Nitrogen Nutrition Research Articles

Optimization of nitrogen application and planting geometry for production of cut chrysanthemums (Chrysanthemum morifolium Ramat.)

Nutrition and planting geometry are the two key factors affecting the production and quality of cut stems in chrysanthemum. The present investigation was undertaken to standardize the nitrogen nutrition and planting geometry for chrysanthemum var. “Yellow Star” cultivated for cut flowers. The data revealed the proportionate increase in plant height, chlorophyll content, days to bud appearance and days to 50% inflorescence anthesis and length of cut stem with increase in nitrogen dose and row spacing. However, flower diameter, number of flowers per stem, cut stem diameter, vase life, and water absorbed by cut flower decreased proportionately with increase in nitrogen dose and row spacing. Application of N@100 Kg ha-1 to chrysanthemum planted at 20x10 cm spacing produced cut stems of acceptable length, more number of flowers of bigger size and optimum postharvest longevity. The amount of nitrogen can be reduced to 1/3rd to grow cut chrysanthemums planted at twice the row spacing for longer cut stems of appreciable vase life.

Quantify the effect of manure fertilizer addition and optimal nitrogen input on rainfed wheat yield and nitrogen requirement using nitrogen nutrition index

Combined manure fertilizer addition with optimal nitrogen (N) input reduces nitrogen demands for wheat while maintaining or increasing its yield and nitrogen productivity. However, the effect of manure addition has not been well explored for dryland wheat production on the Loess Plateau, especially in year with less precipitation. Therefore, a 4-year field experiment was performed: manure fertilizer (with and without) and N fertilization levels (0, 60, 120, 180 and 240 kg ha–1) under two precipitation years (normal and dry year). The target was to quantify the effect of manure addition on: i) wheat yield and nitrogen use efficiency (NUE), ii) crop growth and soil properties, and iii) wheat N status [N accumulation, N nutrition index (NNI)]. Compared with chemical N alone, manure addition increased topsoil organic matter, total nitrogen and the stability of macro-aggregate (R0.25). Manure addition increased grain yield by 12.5% in normal year and by 38.2% in dry year. The improved topsoil quality, root system, biomass (nitrogen) accumulation all occurred in NM120 or NM180 with manure addition, which brought an improvement of wheat yield and NUE with a suitable nitrogen nutrition status. NM180 (i.e., 150 kg N ha–1 +2000 kg ha–1 manure) and NM120 (i.e., 90 kg N ha–1 +2000 kg ha–1 manure) achieved the highest grain yield in normal and dry years, respectively. In summary, the optimal fertilization decision strategy based on precipitation and nitrogen nutrition index can be applied for dryland wheat production.

The influence of nitrogen nutrition on the formation of the balance of nutrients in the agrocenosis of winter wheat

Аim. To study the influence of doses and methods of applying nitrogen fertilizers on the peculiarities of the use and balance of nutrients in the agrocenosis of winter wheat and to form a paradigm of an ecologically balanced fertilization system on leached chernozem. Меthods. Short-term field and analytical. Results. For the first time, under the conditions of sufficient moisture in the Forest Steppe of Ukraine, for the cultivation of winter wheat on leached chernozem, a fertilization system that forms a balanced balance of nutrients in the soil and ensures a grain yield of more than 6.5 t/ha has been substantiated. It was established that with a biological harvest, winter wheat takes the most nitrogen from the soil at the ratio N:P:K = 2.7:1:1.9. It was found that the formation of a balanced nitrogen balance in the soil depended mainly on the doses of nitrogen fertilizers and did not depend on the methods of their application. The potassium balance significantly depended on the removal of straw from the field and the doses of potash fertilizers, the phosphorus balance – on the doses of phosphorus fertilizers. Conclusions. Nitrogen was removed by plants mainly as part of grain yield, potassium – as part of by-products. In the control without fertilizers, removal of nitrogen by grain (4.77 t/ha) was 94 kg/ha, phosphorus – 33, potassium – 25, straw (5.35 t / ha) – 26, 10 and 57 kg/ha, respectively. The most ecologically stable fertilization system was that anticipated leaving winter wheat straw on the field and applying mineral fertilizers in a dose of N110Р60K60, where 60 kg / ha of nitrogen as ammonium sulfate was applied on the frozen soil surface, 30 kg/ha as ammonium nitrate on the soil surface or as urea foliarly in the phase of emergence into the tube (IVth stage of organogenesis) and 20 kg/ha as urea foliarly in the phase of milk-wax maturity (VIIIth stage of organogenesis) on the background of P60K60 applied under deep plowing. Under such conditions, an almost balanced balance of nutrients was achieved in the soil with nitrogen deficiency – 20–22 kg/ha and the accumulation of phosphorus and potassium reserves in the amount of 14–15 and 24 kg/ha, respectively. Obtaining a grain yield of more than 6.5 t/ha based on sustainability requires the application of mineral fertilizers in the dose of N130Р50K40 and under the condition that winter wheat straw remains on the field. In the case of removal of straw from the field, a deficiency of nitrogen and potassium was formed in the soil in the amount of 62–64 and 63 kg/ha with a balanced phosphorus balance, which is evidence of an ecologically unstable fertilization system.

