N100 Treatment Research Articles

N100 as a response prediction biomarker for accelerated 1 Hz right DLPFC-rTMS in major depression

Background and objectiveRepetitive transcranial magnetic stimulation (rTMS) is a safe and effective treatment for major depressive disorder (MDD); however, this treatment currently lacks reliable biomarkers of treatment response. TMS-evoked potentials (TEPs), measured using TMS-electroencephalography (TMS-EEG), have been suggested as potential biomarker candidates, with the N100 peak being one of the most promising. This study investigated the association between baseline N100 amplitude and 1 Hz right dorsolateral prefrontal cortex (R-DLPFC) accelerated rTMS (arTMS) treatment in MDD. MethodsBaseline TMS-EEG sessions were performed for 23 MDD patients. All patients then underwent 40 sessions of 1 Hz R-DLPFC (F4) arTMS over 5 days and a follow-up TMS-EEG session one week after the end of theses arTMS sessions. ResultsBaseline N100 amplitude at F4 showed a strong positive association (p < .001) with treatment outcome. The association between the change in N100 amplitude (baseline to follow-up) and treatment outcome did not remain significant after Bonferroni correction (p = .06, corrected; p = .03, uncorrected). Furthermore, treatment responders had a significantly larger mean baseline F4 TEP amplitude during the N100 time frame compared to non-responders (p < .001). Topographically, after Bonferroni correction, F4 is the only electrode at which its baseline N100 amplitude showed a significant positive association (p < .001) with treatment outcome. LimitationsLack of control group and auditory masking. ConclusionBaseline N100 amplitude showed a strong association with treatment outcome and thus demonstrated great potential to be utilized as a cost-effective and widely adoptable biomarker of rTMS treatment in MDD.

Nitrogen reduction by 20 % with green manure retention reduces soil evaporation, promotes maize transpiration and improves water productivity in arid areas

ContextThe contradiction between high agricultural yields and water resource shortages is becoming increasingly serious. Reducing nitrogen appropriately with green manure retention can ensure high agricultural yields, but it remains unclear whether it can optimize crop water consumption characteristics and improve water productivity (WPc). ObjectiveThis study aims to investigate the effect of green manure retention combined with nitrogen reduction on water use characteristics of maize and its potential mechanisms. MethodsA field experiment was conducted at Wuwei Oasis Agricultural Experimental Station in China from 2020 to 2022, with five treatments: (i) traditional nitrogen application with green manure retention (N100), (ii) nitrogen reduction by 10 % with green manure retention (N90), (iii) nitrogen reduction by 20 % with green manure retention (N80), (iv) nitrogen reduction by 30 % with green manure retention (N70), and (v) nitrogen reduction by 40 % with green manure retention (N60). ResultsThe results showed that compared with the N100 treatment, 0−50 cm maize root biomass (RB), biomass accumulation (BA), and canopy cover (CC) were not significantly reduced in the N80 treatment. This model ensured a stable grain yield (GY) and improved 0−50 cm soil water storage (SWS) by 7.1−13.1 %. It effectively suppressed soil evaporation (E), promoted maize transpiration (T), reduced maize evapotranspiration (ET) by 4.8 %, and increased WPc by 1.8−26.6 %. Structural equation modeling (SEM) suggests that RB was the most important factor for improving WPc. In addition, this system ensures that economic benefits did not decrease. ConclusionIt can be seen that nitrogen reduction by 20 % with green manure retention is a reasonable nitrogen fertilizer management system to alleviate the contradiction between high maize yield and water resource shortages in the region. ImplicationsThe results of this study provide valuable insights into alleviating the contradiction between agricultural production and regional water resource scarcity.

