N2 Level Research Articles

Sugarcane/Soybean Intercropping with Reduced Nitrogen Application Synergistically Increases Plant Carbon Fixation and Soil Organic Carbon Sequestration.

Sugarcane/soybean intercropping and reduced nitrogen (N) application as an important sustainable agricultural pattern can increase crop primary productivity and improve soil ecological functions, thereby affecting soil organic carbon (SOC) input and turnover. To explore the potential mechanism of sugarcane/soybean intercropping affecting SOC sequestration, a two-factor long-term field experiment was carried out, which included planting pattern (sugarcane monocropping (MS), sugarcane/soybean 1:1 intercropping (SB1), and sugarcane/soybean 1:2 intercropping (SB2)) and nitrogen addition levels (reduced N application (N1: 300 kg·hm-2) and conventional N application (N2: 525 kg·hm-2)). The results showed that the shoot and root C fixation in the sugarcane/soybean intercropping system were significantly higher than those in the sugarcane monocropping system during the whole growth period of sugarcane, and the N application level had no significant effect on the C fixation of plants in the intercropping system. Sugarcane/soybean intercropping also increased the contents of total organic C (TOC), labile organic C fraction [microbial biomass C (MBC) and dissolved organic C (DOC)] in the soil during the growth period of sugarcane, and this effect was more obvious at the N1 level. We further analyzed the relationship between plant C sequestration and SOC fraction content using regression equations and found that both plant shoot and root C sequestration were significantly correlated with TOC, MBC, and DOC content. This suggests that sugarcane/soybean intercropping increases the amount of C input to the soil by improving crop shoot and root C sequestration, which then promotes the content of each SOC fraction. The results of this study indicate that sugarcane/soybean intercropping and reduced N application patterns can synergistically improve plant and soil C fixation, which is of great significance for improving crop yields, increasing soil fertility, and reducing greenhouse gas emissions from agricultural fields.

Nitrogen use efficiency of drip irrigated sugar beet as affected by sub-optimal levels of nitrogen and irrigation

Sugar beet has strong drought resistance and requires a large amount of nitrogen (N) during growth. Can deficit irrigation combined with low N supply of sugar beet improve water productivity (WP) and N use efficiency (NUE)? In this field study in 2020–2021, two irrigation regimes (W1, field capacity (FC) of the 0–60 cm soil layer was not lower than 70% from 45 days after emergence (DAE) to harvest period; W2, FC of the 0–60 cm soil layer was not lower than 50% in 45–90 DAE, but was consistent with that of W1 after 90 DAE) and three N application rates (0 (N0), 150 (N1), and 225 (N2) kg N ha−1) were designed. Then, their impacts on taproot yield (TY), water consumption (WC) and N uptake (NU) were explored. The results showed that there was no significant difference in TY between W2 and W1 treatments under the N1 and N2 levels. Under the N1 and N2 levels, the daily water consumption (DWC, 0.121 and 0.125 mm ℃d−1) and daily N uptake (DNU, 53.6 and 71.6 g N ℃d−1) of W2 treatment were significantly lower than the DWC (0.161 and 0.164 mm ℃d−1) and DNU (60.6 and 86.5 g N ℃d−1) of W1 treatment in 0–90 DAE. The W2N1 treatment had similar WP and higher NUE compared with the W1N2 treatment. In addition, the fertilizer-15N recovery rate in W2N1 treatment was 8.8% higher than that in W1N2 treatment, the fertilizer-15N loss rate was 6.6% lower than that in W1N2 treatment, but there was no difference in the fertilizer-15N residue between the two. This study clarified that implementing W2 deficit irrigation (50% FC at the canopy rapid growth stage (45–90 DAE)) and N1 nitrogen application rate (33% nitrogen reduction based on 225 kg N ha−1) could not reduce TY but improve WP and NUE.

Comprehensive Evaluation of Tomato Growth Status under Aerated Drip Irrigation Based on Critical Nitrogen Concentration and Nitrogen Nutrient Diagnosis.

