Increased Nitrogen Levels Research Articles

The effects of nitrogen on rose-scented pelargonium as a potted ornamental plant; growth and development, quality and biochemical characteristics

This study presents a novel approach to the production dynamics of rose-scented pelargonium for pot cultivation as an ornamental plant. It investigates how nitrogen supply affects plant growth, development, quality attributes, and biochemical properties to provide insights for enhanced commercial viability. Nitrogen concentrations (0, 50, 100, 200, and 400 mg l−1) were applied weekly for 3 months. Results show that increased nitrogen levels raised nitrogen concentrations in shoots (1.32%–2.57%) and roots (0.39%–1.27%). Periodic morphological evaluations indicated that the effects of nitrogen doses on growth started to appear after the second month of the experiment. By the end of the experiment (90th day), it was determined that increased nitrogen application resulted in reduced plant height, stem length, internode length, total phenolic compound (TPC) antioxidant capacity (DPPH) and malondialdehyde (MDA). In contrast, increases were observed in the number and length of lateral branches, stem thickness, leaf count, shoot biomass, chlorophyll (Clfs) levels and total carotenoid. MDA, TPC, and Clfs can be considered important biochemical indicators of nitrogen deficiency stress, defense mechanism, and plant quality in rose-scented pelargonium, respectively. It was determined that a minimum nitrogen concentration of 100 mg l−1 is required to obtain healthy, high-quality plants with strong visual appeal for the presentation of rose-scented pelargonium as potted ornamental plants. Higher concentrations may offer an advantage for more compact plant formation. To enhance the market value of rose-scented pelargonium as potted ornamental plants, future studies could include different pot sizes and pinching practices alongside nitrogen fertilization.

Climate change modulates the impact of nitrogen and enhances phosphorus-driven top-down control by zooplankton on harmful algae

Eutrophication and climate change are the main drivers of the increase in Microcystis biomass. These environmental factors also regulate the dynamics between planktonic predators and their prey. Here, we present the results of a controlled laboratory study investigating the top-down control efficiency of Paramecium on Microcystis under different nutrient (nitrogen and phosphorus) levels and climate conditions (current climate: 25 °C, 400 ppm; predicted future climate: 30 °C, 750 ppm). The results showed that Paramecium completely eliminated Microcystis populations under all combinations of nutrient levels and climate conditions. Furthermore, the ability of Paramecium to control Microcystis was modulated by nutrient enrichment and climate change. Specifically, key performance parameters—including the Microcystis population decline index, time for Microcystis elimination, ingestion rate and specific growth rate of Paramecium, and time to reach maximum Paramecium abundance—were inhibited by increasing nitrogen levels but improved by increasing phosphorus levels. This indicates that nitrogen enrichment weakened the ability of Paramecium to control Microcystis, whereas phosphorus enrichment enhanced it. Further analysis revealed that, regardless of nutrient availability, these parameters were optimized under the high-temperature-CO2 scenario, suggesting that climate change has consistently enhanced the top-down control of Microcystis by Paramecium. Notably, an in-depth examination of the overall change patterns of performance parameters and principal component analysis (PCA) revealed that climate change altered the response patterns of these parameters (or their comprehensive scores) to increased nitrogen and enhanced their response magnitude to increased phosphorus. Essentially, climate change compensated for the negative effects of increased nitrogen levels on the performance of Paramecium in controlling Microcystis and amplified the positive effects of increased phosphorus levels. These findings reveal that protozoan predators might enhance their top-down control of harmful algae under the interaction of eutrophication and climate change. This study, using Paramecium and Microcystis as models, provides valuable insights for managing freshwater ecosystems and applying protozoa to mitigate harmful algal blooms.

Effect of Different Doses of Nitrogen on Growth and Grain Yield of Hybrid Maize (Zea mays L., Gold 97)