The Application of Rice Straw with Reduced N Fertilizer Improves the Rice Yield While Decreasing Environmental N Losses in Southern China

To investigate the effects of straw residues with reduced nitrogen (N) fertilizer on greenhouse gas (GHG) and N losses in paddy fields, we conducted a field experiment during two growing seasons in paddy rice systems in southern China to evaluate the impacts of the application of straw residues with reduced N fertilizer on rice yield, GHG emissions, and ammonia (NH3) volatilization. The four treatments included N100 (conventional dose of N fertilizer), SN100 (conventional dose of N fertilizer + straw), N60 (60% of the conventional dose of N fertilizer), and SN60 (60% of the conventional dose of N fertilizer + straw). We found that the yield of the SN60 treatment was slightly reduced, but the partial factor productivity of applied N (PFPN) was significantly increased by 63.9% compared to the N100 treatment. At the same N application rate, the application of straw increased soil organic C (SOC), methane (CH4) emissions, carbon dioxide (CO2) emissions, global warming potential (GWP), greenhouse gas intensity (GHGI), and net ecosystem carbon budget (NECB), but significantly decreased soil N2O emissions and NH3 volatilization. Compared with conventional fertilization (N100), straw residues with reduced N fertilization (SN60) reduced N2O emissions and NH3 volatilization by 42.1% and 23.9%, and increased GHGI and NECB by 11.1% and 18.3%, respectively. The results indicate that straw residues with reduced N fertilizer are a feasible strategy to reduce N losses in paddy fields while increasing carbon sequestration.

Root Reduction Caused Directly or Indirectly by High Application of Nitrogen Fertilizer Was the Main Cause of the Decline in Biomass and Nitrogen Accumulation in Citrus Seedlings.

Citrus is the largest fruit crop around the world, while high nitrogen (N) application in citrus orchards is widespread in many countries, which results not only in yield, quality and environmental issues but also slows down the establishment of citrus canopies in newly cultivated orchards. Thus, the objective of this study was to investigate the physiological inhibitory mechanism of excessive N application on the growth of citrus seedlings. A pot experiment with the citrus variety Orah (Orah/Citrus junos) at four N fertilization rates (0, 50, 100, and 400 mg N/kg dry soil, denoted as N0, N50, N100, and N400, respectively) was performed to evaluate the changes of root morphology, biomass, N accumulation, enzyme activities, and so on. The results showed that the N400 application significantly reduced the total biomass (from 14.24 to 6.95 g/Plant), N accumulation (from 0.65 to 0.33 g/Plant) and N use efficiency (92.69%) in citrus seedlings when compared to the N100 treatment. The partial least squares pathway model further showed that the decline of biomass and N accumulation by high N application were largely attributed to the reduction of root growth through direct and indirect effects (the goodness of fit under the model was 0.733.) rather than just soil N transformation and activity of root N uptake. These results are useful to optimize N management through a synergistic N absorption and utilization by citrus seedlings.

Reducing nitrogen application by 20% under the condition of multiple cropping using green manure after wheat harvesting can mitigate carbon emission without sacrificing maize yield in arid areas

ContextAt the agro-ecosystem scale, a combination of green manure and chemical nitrogen fertilizer improves crop yield but also exacerbates soil CO2 emissions. However, it is unclear whether reducing nitrogen by reapplying green manure to fields can achieve high crop yields and improve carbon mitigation. ObjectiveThis study aims to investigate the effects and underlying mechanisms of carbon emissions in maize fields under green manure reapplication combined with a reduction in nitrogen. MethodsA field experiment comprising five treatments (green manure reapplication combined with traditional nitrogen application (N100), green manure reapplication combined with a reduction in nitrogen of 10% (N90), green manure reapplication combined with a reduction in nitrogen of 20% (N80), green manure reapplication combined with a reduction in nitrogen of 30% (N70), and green manure reapplication combined with a reduction in nitrogen of 40% (N60)) was conducted at an arid oasis region in northwestern China from 2020 to 2022. This study investigated the effects of reducing nitrogen application while reapplying green manure to the field on maize grain yield, soil respiration rate, and carbon emission efficiency (CEE) and analyzed the relationship between soil respiration rate and soil temperature (Ts), soil water content (SWC), and crop biomass accumulation (BA). ResultsThe N80 treatment significantly reduced soil carbon emissions (CE) but did not reduce maize grain yield, and it showed a significant increase in CEE of 7.7% compared with the N100 treatment. In addition, this system can ensure no reduction in net primary production (NPP), net ecosystem production (NEP), and carbon sequestration (CS) potential compared with N100 and significantly improves the NPP/CE value. Soil temperature and crop biomass significantly correlated with soil respiration, which explained 68.4–72.9% and 84.4–88.8% of the seasonal variation of soil respiration, respectively. However, there was no correlation between soil moisture and soil respiration. ConclusionTherefore, reducing nitrogen application by 20% while multiple cropping with green manure application after wheat was a suitable nitrogen fertilizer management measure for improving carbon mitigation in arid areas without sacrificing maize yield. ImplicationsThe results of this study provide valuable insights into long-term agricultural management strategies for achieving high agricultural production and environmental friendliness.

