N2 Treatment Research Articles

Development of a Concurrent Treatment Technique of Ethyl Formate and Mixtures (Nitrogen, Phosphine) to Control Citrus Mealybug (Planococcus citri).

Currently, the fumigant ethyl formate (EF) is stored as a liquified gas in metal cylinders mixed with carbon dioxide (CO2), but this product type is expensive to manufacture, transport, and maintain in cylinders. To address these problems, we developed a new EF fumigation technique with a nitrogen (N2) carrier. In this report, the susceptibility of citrus mealybugs, one of the most resistant mealybugs to fumigants, to EF was assessed; the phytotoxicity of an EF + N2 concurrent treatment applied to banana fruit was examined to evaluate the efficacy compared to the current EF + CO2 product; and the increased efficacy with a phosphine (PH3) addition to EF + N2 was also assessed. Concurrent treatment of EF and N2 was performed at an LC50 concentration of EF. N2 was applied in seven doses from concentrations of 79% to 95%. The phytotoxicity of EF to bananas was assessed by applying EF at 35 mg/L with N2 at 79%, and the color, sugar content, and weight loss of bananas were measured for 14 days after treatment. The EF with N2 treatment resulted in more than 50% mortality at all growth stages of the mealybug, and there was no significant difference between the untreated and treated banana fruits. EF mixed with PH3 showed a higher efficacy than treatment with EF alone, but only a slight increase in efficacy was observed when the PH3 concentration increased. These results indicate that concurrent treatment with EF and N2 can be used to control mealybugs on banana fruits, and combined treatment with EF and PH3 can also enhance the efficacy against mealybugs.

Nitrogen Addition Affects Interannual Variation in Seed Production in a Tibetan Perennial Herb.

The variability observed in the annual seed production of perennial plants can be seen as an indication of changes in the allocation of resources between growth and reproduction, which can be attributed to fluctuations in the environment. However, a significant knowledge gap exists concerning the impacts of nitrogen addition on the interannual seed production patterns of perennial plants. We hypothesized that the addition of nitrogen would impact the annual variations in the seed production of perennial plants, ultimately affecting their overall reproductive efficiency. A multiyear field experiment was conducted to investigate the effects of varying nitrogen supply levels (e.g., 0, 4, and 8 kg N ha-1 yr-1 of N0, N4, and N8) on vegetative and floral traits, pollinator visitation rates, and seed traits over a period of four consecutive years. The results showed that the N0 treatment exhibited the highest levels of seed production and reproductive efficiency within the initial two years. In contrast, the N4 treatment displayed its highest level of performance in these metrics in the second and third years, whereas the N8 treatment showcased its most favorable outcomes in the third and fourth years. Similar patterns were found in the number of flowers per capitulum and the number of capitula per plant. There exists a positive correlation between aboveground biomass and several factors, including the number of flowers per capitulum, the number of capitula per plant, the volume of nectar per capitulum, and the seed production per plant. A positive correlation was found between pollinator visitation and the number of flowers per capitulum or the number of capitula per plant. This implies that the addition of N affected the maintenance of plant aboveground biomass, flower trait stability, pollinator visitation, and, subsequently, the frequency of seed production and reproductive efficiency. Our results suggest that augmenting the nitrogen content in the soil may have the capacity to modify the inherent variability in seed production that is observed across various years and enhance the effectiveness of reproductive processes. These findings have the potential to enhance our comprehension of the impact of nitrogen addition on the reproductive performance of perennial herbaceous plants and the underlying mechanisms of biodiversity in the context of global environmental changes.

Realization of Visible‐Light Detection in InGaZnO Thin‐Film Transistor via Oxygen Vacancy Modulation through N2 Treatments

AbstractInGaZnO (IGZO) thin‐film transistors (TFTs) have gained widespread use in active matrix (AM) displays due to their decent field‐effect mobility and low off current. However, the wide bandgap of IGZO limits their application in visible light detection. This study presents an industry process‐compatible method to achieve visible light detection in IGZO TFTs through N2 treatment during the sputtering and annealing process for the first time. A comparison with control IGZO TFTs shows that the N2‐treated IGZO TFTs exhibit a high responsivity of 0.66 A W−1 and detectivity of 5.40 × 1014 Jones for visible light detection. Based on X‐ray photoelectron spectroscopy analysis and technology computer‐aided design simulations, a model, focusing on oxygen vacancy modulation, is proposed to explain the visible‐light sensitivity in IGZO TFTs with N2 treatment. This work opens up new possibilities for the integration of IGZO photodetector into AM display panels to realize in‐cell environmental detection and biometric recognition.

