOR]

Tantalum nitride thin films are grown on silicon wafers using a mixture of Ar/N2 using DC magnetron sputtering. The influence of nitrogen concentration on various features of tantalum nitride thin films is systematically studied. X-ray diffraction results show characteristic peaks of FCC tantalum nitride with crystallite size gradually increasing upon an augmentation in the nitrogen concentration. Field emission scanning electron microscopy images indicate that the tantalum nitride thin films are made of crystal domains with almost regular boundaries. As nitrogen concentration increases from 10 to 25%, the average domain size increases. Atomic force microscopy (AFM) results show larger surface roughness for the tantalum nitride thin films with higher nitrogen concentration owing to grain boundary diffusivity. Furthermore, quantitative characterization of 3-D surface morphology from AFM micrographs is obtained by multifractal and stereometric analyses. The results of mechanical properties show a decrease in the hardness upon increasing the nitrogen concentration due to variation in the grain size. The obtained results from the four-point probe illustrate that the specimen with higher nitrogen content displays the minimum sheet resistance due to a decrease in inter-grain boundaries emanated from the larger grain size. The current study renders a new insight in controlling the conductivity and the hardness of TaN thin film based on the deposition conditions and provide a correlation between the structural and other properties of TaN films, which is useful for a variety of semiconductor devices. [ABSTRACT FROM AUTHOR]

In the study, Scenedesmus obliquus green algae was cultivated under laboratory conditions at 21±2°C, 16:8 (light:dark) photoperiod and continuous aeration in different nitrogen and phosphorus ratio nutrient medium and its growth was determined. Dry weight, cell density (optical density) and chlorophyll a and b were used to determine the growth of the algae. The best growth was determined in the group consisting of 30 ml NaNO3+10 ml PO4. The amount of biomass obtained was determined as 1.549 gL-1 in this group. The lowest values were the group containing 5 ml NaNO3+5 ml PO4. With the decrease in the amount of nitrogen in the medium, an increase in the amount of carotene and a decrease in the amount of chl a and b were detected. The highest lipid values were determined as 36.7% in the group containing 5 ml NaNO3+5 ml PO4 and 36.2% in the group containing 5 ml NaNO3+10 ml PO4. [ABSTRACT FROM AUTHOR]

Nitrogen availability and light quality affect plant resource allocation, but their interaction is poorly understood. Herein, we analyzed the growth and allocation of dry matter and nitrogen using lettuce (Lactuca sativa L.) as a plant model in a factorial experiment combining three light regimes (100% red light, R; 50% red light + 50% blue light, RB; 100% blue light, B) and two nitrogen rates (low, 0.1 mM N; high, 10 mM N). Red light increased shoot dry weight in relation to both B and RB irrespective of nitrogen supply. Blue light favored root growth under low nitrogen. Allometric analysis showed lower allocation to leaf in response to blue light under low nitrogen and similar leaf allocation under high nitrogen. A difference in allometric slopes between low nitrogen and high nitrogen in treatments with blue light reflected a strong interaction effect on root-to-shoot biomass allocation. Shoot nitrate concentration increased with light exposure up to 14 h in both nitrogen treatments, was higher under blue light with high nitrogen, and varied little with light quality under low nitrogen. Shoot nitrogen concentration, nitrogen nutrition index, and shoot NR activity increased in response to blue light. We conclude that the interaction between blue light and nitrogen supply modulates dry mass and nitrogen allocation between the shoot and root.

Soilless blueberry (Vaccinium corymbosum L.) production is an alternative system that is increasing worldwide in surface area. There is little scientific information available as yet on the agronomic management of this cultivation system. The objective of the present study was to evaluate four N rates (0%, 100%, 200%, and 300% of the reference rate) and three water replacement level (70%, 100%, 130%) on leaf biomass production and leaf N concentration previous to winter fall (May and August 2021) in 10 pot-grown blueberry cultivars (Blue Ribbon, Duke, Camelia, Cargo, Last Call, Legacy, Ochlockonee, Suzie Blue, Ventura, and Victoria). An experiment was conducted in south-central Chile (36°55' S) with first-year plants. During the first growing season, results showed interactions between cultivars, N rates, and water replacement levels; there was a synergistic effect between N rates and water replacement levels on leaf biomass production in 'Duke', 'Camelia', 'Ochlockonee' and 'Suzie Blue'. Overall, the highest leaf biomass production in most cultivars was obtained with an N rate ranging from 33.2 to 53.1 g plant-1 season-1 (100% and 200% N rates, respectively) and 100% and 130% water replacement levels. Water consumption during the season fluctuated between 93.79 a 136.23 L season-1. The highest leaf N concentration in most of the blueberry cultivars was obtained with N rates ranging from 33.2 to 53.1 g plant-1 season-1 and 70% and 100% water replacement levels. Therefore, agronomic management recommendations for N fertilization and water replacement levels in blueberries produced with this growing system cannot be generalized. [ABSTRACT FROM AUTHOR]