Integrative physiological and metabolic traits reveal the mechanisms of chamomile flowers in response to nicotine stress

BackgroundChamomile (Matricaria recutita L.) is an important economic crop after tobacco (Nicotiana tabacum L.) cultivation. The nicotine released into the soil during tobacco cultivation has an impact on various aspects of chamomile growth, including plant height, flowering period, flower yield, and flower quality. We aimed to examine the effects of physiological and metabolic response of chamomile under different concentrations of nicotine stress.ResultsThe study revealed that chamomile growth was positively influenced by nicotine concentrations of 1.0 μg/g (N-1) and 10.0 μg/g (N-10). However, higher nicotine concentrations of 100.0 μg/g (N-100) and 500.0 μg/g (N-500) were found to induce stress as the highest levels of antioxidant enzyme activities and malondialdehyde (MDA) levels were observed under this treatment. In addition, it was observed that nicotine was transported from the roots to other organs during the entire growth period of chamomile and the nicotine levels reached saturation under N-100 treatment. A total of 1096 metabolites were detected by ultra-high-performance liquid chromatography-coupled tandem mass spectrometry (UHPLC–MS/MS) analysis, and 48 differentially expressed metabolites (DEMs) were identified among the groups via widely targeted metabolomics studies. The response of chamomile flowers to nicotine stress is associated with the presence of flavonoids, phenolic acids, organic acids, and other substances. Metabolic regulation under nicotine stress primarily involves processes, such as aminoacyl-tRNA biosynthesis, ABC (ATP-binding cassette) transporter activity, glyoxylate and dicarboxylate metabolism and pyrimidine metabolism.ConclusionsThis report presents the first findings on how nicotine affects the metabolism of chamomile. It also provides a comprehensive understanding of how crops can resist nicotine stress from a metabolic perspective.Graphical

Determination of Combined Effects of Organic and Mineral Fertilizer on Forage Yield and Quality of Annual Ryegrass

The widespread practice of using high doses of nitrogen to increase unit area yield in annual ryegrass introduces ecological and economic problems. This research was carried out over two years and aimed to determine the potential forage yield and quality of annual ryegrass by applying manure, humic acid, and low doses of nitrogen fertilizer, within the framework of sustainable forage crop cultivation. The study was carried out from 2020 to 2022 with three replications according to the randomized block split plots experimental design. According to the study results, the highest values were achieved with combinations that included manure application, and even higher values were observed when manure was applied along with low doses of humic acid and nitrogen. The M20 + H20 + N100 treatment yielded the highest fresh yield, dry matter, and crude protein. The treatments with manure, humic acid, and nitrogen fertilizer had varying effects on the ADF and NDF content of annual ryegrass, resulting in fluctuating values. In conclusion, 20 t manure, 20 L humic acid, and 100 kg ha−1 N application can be suggested for sustainable and higher dry matter production with good quality for annual ryegrass cultivation under semi-humid climatic conditions. The results obtained from this research hold promise for sustainable agricultural practices.

Source–Sink Balance Optimization Depends on Soil Nitrogen Condition So as to Increase Rice Yield and N Use Efficiency