Deficit irrigation combined with nitrogen application in the early growth stage of sugar beet increases the production capacity of canopy and avoids yield loss.

Properly reduced irrigation combined with nitrogen (N) application can be used to improve crop water use efficiency (WUE) in arid regions, but its effect on sugar beet is unknown at present. A two-year field experiment was conducted to evaluate the effects of N application (N0, 0; N1, 150; N2, 225 kg N ha-1 ) on the canopy production capacity (CPC), yield and WUE of sugar beet under normal irrigation (W1, 70% of field capacity (FC)) and deficit irrigation (DI) (W2, 50% FC) in the early growth stage (EGS). The results showed that the W2 treatment reduced the CPC by reducing gas exchange, leaf area index (LAI) and chlorophyll content (SPAD value) of sugar beet leaves compared to the W1 treatment. However, DI combined with N application increased these parameters. Specifically, N application increased the net photosynthetic rate by 40.7% by increased gas exchange, SPAD and LAI compared to the N0 treatment. In addition, N application increased WUE by 12.5% by increasing thickness of upper surface, stomatal aperture and cross-sectional area of petiole. This ultimately led to a significant increase in taproot yield (TY; 19.7%) and sugar yield (SY; 57.6%). Although the TY of the N2 treatment was higher than that of the N1 treatment, the SY and WUE did not increase significantly and the harvest index decreased significantly by 9.3%. DI combined with 150 kg N ha-1 in the EGS of sugar beet increases the WUE in arid areas while avoiding yield loss by improving the CPC. © 2023 Society of Chemical Industry.

Effect of topdressing time on spring maize yield and nitrogen utilization in black soil of northeast China

Topdressing time is crucial to achieving a high yield. To determine the optimum topdressing time for spring maize in the black soil of northeast China in the “one base and one topdressing” mode, the effects of topdressing time of nitrogen (N) fertilizer on maize yield, N utilization, and inorganic N residue and distribution were investigated by using 15N labeling technique. Four treatments were designed: no N fertilizer (N0), N fertilizer topdressing at jointing stage (N1), N fertilizer topdressing at belling stage (N2), and N fertilizer topdressing at tasseling stage (N3). The results showed that compared with N1 and N3, the maize yield, N uptake and N use efficiency (NUE) in N2 treatment significantly increased by 12.1% and 24.7%, 10.0% and 16.0%, and 26.4% and 38.9%, respectively (P < 0.05). The later the topdressing time, the more inorganic N remained in the soil profile (0–60 cm). The rate of potential N loss was higher when the topdressing time was too early or too late. Compared with N1, the residual amount of 15N in the soil profile (0–60 cm) of N2 and N3 treatments increased by 17.2% and 44.8%, respectively. The soil inorganic N (SIN) accumulation in the deep soil profile (40–60 cm) of N2 treatment decreased by 7.6% and 42.7%, respectively, as compared with N1 and N3. Therefore, the application of N fertilizer at the belling stage was beneficial to the high yield and efficient production of maize in the black soil region of Northeast China.

Effects of Water and Nitrogen Coupling on Yield, Quality, Water and Nitrogen Use Efficiencies of Greenhouse Muskmelon

The proficient supply of water and nitrogen is a key factor in facility agriculture. In order to pursue high yields, most farmers blindly irrigate and fertilize, leading to yield reduction, quality decline, soil salinization, and fertility destruction. A successive two-year greenhouse experiment was carried out on fruit quality, yield, irrigation water use efficiency (IWUE), and nitrogen use efficiency (NUE) of greenhouse muskmelon (Cucumis melo L.) under drip fertigation, which can provide a scientific basis for local muskmelon intensive production in Southeast China. The experiments were conducted in 2020 and 2021, with three irrigation levels 80% (W1), 100% (W2), and 120% (W3) of ETc and three N levels 60 (N1), 95 (N2), and 130 (N3) kg N ha−1. The amount of drip irrigation water was determined every 5 days based on crop evapotranspiration (ETc). The seasonal irrigation amount ranged from 209.77 mm to 298.86 mm in 2020 and from 201.22 mm to 286.04 mm in 2021. The highest muskmelon yield was obtained in the treatment of W3N3 with an average of 27.38 t ha−1 in 2020 and 27.10 t ha−1 in 2021. Although the yield was improved by increasing nitrogen supply, there was no significant difference between N2 and N3 treatment in two years under the irrigation level of W2 and W3. The highest irrigation water use efficiency was observed in the W1N3 treatment in 2020 and 2021. The NUE increased with decreasing N rates at the same irrigation level. Under the same nitrogen application level, TSS and Vc under low water (W1) were higher than that under medium water (W2) and high water (W3) treatment. The highest content of nitrate in low water and high nitrogen (W1N3) treatment was 55.41 µg/g in 2020 and 52.50 µg/g in 2021, respectively. The yield and quality of muskmelon are often incompatible, for instance, W2N2 treatment can obtain a higher yield, but W1N2 treatment maximizes Vc, TSS of muskmelon quality. Our findings suggest that the irrigation level of 1.0 ETc, nitrogen level of 95 N ha−1, and 3500 kg·ha−1 of decomposed organic fertilizer was recommended as the best combination, which can improve the yield, quality, IWUE, NUE of muskmelon under drip fertigation with soil mulching in the experimental site.