Nitrogen Acquisition and Transport in the Ectomycorrhizal Symbiosis-Insights from the Interaction between an Oak Tree and Pisolithus tinctorius.

In temperate forests, the roots of various tree species are colonized by ectomycorrhizal fungi, which have a key role in the nitrogen nutrition of their hosts. However, not much is known about the molecular mechanisms related to nitrogen metabolism in ectomycorrhizal plants. This study aimed to evaluate the nitrogen metabolic response of oak plants when inoculated with the ectomycorrhizal fungus Pisolithus tinctorius. The expression of candidate genes encoding proteins involved in nitrogen uptake and assimilation was investigated in ectomycorrhizal roots. We found that three oak ammonium transporters were over-expressed in root tissues after inoculation, while the expression of amino acid transporters was not modified, suggesting that inorganic nitrogen is the main form of nitrogen transferred by the symbiotic fungus into the roots of the host plant. Analysis by heterologous complementation of a yeast mutant defective in ammonium uptake and GFP subcellular protein localization clearly confirmed that two of these genes encode functional ammonium transporters. Structural similarities between the proteins encoded by these ectomycorrhizal upregulated ammonium transporters, and a well-characterized ammonium transporter from E. coli, suggest a similar transport mechanism, involving deprotonation of NH4+, followed by diffusion of uncharged NH3 into the cytosol. This view is supported by the lack of induction of NH4+ detoxifying mechanisms, such as the GS/GOGAT pathway, in the oak mycorrhizal roots.

Exploring the transferability of wheat nitrogen status estimation with multisource data and Evolutionary Algorithm-Deep Learning (EA-DL) framework

Accurate and transferable wheat nitrogen status estimation is very important to plant phenotyping and smart agricultural management. The goal of this study was to establish a wheat nitrogen status estimation model across all growth stages by combining proximal sensing and meteorological data. From 2010–2020, nine multi-nitrogen rates field trials were conducted at five sites involving different wheat varieties. Proximal sensing data were acquired from a Crop Circle sensor at key growth stages and meteorological data were aggregated from planting to the corresponding sensing date. Deep neural network (DNN) and long short-term memory (LSTM) were adopted to estimate above-ground biomass, plant nitrogen uptake, plant nitrogen concentration, and the nitrogen nutrition index. Random forest (RF) was used as a benchmark regression model. Multi-task learning (MTL) based on DNN was conducted to estimate the four nitrogen indicators simultaneously. A genetic algorithm (GA) was tested to optimize the hyperparameters, connection weights, and loss function weights (for MTL) of neural networks separately. The results revealed that DNN (R2 =0.83–0.96) and MTL (R2 =0.81–0.96) achieved an overall comparable high accuracy with RF (R2 =0.83–0.97), whereas LSTM (R2 =0.76–0.93) did not improve the nitrogen status estimation in our dataset. This study presented a concise and efficient framework dedicated to exploring the transferability of phenotypic predictions and provided insights into understanding crop growth and nitrogen dynamics in response to environmental conditions.

New Insights into MdSPS4-Mediated Sucrose Accumulation under Different Nitrogen Levels Revealed by Physiological and Transcriptomic Analysis.