Genetic improvement has been devoted to increasing rice yield by increasing the spikelet number per panicle and the spikelet/leaf ratio. As a result, indica-japonica hybrid rice “Yongyou” varieties with large panicles and superhigh yield potential have been developed. These varieties exhibit significantly higher grain yield and nitrogen use efficiency for grain (NUEg) under moderate and high N supply conditions due to their large sink size, but their yield performance remains obscure under low N input and low soil fertility conditions. In the present study, we investigated four varieties including Yongyou2640 (YY2640, large-panicle india-japonica hybrid variety), Yangliangyou6 (YLY6, two-line indica hybrid variety), Quanyou6 (QY6, three-line indica hybrid variety), and Huanghuazhan (HHZ, indica inbred variety) under two low soil fertility treatments [LF (removing half of soil depth) and CK] and two N fertilizer rates (0 and 100 kg N ha−1) in Central China. The results showed that the grain yield of YY2640 was more responsive to fertility than that of other varieties, which was 19.4–42.3% higher than that of the other three varieties under CK N100 treatment, but it was 14.5–19.4% lower than that of YLY6 and QY6 under LF N0 and LF N100. A higher spikelet/leaf ratio resulted in more biomass and N partition to panicles rather than to leaves under LF N0 and N100. Slightly more post-flowering dry matter obtained from higher leaf N content and crop growth rate failed to compensate for the adverse effects of reduced pre-flowering dry matter accumulation and stem-to-grain translocation during grain filling. This led to the lower NUEg of YY2640 than YLY6 and QY6 under low soil fertility conditions. Based on these findings, the present study suggested that the source–sink relationship of the super hybrid varieties should be optimized according to the soil N supply condition.

Effects of biochar combined with nitrogen reduction on the soil microbial community of rapeseed

ABSTRACT Excessive N critically depresses soil properties. Biochar has the potential to enhance soil health. A two-year field experiment was conducted to analyze the effects of biochar (0, 10, 20 and 40 t ha−1, namely, B0, B10, B20 and B40) combined with N (180, 144 and 108 kg ha−1, namely, N100, N80 and N60) on soil microorganisms. Results showed that B10 significantly promoted soil microbial biomass and had a strong correlation with most microbial groups, mainly reflected in a15:00, 10Me17:0, i18:0, i19:0, i16:0, 16:1w5c, 10Me18:0, 18:0 2OH and 18:00, while N60 decreased fungi and actinomycete content. Soil microbial functional activity was also significantly increased under B10 and B20 treatments and decreased under N80 and N60 treatments, compared to B0 treatment and N100 treatment, respectively. Microbial functional composition was also changed greatly by biochar, and B10 and B20 were closely related to most carbon sources. The combination of B10 and N80 significantly increased soil microbial biomass (total PLFA by 1.4 nM kg−1) and functional activity (Shannon index and Evenness index by 0.8%) compared with conventional N management (N100B0). Our findings reveal that biochar can achieve N reduction and enhance soil microbial diversity and community stability in purple soil regions of southwest China.

Optimum Nitrogen Application Promotes Sweetpotato Storage Root Initiation

Storage root formation of sweetpotato (Ipomoea batatas (L.) Lam) is a complex developmental process relating to the activity of cambium. Little information is available on the relationship between nitrogen (N) application levels and the initiation and development of sweetpotato storage roots (SRs). This study aims to examine how N application rates promoted/inhibited the formation and development of storage roots (SRs) for sweetpotato cultivar ‘Orleans’ during the first 8 weeks after planting. Cuttings were grown in coarse river sand culture supplied with modified Hoagland nutrient solution at four different rates (0 (N0), 50 (N50), 100 (N100) or 200 (N200) mg L−1) of N. The results showed that N100 treatment promoted the formation of primary and secondary cambium, resulting in a significant higher rate of SR formation between 21 and 56 days after transplanting (DAT). Due to the higher N demand after formation of SRs, N200 treatment displayed faster growth, higher N acquisition and the highest efficiency of N use after 35 DAT, but the SR formation rate and SR number per plant remained insignificantly lower than N100 when differentiation of adventitious root was mostly completed (49 DAT), suggesting irreversible an effect of N rate during SR initiation, which eventually affects SR number. The results suggested that the optimal substrate N level for sweetpotato SR initiation is lower than that for following SR growth, which should be considered in the fertilisation scheme.