Evaluating hydrophobic recovery of N2 and H2O(g) plasma modified silk fibroin films aged at ambient and elevated temperatures.

Silk fibroin is a naturally derived polymer with great potential for biomedical use due to its strength, lack of immune response, and ability to biodegrade. The relatively hydrophobic nature of silk, however, can cause challenges with cell adhesion in vivo. Therefore, modification must be performed to improve the surface hydrophilicity, enhancing silk utility in the biomedical space. Low-temperature plasma (LTP) treatment is an established method for polymer modification and has the benefits of being a solvent-free, adaptable process. N2 and H2O(g) LTP treatments are both well-documented as strategies to enhance polar functional groups on a polymer's surface. However, many polymers tend to revert to their original hydrophobic state upon aging, reversing the effects of LTP modification. The hydrophobic recovery of N2 and H2O(g) LTP-modified silk has not been previously studied but has important implications for the uses and longevity of silk substrates in biomedical contexts. The goal of this study was to systematically evaluate the hydrophobic recovery of N2 and H2O(g) LTP-treated silk films. Films were LTP-modified using optimized plasma parameters (applied power, pressure, treatment time) and aged under both ambient and elevated temperature conditions up to 6 weeks after the initial treatment. Silk film surface properties were evaluated immediately after treatment and throughout the aging process using both water contact angle goniometry and x-ray photoelectron spectroscopy. LTP-treated silk films demonstrated a significant decrease in hydrophobicity compared to the untreated controls. Remarkably, both N2 and H2O(g) LTP modifications resulted in surfaces that retained hydrophilic properties over the 6 week aging period. Our findings represent a departure from what has been previously demonstrated in most LTP-modified synthetic polymers, suggesting that the secondary structure of silk fibroin plays a critical role in resisting hydrophobic recovery.

Improving Production Yield and Nutritional Quality of Coastal Glehnia Using Developed Hydroponic Nutrient Solution in Controlled Environment Agriculture

This study was conducted to develop a nutrient solution for coastal glehnia, evaluate the performance of the newly developed nutrient solution, and determine an adequate electrical conductivity (EC) level for growth and bioactive compounds production in controlled environment agriculture (CEA). Coastal glehnia plants cultivated in Hoagland nutrient solution with EC 1, 2, 3, 4, and 5 dS·m−1 for 20 weeks had the same ratio of cations and anions in terms of macro essential elements. Based on the ratio, a new nutrient solution for coastal glehnia was developed. Subsequently, seedlings with two main leaves were grown in Hoagland nutrient solution (H1 and H2; EC 1 and 2 dS·m−1) or a newly developed nutrient solution (N1–5; EC 1–5 dS·m−1) for 23 weeks (about 6 months), and the leaves were harvested every 5 weeks. The N1 treatment resulted in significantly higher accumulated and average shoot fresh and dry weights than in the H1 and H2 treatments. In addition, the total phenolic content and antioxidant capacity per shoot were the highest under the N1 treatment. Individual bioactive compounds, such as xanthotoxin, bergapten, and imperatorin, levels per shoot with the N1 treatment were significantly higher than those with the H1 and H2 treatments. These results demonstrate that the newly developed nutrient solution of EC 1 dS·m−1 increases the biomass and bioactive compound levels of coastal glehnia and is suitable for cultivating coastal glehnia in CEA, such as vertical farms and greenhouses.