In order to provide a theoretical basis for the rational application of nitrogen fertilizer for tomatoes under aerated drip irrigation, a model of the critical nitrogen dilution curve was established in this study, and the feasibility of the nitrogen nutrition index (NNI) for the real-time diagnosis and evaluation of the nitrogen nutrient status was explored. The tomato variety "FENOUYA" was used as the test crop, and aerated drip irrigation was adopted by setting three levels of aeration rates, namely, A1 (dissolved oxygen concentration of irrigation water is 5 mg L-1), A2 (dissolved oxygen concentration of irrigation water is 15 mg L-1), and A3 (dissolved oxygen concentration of irrigation water is 40 mg L-1), and three levels of nitrogen rates, namely, N1 (120 kg ha-1), N2 (180 kg ha-1) and N3 (240 kg ha-1). The model of the critical nitrogen concentration dilution of tomatoes under different aerated treatments was established. The results showed that (1) the dry matter accumulation of tomatoes increased with the increase in the nitrogen application rate in a certain range and it showed a trend of first increase and then decrease with the increase in aeration rate. (2) As the reproductive period progressed, the nitrogen concentration in tomato plants showed a decreasing trend. (3) There was a power exponential relationship between the critical nitrogen concentration of tomato plant growth and above-ground biomass under different levels of aeration and nitrogen application rate, but the power exponential curves were characterized by A1 (Nc = 15.674DM-0.658), A2 (Nc = 101.116DM-0.455), A3 (Nc = 119.527DM-0.535), N1 (Nc = 33.819DM-0.153), N2 (Nc = 127.759DM-0.555) and N3 (Nc = 209.696DM-0.683). The standardized root mean square error (n-RMSE) values were 0.08%, 3.68%, 3.79% 0.50%, 1.08%, and 0.55%, which were less than 10%, and the model has good stability. (4) The effect of an increased nitrogen application rate on the critical nitrogen concentration dilution curve was more significant than that of the increase in aeration rate. (5) A nitrogen nutrition index model was built based on the critical nitrogen concentration model to evaluate the nitrogen nutritional status of tomatoes, whereby 180 kg ha-1 was the optimal nitrogen application rate, and 15 mg L-1 dissolved oxygen of irrigation water was the optimal aeration rate for tomatoes.

Protein Kinase N1 Level Predicts Acute Kidney Injury in Patients Undergoing Cardiac Surgery: A Prospective Cohort Study

Introduction: The objective of this study was to examine the utility of protein kinase N1 (PKN1) as a biomarker of cardiac surgery-associated AKI (CSA-AKI). Methods: A prospective cohort study of 110 adults undergoing on-pump cardiac surgery was conducted. The associations between post-operative PKN1 and CSA-AKI, AKI severity, need for renal replacement therapy (RRT), duration of AKI, length of ICU stay, and post-operative hospital stay were evaluated. Results: Patients were categorized into three groups according to PKN1 tertiles. The incidence of CSA-AKI in the third tertile was 3.4-fold higher than that in the first. PKN1 was an independent risk factor for CSA-AKI. The discrimination of PKN1 to CSA-AKI assessed by ROC curve indicated that the AUC was 0.70, and the best cutoff was 5.025 ng/mL. This group (>5.025 ng/mL) was more likely to develop CSA-AKI (p < 0.001). The combined AUC of EuroSCORE, aortic cross-clamp time, and PKN1 was 0.82 (p < 0.001). A higher level of PKN1 was related to increased need for RRT, longer duration of AKI, and length of ICU and post-operative hospital stays. Conclusions: PKN1 could be a potential biomarker for the prediction of CSA-AKI. The combination of PKN1, EuroSCORE, and aortic cross-clamp time was likely to predict the occurrence of CSA-AKI.

The Impact of Different Nitrogen Levels on the Tuber Yield and Anthocyanin Synthesis of Purple Potatoes

The biosynthesis of anthocyanins is influenced by external environmental conditions such as light, temperature, and nitrogen level, with nitrogen level being a key factor in anthocyanin synthesis and accumulation. Nitrogen level regulates the transcription factors involved in the anthocyanin synthesis pathway, with low nitrogen levels promoting anthocyanin accumulation, while high nitrogen levels have the opposite effect. Purple potatoes are a type of cultivated crop that is rich in anthocyanins and has unique economic value. Nitrogen fertilizer is crucial to improve the agronomic traits, yield, quality, and anthocyanin content of purple potatoes. In this study, the impact of four different nitrogen concentrations—0 kg/hm2 (N0), 90 kg/hm2 (N1), 225 kg/hm2 (N2) and 360 kg/hm2 (N3)—on the agronomic traits, yield, quality, and anthocyanin content of purple potatoes, ‘Huasong 66’, at different stages were investigated by using physiological index measurement and RNA-seq technology. It was found that the purple potato ‘Huasong 66’ was more sensitive to low nitrogen (N1). Under N1 level of nitrogen fertilization, ‘Huasong 66’ possessed the finest agronomic traits, yield, and quality, and the total anthocyanins in the tubers were significantly increased. Furthermore, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that nitrogen levels in purple potato tubers primarily affect genes related to nutrient transport and metabolism by regulating carbon and nitrogen metabolism, enzyme catalysis and binding, and signal transduction. In addition, nine candidate genes related to the anthocyanin synthesis pathway had been preliminarily screened. These results provide a basis to understand the impact of different nitrogen levels on the tuber yield and anthocyanin synthesis of purple potatoes.