Nitrogen-fixing cyanobacteria have the potential to improve nitrogen use efficiency through the reduction of ammonia volatilization in red soil paddy fields

Nitrogen-fixing cyanobacteria (NFC) biofertilizers have demonstrated great potential in improving rice yield and soil fertility. However, few studies have systematically evaluated the effects of combined application of NFC biofertilizers and chemical nitrogen (N) fertilizer on ammonia (NH3) volatilization and rice N absorption in red soil paddy fields. Therefore, we conducted a 2-year single cropping paddy field study to determine the NH3 volatilization loss from paddy soil, as well as rice yield and N use efficiency (NUE). The experiment designed five treatments, including one control (CK, no N applied) and four experimental treatments (N100, complete application of chemical N fertilization; RN50, replacing half of chemical N fertilizer with NFC; RN100, complete replacement of chemical N fertilizer with NFC; N50, only half application of chemical N fertilizer) based on different chemical N fertilizer and NFC biofertilizers application ratios. The results showed that the average cumulative NH3 volatilization losses of RN50 and N50 treatments were reduced by 41.63% and 45.34% than that of N100 treatment, respectively, mainly due to the reduction of ammonium N content in the overlying water and topsoil. The average NUE of RN50 and N50 treatments were 57.85% and 48.49%, which were 43.83% and 20.56% higher than that of N100, respectively. Path analysis results showed that the application of NFC increased the total soil N content and mitigated the volatilization of NH3, which increased the residence time of N in the paddy field, thereby increasing the NUE of rice. The average rice yield of RN50 was 5603.85 kg ha−1, which was not significantly different from N100, but 18.62% higher than N50. Although RN100 elevated NUE and reduced NH3 volatilization, its grain yield was significantly lower than that of N100. These results suggest that the replacement of an appropriate proportion of chemical N fertilizer with NFC could be a promising approach to mitigating NH3 volatilization, enhancing rice NUE, and maintaining rice yield in red soil paddy fields.

10-Year fertilization alters soil C dynamics as indicated by amino sugar differentiation and oxidizable organic C pools in a greenhouse vegetable field of Tianjin, China

Understanding the temporal changes of soil organic C (SOC) pools and microbial residues is essential for clarifying SOC dynamics in agroecosystems; however, this information remains largely unclear in greenhouse vegetable production (GVP) systems. Here, based on information of SOC pools (i.e., oxidizable organic C pools) and microbial residue C (MRC, as indicated by amino sugars differentiation), a 10-year (2009–2019) field experiment with fertilization was conducted to evaluate how fertilization alters SOC dynamics in a GVP field in Tianjin, China. The experiment includes four treatments (equal N, P2O5, and K2O inputs): 100% chemical N (N100), 50% substitution of chemical N with manure-N (N50M50), straw-N (N50S50), and manure-N plus straw-N (N50M25S25). Results showed that the values of SOC, lability index, and C management index increased and decreased linearly with time in N50M50- and N100-amended soils, respectively, which were mainly induced by the changes in labile C fractions. Based on logistic regression models, we found that these indices in straw-amended soils (N50M25S25 and N50S50) were rapidly increased between 2009 and 2013, and then approach steady levels between 2015 and 2019. These findings suggested that we should guarantee enough C inputs to maintain the level and quality of SOC, otherwise it will cause C loss in the unique GVP soils. Besides, straw-amended treatments increased MRC contents and enlarged their contributions to SOC sequestration, whereas these indices in N100 treatment decreased linearly with the time of fertilization. In conclusion, long-term chemical application alone was not beneficial for SOC accumulation, whereas organic amendments brought several benefits for SOC sequestration in GVP soils. Our results implied that C sequestration in GVP soils is to a large extent determined by the amounts and time of fertilization.

English

The effects of reducing N fertilizer use on soil NO3--N content and cotton yield were studied through a three-year (2015 to 2017) field experiment in South Xinjiang of China. Cotton was sown under drip irrigation system using five N fertilizer reduction treatments as: conventional N application rate (N100), N application rate reduced by 16.67% (N-16.67), 33.33% (N-33.33), 50% (N-50), and 100% (N-100). The data were recorded for changes in soil NO3--N content, and the SPAD value of cotton leaves was recorded at the peak bolling stage. The total N content of the plant was recorded at the boll formation stage, while yield was recorded at maturity. The results revealed that the soil NO3--N content in N-16.67, N-33.33, N-50, and N-100 treatments decreased by 10.8, 45.5, 60.7 and 72.3% compared to N100 treatment, respectively. The SPAD values of N-16.67 and N-33.33 treatments were significantly higher than those of N100 treatment, while the SPAD values of N-50 and N-100 treatments were significantly decreased. The total N content of cotton was significantly decreased with the increase in the proportion of N fertilizer reduced. The seed cotton yield in N-16.67 and N-33.33 treatments increased by 9.2 and 7.9% compared to the N100 treatment, respectively. However, the cotton yield decreased significantly when the N application rate was reduced by 50 and 100%. The relationship between the N fertilizer reduction rate and cotton yield suggested that the N application rate can be reduced by 18.47–45.50% without compromising the cotton yield in South Xinjiang of China. © 2021 Friends Science Publishers