Nitrogen Application Alleviates Impairments for Jatropha curcas L. Seedling Growth under Salinity Stress by Regulating Photosynthesis and Antioxidant Enzyme Activity

Jatropha curcas L. is a promising bioenergy source, and its seedling stage is sensitive to salinity. Nitrogen application presents an effective strategy for alleviating the adverse consequences of salinity stress. However, the responses of plant growth and physiology of Jatropha curcas L. seedlings to nitrogen application under salinity stress remain unclear. As a result, a one-year greenhouse plot experiment was conducted to investigate the effects of nitrogen application on the plant growth, antioxidant enzyme activity, and photosynthesis of Jatropha curcas L. seedlings under saline conditions. Experiment treatments consisted of three salinity stresses (mild salinity stress, S1: 2 g/kg; moderate salinity stress, S2: 4 g/kg; and severe salinity stress, S3: 6 g/kg), four nitrogen application rates (N0: 0 gN/plant; N1: 20 gN/plant; N2: 60 gN/plant; and N3: 100 gN/plant), and a control treatment (CK) which was without salinity stress and nitrogen application. The results showed that salinity stress substantially reduced plant growth of Jatropha curcas L. seedlings. As the salinity stress increased, the reduction in plant growth also increased. The S3 treatment had the lowest leaf area, leaf biomass, and total biomass, which decreased by an average of 70.4%, 66.3%, and 69.9%, respectively, compared to CK. Nitrogen application could compensate for these impairments of plant growth from salinity stress by promoting antioxidant enzyme activity and photosynthesis. As for mild and moderate salinity stresses, the maximum plant growth was found in the N3 treatment, with the maximum antioxidant enzyme activity, photosynthetic pigment, photosynthetic characteristic, and chlorophyll fluorescence. As for severe salinity stress, higher plant growth was found in N2 and N3 treatments, and there were no significant differences between N2 and N3 treatments. It also should be noted that the maximum photosynthetic characteristic and chlorophyll fluorescence were found in N2 treatment under severe salinity stress. In conclusion, nitrogen application could be an alternative strategy to improve the salinity tolerance of Jatropha curcas L. growth. The nitrogen application rate of 100 gN/plant could be recommended for low and moderate salinity stresses, while 60 gN/plant could be recommended for severe salinity stress. However, higher nitrogen application rate (&gt;100 gN/plant) under mild and moderate salinity stress and the effects of reactive oxygen species under salinity stress should be further evaluated.

Effect of water and nitrogen coupling regulation on the growth, physiology, yield, and quality attributes and comprehensive evaluation of wolfberry (Lycium barbarum L.).

The characteristics of the growing environment (arid and semi-arid regions with abundant light), wastage of water, types of fertilizers used, quality of the plants, and the decline in yield due to the need for large quantities of water and fertilizers are the most significant obstacles to wolfberry cultivation. To cope with the scarcity of water caused by the increase in the area of wolfberry cultivation and to improve the efficiency of the utilization of water and fertilizers, a two-year field experiment was conducted in a typical area of the central dry zone of Ningxia in 2021 and 2022. The effects of different water and nitrogen coupling on the physiology, growth, quality, and yield of wolfberry were investigated, and a water and nitrogen management model with better indicators was constructed based on the TOPSIS model and a comprehensive scoring method. In the experiment, three irrigation quotas of 2,160, 2,565, and 2,970 m3 ha-1 (I1, I2, and I3) and three N applications of 165, 225, and 285 kg ha-1 (N1, N2, and N3) were established; the local conventional management served as the control (CK). The results showed that the growth index of wolfberry was most significantly affected by irrigation, followed by the water and nitrogen interaction effect, and the nitrogen application had the least effect. The growth and development of wolfberry plants mainly takes place during the fruit ripening and flowering periods, and growth almost stops after entering the fruit ripening period. The chlorophyll (SPAD) values were affected by irrigation and nitrogen application to a significant level, except for during the spring tip period, but the effect of water and nitrogen interaction was not significant. The SPAD values of N2 treatment were better under different irrigation. The daily photosynthetic activity of wolfberry leaves peaked between 10:00 am and noon. The daily photosynthetic dynamics of wolfberry were affected by irrigation and nitrogen application to a significant level during the fruit ripening period, and the transpiration rate and leaf water use efficiency were affected by water and nitrogen interaction to a significant level during 8:00 am and noon, while the effect was not significant during the spring tip period. The yield, dry-to-fresh ratio, and 100 grain weight of wolfberry were significantly affected by the irrigation, nitrogen application, and their interaction effects. Specifically, the two-year yield with I2N2 treatment increased by 7.48% and 3.73%, respectively, compared to CK. The quality indices were significantly affected by irrigation and nitrogen application, except for the total sugars; other indexes were also significantly affected by water and nitrogen interaction effects. The evaluation of the TOPSIS model showed that the I3N1 treatment yielded the best quality of wolfberry, and the results of the integrated scoring method based on the growth, physiology, yield, and quality indicators and water-saving objectives showed that the I2N2 (2,565 m3 ha-1, 225 kg ha-1) treatment was the optimal water and nitrogen management mode for drip-irrigated wolfberry. Our findings provide a scientific basis for the optimal irrigation and management of fertilization of wolfberry in arid regions.

