NITRATE ACCUMULATION IN CELERY AS AFFECTED BY GROWING SYSTEM AND N CONTENT IN THE NUTRIENT SOLUTION

Measurements were made of plant, root, and nodule dry matter, nodule number, acetylene reduction by nitrogenase, plant N content, and shoot height of Medicago sativa L. cv. Algonquin and expressed chiefly as rate constants of growth (k1′). The effects of the nature and quantity of solid substratum, of the form and concentration of combined N and of symbiotic and non-symbiotic growth, were compared in optimum growth room conditions. Plants grew at the same maximum k1′ in vermiculite with or without gravel and in a soil mix when supplied with 15 mM NO3− in the nutrient solution. Plant growth was retarded with decreasing pot size but maximum nodule growth k1′ occurred in 7-cm pots. Nodulation and nitrogenase activity showed maximum k1′ with least added N but moderate additions produced larger yields of roots and nodules. Plant growth in dry matter and N content, expressed as k1′, yield, or absolute rate (k1′∙yield), was under no circumstance increased by symbiosis in this phase of exponential growth. Nodulation was completely inhibited by 15 mM NO3− and higher concentrations of N were generally inhibitory. A transient, postgerminative treatment with 15 mM NO3− provided a sustained boost to growth. Combined N supplied as NO2− or NH4+ at 15 mM in the nutrient solution without NO3− suported k1′ values comparable to those obtained with less than 1.5 mM NO3−.

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Effect of Reduced Nitrogen and Supplemented Amino Acids Nutrient Solution on the Nutritional Quality of Baby Green and Red Lettuce Grown in a Floating System

Agronomy ◽

10.3390/agronomy10070922 ◽

2020 ◽

Vol 10 (7) ◽

pp. 922 ◽

Cited By ~ 1

Author(s):

Pavlos Tsouvaltzis ◽

Dimitrios S. Kasampalis ◽

Danai-Christina Aktsoglou ◽

Nikolaos Barbayiannis ◽

Anastasios S. Siomos

Keyword(s):

Amino Acids ◽

Nutrient Solution ◽

Nutritional Quality ◽

Mineral Nitrogen ◽

Leafy Vegetables ◽

Nitrate Accumulation ◽

Nitrogen Reduction ◽

Soluble Solid ◽

Floating System

Excessive nitrogen fertilization results in nitrate accumulation in leafy vegetables. Reducing the dose of mineral nitrogen or using alternate fertilizers lowers the nitrate accumulation; however, a critical minimum level of mineral nitrogen is necessary to maintain yield and nutritional quality. The aim of this study was to evaluate the effect of two levels of mineral nitrogen (100% and 50%) and three levels of an amino acid solution (0, 0.3, and 0.9%) in the nutrient solution of two baby lettuce cultivars (green and red) grown in a floating system. Nitrogen reduction did not affect yield (12.9–13.4 and 11.0–11.3 g/plant, respectively) but reduced nitrate accumulation (by 43 and 19%, respectively) in both green and red lettuce, while enhancing phenolic content (by 28%) and antioxidant capacity (by 69%) in green lettuce and soluble solid (by 7%) and total chlorophyll content (by 9%) in red lettuce. Although nitrate accumulation was prevented (< 355 mg/kg FW) and most nutritional components increased in both lettuce types by amino acids supplementation, plant growth was negatively affected, especially in red lettuce, in both concentrations of amino acids (reduction by 9 and 35% in 0.3 and 0.9%, respectively). In both lettuce types, proline content increased by 0.9% amino acids supplementation (by 45%), implying a probable induction of a stress condition. Mineral nutrients were slightly affected by nitrogen reduction, which was probably perceived as an abiotic stress.

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Nitrate accumulation reduction using chloride in the nutrient solution on lettuce growing by NFT in semiarid climate conditions

Journal of Plant Nutrition ◽

10.1080/01904169809365515 ◽

1998 ◽

Vol 21 (8) ◽

pp. 1705-1714 ◽

Cited By ~ 14

Author(s):

Miguel Urrestarazu ◽

Adela Postigo ◽

Maricarmen Salas ◽

Agustín Sánchez ◽

Gilda Carrasco

Keyword(s):

Nutrient Solution ◽

Nitrate Accumulation ◽

Climate Conditions ◽

Semiarid Climate

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Relationship between soil nitrate accumulation and in-season corn N nutrition indicators