Analysis and Implementation of CNN in Real- time Classification and Translation of Kanji Characters

This research explores the training outcomes of the Convolutional Neural Network (CNN) algorithm applied to Kanji character recognition. It employs a CNN architecture with 10 layers for recognizing digital image of Kanji characters from N5 to N1 levels. The training of the CNN model reveals varying accuracies, influenced by factors such as architecture, training data size, and data quality. The lowest accuracy, occurring at the beginning of training, highlights challenges like poor random weight initialization and suboptimal architecture. Conversely, the highest accuracy demonstrates the optimal predictive ability of the model after multiple training iterations. The iterative training process refines the model's accuracy over time, with initial challenges paving the way for a better understanding of the data for future improvements. In the subsequent analysis and system development phase, two algorithms are compared to assess the effectiveness of the CNN algorithm in Kanji character recognition. Testing is conducted at various complexity levels to systematically evaluate accuracy. This testing involves complexity levels at each Kanji character level to assess system accuracy. The developed model shows potential for real-time classification of Kanji characters, with a focus on error rate and accuracy during training and testing. The built model can essentially be used to evaluate the ability to recognize Kanji characters effectively. The model's performance can be assessed based on the error rate and accuracy achieved during the training and testing processes.

Modeling Spring Maize Grain Filling under Film Mulching and Nitrogen Application in a Cold and Arid Environment

The grain-filling process is a key stage in ensuring a high yield of maize. Nitrogen is one of the nutrient elements most essential for maize, especially in cold and arid areas. To evaluate the effects of plastic-film mulching and nitrogen application on the maize grain-filling process, the impact of different plastic-film mulching (degradable plastic film, J; common plastic-film mulching, P) and nitrogen fertilizer levels (0 kg·ha−1, N0; 160 kg·ha−1, N1; 320 kg·ha−1, N2; 480 kg·ha−1, N3) on maize grain-filling characteristic parameters and final 100-kernel weight were tested in 2021 and 2022. The results showed that the interaction between film mulching and nitrogen application significantly (p &lt; 0.05) affected the filling characteristic parameters and final 100-kernel weight of maize. The final 100-kernel weight was highest at the N2 nitrogen application level, which was 7.69–38.13% higher under degradable plastic-film mulching and 3.17–38.06% higher under common plastic-film mulching than at other levels. The nitrogen application level significantly (p &lt; 0.05) increased grain-filling duration and rate. The duration time in reaching the maximum grain-filling rate under the N2 nitrogen application level was around 1.1967–5.7835 d under degradable plastic-film mulching and 2.8688–8.1704 d under the common plastic-film mulching, with the maximum and average grain-filling rate increased by 0.0595–0.2063 g·d−1 and 0.0447–0.1423 g·d−1 under degradable film mulching and 0.1418–0.3058 g·d−1 and 0.1082–0.2125 g·d−1 under common film mulching, respectively. The nitrogen application levels of N2 and N3 under two plastic-film mulching methods prolonged the duration of the rapid and slow increase period of grain filling and increased the grain-filling rate and the average rate. The average grain-filling rate at the N2 level increased by 0.0469–0.1759 g·d−1 and 0.0090–0.0454 g·d−1 under degradable film mulching and 0.1113–0.2581 g·d−1 and 0.0203–0.0648 g·d−1 under common film mulching, respectively. Therefore, common plastic film mainly prolonged the duration of the gradual increase period of grain filling and increased the grain-filling rate; meanwhile, the effect of degraded plastic film on the grain-filling rate increase and prolonging of the grain-filling duration was gradually highlighted during the rapid and the slow period of increase. In addition, the 320 kg·ha−1 of nitrogen application level under both common plastic-film mulching and degradable-film mulching was more conducive to prolonging the grain-filling duration of maize, which increased the grain-filling rate and 100-kernel weight, laying a foundation for a high yield of maize.