Response to Growth and Yield of Purple Eggplant (Solanum melongena L.) Yufita F1 Variety on the Mutiara NPK Fertilizer and Kayabio Biological Fertilizer

The aims of this study were: (1) to determine the response of the growth and yield of the purple eggplant variety Yufita F1 to the application of Mutiara NPK fertilizers and KayaBio biological fertilizers and their interactions and (2) to obtain appropriate doses of Mutiara NPK fertilizer and KayaBio biological fertilizers to produce good growth and yield of purple eggplant of the Yufita F1 variety. This research was conducted from March to June 2020 at the Experimental Garden of the East Kalimantan Institute for Agricultural Research and Technology, Jalan Gunung Lingai, Kelurahan Gunung Lingai, Sungai Pinang District, Samarinda City. The study used a 4x4 factorial experiment in a randomized block design (CRBD). The first factor was the dose of Mutiara NPK fertilizers (N) consisting of 4 levels, namely: without Mutiara NPK (n0), 200 kg ha-1 (n1); 300 kg ha-1 (n2), and 400 kg ha-1 (n3). The second factor was the dose of KayaBio biological fertilizers consisting of 4 levels, namely: without KayaBio biological fertilizer (k0), 20 kg ha-1 (k1), 25 kg ha-1 (k2), and 30 kg ha-1 (k3). Overall there were 16 treatment combinations, each repeated three times. The results showed that: (1) response to plant height at 14, 28, and 42 days after planting, number of fruits per plant, fruit length, fruit diameter, fruit weight per plant, and fruit production were significantly different to very significantly different from fertilizer application Mutiara NPK. The highest fruit production was produced in the 300 kg ha-1 (n2) treatment, namely 16.59 tons ha-1, and the lowest was produced in the treatment without Mutiara NPK fertilizer (n0), which was only 10.53 tons ha-1; (2) the response of plant height at 14, 28, and 42 days after planting, the number of fruits per plant, fruit length, fruit weight per plant, and fruit production were not significantly different. In contrast, the response of fruit diameter was highly different from the application of KayaBio biological fertilizers. The highest fruit production was produced in the 25 kg ha-1 (k2) treatment, namely 16.18 tons ha-1, and the lowest was produced in the treatment without KayaBio biological fertilizers (k0), which was only 12.57 tons ha-1; and (3) the response of plant height aged 14, 28, and 42 days after planting, number of fruits per plant, fruit length, fruit diameter, fruit weight per plant, and fruit production were not significantly different to the interaction between Mutiara NPK fertilizer and KayaBio biological fertilizer.

Response genotypes of sunflower (Helianthus annuus L.) and amount of nitrogen fertilizer on growth characteristics, oil yield, and its percentage

The field experiment was conducted during the spring and autumn seasons of 2021 in the Al-Haritha area, AL- Basra Governorate, to study the response of six genotypes of sunflower (Local, Aqmar, Ishaqi 1, Ishaqi 2, Turki Tarzan and Shmoos) and four levels of nitrogen fertilizer control treatment N0, N1 = (N100 kg. ha -1), N2 = (N200 kg.ha-1) and N3 = (N300 kg.ha-1) according to the complete randomized block design RCBD with three replications in the order of the split-plot design (the levels of nitrogen fertilization were distributed in the main plot and the varieties in the secondary Sub-plot). Results showed the superiority of the Shmoos genotype with the highest average number of leaves that, reached (27.05 and 29.41) leaves. plant-1. while the nitrogen fertilizer effect showed a superior fertilizer level of N3, which gave (26.32 and 29.94) leaves. plant-1. As for characteristic of fertility percentage, there were no significant differences between the genotypes (Local, Aqmar, and Tarzan) for the spring season; it appears the superiority of fertilizer level N3, which gave (93.79 and 91.79), Shmoos genotype was superior with the highest average yield of an individual plant (78.50 and 84.73) gm.plant-1 compared to the local genotype, which gave the lowest average of (44.80, and 51.23) gm.plant-1 for the two seasons, respectively, and N3 level of fertilizer, which gave average (77.82 and 88.88) gm.plant-1 and local composition outperformed the proportion of oil (39.55 and 41.13%) and the Shmoos genotype in the total oil yield (1161.4 and 1461.3) kg.ha-1, while this study showed the superiority of the fertilizer level N0 with the oil percentage, which gave (39.63 and 43.65%). As for the total oil yield, the composition was superior to Shamus by giving the highest mean of oil yield (1161.4 and 1461.3) kg.ha-1 for two seasons, respectively, and the superiority of the fertilizer level N3, which gave the highest oil yield (1,247.6 and 1673.6) kg.ha-1, for two seasons, respectively. Keywords: sunflower, genetic structures, nitrogen fertilizer