This study investigates the impact of various nitrogen doses on the growth and grain yield of hybrid maize (Zea mays L., Gold 97). Nitrogen plays an important role in crop phenology, morphology, and grain yield of maize plants. A field experiment was conducted in a randomized complete block design with six levels of nitrogen (150, 160, 170, 180, 190, and 200 kg/ha) in four replications to evaluate the effect of different doses of nitrogen on the growth and yield of maize. Germination percentage, Days to 75% tasselling and silking, plant height, number of leaves, leaf area (LAI), cobs length, grain per row, pod, and total grain yield were recorded. Maximum germination was found in 180 kg N /ha. Plant height, number of leaves, and leaf area (LAI) were found to be maximum in the plots treated with 180-200 kg/ha of N. This field experiment revealed that different nitrogen dose has significant effects on days to 75% Tasselling and silking and found to be maximum in 180 kg/ha N treated plot. Also, nitrogen has a significant effect on cobs length, and grain per row was found highest at 180 kg N/ha. The highest Grain yield was found 180 kg/ha N treated plot. Findings have demonstrated that increasing nitrogen levels can often lead to increased grain yield up to a certain point, after which the yield plateaus or even declines. These findings provide valuable guidance for optimizing agricultural practices to meet the increasing global demand for cereal crops.

Effect of different doses of nitrogen and inoculation with Azospirillum brasilense on the productive characteristics of maize

This study assessed the effects of different nitrogen doses on maize crops, with and without the inoculation of Azospirillum brasilense. The experiment was carried out during the 2020/2021 harvest season in the administrative department of Concepción, district of Horqueta, Paraguay, at the coordinates of 23°14'31.7" S and 56°53'05.9" W. The experiment followed a randomized complete block design (RCBD) arranged in a factorial design (4 X 2). Factor A included nitrogen doses (0, 40, 80, and 120 kg ha-1), while factor B corresponded to the bacterial inoculation (with and without A. brasilense). The experiment was performed in three replications; each experimental unit (EU) was 22.5 m2. The study evaluated the following characteristics: plant height, cob insertion height, cob length and diameter, weight of 1000 kernels, and kernel yield. The data were analyzed using analysis of variance (ANOVA), and the averages were compared using Tukey's test at a 5% probability of error. Regression analysis was also carried out during the study. The experiment results demonstrated that increased nitrogen levels positively affected the measured characteristics, fitting a quadratic model, except for cob insertion height. Inoculation with A. brasilense significantly increased corn growth and productivity. The interaction of both factors produced a significant increase in cob length. Based on the experiment results, applying 104.30 kg ha-1 of N in combination with A. brasilense inoculation is recommended for improved maize production.

Effects of different nitrogen application rates and picking batches on the nutritional components of Lycium barbarum L. fruits.

Lycium barbarum L., commonly known as wolfberry, is not only a traditional Chinese medicine but also a highly nutritious food. Its main nutrients include L. barbarum polysaccharide, flavonoid polyphenols, carotenoids, alkaloids, and other compounds, demonstrating its wide application value. This study investigated the effects of nitrogen application on the accumulation of the main nutrients and metabolites in wolfberry fruits under three different nitrogen application rates, namely, N1 (20% nitrogen (N) reduction, 540 kg·ha-2), N2 (medium N, 675 kg·ha-2), and N3 (20% nitrogen increase, 810 kg·ha-2,which is a local conventional nitrogen application amount.). Additionally, due to continuous branching, blossoming, and fruiting of wolfberry plants during the annual growth period, this research also explored the variation in nutritional composition among different harvesting batches. The contents of total sugar and polysaccharide in wolfberry fruit were determined by Fehling reagent method and phenol-sulfuric acid method, respectively;The content of betaine in fruit was determined by high-performance liquid chromatography,and the flavonoids and carotene in the wolfberry fruits were determined by spectrophotometry. Analysis of data over three consecutive years revealed that as nitrogen application increased, the total sugar content in wolfberry fruits initially decreased and then increased. The levels of L. barbarum polysaccharides, total flavonoids, and total carotenoids initially increased and then decreased, while the betaine content consistently increased. Different picking batches significantly impacted the nutrient content of wolfberry fruits. Generally, the first batch of summer wolfberry fruits had greater amounts of total sugar and flavonoids, whereas other nutrients peaked in the third batch. By employing a broadly targeted metabolomics approach, 926 different metabolites were identified. The top 20 differentially abundant metabolites were selected for heatmap generation, revealing that the contents of L-citrulline, 2-methylglutaric acid, and adipic acid increased proportionally to the nitrogen gradient. Conversely, the dibutyl phthalate and 2, 4-dihydroxyquinoline contents significantly decreased under high-nitrogen conditions. The remaining 15 differentially abundant metabolites, kaempferol-3-O-sophorosid-7-O-rhamnoside, trigonelline, and isorhamnosid-3-O-sophoroside, initially increased and then decreased with increasing nitrogen levels. Isofraxidin, a common differentially abundant metabolite across all treatments, is a coumarin that may serve as a potential biomarker for wolfberry fruit response to nitrogen. Differentially abundant metabolites were analyzed for GO pathway involvement, revealing significant enrichment in metabolic pathways and biosynthesis of secondary metabolites under different nitrogen treatments. In conclusion, a nitrogen application of 675 kg·ha-2, 20% less than the local farmers' actual application, was most beneficial for the quality of four-year-old Ningqi 7 wolfberry fruits. Consumers who purchase wolfberry-dried fruit for health benefits should not consider only the first batch of summer wolfberry fruits. These results offer a broader perspective for enhancing the quality and efficiency of the wolfberry industry.