Nitrogen nutrition participates in many physiological processes and understanding the physiological and molecular mechanisms of apple responses to nitrogen is very significant for improving apple quality. This study excavated crucial genes that regulates sugar metabolism in response to nitrogen in apples through physiology and transcriptome analysis, so as to lay a theoretical foundation for improving fruit quality. In this paper, the content of sugar and organic acid in apple fruit at different developmental periods under different nitrogen levels (0, 150, 300, and 600 kg·hm-2) were determined. Then, the transcriptomic analysis was performed in 120 days after bloom (DAB) and 150 DAB. The results showed that the fructose and glucose content were the highest at 120 DAB under 600 kg·hm-2 nitrogen level. Meanwhile, different nitrogen treatments decreased malate content in 30 and 60 DAB. RNA-seq analysis revealed a total of 4537 UniGenes were identified as differentially expressed genes (DEGs) under nitrogen treatments. Among these DEGs, 2362 (52.06%) were up-regulated and 2175 (47.94%) were down-regulated. The gene co-expression clusters revealed that most DEGs were significantly annotated in the photosynthesis, glycolysis/gluconeogenesis, pyruvate metabolism, carbon metabolism, carbon fixation in photosynthetic organisms and plant hormone signal transduction pathways. The key transcription factor genes (ERF, NAC, WRKY, and C2H2 genes) were differentially expressed in apple fruit. Sugar and acid metabolism-related genes (e.g., HXK1, SPS4, SS2, PPC16-2, and MDH2 genes) exhibited significantly up-regulated expression at 120 DAB, whereas they were down-regulated at 150 DAB. Furthermore, the MdSPS4 gene overexpression positively promoted sucrose accumulation in apple callus and fruit. In conclusion, the combinational analysis of transcriptome and the functional validation of the MdSPS4 gene provides new insights into apple responses to different nitrogen levels.

Phosphorus and nitrogen nutrition in swine production.

Phosphorus and nitrogen nutrition in swine production.

Effect of water regime, nitrogen level and biostimulants application on yield and quality traits of wild rocket [Diplotaxis tenuifolia (L.) DC.

Wild rocket is an expanding vegetable crop, especially as a fresh-cut product that requires high quality standards. These can be achieved through appropriate management of agronomic practices such as water supply and nitrogen nutrition, in combination with emerging techniques such as the application of biostimulating substances. Hence, this study is focused on evaluating the response of the wild rocket to the application of two biostimulants in relation to different water regimes and nitrogen levels. The combined effect of two watering regimes (WR) (restoration of 50% and 100% of crop evapotranspiration-ETc, named WR50 and WR100, respectively); three N levels (NL) (0, 75 and 150 kg ha-1 N, named N0, N75 and N150, respectively); two biostimulants (BS) based on seaweed extract (SW), Azoxystrobin (AZ) and an untreated control (C) are investigated. The split-split plot experimental design with three replicates was used by arranging WR in the main plots, NL in the subplots and BS in the sub-subplots. Experiment was carried out in an unheated greenhouse during two growth cycles. Water shortage caused root biomass/total biomass ratio (RR) increase by 11.3% and 31.1% drop in yield, mainly because of the reduction in leaf size and number. Total phenols (TP), total antioxidant activity (TAA), total carotenoids (TCa) and nitrate (Ni) content were higher in WR50 in respect to WR100 by 10.4%, 18.7%, 12.0%, and 35.5%, respectively, while total chlorophyll (TCh) was lower by 5.3%. The increase of NL between N0 and N150 raised yield (222%), TCh (32.5%) and Ni (288.3), but reduced RR (43%), TP (16.2%), TAA (21.4%) and TCa (31.0%). SW and AZ increased yield respectively by 10.3% and 16.9%, mainly because raised leaf number for SW and leaf size for AZ. Moreover, SW increased RR by 7.2%, while AZ reduced it by 17.2%. SW and AZ improved TP, TAA, TCh and TCa respectively by 8.8%, 13.1%, 10.2% and 23.8% and by 10.8%, 19.7%, 16.0% and 35.6%. BS reduced Ni content by 21.5 (SW) and 36.8% (AZ). SW and AZ have shown good biostimulating efficacy by increasing yield and improving quality, reducing the harmful effects of water deficit. Tested BSs can be a useful tool for wild rocket farmers, especially under scarce water resources.