Nitrogen uptake preference and allocation in Populus cathayana in response to drought stress

The preference for different nitrogen (N) forms may enhance plant survival and fitness. However, little information is known about how soil water availability, N addition, and their interaction dynamically impact plant N uptake preference and allocation. Here, we conducted a pot experiment using Populus cathayana cuttings, consisting of soil water regime (well watering control/mild drought/intensive drought: 80/60/40 % of field capacity) combined with N addition (N0 as control/N4/N8: 0/4/8 g N m−2 yr−1) treatments based on 15N isotope tracer technology. Two tracer solution (15NH4NO3/NH415NO3, both at 10.2 atom%) were used in N4/N8 treatments. Root, stem and leaf were collected at 6 h, 1, 3, 7, 14, and 31 days after labeling. Results showed that N addition significantly increased plant biomass and N accumulation, and decreased N allocation to leaf. Drought significantly decreased plant biomass, N accumulation, and N uptake (indicated by δ15N), and intensive drought reduced more than mild drought did. Nitrogen allocation to leaf was increased by drought. NO3- uptake by P. cathayana (indicated by δ15N in NH415NO3 treatment) was correlated significantly positively with total root length (TRL), total root surface area (TRA), specific root length (SRL), specific root area (SRA), root vitality, and root nitrate reductase (NR) activity. Intensive drought significantly reduced TRL, TRA, SRL, SRA, root vitality, and root NR activity under N4 and N8 treatments, which resulted δ15N in NH415NO3 treatment reduction and lower than in 15NH4NO3 treatment, so P. cathayana exhibited ammonium preference under intensive drought treatment. Our study provides an essential insight into how plants adapt and prefer different N forms under drought stress in nature.

Improvement of Interface Properties for Thermally Oxidized SiC/SiO&lt;sub&gt;2&lt;/sub&gt; MOS Capacitor by Post Oxidation Annealing Treatment

In this work, we report an innovative approach to improve the interface properties of SiC/SiO2 metal oxide semiconductor (MOS) capacitors. High temperature (1350°C) oxidation under different ambient is followed by a combination of post-oxidation annealing (POA) treatments using N2, N2O and NO gases. TOF-SIMS analysis shows silicon and nitrogen peaks near the SiC/SiO2 interface. The silicon peak is attributed to the emission of silicon and carbon atoms during high temperature oxidation. The accumulation of nitrogen is caused by the presence of nitrogen during oxidation or POA. One of the lowest interface-trap densities along with good dielectric strength has been demonstrated with the N2 and NO gas POA treatment.

Influence of Plant Growth Retardants and Nitrogen Doses on the Content of Plant Secondary Metabolites in Wheat, the Presence of Pests, and Soil Quality Parameters

Wheat is the cereal most susceptible to lodging, particularly during the flowering period and at the early ripening stage. The use of plant growth retardants (PGRs) is especially recommended when intensive nitrogen (N) fertilisation is applied, which increases the susceptibility of plants to lodging. This paper presents the results of tests into the effects of PGRs (PGR0—control; PGR1—chlormequat chloride (CCC) + trinexapac-ethyl (TE); PGR2—chlormequat chloride (CCC) + ethephon (ET)), and N dose—N0, N20, N40, and N60 [0, 20, 40, and 60 kg N ha−1] on the content of selected plant secondary metabolites (PSM) in the Indian dwarf wheat (Triticum sphaerococcum Percival) of the Trispa cultivar, and on the abundance of insect pests. In the developmental stage of wheat (BBCH 39), insects were collected with an entomological net. The study also investigated the effect of experimental factors on the physicobiochemical properties of the soil (pH in KC, granulometric composition, total organic carbon TOC, total nitrogen TN, fractional composition of humus, and the activity of enzymes). An increase in the plant secondary metabolite (PSM) and FRAP (ferring reducing ability of plasma) contents following the application of PGRs and N fertilisation already from as low a rate as 20 kg ha−1 was demonstrated. A significant positive correlation was noted between the abundance of Oulema spp. and the contents of total polyphenols, chlorogenic acid, and FRAP. No such relationship was noted for Aphididae or Thysanoptera. TOC content was higher on the plots on which N fertilisation was applied at the highest rate and after the application of PGRs. The factor determining the TN content was N fertilisation. Soil samples of the PGR0 N0 treatment were characterised by the greatest proportion of carbon in the humic and fulvic acid fractions and by the smallest proportion of carbon in the humin fraction. N fertilisation increased the proportion of carbon in the humin fraction on the plots on which no PGRs were applied. The study demonstrated an increase in the activity of oxidoreductive enzymes following the application of higher N rates. The application of PGRs resulted in no inhibition of enzymes in the soil compared to the control (PGRs0).