Canadian Journal of Plant Science ◽

10.4141/cjps2011-086 ◽

2012 ◽

Vol 92 (2) ◽

pp. 331-339 ◽

Cited By ~ 10

Author(s):

Noura Ziadi ◽

Gilles Bélanger ◽

Annie Claessens

Keyword(s):

Grain Yield ◽

Growth And Yield ◽

Soil Nitrate ◽

Threshold Values ◽

Nitrate Accumulation ◽

N Accumulation ◽

N Content ◽

N Nutrition ◽

Stage Of Development ◽

Data Points

Ziadi, N., Bélanger, G. and Claessens, A. 2012. Relationship between soil nitrate accumulation and in-season corn N nutrition indicators. Can. J. Plant Sci. 92: 331–339. Nitrogen management tools are required to optimize crop growth and yield while minimizing the likelihood of N losses to the environment. We previously determined that non-limiting N conditions for near maximum corn (Zea mays L.) grain yield are reached with the following threshold values for three in-season plant-based indicators of corn N nutrition determined at approximately the V12 stage of development: N nutrition index (NNI) = 0.88, leaf N (NL) concentration = 32.7 mg N g−1 leaf DM, and relative chlorophyll meter (RCM) values = 0.95. Our objective was to study the relationship between these plant-based indicators and soil NO3-N content in an effort to develop tools to reduce the likelihood of soil NO3-N accumulation without affecting grain yield. This study at 5 site-years in Québec consisted of six N fertilizer rates (20–250 kg N ha−1). The NNI, NL concentrations, RCM values, and soil (0–0.15 m) NO3-N content were measured weekly from July to early August, while soil NO3-N content to a 0.90-m depth was measured in late August and October. During the growing season from July to early August, the proportion of data points above the average soil NO3-N content was greater under non-limiting N conditions (NNI ≥ 0.88, NL concentrations ≥ 32.7 mg N g−1 leaf DM, or RCM values ≥ 0.95) than under limiting N conditions. Furthermore, the mean soil NO3-N content of the data points above the general average was much higher under non limiting than limiting N conditions in late August (167 vs. 78 kg NO3-N ha−1 for NNI and RCM; 166 vs. 112 kg NO3-N ha−1 for NL concentration) and October (68 vs. 49 kg NO3-N ha−1). High soil NO3-N accumulation during the season and at harvest occurs only when in-season plant-based N indicators are greater than their threshold values.

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Nodulation and Plant Growth of Shepherdia ×utahensis ‘Torrey’ Topdressed with Controlled-release Fertilizer

HortScience ◽

10.21273/hortsci15260-20 ◽

2020 ◽

Vol 55 (12) ◽

pp. 1956-1962

Author(s):

Ji-Jhong Chen ◽

Heidi Kratsch ◽

Jeanette Norton ◽

Youping Sun ◽

Larry Rupp

Keyword(s):

Controlled Release ◽

Plant Growth ◽

Nutrient Solution ◽

Dry Weight ◽

Nodule Formation ◽

N Leaching ◽

Gas Exchange Parameters ◽

N Content ◽

Controlled Release Fertilizer ◽

Application Rates

Shepherdia ×utahensis ‘Torrey’ (‘Torrey’ hybrid buffaloberry) is an actinorhizal plant that can fix atmospheric nitrogen (N2) in symbiotic root nodules with Frankia. Actinorhizal plants with N2-fixing capacity are valuable in sustainable nursery production and urban landscape use. However, whether nodule formation occurs in S. ×utahensis ‘Torrey’ and its interaction with nitrogen (N) fertilization remain largely unknown. Increased mineral N in fertilizer or nutrient solution might inhibit nodulation and lead to excessive N leaching. In this study, S. ×utahensis ‘Torrey’ plants inoculated with soils containing Frankia were irrigated with an N-free nutrient solution with or without added 2 mm ammonium nitrate (NH4NO3) or with 0.0 to 8.4 g·L−1 controlled-release fertilizer (CRF; 15N–3.9P–10K) to study nodulation and plant morphological and physiological responses. The performance of inoculated plants treated with various amounts of CRF was compared with uninoculated plants treated with the manufacturer’s prescribed rate. Plant growth, gas exchange parameters, and shoot N content increased quadratically or linearly along with increasing CRF application rates (all P < 0.01). No parameters increased significantly at CRF doses greater than 2.1 g·L−1. Furthermore, the number of nodules per plant decreased quadratically (P = 0.0001) with increasing CRF application rates and nodule formation were completely inhibited at 2.9 g·L−1 CRF or by NH4NO3 at 2 mm. According to our results, nodulation of S. ×utahensis ‘Torrey’ was sensitive to N in the nutrient solution or in increasing CRF levels. Furthermore, plant growth, number of shoots, leaf area, leaf dry weight, stem dry weight, root dry weight, and N content of shoots of inoculated S. ×utahensis ‘Torrey’ plants treated with 2.1 g·L−1 CRF were similar to those of uninoculated plants treated with the manufacturer’s prescribed rate. Our results show that S. ×utahensis ‘Torrey’ plants inoculated with soil containing Frankia need less CRF than the prescribed rate to maintain plant quality, promote nodulation for N2 fixation, and reduce N leaching.