A new in vitro monitoring system reveals a specific influence of Arabidopsis nitrogen nutrition on its susceptibility to Alternaria brassicicola at the seedling stage.

Seedling growth is an early phase of plant development highly susceptible to environmental factors such as soil nitrogen (N) availability or presence of seed-borne pathogens. Whereas N plays a central role in plant-pathogen interactions, its role has never been studied during this early phase for the interaction between Arabidopsis thaliana and Alternaria brassicicola, a seed-transmitted necrotrophic fungus. The aim of the present work was to develop an in vitro monitoring system allowing to study the impact of the fungus on A. thaliana seedling growth, while modulating N nutrition. The developed system consists of square plates placed vertically and filled with nutrient agar medium allowing modulation of N conditions. Seeds are inoculated after sowing by depositing a droplet of conidial suspension. A specific semi-automated image analysis pipeline based on the Ilastik software was developed to quantify the impact of the fungus on seedling aerial development, calculating an index accounting for every aspect of fungal impact, namely seedling death, necrosis and developmental delay. The system also permits to monitor root elongation. The interest of the system was then confirmed by characterising how N media composition [0.1 and 5mM of nitrate (NO3-), 5mM of ammonium (NH4+)] affects the impact of the fungus on three A. thaliana ecotypes. Seedling development was strongly and negatively affected by the fungus. However, seedlings grown with 5mM NO3- were less susceptible than those grown with NH4+ or 0.1mM NO3-, which differed from what was observed with adult plants (rosette stage). The developed monitoring system allows accurate determination of seedling growth characteristics (both on aerial and root parts) and symptoms. Altogether, this system could be used to study the impact of plant nutrition on susceptibility of various genotypes to fungi at the seedling stage.

Novel, high-yielding lettuce phenotype generated by urea amine nitrogen nutrition displays contrasting traits to those of nitrate- or ammonium-fertilized plants

Fertilizing intact plants with particular forms of nitrogen (N), at equal concentrations of total N, gives rise to N-form-specific morphological and physiological phenotypes. Urea amine nitrogen is only transiently available in soil, thus its effects on plants have not been as well-defined. By stabilizing the N source urea amine, we have begun to characterize a third phenotype in addition to those recognized for nitrate and ammonium. We show that non-limiting rates of stabilized amine nitrogen (SAN) induce specific traits in greenhouse-grown lettuce, that lead to increased yields compared to controls treated with conventional industry standard fertilizers, un-stabilized urea, calcium nitrate or ammonium nitrate. These were supplied at the same total weight of N, via the soil or foliarly, to seedlings of Lactuca sativa L. cv ‘Tom Thumb’ and/or ‘Lollo Rosso’. Initially tap root length, lateral root development and leaf chlorophyll content are increased by SAN. As plants mature, leaf biomass increases at a faster rate under SAN nutrition, and larger harvest weights are finally attained, and/or a given head weight is achieved more rapidly. We conclude that plants respond positively to the maintenance of nitrogen in ureic-amine form, by initially partitioning more biomass to roots whilst increasing photosynthesis. These changes allow provision of more soil-sourced and carbon-based resources to the leaves of maturing plants. Leafy vegetable yields can be increased using stabilized urea amine fertilizer. We identify proxy traits for yield in young seedlings, which could be utilized in breeding and phenotyping programs for a wide range of species.

Effective fucoxanthin production in the flagellate alga Poterioochromonas malhamensis by coupling heterotrophic high-cell-density fermentation with illumination.

The unicellular flagellate algae Poterioochromonas malhamensis is a potential fucoxanthin-rich resource for sustainable and cost-effective fucoxanthin production. Light and nutrients are critical regulators for the accumulation of fucoxanthin in P. malhamensis. In this study, the maximum fucoxanthin yield of 50.5mgL-1 and productivity of 6.31mgL-1 d-1 were achieved by coupling high-cell-density fermentation with illumination. It was found that the combined use of organic and inorganic nitrogen (N) nutrition could improve the fucoxanthin yield as single inorganic or organic N had limitation to enhance cell growth and fucoxanthin accumulation. White light was the optimal light quality for fucoxanthin accumulation. Under white light and a moderate light intensity of 150μmolm-2 s-1, the highest biomass concentration and fucoxanthin content reached 32.9gL-1 and 1.56mgg-1 of dry cell weight (DCW), respectively. This is the first study on effective fucoxanthin production in P. malhamensis by integrating illumination with high-cell-density fermentation, which paved the way for further development of P. malhamensis as a potential source for commercial fucoxanthin production.