Influence of Flow-Gas Composition on Reaction Products of Thermally Treated NMC Battery Black Mass

The recycling of lithium-ion batteries (LIBs) is becoming increasingly important regarding the expansion of electromobility and aspects of raw material supply. Pre-treatment and liberation are crucial for a sufficient recovery of all relevant materials from LIBs. Organic removal and phase transformations by thermal pre-treatment are beneficial in many respects. This study deals with the influence of flow-gas composition on reaction products and water-based lithium recovery after thermal treatment. Therefore, a spent NMC black mass was thermally treated at 610 °C in a moved bed batch reactor under an N2 atmosphere and mixtures of N2 with 2.5% and 5% O2. Since the phase transformation of the lithium content to Li2CO3 is targeted for water leaching, a treatment under a CO2 atmosphere was studied as well. The resulting off-gas was analyzed by FTIR, and the black mass was characterized by XRD. Afterward, water washing of the black mass was carried out for selective lithium recovery. The gained lithium product was analyzed for the purity and phases present. The addition of O2 resulted in reduced reduction reactions of lithium metal oxides and lower Li-yields in the water leaching compared to the other two atmospheres. In the case of CO2, the formation of Li2CO3 is favored compared to LiF, but the Li-yield of 56% is comparable to N2 treatment.

Effects of Short-term Nitrogen Addition on Soil Organic Carbon Components in Robinia pseudoacacia L. Plantation

Nitrogen (N) deposition in the context of human activities continuously affects the carbon cycle of ecosystems. The effect of N deposition on soil organic carbon is related to the differential responses of different carbon fractions. To investigate the changes in soil organic carbon fraction and its influencing factors in the context of short-term N deposition, four N addition gradients:0 (CK), 1.5 (N1), 3 (N2), and 6 (N3) g·(m2·a)-1 were set up in acacia plantations based on field N addition experiments, and the soil physicochemical properties, microbial biomass, and enzyme activities were measured in June and September. The results showed that:① exogenous N input reduced soil pH, promoted the increase in soluble organic carbon content, and increased soil nitrogen effectiveness. ② Short-term N addition significantly reduced soil organic carbon content, and the response of each component of organic carbon to N addition was different. Among them, the content of easily oxidized organic carbon was significantly reduced and reached the lowest value under the N2 treatment, with 54.4% and 48.2% reduction compared with that of the control, respectively, and the content of inert organic carbon increased, although the increase was not significant. Nitrogen addition reduced the soil carbon pool activity and improved the stability of the soil carbon pool. Soil carbon pool activity reached its lowest under the N3 and N2 treatments, with a decrease of 53.3% and 52.80%, respectively, compared to that of the control. ③Random forest modeling indicated that the soil microbial biomass stoichiometry ratio, microbial biomass carbon, and AP were the key factors driving the changes in soil organic carbon activity under short-term N addition, explaining 65.96% and 66.68% of the changes in oxidizable organic carbon and inert organic carbon, respectively. Structural equation modeling validated the results of the random forest modeling, and soil microbial biomass stoichiometric ratios significantly influenced carbon pool activity. Short-term nitrogen addition changed soil microbial biomass and its stoichiometric ratio in the acacia plantation forest mainly through two pathways, i.e., increasing soil nitrogen effectiveness and promoting soil acidification and inhibiting extracellular carbon hydrolase activity, thus changing the soil carbon fraction ratio and participating in the soil organic carbon cycling process.

Changes in Soil Rhizobia Diversity and Their Effects on the Symbiotic Efficiency of Soybean Intercropped with Maize

It has been established that maize/soybean intercropping can improve nitrogen use efficiency. However, few studies have addressed how maize/soybean intercropping affects nitrogen-fixing bacterial diversity and N fixation efficiency of intercropped soybean. In this study, nitrogen-fixing bacterial communities, N fixation efficiency, and their relationships with soil properties under three nitrogen fertilization application rates (N0 0 kg/ha, N1 40 kg/ha, N2 80 kg/ha) were explored through field experiments. Nitrogen fixation and nitrogen-fixing bacteria diversity were assessed using 15N natural abundance, Illumina high-throughput sequencing, and nifH (nitrogen fixation) gene copies quantification in the rhizosphere soil of intercropped soybean. The results showed that nitrogen application rates significantly decreased the nitrogen-fixing bacteria diversity, nitrogen fixation efficiency, and nifH gene copies in the rhizosphere soil. Nitrogen fixation efficiency, nodule number, and dry weight of intercropped soybean were highest in the N0 treatment, and nitrogen fixation was the highest in the N1 treatment. The nitrogen-fixing efficiency in N0, N1, and N2 treatments increased by 69%, 59%, and 42% and the nodule number of soybean was 10%, 22%, and 21%, respectively, compared with monocultures. The soybean nitrogen-fixing bacteria diversity in intercropping under N0 and N1 treatments significantly increased compared with monocultures. There was a significant positive correlation between soil nifH gene copies and N fixation efficiency and a negative correlation with soil available nitrogen. Bradyrhizobium abundance in soybean rhizosphere soil decreased significantly with the increase in nitrogen application rates and was significantly correlated with soil AN (available nitrogen) and pH content in the soybean rhizosphere. These results help us to understand the mechanisms by which nitrogen use efficiency was improved, and nitrogen fertilizer could be reduced in legume/Gramineae intercropping, which is important to improve the sustainability of agricultural production.