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Nitrogen Nutrition of Cowpea (Vigna unguiculata)

Experimental Agriculture ◽

10.1017/s0014479700008127 ◽

1977 ◽

Vol 13 (4) ◽

pp. 369-380 ◽

Cited By ~ 46

Author(s):

A. R. J. Eaglesham ◽

F. R. Minchin ◽

R. J. Summerfield ◽

P. J. Dart ◽

P. A. Huxley ◽

...

Keyword(s):

Nutrient Solution ◽

Vigna Unguiculata ◽

Nitrogen Nutrition ◽

N Content ◽

N Assimilation ◽

Total Plant ◽

Reported Data ◽

Total Seed ◽

N Status

SUMMARYEffectively nodulated, pot-grown cowpea plants were irrigated with nutrient solution containing 25 ppm 15N, and the relative contributions to total plant N status of inorganic and nodule-fixed N were determined. Maximum rates of N assimilation occurred during pod-fill, with nodules contributing ten times more nitrogen than the applied source. Symbiotic fixation supplied over 80% of total plant N throughout growth, and contributed significantly to seed N during late pod-fill, when nutrient N assimilation was negligible. Vegetative N content was greatest at mid pod-fill, and mobilization from this 'pool' was equivalent to 44% of total seed N. The implications of these (and previously reported) data are discussed.

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Evaluation of the Non-destructive Method Efficiency of Estimating Nitrogen Content in Jambu Plants Grown in Hydroponic System

Journal of Agricultural Studies ◽

10.5296/jas.v8i2.16380 ◽

2020 ◽

Vol 8 (2) ◽

pp. 466

Author(s):

Italo Marlone Gomes Sampaio ◽

Mário Lopes da Silva Júnior ◽

Erika Da Silva Chagas ◽

Ricardo Falesi Palha de Moraes Bittencourt ◽

Vivian Christine Nascimento Costa ◽

...

Keyword(s):

Nitrogen Content ◽

Nutrient Solution ◽

Linear Models ◽

Nitrogen Concentration ◽

Chlorophyll Concentration ◽

Technical Information ◽

Dry Mass ◽

Leafy Vegetables ◽

Total Chlorophyll ◽

N Content

Jambu is considered a leafy vegetable with expressive relevance in the regions that compose the Brazilian Amazon. However, there are challenges regarding its cultivation, particularly for the nutritional management, since there is little technical information that allows an increase in the efficiency of its production. In this sense, nitrogen (N) gains prominence, since it is related to the increased yield and quality of leafy vegetables, therefore its monitoring of N content in plants is necessary. The objective of this study was to evaluate the efficiency of using the SPAD index to estimate the N content of jambu leaves, total chlorophyll concentration, as well as its relationship with dry mass accumulation due to the increase of nitrogen concentration in the nutrient solution. The design used was completely randomized with eight replications. The treatments were six nitrogen concentrations in the nutrient solution (11, 13, 15, 17, 19 and 21 mmol L-¹). After 21 days of transplantation, the SPAD index was measured. Then, these plants were collected to quantify the total chlorophyll, dry mass and nitrogen content. In general, the variables were explained by increasing linear models. There was a positive correlation between the SPAD index and the other characteristics evaluated. Based on the results, the best response at the concentration of 21 mmol L-¹ in the nutrient solution stands out. In addition, the SPAD index has potential to be used in the diagnosis of nitrogen status in jambu leaves.