Effects of hypobaria, hyperoxia, and nitrogen form on the growth and nutritional quality of lettuce

The objectives of this research were to investigate the impact of hypobaria, hyperoxia, and nitrogen form on the growth and nutritional quality of plants. Pre-culture 20-day-old lettuce (Lactuca sativa L. var. Rome) seedlings grew for 25 days under three levels of total atmospheric pressure (101, 54, and 30 kPa), two levels of oxygen partial pressure (21 and 28 kPa), and two forms of nitrogen (NO3N and NH4N). The ratios of NO3N to NH4N included 3: 1, 4: 0, 2: 2, and 0: 4. The nitrogen quantity included two levels, i.e. N1, 0.1 g N kg−1 dry matrix and N2, 0.2 g N kg−1 dry matrix. The growth status of lettuce plants in different treatments differentiated markedly. Regardless of the nitrogen factor, the growth status of lettuce plants treated with total atmospheric pressure/oxygen partial pressure at 54/21 was equivalent to the treatment of 101/21. Under the hypobaric condition (54 kPa), compared with 21 kPa oxygen partial pressure, hyperoxia (28 kPa) significantly inhibited the growth of lettuce plants and the biomass (fresh weight) decreased by 60.9%-69.9% compared with that under 101/21 treatment. At the N1 level, the sequence of the biomass of lettuce plants supplied with different ratios of NO3N to NH4N was 3: 1 > 4: 0 > 2: 2 > 0: 4, and there were higher concentrations of chlorophyll and carotenoid of lettuce plants supplied with the higher ratio of NO3 to NH4. At the N2 level, the effects of different ratios of NO3N to NH4N on lettuce plants were similar to those at the N1 level. The high nitrogen (N2) promoted the growth of lettuce plants such as 54/21/N2 treatments. Both form and nitrogen level did not affect the stress resistance of lettuce plants. Hypobaria (54 kPa) increased the contents of N, P, and K and hyperoxia (28 kPa) decreased the content of organic carbon in lettuce plants. The high nitrogen (N2) improved the content of total N and the N uptake. The ratios of NO3N to NH4N were 4: 0 and 3: 1, lettuce could absorb and utilize N effectively. This study demonstrated that hyperoxia (28 kPa) inhibited the growth of lettuce plants under the hypobaric condition (54 kPa), and high level of nitrogen (0.2 g N kg−1 dry matrix) and NO3N: NH4N at 3: 1 markedly enhanced the growth, the contents of mineral elements and the nutritional quality of lettuce plants.

Effect of Sowing Methods and Nitrogen Levels on Growth, Yield and Economics of Oats (Avena sativa L.) under Mid-Hills of Himachal Pradesh, India

In Himachal Pradesh, farmers typically possess small land holdings where machinery isn't practical for various sowing techniques, limiting them to broadcasting. Regarding nitrogen, it facilitates more vegetative growth by enhancing the photosynthetic rate. The higher the nitrogen content, the greater the vegetative growth potential. Therefore, present investigation titled “Effect of Sowing Methods and Nitrogen Levels on Growth, Yield and Economics of Oats (Avena sativa L.) under Mid-hills of Himachal Pradesh, India” was conducted during rabi season of 2022-23 at Chamelti Agriculture Farm, MS Swaminathan School of Agriculture, Shoolini University of Biotechnology and Management Sciences, Solan, Himachal Pradesh. The field experiment was laid out in Split Plot Design comprising twelve treatments with three replications. The experiment consists of three sowing methods in main plot i.e., (S1) Broadcasting, (S2) Line sowing and (S3) Crisscross and four levels of nitrogen N0 (0 kg ha-1), N1 (75 kg ha-1), N2 (100 kg ha-1) and N3 (125 kg ha-1) as sub plot. OL 12 variety of oats was used for sowing. Sowing methods and nitrogen levels were done as per treatment. Other crop management practices were followed as per the recommendation of the area. Results indicated that among the sowing methods, (S3) crisscross, recorded significantly higher growth and yield, over line sowing and broadcasting which was on par with (S2) line sowing over the rest of the treatments except for grain, straw and biological yield. In case of nitrogen levels, (N3) application of 125 kg N ha-1 recorded significantly higher growth and yield of oats, over rest of the nitrogen levels and was on par with 100 kg N ha-1. Economically, (S3) crisscross sowing with application of (N3) 125 kg N ha-1 resulted in higher gross returns, net returns and B: C ratio under Mid Hills of Himachal Pradesh.

The severity and yield effects of the chocolate spot disease in faba bean affected by intercropping and nitrogen input.