Green-in-green biohybrids as transient biotriboelectric nanogenerators

Green self-powered devices based on biodegradable materials have attracted widespread attention. Here, we propose the construction of the transient biotriboelectric nanogenerator (TENG) using green-in-green bionanocompoites. The green-in-green nanocomposites, cellulose nanocrystal (CNC)/polyhydroxybutyrate (PHB), are prepared with a high-pressure molding method. The CNC promotes the degradation and enhances the dielectric constant of CNC/PHB. It further allows for the significant improvement of the triboelectric output of CNC/PHB-based TENG. The voltage output and current output of CNC/PHB-based TENG are 5.7 and 12.5 times higher than those of pristine PHB-based TENG, respectively. Also, the bio-TENG exhibits admirable signal stability in over 20000 cycles. Despite the high hardness of CNC/PHB, a soft but simple-structured arch sensor is successfully assembled using CNC/PHB-based TENG. It can attain the precise real-time monitoring of various human motions. This study may provide new insights into the design/fabrication of green functional materials, and initiate the next wave of innovations in eco-friendly self-powered devices.

Compost and plant growth-promoting bacteria enhanced steviol glycoside synthesis in stevia (Stevia rebaudiana Bertoni) plants by improving soil quality and regulating nitrogen uptake

Stevia ( Stevia rebaudiana Bertoni) is an important industrial crop, and its leaves contain steviol glycosides (SGs), which are valuable compounds because they are characterized by a high sweetness and low caloric content. SGs yield depends on nitrogen (N) nutrition; however, the role of N uptake in SGs synthesis needs clarification, especially in organic farming systems that depend on organic and biofertilizers. Plant growth-promoting bacteria (PGPB; i.e., Azospirillum brasilense and Bacillus circulans ) and compost were used to study the effect of N nutrition on SGs yield. The experiment consisted of five N treatments with or without PGPB inoculation. The fertilization treatments were: C = without N, T 1 = urea, T 2 = compost, T 3 = urea and compost (75% of N from urea and the rest from compost) and T 4 = urea and compost (50% of N from urea and the rest 50% from compost). Compost and PGPB increased the soil quality indicators and enhanced the synthesis of chlorophyll and nutrient uptake by stevia plants. Mixtures of compost and urea under inoculation with PGPB enhanced soil microbes and enzymatic activity. The highest significant value of nitrogen use efficiency (NUE) resulted from urea alone, while the maximum phosphorus (P) and potassium (K) uptake came from compost. Although urea led to an increase in stevia N uptake, it led to a clear decrease in SGs yield. Urea decreased the total soluble sugar and leaf C/N ratio by 29% and 31%, respectively, compared to those of C. T 4 increased the SGs concentration by 74% and 46%, respectively, compared to that of urea alone in the presence and absence of PGPB. PGPB enhanced the soil quality and promoted nutrient uptake, resulting in significant increases in SGs yield. Regulating N uptake enhanced synthesis of soluble sugars and increased the C/N ratio, which caused an increase in SGs production. The use of compost and plant growth-promoting bacteria is a suitable strategy to produce stevia plants with low rates of inorganic nitrogen without any yield loss. • Compost and plant growth-promoting bacteria (PGPB) enhances stevia growth. • Compost and PGPB reregulate N-uptake in stevia plants. • Urea decreased the total soluble sugar and leaf C/N ratio. • Regulating N-uptake increased the synthesis steviol glycosides (SGs). • The findings might be an aid for sustainable N management in stevia production.