Appropriate Water and Nitrogen Regulation Improves the Production of Wolfberry (Lycium barbarum L.)

Wolfberry (Lycium barbarum L.) production in arid and semi-arid areas is drastically affected by the low utilization rate of soil and water resources and the irrational application of water and nitrogen fertilizers. Thus, this study explored a high-yielding, high-quality, and efficient irrigation and nitrogen regulation model to promote the production efficiency of wolfberry and rational utilization of water and land resources in arid and semi-arid areas. We compared and analyzed the effects of different soil water treatments (the upper and lower limits of soil water were estimated as the percentage of soil water content to field water capacity (θf), with the following irrigation regimen: adequate irrigation (W0, 75–85% θf), mild water deficit (W1, 65–75% θf), moderate water deficit (W2, 55–65% θf), and severe water deficit (W3, 45–55% θf)) and nitrogen levels (no nitrogen (N0, 0 kg·ha−1), low nitrogen (N1, 150 kg·ha−1), moderate nitrogen (N2, 300 kg·ha−1), and high nitrogen (N3, 450 kg·ha−1)) on the growth, physiology, and production of wolfberry. The results showed that water regulation, nitrogen application level, and their interaction significantly affected plant height and stem diameter growth amount (p < 0.05). Additionally, the relative chlorophyll content of wolfberry leaves first increased and then decreased with increasing nitrogen levels and water deficit. The average net photosynthetic rate (Pn), stomatal conductance (gs), intercellular carbon dioxide concentration, and transpiration rate (Tr) reached the highest values in plants exposed to W0N2 (19.86 μmmol·m−2·s−1), W1N1 (182.65 mmol·m−2·s−1), W2N2 (218.86 μmol·mol−1), and W0N2 (6.44 mmol·m−2·s−1) treatments, respectively. Pn, gs, and Tr were highly correlated with photosynthetically active radiation and water vapor pressure difference (goodness-of-fit: 0.366–0.828). Furthermore, water regulation and nitrogen levels exhibited significant effects on the yield and water- (WUE), and nitrogen-use efficiency (NUE) (p < 0.01), and their interactions exhibited significant effects on the yield, WUE, and nitrogen partial productivity of wolfberry plants (p < 0.05). Moreover, the contents of total sugar, polysaccharides, fats, amino acids, and proteins were the highest in W1N2, W1N2, W1N2, W2N3, and W0N2 treatments, respectively, which were increased by 3.32–16.93%, 7.49–54.72%, 6.5–45.89%, 11.12–86.16%, and 7.15–71.67%, respectively. Under different water regulations (except for the W3 condition) and nitrogen level treatments, the net income and input–output ratio of wolfberry were in the order W1 > W0 > W2 > W3 and N2 > N3 > N1 > N0. The TOPSIS method also revealed that the yield, quality, WUE, NUE, and economic benefits of wolfberry improved under the W1N2 treatment, suggesting that WIN2 might be the most suitable irrigation and nitrogen regulation model for wolfberry production in regions with scarce land and water resources such as the Gansu Province and areas with similar climate.