Nitrogen loss via runoff and leaching from paddy fields with the proportion of controlled-release urea and conventional urea rates under alternate wetting and drying irrigation.

Alternate wetting and drying irrigation (AWD) can reduce non-point source pollution from paddy fields by mitigating field water depth. However, the influence of compounding modes of polymer-coated urea (PCU) and conventional urea (CU) on nitrogen (N) loss via runoff and leaching from paddy fields under AWD conditions remains unclear. To address this question, in this study, a 2-year field experiment was set up with three N management treatments: (a) 100% CU (N1), (b) 60% PCU + 40% CU (N2), and (c) 100% PCU (N3), at an equivalent N rate of 240kgha-1 that was applied to traditional continuously flooded (CI) and AWD systems. The results of this experiment showed a high-risk period of N loss from the paddy fields within 7 d after basal fertilization and 5days after tillering fertilization. AWD reduced irrigation frequencies by 3.5 times and total input of irrigation water by 38.1%, increasing water utilization from precipitation by 44.4% than CI and reducing the volume of runoff by 46.1% and leaching water by 22.1%. This reduced the total N (TN) loss through runoff and leaching under AWD. In the N2 and N3 treatment groups, N concentration in floodwater decreased from 33.8 to 24.9%, TN loss via runoff decreased by 35.3 to 25.0%, and leaching decreased by 41.7 to 30.3% from the paddy field compared to N1. With the same N mode, AWD showed a higher N uptake (from jointing to maturity stage) and rice yield compared to CI. Besides, N2 and N3 had higher N uptake compared to N1 under the two irrigation regimes. Moreover, the AWDN3 and AWDN2 treatments resulted in the lowest and second-lowest loss of TN via runoff (2.21 to 2.66kgha-1) and leaching (8.14 and 10.21kgha-1), respectively, from the paddy fields and had the relatively high N uptake in rice in the maturity stage. Remarkably, compared with N3, N2 had a comparable grain yield under CI; however, it showed a higher yield under AWD, suggesting that there is a positive interaction in the rice yield between the AWD and compounding N (PCU + CU) fertilization practice. Thus, AWD coupled with N2 could be recommended as a useful approach to reduce N loss via runoff and leaching from paddy fields, which could increase the grain yield of middle-season rice.

Effect of biochar and nitrogen fertilizers on maize seedling growth and enzyme activity relating to nitrification

AbstractMaximizing nitrogen use efficiency (NUE) involves synchronizing the interplay between nitrogen preferential crops and the nitrogen transformation pathways of soil. Biochar may benefit specific N‐preference crops in relatively unsuitable soil environments; however, experimental data are lacking. This study tested eight treatments, consisting of four nitrogen treatments (N0 = control; N1 = NH4Cl; N2 = NaNO3; and N3 = 1:1 ratio of NH4+ and NO3−) each with biochar applied at 0% or 2% (w/w). The results show that biochar and/or nitrogen application enhanced maize seedling biomass and NO3−‐based fertilizer resulted in higher seedling biomass than NH4+‐based fertilizer. With the application of biochar and NH4+‐based fertilizer, maize seedling biomass increased and soil NH4+‐N content was significantly reduced compared with NH4Cl sole application. Correlation analysis and redundancy analysis revealed that SOC content and inorganic nitrogen content were the main factors influencing maize growth and N absorption. Biochar with or without nitrogen fertilizer (except N1 treatment) significantly increased β‐1,4‐glucosidase (BG) activity. Co‐application treatments also resulted in higher vector length, an indicator of C limitation—the increment might add to the risk of microbial C limitation. The activity of ammonia monooxygenase (AMO), a key enzyme in nitrification, decreased with the co‐application of biochar and nitrogen, suggesting the alteration of nitrogen transformation.