Application of Gliricidia sepium Tree Leaves and Nitrogen Fertilizer to Improve Tomato Production and Soil Properties

Excess use of agrochemicals for intensive cultivation affects crop quality and destroys agro-ecosystems, and eventually creates health hazards. The study aims to investigate the effect of Gliricidia sepium (GS) tree leaf as suitable green manures for supplementing nutrient supply along with nitrogen (N) fertilizer to produce quality tomato and soil fertility improvement. A field experiment was conducted at the Bangabandhu Sheikh Mujibur Rahman Agricultural University, Bangladesh, from November 2016 to March 2017. The experiment was laid out in a randomized complete block design (two factors) with three replications. There were nine treatment combinations with three levels of GS tree leaves (5, 10 and 15 t ha−1) and three doses of N (0, 50 and 100% of the recommended dose of fertilizer). The highest tomato yield was recorded in GS15×N100 treatment combination, which was 41.68% higher compared to the control treatment. Decreasing C: N ratio in increasing dose of GS and N treated plot indicated the quality of tree leaves that ensures faster decomposition and high nutrient release pattern of this species. Increasing rate of soil pH and cation exchange capacity (CEC) in different treatments as compared to initial soil showed soil fertility improvement. Overall, the results indicated that quality tomato could be grown successfully by the application of G. sepium tree leaves along with an appropriate amount of N fertilizer.&#x0D; Ann. Bangladesh Agric. (2020) 24(1) : 77-87

Effects of nitrogen fertilizer reduction and biochar application on paddy soil nutrient and nitrogen uptake of rice

We explored the impacts of nitrogen (N) reduction and biochar application on soil fertility and nutrient uptake of rice in early and late seasons of 2018 with a field experiment. There were six treatments, including control (no N application, CK), conventional N application (N100), 20% N reduction (N80), 20% N reduction plus biochar application (N80+BC), 40% N reduction (N60), 40% N reduction plus biochar application (N60+BC). Our results showed that 20% and 40% N reduction and/or with biochar application did not affect soil pH, organic matter, total N, total phosphorous (P), total potassium (K), ammonium N, available P and K in comparison with N100 treatment. N80+BC and N60+BC substantially increased soil cation exchange capacity (CEC) at tillering stage and electrical conductivity (EC) at heading stage in late season, respectively. Compared with the treatment with single N reduction, N80+BC significantly increased soil available K in early and late seasons and soil pH and total N in late season, while N60+BC increased soil total K at mature stage in early season. Soil nitrate content was decreased along with the growth stages for all treatments in early season. Compared with tillering stage, soil nitrate N content in conventional N application at heading stage and mature stage was decreased by 50.0% and 71.6%, respectively. Soil nitrate content in biochar treatment only was decreased by 6.3%-45.5%. N application along with biochar application had no significant effects on plant N uptake and utilization in early season. However, N reduction with biochar application significantly increased plant N uptake and N utilization rate by 34.8%-52.4% in late season, compared to conventional N application and single N reduction. Our findings suggest that adequate N reduction along with biochar application could maintain soil health and improve plant N uptake and utilization efficiency.

Substitution of Inorganic Nitrogen Fertilizer with Green Manure (GM) Increased Yield Stability by Improving C Input and Nitrogen Recovery Efficiency in Rice Based Cropping System