Response of tomato (Solanum lycopersicum) to varying levels of irrigation and nitrogen under trickle fertigation

An experiment was conducted during 2022 and 2023 at Lovely Professional University, Jalandhar, Punjab to study the response of tomato (Solanum lycopersicum L.) to 3 irrigation levels [I1, 70%; I2, 85% and I3, 100% of IWR] and 3 nitrogen fertilization levels [N1, 70%; N2, 85% and N3, 100% of RDN] in split plot design. On individual effect basis, the fruit yield first increased with the increase in amount of applied irrigation water in I2 (95.6 t/ha) and then decreased in I3 (93.5 t/ha). Irrigation water use efficiency (IWUE) was the highest in I2 (3.73 t/ha-cm). Plant growth, tomato yield and IWUE were significantly higher in N2 than that were found in N1 and N3. Nitrogen use efficiency (NUE) decreased with increasing nitrogen levels (N2 and N3) but it increased with increasing amount of water applied (I3). The treatments having deficit irrigation level as I1 and I2, significantly enhanced the lycopene content (27 to 33 µg/g) and reduced the nitrate content (74 to 95 mg/kg) in the fruit over full irrigation level I3. Nitrate content was highest in N3 (100 mg/kg). Among all the combination of irrigation and nitrogen fertilization levels the interaction of I2N2 (85% of IWR and RDN) was found the best to grow the drip-irrigated tomato crop. This combination gave optimum plant growth (87.5 cm), fruit yield (100 t/ha), IWUE (3.93 t/ha-cm), NUE (0.79 t/kg) and good quality fruit. The findings can be utilized for irrigation planning and nitrogen management in tomato cultivation and to conserve available fresh water resources in water scare regions of Punjab. In order to promote trickle fertigation at village level, the awareness programs for farmers could be conducted.

Effect of Crop Establishment Methods and Nitrogen Levels on Phenology, Quality, Nutrient Content and Uptake of Coarse Rice

A field experiment was conducted during the kharif season of 2020 at the farm of College of Agriculture, Kaul (Kaithal) of CCS Haryana Agricultural University, Hisar. The objective of the experiment was to study the response of a short-duration non-scented rice variety called HKR-48 to nitrogen fertilization under two different methods of crop establishment. The experiment followed a randomized complete block design (RBD) factorial design with the two establishment methods (direct seeding and transplanting) as main plot treatments and six levels of nitrogen (0, 30, 60, 90, 120, and 150 kg/ha) as sub-plot treatments, with three replications. The results of the experiment showed that the transplanted crop took longer to initiate tillering, anthesis (flowering), and reached maturity slightly earlier compared to the direct-seeded crop. However, both establishment methods showed similar timing for panicle emergence. The methods of crop establishment did not have a significant effect on kernel length, kernel breadth, NPK content, and protein content of the grains. However, the transplanted crop had improved hulling, milling, and head rice recovery compared to the direct-seeded crop. With increasing nitrogen levels, there was a delay in the days taken to attain tillering, panicle emergence, anthesis, and physiological maturity, following a graded response. The kernel length and breadth were not influenced by the graded doses of nitrogen. However, the quality parameters such as hulling, milling, head rice recovery, and protein content of the grains improved significantly with increasing nitrogen levels. The phosphorus (P) and potassium (K) content in the grain and straw remained unaffected by the different nitrogen doses, except for nitrogen content. The uptake of NPK by the crop (grain and straw) showed an increasing trend with higher nitrogen application

The impact of different preceding crops on soil nitrogen structure and nitrogen cycling in tobacco-planting soil

Soil nitrogen content, structure, and nitrogen cycling play a crucial role in tobacco growth quality, with different preceding crops having varying impacts on tobacco cultivation soil. This study conducted using field experiments, employed three treatments with different preceding crops, namely tobacco, barley, and rapeseed, to investigate the effects of different preceding crops on soil nitrogen structure and the expression levels of soil nitrogen cycling-related functional genes in tobacco cultivation soil. The results indicated that different preceding crops had varying effects on the content of different nitrogen forms in tobacco cultivation soil. Ammonium nitrogen and nitrate nitrogen were the two nitrogen forms which were most influenced by preceding crops, with the ammonium nitrogen content in soils following barley and rapeseed preceding crops increasing by 82.88% and 63.56%, respectively, compared to sole tobacco cultivation. The nitrate nitrogen content in tobacco cultivation soil was 26.97% higher following barley preceding crops and 24.39% higher following rapeseed preceding crops compared to sole tobacco cultivation. Simultaneously, different preceding crops also affected the expression levels of nitrogen cycling-related genes in tobacco cultivation soil. In the nitrification process, amoA was significantly impacted, with its expression reduced by 64.39% and 72.24% following barley and rapeseed preceding crops, respectively, compared to sole tobacco cultivation. In the denitrification process, except for the narG gene, all other genes were subjected to varying degrees of inhibition when preceded by barley and rapeseed crops. Correlation analysis between soil nitrogen structure and the expression levels of nitrogen cycling-related genes revealed that increased nitrogen levels suppressed the expression of Arch-amoA. Additionally, ammonium nitrogen strongly influenced the expression levels of most soil nitrogen cycling functional genes. In conclusion, preceding crops alter soil nitrogen structure, possibly due to changes in soil microorganisms, and different preceding crops modified the expression levels of nitrogen cycling-related genes in tobacco cultivation soil, consequently affecting the proportions of various nitrogen forms in the soil.