Spectral assessments of N-related maize traits: Evaluating and defining agronomic relevant detection limits

The spectral sensing of nitrogen (N)-related traits and the grain yield of maize ( Zea mays L.) is widely used in agricultural practice because it is rapid, non-destructive, and cost-efficient. However, there exists a lack of agronomically supported spectral detection limits. The agronomic aspects have not yet been fully considered based on commonly used statistical measures such as the coefficient of determination (R²), the root-mean-square error (RMSE), and the mean absolute error (MAE) and should therefore be extended. In the present study, we evaluated regression models of spectral indices derived from an unmanned aerial vehicle (UAV) by capturing N-related traits such as above-ground and grain N uptake, the nitrogen nutrition index (NNI), and grain yield covering data sets of two years, sites, and four developmental stages of maize. The results suggest that an agronomic evaluation exclusively adopting widely used statistical measures is not fully adequate. The R² is essentially influenced by differentiation of the trait, which in turn depends on year effects and growth stages. Further statistics such as RMSE and MAE average the error and lead to an under- and overestimation for most observations. In this investigation, we defined an appropriate agronomical error interval for above-ground and grain N uptake, NNI, and grain yield of ± 40 and ± 25 kg N ha −1 , ± 0.2, and ± 1.4 t ha −1 , with a probability of at least 80%. These interval limits are consistent across years and growth stages. The consistency occurs because most spectral indices are dominated by biomass. Across all of them, the best-performing spectral indices combine GREEN, REDEDGE, and NIR bands. For spectral indices using the RED band, the range of the agronomic error interval performed equally with a slightly worse probability of data points inside the error limits. Agronomically based error limits should be included in addition to common statistical measures in the spectral assessment of N-related traits of maize and grain yield to optimize the ex-ante and/or ex-post analysis of N-fertilization.

Effect of Differentiated Nitrogen Nutrition on Aboveground Biomass of Selected Cultivars of Cannabis sativa L. Cultivated Under Central European Conditions

Abstract Hemp (Cannabis sativa L.) is one of the traditional crops currently being newly re-introduced in Slovakia and cultivated for multi-purpose uses, while still there is a lack of crop biomass yield data. The main objective of the paper is to document the yield of aboveground biomass of selected cultivars of hemp ('Bialobrzeskie', 'Felina', 'Santhica', 'Epsilon', and 'Futura'), which were tested in the pilot open-field experiments conducted during 2009 − 2012, immediately after a wave of legislative changes. The trial was agronomically designed including three nitrogen treatments as follows: (i) T1 30 kg N/ha (the full 30 kg/ha in the phenophase BBCH 31), (ii) T2 60 kg N/ha (dividing on 30 + 30 kg/ha in the phenophase BBCH 31 and 51, respectively), and (iii) T3 90 kg N/ha (dividing on 30 + 30 + 30 kg/ha in the phenophase BBCH 31, 51 and 59, respectively); whereas NPK 15-15-15 in the dose of 200 kg/ha was applied before the sowing all across the treatments. The total average dry matter (DM) yield of 9.49 t/ha was achieved, ranging from 2.12 to 16.80 t/ha. DM yield was affected mainly by years (F-ratio 337.40, P-value 0.0000), followed by nitrogen treatment (F-ratio 47.86, P-value 0.0001), then by cultivars (F-ratio 22.37, P-value 0.0019) and finally by replications (F-ratio 0.65, P-value 0.58). However, the need for further studies aimed to quantify more precisely the response of the cultivars to the weather and soil conditions is necessary, especially the cultivars of new and foreign origin.

Precision nitrogen management regimes to obtain high yield and good eating quality of medium indica hybrid rice in mechanical transplanting with bowl-type nursery tray (MTB) based on the critical nitrogen concentration