A long-term field experiment was carried out (since 2008) for evaluating the effects of different substitution rates of inorganic nitrogen (N) fertilizer by green manure (GM) on yield stability and N balance under double rice cropping system. Treatments included, (1) N0 (no N fertilizer and no green manure); (2) N100 (recommended rate of N fertilizer and no green manure); (3) N100-M (recommended rate of N fertilizer and green manure); (4) N80-M (80% of recommended N fertilizer and green manure); (5) N60-M (60% of recommended N fertilizer and green manure); and (6) M (green manure without N fertilization). Results showed that, among all treatments, annual crop yield under N80-M treatment was highest. Crop yield did not show significant differences between N100-M and N80-M treatments. Substitution of different N fertilizer rates by GM reduced the yield variability index. Compared to the N0 treatment, yield variability index of early rice under N100-M, N80-M, and N60-M treatments was decreased by 11%, 26%, and 36%, respectively. Compared to the N0 treatment, yield variability index of late rice was decreased by 12%, 38%, 49%, 47%, and 24% under the N100, N100-M, N80-M, N60-M, and M treatments, respectively. During period of 2009–2013 and 2014–2018, nitrogen recovery efficiency (NRE) was highest under N80-M treatment and N balance was highest under N100 treatment. NRE of all treatments with GM was increased over the time from 2009–2013 to 2014–2018. All treatments with GM showed increasing trend of SOC over the years. Substitution of N fertilizer by GM also increased C inputs and soil C:N ratio compared to the N100 and N0 treatments. Boosted regression model indicated that C input, N uptake and AN were most influencing factors of crop yield. Thus, we concluded that N fertilization rates should be reduced by 20% under GM rotation to attain high yield stability of double rice cropping system through increasing NRE and C inputs.

Effects of Nitrogen Fertilization and Seed Piece Applied Fungicides on Establishment, Tiller Dynamics, and Sucrose Yields in Successively Planted Sugarcane

Sugarcane (Saccharum spp.) successive planting causes 25–30% yield reduction in comparison to fallow or rice rotation planting in a three-year production cycle on Florida Histosols. Field experiments were established to manage the yield losses associated with successive planting through nitrogen fertilization and seed piece application of fungicides in plant and first ratoon crops each at two sites. Nitrogen fertilization treatments included 0 (N0), 50 (N50), and 100 (N100) kg ha−1 applied in furrows at the time of planting, and one split application (N50+50) with 50 kg ha−1 applied at planting and 50 kg ha−1 applied at 90 days after planting as side-dress. Fungicides treatments were mancozeb at 2.5 kg a.i. (active ingredient) ha−1, mefenoxam at 0.57 kg a.i. ha−1, and azoxystrobin at 0.30 kg a.i. ha−1 applied to seed cane pieces laid in the furrows at planting. Nitrogen fertilization showed increasing trends of the tiller and millable stalks production in plant and ratoon crops. N response varied with the time of ratooning. Overall, N50+50 produced greater tons of cane per hectare (TCH) and tons of sucrose per hectare (TSH) compared to other N treatments in plant crop and late season ratoon crop (ratooned in March). N100 treatment enhanced tillering and TCH in December ratooned crop. In 2016 plant crop, mefenoxam produced higher TCH than others, but no carryover effects were observed in ratoon crops. Both nitrogen fertilization and fungicides seem to be promising cultural practices to minimize yield losses in successive sugarcane planting in Histosols.

Neurofeedback-Based Enhancement of Single-Trial Auditory Evoked Potentials: Treatment of Auditory Verbal Hallucinations in Schizophrenia.

Auditory verbal hallucinations depend on a broad neurobiological network ranging from the auditory system to language as well as memory-related processes. As part of this, the auditory N100 event-related potential (ERP) component is attenuated in patients with schizophrenia, with stronger attenuation occurring during auditory verbal hallucinations. Changes in the N100 component assumingly reflect disturbed responsiveness of the auditory system toward external stimuli in schizophrenia. With this premise, we investigated the therapeutic utility of neurofeedback training to modulate the auditory-evoked N100 component in patients with schizophrenia and associated auditory verbal hallucinations. Ten patients completed electroencephalography neurofeedback training for modulation of N100 (treatment condition) or another unrelated component, P200 (control condition). On a behavioral level, only the control group showed a tendency for symptom improvement in the Positive and Negative Syndrome Scale total score in a pre-/postcomparison ( t(4) = 2.71, P = .054); however, no significant differences were found in specific hallucination related symptoms ( t(7) = -0.53, P = .62). There was no significant overall effect of neurofeedback training on ERP components in our paradigm; however, we were able to identify different learning patterns, and found a correlation between learning and improvement in auditory verbal hallucination symptoms across training sessions ( r = 0.664, n = 9, P = .05). This effect results, with cautious interpretation due to the small sample size, primarily from the treatment group ( r = 0.97, n = 4, P = .03). In particular, a within-session learning parameter showed utility for predicting symptom improvement with neurofeedback training. In conclusion, patients with schizophrenia and associated auditory verbal hallucinations who exhibit a learning pattern more characterized by within-session aptitude may benefit from electroencephalography neurofeedback. Furthermore, independent of the training group, a significant spatial pre-post difference was found in the event-related component P200 ( P = .04).