Productivity of Fodder Maize (Zea mays L.) SFM-1 under Varied Sowing Dates and Nitrogen Levels

This field experiment was carried out at Faculty of Agriculture, Wadura, Sher-e-Kashmir University of Agricultural Sciences & Technology of Kashmir during (April-October) kharif, 2022. The experiment was laid out in the split-plot design with four sowing dates (15th April, 15th May, 15th June and 15th July) and four nitrogen levels (0, 60, 120 and 180 kg ha-1) with three replications to study the effect of sowing dates and levels of nitrogen on growth, biomass, yield, quality and the nitrogen use efficiency of fodder maize. The growth parameters viz., plant height, leaf area index, number of leaves per plant were significantly influenced by varying sowing dates and nitrogen levels and higher values of these parameters were obtained with early sowing of 15th April. The dry matter accumulation, number of leaves per plant and green fodder yield were significantly higher at early sowing of 15th April. The maximum crude protein content (%) and ash content (%) were also recorded with sowing on 15th April. In case of nitrogen levels, the growth, yield and quality parameters viz., plant height, leaf area index, leaf stem ratio, number of leaves per plant, dry matter yield, green fodder yield, dry fodder yield, crude protein and ash content were significantly improved up to nitrogen level N3. However, NDF (%) and ADF (%) decreased with an increase in nitrogen levels and was lowest at N3 level.

Eficiência do nitrogênio em pastagens de capim-marandu adubadas com doses crescentes de nitrogênio

ABSTRACT: The use of nitrogen (N) in pastoral ecosystems leads to increased productivity, as it allows the plant to elongate its leaves and, therefore, grazing herbivores harvest the green leaves. However, there are very volatile N sources, which can be replaced by ammonium nitrate, which is less volatile and less dependent on the application in rainy days. The treatments are compound of Marandu palisade grass pastures managed under continuous stocking at a canopy height of 25 cm, with different levels of N fertilizer: 0, 75, and 150 kg ha-1year-1, as ammonium nitrate (32% of N), with four replicates (pastures) in a completely randomized design. Nitrogen uptake (54.9, 96.5, 113.8 kg N ha-1) and N nutrition index (0.67, 0.98, 1.15) were different between N level, respectively, 0, 75 and 150 kg ha-1 year-1. The N recovery (58.3, 40.9 %) differed between 75 and 150 kg ha-1 year-1, respectively. The dose of 75 kg N kg ha-1 year-1 results in better N utilization, while the dose of 150 kg N ha-1 year-1 enables greater stocking rate; therefore, requiring less grazing area.

Effect of Different Nitrogen and Potassium Levels on Yield and Nutrient Uptake of RNR 15048 during Summer Season in Southern Odisha

Background: The low glycemic rice variety RNR 15048 was introduced in Southern Odisha recently but the nitrogen and potassium requirement was not worked out for rabi / summer season. Methods: In this study, RNR 15048, a low glycemic index rice variety, was conducted in a split plot design with four main plots at 0, 50, 100 and 150 kg of nitrogen per hectare and three subplot levels at 0, 30 and 60 kg of potassium per hectare, each of which was reproduced three times. Result: A significant increase in yield, yield components and NPK uptake was noted with increase in nitrogen levels from 0 to 50, 100 and 150 kg/ha and potassium levels from 0 to 30 and 60 kg/ha.