Study the disease suppression efficiency, yield losses rate, and yield benefits of intercropped faba bean against chocolate spot under nitrogen (N) input, to clarify the effectiveness of intercropping faba beans in controlling chocolate spot and its contribution to yield increase. Four N input levels and disease suppression treatments were discovered when faba bean-wheat intercropped was used. Adding N enhanced the chocolate spot's the area under disease progression curve (AUDPC) by 27.1-69.9%. In contrast to monoculture, intercropping reduced the AUDPC of the chocolate spot by 32.4-51.0% (P<0.05). Interestingly, the relative control efficacy (RCE) of intercropping at the EShan site was better. With disease suppression or non-suppression, N input increased grain yield loss and its components in faba bean. The total yield advantage effect (TE) and disease-suppressed yield recovery effect (DSE) of faba bean intercropped at the two experimental sites were significantly increased under N input (N1 and N2 level). The proportion of recovery yield due to intercropping suppressed disease (DSE/TE ratio) in Eshan (52.1%) was higher than that in Xundian (40.9%), and the DSE of intercropping played an indispensable role in the two sites. Regression analysis of AUDPC and grain yield loss amount showed that one unit increase in chocolate spot AUDPC could cause a grain yield loss of 0.38-0.86 kg·ha-1 . The partial land equivalent ratio(pLER) of intercropping faba beans at the EShan site was>0.33. In conclusion, intercropped faba bean with nitrogen treatment (45~90 kg·ha-1 ) was the best choice for maximizing the intercropping disease control effect. This article is protected by copyright. All rights reserved.

Is selective neck dissection effective for N1 (Level Ⅰ)? A systematic review

ObjectiveThis systematic review and meta-analysis aimed to compare the effectiveness of selective neck dissection (SND) and comprehensive neck dissection (CND) in patients with oral squamous cell carcinoma N1 (Level I). MethodsRandomized controlled trials and prospective and retrospective non-randomized clinical studies were selected and evaluated for the certainty of evidence using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. The statistical analysis was performed using Review Manager 5.4 software. ResultsWe included one observational study. The analysis revealed no difference in survival rates (overall survival, disease-specific survival, and regional control) between SND and CND for oral squamous cell carcinoma N1 (level I) cases. In the included study, the risk of bias was high, total sample size was small, and certainty of evidence was rated as "very low.". ConclusionThis systematic review and analysis suggested no difference in effectiveness between SND and CND; however, a high certainty of evidence could not be determined. Such evidence needs to be established through future systematic reviews, including randomized controlled trials with larger sample sizes.

Development of critical K dilution curves for diagnosing sweetpotato K status.

Scientific and reasonable application of potassium fertilizer is an important agronomic measure to achieve high yield and high quality of sweetpotato, and it is of great significance to determine the appropriate amount of potassium fertilizer in the field. For this we constructing a model of the critical K dilution curve (CKDC) of sweetpotato under different N levels to determine crop nutritional statuses. In this study, a 3-year field experiment was conducted in Zhejiang Province in China, using two nitrogen levels (N0: 0kg ha-1 and N1: 120kg ha-1) and five K fertilization rates (K0: 0, K1: 75, K2: 150, K3: 225, K4: 300kg ha-1) for two sweetpotato cultivars of 'Shang 19' and 'Yan 25'. Plant dry matter first increased and then decreased and the K concentration increased continuously with an increase in K application rate. The required amount of K fertilizer to achieve maximum sweetpotato yield under high N conditions was greater than that under low nitrogen conditions. A new CKDC based on dry matter and K concentration was created to assess K nutrition in sweetpotato. At two N levels, CKDC was expressed by the negative power function equation, aboveground: Kc(N0)=5.30W-0.463, R2=0.79, and Kc(N1)=4.23W-0.298, R2=0.78, under-ground: Kc(N0)=1.38W-0.125, R2=0.81, and Kc(N1)=1.32W-0.132, R2=0.72;whole-plant: Kc(N0)=4.31W-0.421, R2=0.80; Kc(N1)=3.89W-0.415, R2=0.79. There is no significantly different for CKDC of whole-plant and underground between N0 and N1 levels, while there is significantly different for CKDC of aboveground between N0 and N1 levels. N fertilizer can strengthen the dilution effect of K concentration, and its effect on the aboveground is greater than that on the underground and whole-plant. Then, potassium nutrition indexes were constructed to identify K nutrition status and could be used as a reliable indicator for K nutrition diagnosis of sweetpotato. The results provide a theoretical basis to improve K fertilization management and sustainability of sweetpotato.

Students' Learning Autonomy: A Case Study of Undergraduate Course of Japanese Language Program.