Effects of short-term N addition on soil C fluxes in alpine Sibiraea angustata scrub on the eastern margin of the Qinghai-Tibetan Plateau

Although knowledge of the impact of N enrichment on soil C fluxes is scant, such information is highly critical for estimating the global C budget under elevated N deposition. To quantify the effects of short-term N addition on soil C sequestration in an alpine scrub ecosystem, we conducted a field experiment for Sibiraea angustata scrub on the eastern margin of the Qinghai-Tibetan Plateau in China. We quantified the soil C pool (0–30cm) and C fluxes in litterfall, fine root (<2mm diameter) production (FRP), and soil CO2 emission (heterotrophic respiration, Rh) over four years with four levels of N addition (N0; control, N20; 20, N50; 50, and N100, 100kgNha−1year−1). The results showed that at control plots the total C-input (433±33gCm−2year−1) via FRP (360±34gCm−2year−1) and litterfall (73±1gCm−2year−1) was close to the C-output via Rh (466±5gCm−2year−1), which demonstrates that the S. angustata scrub soil C is at equilibrium status. However, adding N, particularly the N100 treatment, significantly affected the soil C balance; the soil became a C sink (163±46gCm−2year−1) by increasing FRP (+63%) rather than by increasing litterfall (P>0.05) or reducing Rh (P>0.05). As a result, the soil C pool (0–30cm) increased significantly. In conclusion, these results suggest that fine roots play a dominant role in the C balance of an alpine scrub ecosystem due to large C-inputs to the soil. Moreover, short-term high N enrichment causes sequestration of additional atmospheric CO2, largely because of the stimulation of fine root growth rather than increased inputs of aboveground plant litterfall or reductions in soil CO2 emission.

Vine nitrogen status and volatile thiols and their precursors from plot to transcriptome level.

BackgroundVolatile thiols largely contribute to the organoleptic characteristics and typicity of Sauvignon blanc wines. Among this family of odorous compounds, 3-sulfanylhexan-1-ol (3SH) and 4-methyl-4-sulfanylpentan-2-one (4MSP) have a major impact on wine flavor. These thiols are formed during alcoholic fermentation by the yeast from odorless, non-volatile precursors found in the berries and the must. The present study investigates the effects of vine nitrogen (N) status on 3SH and 4MSP content in Sauvignon blanc wine and on the glutathionylated and cysteinylated precursors of 3SH (Glut-3SH and Cys-3SH) in the berries and the must. This is paralleled by a RNA-seq analysis of gene expression in the berries. The impact of N supply on the expression of the glutathione-S-transferase 3 and 4 (VviGST3 and VviGST4) and the γ-glutamyltranspeptidase (VviGGT), considered as key genes in their biosynthesis, was also evaluated.ResultsN supply (N100 treatment) increased the 3SH content in wine while no effect was noticed on 4MSP level. Furthermore, N supply increased Glut-3SH levels in grape berries at late berry ripening stages, and this effect was highly significant in must at harvest. No significant effect of N addition was noticed on Cys-3SH concentration. The transcript abundance of the glutathione-S-transferases VviGST3 and VviGST4 and the γ-glutamyltranspeptidase (VviGGT), were similar between the control and the N100 treatment. New candidate genes which might be implicated in the biosynthetic pathway of 3SH precursors were identified by whole transcriptome shotgun sequencing (RNA-seq).ConclusionsHigh vine N status has a positive effect on 3SH content in wine through an increase of Glut-3SH levels in grape berries and must. Candidate GSTs and glutathione-S-conjugates type transporters involved in this stimulation were identified by RNA-seq analysis.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-016-0836-y) contains supplementary material, which is available to authorized users.