Effect of Different Levels of Nitrogen and Phosphorus on Yield and Nutrient Uptake of Low Glycemic Index Rice Variety RNR 15048 during Summer Season

A low glycemic index fine rice variety RNR 15048 (Telangana Sona) suitable for both kharif and summer seasons was introduced in southern Odisha in 2019 kharif season. Its nitrogen and Phosphorus requirement was not worked out for kharif / rabi / summer seasons. An experiment was conducted during summer season of 2022 at M.S. Swaminathan School of agriculture (MSSSoA), Parlakhemundi, Odisha to study the effect of nitrogen and phosphorus levels on yield attributes and yield of low glycemic rice variety RNR 15048 in split plot design with four levels of nitrogen (0, 50, 100 and 150 kg/ha) in main plots and three levels of phosphorus (0, 30 and 60 kg/ha) in subplots replicated three times. The panicle number, number of spike lets per panicle, number of filled spike lets and 1000 grain weight, grain, straw and biological yield and NPK uptake in grain and straw increased significantly with increase in nitrogen levels from 0 to 50, 100 and 150 kg ha-1 and phosphorus level from 0 to 30 and 60 kg ha-1. For low glycemic index rice variety RNR 15048 during summer, application of 150 kg N and 60 kg P2O5 along with 50 kg K2O ha-1 found to give higher yield in southern Odisha.A low glycemic index fine rice variety RNR 15048 (Telangana Sona) suitable for both kharif and summer seasons was introduced in southern Odisha in 2019 kharif season. Its nitrogen and Phosphorus requirement was not worked out for kharif / rabi / summer seasons. An experiment was conducted during summer season of 2022 at M.S. Swaminathan School of agriculture (MSSSoA), Parlakhemundi, Odisha to study the effect of nitrogen and phosphorus levels on yield attributes and yield of low glycemic rice variety RNR 15048 in split plot design with four levels of nitrogen (0, 50, 100 and 150 kg/ha) in main plots and three levels of phosphorus (0, 30 and 60 kg/ha) in subplots replicated three times. The panicle number, number of spike lets per panicle, number of filled spike lets and 1000 grain weight, grain, straw and biological yield and NPK uptake in grain and straw increased significantly with increase in nitrogen levels from 0 to 50, 100 and 150 kg ha-1 and phosphorus level from 0 to 30 and 60 kg ha-1. For low glycemic index rice variety RNR 15048 during summer, application of 150 kg N and 60 kg P2O5 along with 50 kg K2O ha-1 found to give higher yield in southern Odisha.

Performance of wheat (Triticum aestivum L.) under different planting patterns and nitrogen levels

The field experiment was conducted on the research farm of Department of Agronomy, Lovely Professional University, Phagwara (Punjab) on, “Performance of wheat (Triticum aestivum L.) under different planting patterns and nitrogen levels”. The field study was conducted in Split Plot Design with three planting patterns viz. 2 rows/bed, cross sowing, flat sowing in main plots and five nitrogen levels viz. 0 kg/ha, 40 kg/ha, 80 kg/ha, 120 kg/ha, 160 kg/ha in sub plots. The result revealed that significantly higher grain yield was obtained from two rows/bed (43.86 q/ha) followed by cross sowing (42.48 q/ha) and flat sowing (40.77 q/ha). Also bed sowing increased grain yield of wheat by 4.2 and 7.6 % than cross and flat sowing respectively. Also cross sowing method recorded significantly more grain yield than line sowing method. Grain yield was significantly higher with use of 160 kg N/ha (54.95 q/ha) as compared to all other nitrogen levels. There was subsequent and significant increase in grain yield of wheat with successive increase in nitrogen level from 0 to 160 kg/ha. Grain yield of 0 kg N/ha was significantly less than all other nitrogen levels. There was 100.4, 92.7, 60.0 and 19.6 percent increased in grain yield of wheat with the application of 160 Kg, 120 Kg, 80 kg and 40 kg N respectively as compared to 0 kg N/ha (control).

Response of sesame (<i>Sesamum indicum</i> L.) to moisture regime and nitrogen fertilizer in Ilorin, Nigeria

A potted experiment was conducted at the Faculty of Agriculture screen house, University of Ilorin, Nigeria in 2018 and 2019 planting seasons to evaluate the performance of sesame to different moisture regimes and nitrogen fertilizer application. The experiment was a factorial fitted into a randomized complete block design and replicated four times. The treatments consisted of four nitrogen levels (0, 30, 60 and 90 kg N/ha) and four moisture regimes (every day, every five days, every ten days, and fifteen days). Data were collected on growth parameters (plant height, number of leaves per plant as well as yield component (seed yield per plant) Data were analyzed by the analysis of variance, using the GenStat 17th edition and significant means were separated by the least significant difference at 5% probability level. The result of the study revealed that increasing nitrogen levels from 0 to 90kgN/ha and moisture regimes from 15 days to every day resulted in a significant (p<0.05) increase in plant height, number of leaves and yield per plant and farmers are therefore encouraged to cultivate sesame crop using these rates for maximum yield. From the result of the study, using Nitrogen fertilizer at the rate 60 kgha-1 increased the growth and yield attribute of sesame and therefore should be encourage among farmers.