Apple tea wine having phytochemical potential of tea and apple, is an option to improve quality characteristics of wine. However, quality of wine is greatly dependent on different initial variables which need to be optimized before preparation of any wine with desirable quality characteristics. Therefore, present study was conducted to investigate the effects of different initial variables, i.e., tea concentration (3–5 g tea per 100 ml of the apple juice), sugar concentration (18–22°B), DAHP concentration (0.1–0.3%), KMS concentration (50–150 ppm) and inocula size (2.5–7.5%) on quality attributes of apple tea wine. Results indicated that for all the variables under study exerted a significant effect on the alcoholicity and sensory quality characteristics of apple tea wine and the same has been observed during the cluster analysis of the data. The optimum wine qualities; rate of fermentation (0.78°B/24 h), ethanol (7.83%), volatile acidity (0.025%), fusel alcohol (84.62 mg/l) and overall acceptability (8.27) with 0.81 desirability were obtained using 4 g tea, 20°B initial sugar concentration, 0.2% DAHP, 100 ppm KMS and 5% inoculum size. Verification experiments were conducted to compare predicted and actual values, which were found to nearly concur, confirming that models were capable of reasonably and accurately predicting the dependent variables. The developed conditions will help in improving the quality of apple tea wine and no doubt will open a new door for fruit wine industry with a new product. [ABSTRACT FROM AUTHOR]

Copyright of Acta Agronomica Sinica is the property of Crop Science Society of China 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.)

The decay and holding time of nitrogen concentration was characterized in a controlled-atmosphere warehouse with half life of pressure of 165 s. The relationship of nitrogen concentration, nitrogen holding timeand grain temperature was further studied. The results showed that, the nitrogen concentration gradually decreases with the time, when the nitrogen concentration in the controlled-atmosphere warehouse reached to the target concentration of 98.0%. The concentration of nitrogen was related to nitrogen leakage and sorption.An increase of the nitrogen concentration required that the amount of supplemental nitrogen is greater than the amount of leakage. When there is no nitrogen supplement in the controlled-atmosphere warehouse, the monthly decrease of nitrogen concentration is 1.6%; when the monthly nitrogen supplement is greater than 12.4% of the grain warehouse volume, the nitrogen concentration will increase by 0.1% ～ 0.9%; the monthly nitrogen supplement is greater than 27.0% of the grain warehouse volume, the nitrogen concentration will greater than 1.0%. In addition, the amount of nitrogen supplementation has no direct effect on the temperature of the grain.

Fucoxanthin and fatty acids are active substances that are beneficial to the growth and immunity of humans and aquatic animals. However, relatively few species have been exploited for fucoxanthin and fatty acids in the industry. At the same time, due to its low extract content, poor stability, high production cost, and serious seasonal and regional limitations, the industry cannot normally meet the greater demand of the international market. Therefore, this experiment seeks to improve the fucoxanthin and fatty acid content of C. weissflogii by adjusting the nitrogen concentration in the culture medium. It was found that when the nitrogen concentration was 150 mg L−1, the cell number was 1.5 × 106 cell mL−1, and the average biomass was 0.75 g L−1. The mean value of carotenoid concentration was 2.179 mg L−1. The average concentration of fucoxanthin was 1.547 mg g−1. When the nitrogen concentration was 75 mg L−1, the fatty acid content reached its highest. By adjusting the concentration of nitrogen, the contents of fucoxanthin and fatty acids were increased. The results provided a theoretical basis for commercial extraction of fucoxanthin and fatty acids and further promoted the industrialization of fucoxanthin and fatty acids.

Microalgae are considered promising resources for producing a variety of high-value-added products, especially for lipids and pigments. Alkalophilic microalgae have more advantages than other microalgae when cultured outdoors on a large scale. The present study investigated the comprehensive effects of different nitrogen concentrations on fucoxanthin (Fx), lipids accumulation and the fatty acid profile of the alkaliphilic microalgae Nitzschia sp. NW129 to evaluate the potential for simultaneous production of Fx and biofuels. Fx and Lipids amassed in a coordinated growth-dependent manner in response to various concentrations, reaching 18.18 mg g–1 and 40.67% dry weight (DW), respectively. The biomass of Nitzschia sp. NW129 was 0.58 ± 0.02 g L–1 in the medium at the concentration of 117.65 mM. The highest productivities of Fx (1.44 mg L–1 d–1) and lipid (19.95 ± 1.29 mg L–1 d–1) were obtained concurrently at this concentration. Furthermore, the fatty acid methyl esters revealed excellent biofuel properties with an appropriate value of the degree unsaturation (49.97), cetane number (62.72), and cold filter plugging point (2.37), which met the European standards for biofuel production (EN14214). These results provided a reliable strategy for further industrialization and comprehensive production of biofuel and Fx by using the alkaliphilic microalgal Nitzschia sp. NW129.