Mechanical transplanting with bowl-type nursery tray (MTB) is a new mechanical cultivation approach to obtain high-yield and superior-quality rice. However, the precision of nitrogen (N) management regimes for obtaining high-yield and good-quality medium indica hybrid rice in MTB is unclear. Therefore, field experiments were conducted with five N application amounts for two medium indica hybrid cultivars in MTB in three studied years. The results indicated that the highest grain yield reached 10.40–12.27 t ha−1 when the N application amount was increased to approximately 245 kg ha−1 across cultivars. In addition, increasing the N application rate significantly decreased the eating quality of both cultivars in the three years in MTB (P < 0.05). The intersections of “high yield” and “good quality” were found at the site with 90% of the maximum yield and optimal eating quality. The corresponding N application amount was 130–140 kg ha−1 across cultivars and years. Critical nitrogen concentration (Nc) models based on total dry matter (TDM), stem and sheath dry matter (SDM), and leaf area index (LAI) had higher fitting precision and predictive abilities for the N content of rice plants (R2 >0.9) than the Nc model based on leaf dry matter (LDM) in both cultivars. However, the stability was poor among the different study years for the nitrogen nutrition index (NNI) calculated using NcTDM compared with those calculated using NcSDM and NcLAI. The reliable NcSDM and NcLAI models were expressed as Nc= 1.97SDM−0.42 (R2 =0.91;RMSE=0.11;n-RMSE=8.94%) and Nc= 3.72LAI−0.34 (R2 =0.93;RMSE=0.37;n-RMSE=15.54%) for medium indica hybrid rice in MTB. The yield increased linearly with NNI from 0 to 0.99 before heading and from 0 to 0.88 at heading in both cultivars. The yield did not increase further with increasing NNI when NNI reached the upper threshold value. However, increasing NNI significantly decreased eating quality (P < 0.05). Finally, the lower threshold value of NNIs obtained 90% of the maximum yield and optimal eating quality were recommended as 0.94, 0.96, 0.90, and 0.80 at the late stage of tillering, initial booting, middle stage of booting, and heading, respectively. This study provides important theoretical references for precise N management of medium indica hybrid cultivars in MTB.

The aromatic profile of wine distillates from Ugni blanc grape musts is influenced by the nitrogen nutrition (organic vs. inorganic) of Saccharomyces cerevisiae

Although the impact of nitrogen nutrition on the production of fermentative aromas in oenological fermentation is well known today, one may wonder whether the effects studied are the same when winemaking takes place at high turbidities, specifically for the production of wines intended for cognac distillation. To that effect, a fermentation robot was used to analyze 30 different fermentation conditions at two turbidity levels with several factors tested: (i) initial addition of nitrogen either organic (with a mixture of amino acids - MixAA) or inorganic with di-ammonium phosphate (DAP) at different concentrations, (ii) variation of the ratio of inorganic/organic nitrogen (MixAA and DAP) and (iii) addition of different single amino acids (alanine, arginine, aspartic acid and glutamic acid). A metabolomic analysis was carried out on all resulting wines to have a global vision of the impact of nitrogen on more than sixty aromatic molecules of various families. Then, at the end of the alcoholic fermentation, the wines were micro-distilled. A first interesting observation was that the aroma profiles of both wines and distillates were close, indicating that the concentration factor is rather similar for the different aromas studied. Secondly, the fermentation kinetics and aroma results have shown that the nitrogen concentration effect prevailed over the nature of nitrogen. Although the lipid concentration was in excess, an interaction between the assimilable nitrogen and lipid contents was still observed in wines or in micro-distillates. Alanine is involved in the synthesis of acetaldehyde, isobutanol, isoamyl alcohol and isoamyl acetate. Finally, it was demonstrated that modifying the ratio of assimilable nitrogen in musts is not an interesting technological response to improve the aromatic profile of wines and brandies. Indeed, unbalance the physiological ratio of the must by adding a single source of assimilable nitrogen (organic or inorganic) has been shown to deregulate the synthesis of most of the fermentation aromas produced by the yeast. Wine metabolomic analysis confirmed the results that had been observed in micro-distillates but also in the other aromatic families, especially on terpenes. The contribution of solid particles, but also yeast biosynthesis (via sterol management in must) to wine terpenes is discussed. Indeed, the synthesis of terpenes in this oenological context seems to be favored, especially since the concentration of assimilable nitrogen (in addition to the lipid content) favor their accumulation in the medium. A non-negligible vintage effect on the terpene profile was also demonstrated with variations in their distribution depending on the years.Thus, the present study focuses on the metabolism of wine yeasts under different environmental conditions (nitrogen and lipid content) and on the impact of distillation on the fate of flavor compounds. The results highlight once again the complexity of metabolic fluxes and of the impact of nitrogen source (nature and amount) and of lipids. Furthermore, this study demonstrates that beyond the varietal origin of terpenes, the part resulting from the de novo synthesis by the yeast during the fermentation cannot be neglected in the context of cognac winemaking with high levels of turbidity.