Creep deformation and constitutive modelling of 316LN SS with varying nitrogen content

In this investigation, two different constitutive models were employed to examine the creep deformation and damage behaviour of nuclear grade austenitic 316LN SS with four different nitrogen contents (0.07–0.22 wt%) at 923 K. Creep deformation resistance of the alloys investigated by “internal-stress based kinetic creep law” for primary and secondary creep stages revealed an increase in internal stress and decrease in obstacle spacing accompanied with lower dynamic recovery with increasing nitrogen. The aforementioned outcomes substantiated the experimentally observed beneficial role of nitrogen on lowering of creep strain rate with increasing nitrogen level. In contrast to the above observations, the analysis of coupled creep deformation and damage using the Kachanov-Rabotnov model and the subsequent development of iso-damage contours indicated evolution of higher creep damage at lower strains with increasing nitrogen content. With increasing % nitrogen, damage rate dominated over the strain rate thus justifying the observed significant intergranular damage at and above 0.14% N. Based on the above results and in-house studies on low cycle fatigue and creep–fatigue interaction, optimum nitrogen content is suggested between 0.07 and 0.14% N in 316LN SS that combines the benefits of low nitrogen content and strengthening effects of high nitrogen content.

Performance of Promising Rice Genotypes as Affected by Different Nitrogen Levels in Central Terai of Nepal

Application of appropriate level of nitrogen (N) for rice is a key to increase nitrogen use efficiency thereby yields. Six rice genotypes under six N levels were evaluated in a split plot design with three replications under irrigated conditions in National Rice Research Program, Dhanusha during 2020 with the objective of determining the high yielding variety and the best dose of N for obtaining higher yield. The six rice genotypes were NR 2168, NR 2158, NR 2157-122, NR 2175, NR 2182 and PR 126 while various N levels were 0. 75, 100, 125, 150 and 175 kg N ha-1. The results indicated that NR 2182 recorded the highest grain yield of 5.28 t ha-1 while PR 126 recorded the lowest grain yield 3.98 t ha-1. A linear increase in grain yield was observed with a continuous increase in N level from 0 to 150 kg ha-1 while it decreased thereafter. The grain yield was significantly higher with the application of 150 kg N ha-1 as compared to control. Agronomic N use efficiency for studied rice genotypes varied significantly and ranged from negative to 12.63 kg grain yield per kg of N applied. NR 2182 recorded the highest value of agronomic nitrogen use efficiency for the N level of 150 kg ha-1. It can be concluded that increasing nitrogen levels resulted in significant variations in the response of different varieties, with all varieties consistently recording lower yields at highest N levels. Thus, opting for an intermediate N level appears both economically prudent and environmentally sustainable.

Effects of Different Nitrogen Levels on Lignocellulolytic Enzyme Production and Gene Expression under Straw-State Cultivation in Stropharia rugosoannulata.

Stropharia rugosoannulata has been used in environmental engineering to degrade straw in China. The nitrogen and carbon metabolisms are the most important factors affecting mushroom growth, and the aim of this study was to understand the effects of different nitrogen levels on carbon metabolism in S. rugosoannulata using transcriptome analysis. The mycelia were highly branched and elongated rapidly in A3 (1.37% nitrogen). GO and KEGG enrichment analyses revealed that the differentially expressed genes (DEGs) were mainly involved in starch and sucrose metabolism; nitrogen metabolism; glycine, serine and threonine metabolism; the MAPK signaling pathway; hydrolase activity on glycosyl bonds; and hemicellulose metabolic processes. The activities of nitrogen metabolic enzymes were highest in A1 (0.39% nitrogen) during the three nitrogen levels (A1, A2 and A3). However, the activities of cellulose enzymes were highest in A3, while the hemicellulase xylanase activity was highest in A1. The DEGs associated with CAZymes, starch and sucrose metabolism and the MAPK signaling pathway were also most highly expressed in A3. These results suggested that increased nitrogen levels can upregulate carbon metabolism in S. rugosoannulata. This study could increase knowledge of the lignocellulose bioconversion pathways and improve biodegradation efficiency in Basidiomycetes.