This article is devoted to development of high-strength corrosion-resistant austenitic steel with a nitrogen content of 0.7–1.0 wt.% for use as oil equipment shafts. Steel after cold deformation has high strength and ductility properties: yield strength above 2000 MPa, relative elongation 8–9%, and impact strength 65 J/cm2. Steel high strength is due to its high nitrogen content and high degree of cold deformation. The steel withstands NACE hydrogen sulfide stress cracking testing. [ABSTRACT FROM AUTHOR]

Summary: While plant δ15N values have been applied to understand nitrogen (N) dynamics, uncertainties regarding intraspecific and temporal variability currently limit their application. We used a 28 yr record of δ15N values from two Mojave Desert populations of Encelia farinosa to clarify sources of population‐level variability.We leveraged > 3500 foliar δ15N observations collected alongside structural, physiological, and climatic data to identify plant and environmental contributors to δ15N values. Additional sampling of soils, roots, stems, and leaves enabled assessment of the distribution of soil N content and δ15N, intra‐plant fractionations, and relationships between soil and plant δ15N values.We observed extensive within‐population variability in foliar δ15N values and found plant age and foliar %N to be the strongest predictors of individual δ15N values. There were consistent differences between root, stem, and leaf δ15N values (spanning c. 3‰), but plant and bulk soil δ15N values were unrelated.Plant‐level variables played a strong role in influencing foliar δ15N values, and interannual relationships between climate and δ15N values were counter to previously recognized spatial patterns. This long‐term record provides insights regarding the interpretation of δ15N values that were not available from previous large‐scale syntheses, broadly enabling more effective application of foliar δ15N values. [ABSTRACT FROM AUTHOR]

In order to investigate the effects of the coupling of nitrogen nutrition (N) and carbon dioxide (CO2) on the leaf chlorophyll fluorescence value (SPAD) of purple pak-choi, nitrogen content (YN), temperature (YT) and humidity (YRH) under hydroponic conditions, six nitrogen coupling treatments including C0N0, C0N2, C0N4, CINO, C1N2 and C1N4, were set with Nanjing local purple pak-choi as the experimental material, among which the nitrogen concentration in the hydroponic solution was set. to be without exogenous nitrogen (NO), 0. 2 g • L-1 exogenous nitrogen (N2) and 0. 4 g • L-1 exogenous nitrogen (N4) in the diluent of hydroponic solution. Then, the changes of SPAD, YN, YT and YRH in leaves after transplanting were studied under the treatments of no CO2 growth agent (CO) and CO2 growth agent (Cl) at each nitrogen concentration. The results showed that the application of CO2 could significantly improve the leaf SPAD of purple pak-choi (PVO. 05). After transplanting, the leaf SPAD of purple pak-choi under C1N4 treatment was higher before November 16, and then it. was the highest under C1N2 treatment. Increasing the N content in the hydroponic solution before November 11 was helpful to increase the YN content in leaves, but it was not conducive to the increase of YN content in leaves after November 11. The YN content in leaves was higher under the treatments of CINO and C1N2. Both N and CO2 could significantly reduce the YT of leaves (P<0. 05). In addition, the coupling treatment of N and CO2 signFIicantly affected the YRH of leaves (P<0. 05), and high concentration of N could increase the YRH of leaves, and the effect was more obvious when increasing CO2 after November 11. It should be noted that there was significant correlation among various indexes of leaves at the same time (_PV0. 05). The Pearson analysis showed that the increase of YT at the early growth stage directly reduced the leaf SPAD, YN and YRH of purple pak-choi, and the increase of YT at the later growth stage was beneficial to the increase of SPAD, YN and YRH. YN and YRH were positively correlated with chlorophyll SPAD (P< 0. 01). In conclusion, the reasonable coupling of nitrogen and CO2 in hydroponic solution could increase the contents of chlorophyll and nitrogen in the leaves of hydroponic purple pak-choi, and the results could provide theoretical basis for the accurate management of nitrogen and CO2 in the hydroponic purple pak-choi. [ABSTRACT FROM AUTHOR]