This research aimed to determine the impact of the effectiveness in the application of an independent method of teaching students on their progress in achieving a certain level of Japanese. The study used key methods that implied the experimental involvement of 60 3rd- and 4th-year American and Chinese students with the N3 and N2 levels of Japanese to pass a simplified version of the international JLPT (Japanese Language Proficiency Test) after applying the autonomy learning methodology. The analysis and processing of the experimental exam results were performed using the Microsoft Excel program and derivation of the average statistical percentage of the number of points scored at each stage of the N3 and N2 exams. The results of the study and the test scores led to the conclusion that the most difficult tasks for American students are those in writing and reading. On the other hand, Chinese students have difficulties in listening and speaking Japanese over linguistic phonetic differences and complex grammar compared to Chinese. Referring to the N2 group of American and Chinese students, their scores are somewhat equal due to the total complexity of this level, which requires utmost care for all four skills of foreign language learning. The present findings can serve as auxiliary material for the educational sphere in terms of an individual approach in autonomy learning to more effectively study Japanese and obtain positive results when passing the JLPT test.

Impact of soil fertility characteristics on artificial fertility gradient approach developed using sorghum (Sorghum bicolor) in Alfisols

In the advent of precision agriculture, applying fertilizer based on soil testing is a crucial tool to prescribe nutrient levels for crops, to increase nutrient use efficiency and production. A field experiment was conducted in a farmer's field in the Dindigul district, Southern agro-climatic zone of Tamil Nadu to ascertain the effect of artificial soil fertility gradient method on soil fertility, green fodder production of sorghum (Sorghum bicolor (L.) Moench) (var. CO 30) and nutrient absorption. A fertility gradient technique has been investigated to produce fertilizer recommendations for location-specific in red soils (Alfisols, Typic Rhodustalf). The experimental field was separated into three equal strips: strip I, II, and III, which received applications of the three graded levels of ertilizer N0P0K0, N1P1K1, and N2P2K2, respectively. Urea, single super phosphate, and muriate of potash fertilizers, respectively, were used to apply NPK. As a gradient crop, S. bicolor was raised. The N1 level was set based on the general fertilizer recommendation of feed sorghum, while the P1 and K1 values were set based on the soil’s ability to fix 100 kg ha-1 of phosphorus and 100 kg ha-1 of potassium, respectively. Plant samples were taken at harvest time, and their NPK content and nutrient uptake were determined. With addition of graded doses of nitrogen, phosphorus and potassium fertilizer in Strip I, II &amp; III increased the soil's available N, P &amp; K status substantially in the order of Strip I&lt;II&lt;III and minimize the heterogeneity in the soil population , management strategies employed, and prevailing climate conditions to induce fertility variations in the same field. The outcomes showed that sorghum crop yields for fodder (Strip III – 25.01 t ha-1) and NPK uptake were significantly impacted by the application of graded amounts of NPK fertilizers.

Nitrogen fertilizer combined with DPC+ chemical topping agent can improve cotton yield by enhancing antioxidant enzyme activity and improving the endogenous hormone balance

Nitrogen fertilizer and fortified DPC (DPC+) chemical topping agent management is essential for replacing manual topping and achieving simplified cotton cultivation. However, the response of cotton physiological characteristics to the interaction between nitrogen fertilizer and DPC+ and the relationship between this interaction and yield remain unclear. A 2-year field experiment was conducted to investigate the effects of nitrogen rates (N1, 150; N2, 300; N3, 450 kg ha−1) and DPC+ doses (D1, 450; D2, 750; D3, 1050 mL ha−1) and D0 (manual topping) on antioxidant enzymes, endogenous hormone content and balance, reproductive organ dry matter (RODM) and yield. N1D1, N2D2, and N3D3 significantly improved the RODM and yield, with N2D2 having 3.5 − 37.1% higher RODM levels than N1D1 and N2D2. At the N1 level, D1 decreased malondialdehyde (MDA) content by 4.1 − 35.6% compared to D0, D2 and D3, and increased catalase (CAT) activity and abscisic acid (ABA) content by 69.7% and 34.2% than D0, respectively. At the N2 level, D2 decreased the MDA content by 16.1 − 51.9% and increased peroxidase and CAT activity and ABA and gibberellic acid contents by 12.7 − 355.7% compared to D0, D1, and D3. Furthermore, D2 decreased indole-3-acetic acid (IAA) content and IAA/ABA by 12.1% and 30.5% in boll opening but increased trans-zeatin-riboside (ZR) content by 25.5% compared to D0. At the N3 level, D3 increased ZR/ABA by 20.1% compared to D0. Overall, the interactions between appropriate nitrogen levels and DPC+ doses can increase cotton yield by enhancing antioxidant enzyme activity and promoting endogenous hormone homeostasis, with N2D2 performing best.