Comprehensive evaluation of Robinia Pseudoacacia L. seedlings in an irrigated nursery for use in forestry and gardening in the lower Volga region

The generic complex of Robinia is a fundamental and key component for urbanized and agroforestry zones. Robinia pseudoacacia L. is widely used in landscaping and protective forest plantations. Planting material has sufficient stability and durability. The studies were carried out in the nursery of the Nizhnevolzhskaya Station for tree species breeding (No. 34:36:0000:14:0178) by field stationary and laboratory methods using generally recognized methodological schemes for organizing work and constructing samples, statistical processing of primary information and analysis of variance were carried out according to generally accepted methods. The object was seedlings of the same age of Robinia pseudoacacia L. The purpose of the study was to substantiate the biometric characteristics of seedlings of Robinia pseudoacacia L. to assess the potential reclamation and decorative functions of plantations in the dry steppe conditions of the Lower Volga region. Physiological indicators of the breed have been established to determine the level of stability of the generic complex Robinia. The reaction of the pigment complex of robin plantations in the conditions of the Volgograd region was revealed. The stock of nodule bacteria Robinia pseudoacacia L at the end of the juvenile period was determined. Robinia plants are in optimal condition, actively carry out metabolic processes and protein synthesis and do not experience nitrogen deficiency (at the level of 18.4 ± 0.3), which indicates a sufficient level of nitrogen nutrition, active synthesis of metabolites, active growth and development plants. During the first year of vegetation, a specific reaction of Robinia was shown at the morpho-physiological level. Plants form a good growth, a high mass of roots and aerial mass, contribute to an active entry into symbiotic relationships with nitrogen-fixing bacteria, contain a sufficient amount of chlorophylls, flavonoids, xanthophylls. This plantation planting material of Robinia pseudoacacia L. of seed origin is recommended for creating highly productive protective plantings and plantings of greenery for various purposes in settlements and beyond in the Lower Volga region.

Rice nitrogen nutrition monitoring classification method based on the convolution neural network model: Direct detection of rice nitrogen nutritional status.

The nitrogen nutrition status affects the main factors of rice yield. In traditional rice nitrogen nutrition monitoring methods, most experts enter the farmland to observe leaf color and growth and apply an appropriate amount of nitrogen fertilizer according to the results. However, this method is labor- and time-consuming. To realize automatic rice nitrogen nutrition monitoring, we constructed the Jiangxi rice nitrogen nutrition monitoring model based on a convolution neural network (CNN) using the same region rice canopy image in different generation periods. Our CNN model was evaluated using multiple evaluation criteria (Accuracy, Recall, Precision, and F1 score). The results show that the same CNN model could distinguish the rice nitrogen nutrition status in different periods, which can completely realize the automatic discrimination of nitrogen nutrition status so as to guide the scientific nitrogen application of rice in this area. This will greatly improve the discrimination efficiency of the nitrogen nutrition status and reduce the time and labor cost. The application of the proposed method also proved that the CNN model can be applied in the discrimination of the nitrogen nutrition status. Among CNN models, GoogleNet model proposed a CNN architecture named Inception which can improve the depth of the network and extract higher-level features without changing the amount of calculation of the model. The GoogleNet model achieved the highest accuracy, 95.7%.

Effect of Nitrogen Nutrition and Planting Date on the Yield and Physicochemical Parameters of Flowering Chinese Cabbage

The nitrogen requirements of flowering Chinese cabbage are unknown. Our study aimed at investigating the effect of varied nitrogen nutrition levels (including 50, 70, 90, 110, and 130 mg N per dm3, described as N-50 to N-130, respectively) on the yield of flowering Chinese cabbage (Brassica campestris L. ssp. chinensis var. utilis Tsen et Lee) grown in two varied soilless cultivation systems (substrate and hydroponic) and seasons (spring and autumn). We confirmed that the intensity of the nitrogen nutrition modified the yield of plants within a range of 50 to 90 mg N; the yields were increased; however, the higher N concentrations were not effective. In both cultivation systems, the content of K, Ca, and Fe in leaves was higher in autumn compared to spring. Nitrogen nutrition improved the weight of plants—an effect that varied depending on the system of cultivation—and increased the phenolic content. N-90 was the optimal level of nitrogen nutrition. More intensive N-nutrition did not significantly modify plant yields or phenolic content. We Concluded that N fertilisation might be an effective tool to obtain plants with high bioactive compound content.