Soil Nutrient, Salinity, and Alkalinity Responses of Dendrocalamopsis oldhami in High-Latitude Greenhouses Depending on Planting Year and Nitrogen Application

This study explored the viability of greenhouse cultivation of Dendrocalamopsis oldhami under the “South Bamboo North Transplanting” initiative. In this study, the effects of planting year and nitrogen application on changes in soil nutrient levels, salinity, and alkalinity over the plant growth period were explored. After the introduction and planting of bamboo in 2017, a soil layer with a thickness of 0–40 cm was sampled at the end of the shooting stage in the greenhouse between 2017 and 2019 (late August), and the bamboo shoot yield and standing culm density were measured. Following the application of nitrogen to the bamboo groves in 2019, three nitrogen levels were established: no nitrogen (N1:0 g grove−1), medium nitrogen (N2:540 g grove−1), and high nitrogen (N3:1080 g grove−1). Soil layers at depths of 0–20 and 20–40 cm were sampled during the shoot elongation stage (late May) and at the end of the shooting stage (late August). The yield and nutrient content of bamboo shoots under different nitrogen treatments were also investigated. The results showed that Ca2+ and HCO3− were the main salt ions in greenhouse soil. With later planting years, the total number of cations (Ca2+, Na+, Mg2+, and K+) decreased, whereas the total number of anions (HCO3−, SO42−, NO3−, and Cl−) increased, resulting in a decrease in the percentage of exchangeable sodium (ESP), pH, and electrical conductivity (EC). The diameter at breast height, individual weight, and quantity of bamboo shoots increased annually, and the standing culm density increased by 1.4 times. Each year, the total nitrogen content decreased, whereas the alkali-hydrolyzed nitrogen, available phosphorus, and available potassium contents increased. Nitrogen application resulted in a significant decrease in ESP and pH and an increase in the total anion, cation, and EC values. It also reduced soil organic carbon, total nitrogen, total phosphorus, total potassium, available phosphorus, and available potassium. Nitrogen application increased the number of bamboo shoots, total yield, and accumulation of N and P; however, there was no significant difference between N2 and N3. In conclusion, the salinization of calcareous soil was alleviated, and the available nutrients were activated following the introduction of D. oldhami from south to north. The mineralization rates of organic matter and soil fertility increased. Soil acidification and EC decreased at the end of the shoot stage. Nitrogen application acidified the soil, and the yield and soil salt accumulation increased with increasing nitrogen levels. The nutrient uptake efficiencies of nutrients at high nitrogen levels were lower than those at medium nitrogen levels. Therefore, soil salt concentrations with values 0.26 < EC < 0.42 hindered the nutrient uptake of D. oldhami.

Effects of Irrigation Scheduling and Nitrogen Levels on Soil Nutrient and Their Uptake in Radish (Raphanus Sativus L.) in Mid Hills of North-Western Himalayas, India

ABSTRACT Irrigation and N are the main two limiting factors for the radish growth and soil nutrient pool. Inappropriate irrigation and nitrogen application can negatively affect the soil nutrient status and accelerate nutrient losses which can lead to ground water pollution and soil degradation. In this study, four irrigation schedules viz. I0 (no irrigation), I1-IW/CPE = 0.8, I2-IW/CPE = 1.0, I3-IW/CPE = 1.2 and three N levels i.e. N0 (no N application), N1 (75% RDN) and N2 (100% RDN) were evaluated and replicated thrice in a RBD (factorial) during 2016–17 and 2017–18 at experimental farm of Dr YSP University of Horticulture and Forestry Nauni, Solan (HP), on sandy loam soil. Results revealed that irrigation and nitrogen levels had a significant effect on soil nutrient contents and maximum available N, P contents were observed under N2I1, N0I0 respectively, while available K, Ca, Mg and sulfate sulfur were highest under N2I3. Nutrient uptake significantly enhanced with increase in irrigation and N levels due to their solubilility and mobility. Lowest values were recorded under control. Nitrogen use efficiency decreased with increase in nitrogen levels. Results of study could be highly supportive in selecting appropriate irrigation schedule (I3) and N (100% RDN) level for fertility and efficient management of scarce water resources.