Enhancing Rice Yield and Nitrogen Utilization Efficiency through Optimal Planting Density and Reduced Nitrogen Rates

Rice yields can only be achieved by selecting a high-quality population. Nitrogen rates and transplanting density play a significant role in determining population quality and yield. Field experiments were conducted in Heshan District, Hunan Province, China, to explore suitable nitrogen rates and appropriate transplanting densities for rice production in 2021 and 2022. In this study, three levels of nitrogen, e.g., N1, N2, and N3 (0, 150, and 210) kg ha−1, and three transplanting densities, e.g., B1, B2, and B3 (1, 2, and 3) seedlings per hill were used to study their individual or combined effects on rice (Taiyou 390) population quality, yield, and yield components, nitrogen-related enzyme activities, and nitrogen absorption and utilization efficiency. The results showed that N2B3 had the highest yield, with an average yield of 9.30 t ha−1 in two years, which was 3.7~49.6% higher than other treatments. This increase was attributed to higher dry matter accumulation (1538.22 g m−2) and effective panicle number (435.2 × 104 ha−1), influenced by increased nitrate reductase activity at the booting stage and glutamine synthase at the heading stage, along with maintenance of higher SPAD value and leaf area index. Nitrogen rates and transplanting densities significantly affected nitrogen use efficiency, with the contribution rate of nitrogen fertilizer to yield decreasing as nitrogen rates increased. However, N2B3 improved nitrogen use efficiency and stabilized rice yield by reducing nitrogen fertilizer application. This study suggested that N2B3 treatment could enhance rice yield by improving plant nitrogen use efficiency under low nitrogen supplementation.

STUDY OF THE GENETIC DIVERSITY OF SOME GENOTYPES OF MAIZE UNDER TWO LEVELS OF NITROGEN FERTILIZATION

The present study aimed to determine the genetic divergence of seven maize genotypes (Al-Maha, Sumer, Al-Fajr, Baghdad, 5018, 4 × 1 single hybrid, and 4 × 2 single hybrid) under two varied levels of nitrogen fertilization (92 and 276 kg N ha-1). The experiment occurred in 2022 in a randomized complete block design (RCBD) with a split-plot arrangement and three replications at the College of Agricultural Engineering Sciences, University of Baghdad, Iraq. The nitrogen fertilization levels served as main plots, with the maize genotypes allocated as the subplots. The results revealed that genetic variance was higher than the environmental variance for most traits, and the coefficient of phenotypic variation was close to the genetic variation coefficient under the two levels of nitrogen fertilization. Heritability (broad sense) at the 92 kg N ha-1 (N1 level) was the highest for traits. i.e., ear height, grains per row, grains per ear, individual plant yield, yield per unit area, days to 50% male flowering, leaf area, ear length, rows per ear, and 100-grain weight, with values of 92.556%, 90.760%, 90.123%, 95.007%, 95.007%, 88.976%, 89.974%, 88.748%, 85.521%, and 89.690%, respectively. For the N level of 276 kg ha-1 (N2 level), the heritability in a broad sense was high for the traits, viz., days to 50% male flowering (91.546%), plant height (96.150%), ear height (91.038%), ear length (92.454%), individual plant yield (98.108%), yield in the unit area (98.108%), and plant dry weight (85.488%). The cluster analysis divided the maize genotypes into four and five cluster groups under the nitrogen fertilization level of 92 and 276 kg N ha-1, respectively. These different groups of maize genotypes could be due to the genetic divergence among the genotypes resulting from their varied genetic makeup and origin.

Effect of Nano Urea and Zinc on Growth and Yield of Baby Corn (Zea mays L.) under Prayagraj Condition

A field experiment was conducted at the Crop Research Farm (CRF), Department of Agronomy, Naini Agricultural Institute, Sam Higginbottom University of Kharif season 2022. The experiment comprised of ten treatments of different combinations of Nanourea and Zinc nutrient management replicated thrice in a Randomized Block Design. The main objective of the experiment was to evaluate the “Response of Nano urea and Zinc on growth and yield of Baby corn (Zea mays L.)” Prayagraj condition. The three level of nano urea levels N1- 1 ml/l foliar spray nano urea, N2 -2 ml/l foliar spray nano urea and N3 - 3 ml/l foliar spray nano urea. Where-as three levels of zinc include like Z1- 20 kg/ha zinc, Z2- 25 kg/ha zinc and Z3- 30 kg/ha zinc. From the present investigation it may be concluded that the profitable production of baby corn can be secured by ZnSO4 30 kg/ha + Nanourea 3 ml/lt. (T9). Highest Gross returns (92087.17 ₹/ha), Net returns (61352.17 ₹/ha) and B:C ratio (2.00) were recorded significantly high with the application of ZnSO4 30 kg/ha + Nano urea 3 ml/lt.

Combining nitrogen effects and metabolomics to reveal the response mechanisms to nitrogen stress and the potential for nitrogen reduction in maize

The physiological and metabolic differences in maize under different nitrogen (N) levels are the basis of reasonable N management, which is vital in improving fertilizer utilization and reducing environmental pollution. In this paper, on the premise of defining the N fertilizer efficiency and yield under different long-term N fertilization treatments, the corresponding differential metabolites and their metabolic pathways were analyzed by untargeted metabolomics in maize. N stress, including deficiency and excess, affects the balance of carbon (C) metabolism and N metabolism by regulating C metabolites (sugar alcohols and tricarboxylic acid (TCA) cycle intermediates) and N metabolites (various amino acids and their derivatives). L-alanine, L-phenylalanine, L-histidine, and L-glutamine decreased under N deficiency, and L-valine, proline, and L-histidine increased under N excess. In addition to sugar alcohols and the above amino acids in C and N metabolism, differential secondary metabolites, flavonoids (e.g., kaempferol, luteolin, rutin, and diosmetin), and hormones (e.g., indoleacetic acid, trans-zeatin, and jasmonic acid) were initially considered as indicators for N stress diagnosis under this experimental conditions. This study also indicated that the leaf metabolic levels of N2 (120 kg ha–1 N) and N3 (180 kg ha–1 N) were similar, consistent with the differences in their physiological indexes and yields over 12 years. This study verified the feasibility of reducing N fertilization from 180 kg ha–1 (locally recommended) to 120 kg ha–1 at the metabolic level, which provided a mechanistic basis for reducing N fertilization without reducing yield, further improving the N utilization rate and protecting the ecological environment.

Abstract WP226: Circadian Rhythm Influences Immune Response In Ischemic Stroke Mice

Background: Stroke leads to disability and death worldwide. There is evidence that stroke affects the immune system function, and the clock gene controls the immune system. Stroke elevates the inflammatory cascade. Immune response controls the stroke pathology. However, it is unclear if the circadian rhythm influences the immune system in ischemic stroke mice and affects stroke outcomes. Hypothesis: We hypothesized that immune response might be affected by a circadian rhythm that aggravates stroke pathology in a mouse suture occlusion model Methods: Seven to eight-month-old C57BL/6J (Wild Type, n=8-10 mice/group) mice were randomly assigned to do stroke at the different time points of the day following zeitgeber time at ZT0, ZT6, ZT12, and Z18. Cerebral Ischemia was induced by occlusion of the middle cerebral artery (MCAO) for 60 min. Whole blood was analyzed using flow cytometry, and we observed macrophages (M1, M2), neutrophils (N1, N2), Anti-inflammatory IL10, and pro-inflammatory TNF-α cytokines at 24h and 48h. Forty-eight hours after stroke, TTC staining was done to estimate brain infarction, and the infarct area was measured using NIH-Image J software. Results: There was a significant increase ( p &lt;0.005) in TNF-α (9±2.50) and significant low IL-10 (5.12±1.35) ( p &lt;0001) at (ZT6, noon) stroke at 48h during a deep sleep period (ZT6, noon) stroke in comparison to fully awake period stroke. We found a significant increase ( p &lt;001) in M1 (54.12±5.16) macrophage and a significant decrease ( p &lt;001) in M2 (45.87±5.16) macrophage at ZT6 (noon) compare to other zeitgeber time points. We also found a significantly higher M1:M2 ratio (1.17) at ZT6. Additionally, we found that neutrophil N1 (66.88±4.39) level was significantly ( p &lt;0001) elevated while neutrophil N2 (33.88±4.43) was significantly reduced at ZT6 (noon) sleep period in comparison to ZT0, ZT12, and Z18 time points. We also found a considerably higher N1:N2 ratio (1.97) at ZT6. Conclusion: This study demonstrates that mice brain infarcts are influenced by immune responses that aggravate stroke pathology during their sleep period (noon/ZT6) than during their awake period (midnight/ZT18).