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The Effect of Growth Medium Temperature on Corn Salad [Valerianella locusta (L.) Laterr] Baby Leaf Yield and Quality

HortScience ◽

10.21273/hortsci.46.12.1619 ◽

2011 ◽

Vol 46 (12) ◽

pp. 1619-1625 ◽

Cited By ~ 10

Author(s):

Luisa Dalla Costa ◽

Nicola Tomasi ◽

Stefano Gottardi ◽

Francesco Iacuzzo ◽

Giovanni Cortella ◽

...

Keyword(s):

Nutrient Solution ◽

Plant Performance ◽

Postharvest Quality ◽

Nitrate Content ◽

Temperature Modulation ◽

Root Temperature ◽

Nitrate Accumulation ◽

Medium Temperature ◽

Positive Effects ◽

Fresh Vegetables

Soil temperature has a crucial impact on physiological processes and growth of plants with important consequences for plant productivity and food safety including nitrate accumulation in leaf blades of leaf vegetables. Consumer demand for high-quality, fresh-cut vegetables has increased rapidly in the last decades, and temperature modulation can help control nitrate concentration in fresh vegetables, an important trait of product safety. Corn salad plants [Valerianella locusta (L.) Laterr., cultivar Gala] were grown at three root temperatures (15, 20, and 25 °C) in a floating system. This experimental setup allowed to directly evaluate the effect of root temperature on yield and plant quality excluding the effect on soil processes and properties. Nutrient solution was renewed weekly and kept aerated while air temperature was maintained constant at 20 °C for all treatments during the entire time of experiments. At harvest, plants were collected, the shelf life evaluated, and the nutrient uptake [NO3−, iron (Fe) from 59Fe-o,oEDDHA, and 35SO42−] and mineral content were determined. Results showed that growing conditions at 20 °C of the nutrient solution led to the best plant performance in terms of yield, nitrate content at leaf level, root biomass, leaf area, and greenness with positive effects on postharvest quality, i.e., less rapid leaf loss of greenness and leaf fresh weight (FW) loss during conservation at 4 °C. At this temperature condition of the nutrient solution, it has also been observed an enhanced functionality of mechanisms involved in the acquisition of nutrients like NO3−, Fe, and SO42−, which are known to play an important role in nitrate level in leaf tissues of crops. Plants grown at 15 °C showed minor growth, whereas the nutrient solution at 25 °C caused stress for the plants affecting negatively the quality and yield. Overall, the results obtained showed that root temperature plays a fundamental role in several plant processes that affect yield and its quality; for hydroponic system cultivations, a level of growing-medium temperature close to that of the surrounding air seems suitable.

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Physiological and Transcriptome Analysis Reveals the Differences in Nitrate Content Between Lamina and Midrib of Flue-Cured Tobacco

10.21203/rs.3.rs-436881/v1 ◽

2021 ◽

Author(s):

Yuqing Feng ◽

Yuanyuan Zhao ◽

Yafei Li ◽

Jun Zhou ◽

Yujing Li ◽

...

Keyword(s):

Transcriptome Analysis ◽

Molecular Mechanisms ◽

Carbon Fixation ◽

High Capacity ◽

Carotenoid Biosynthesis ◽

Nitrate Content ◽

Nitrate Accumulation ◽

N Content ◽

Chlorophyll Metabolism ◽

Tobacco Specific Nitrosamines

Abstract Nitrate is an important precursor of tobacco-specific nitrosamines (TSNAs) and remarkable difference in nitrate accumulation between lamina and midrib of flue-cured tobacco has long been observed. However, the physiological and molecular mechanisms underpinning this difference remain poorly understood. In this study, physiological and genetic factors impacting nitrate accumulation were identified in pot experiments using flue-cured tobacco K326 with contrasting nitrate content between lamina and midrib. The results showed that three times higher of NO3-N content was observed in midrib than that in lamina, along with lower pigment, NH4-N content, NRA, SSA and GSA in midrib. Transcriptome analysis revealed that expression of genes involved in porphyrin and chlorophyll metabolism, carotenoid biosynthesis, photosynthesis-antenna proteins, photosynthesis, carbon fixation in photosynthetic organisms, starch and sucrose metabolism, nitrogen metabolism and biosynthesis of amino acids were significantly lower in midrib than in lamina. qRT-PCR results showed that the expression level of nitrate transporter genes LOC107782967, LOC107806749, LOC107775674, LOC107829632, LOC107799198, LOC107768465 decreased by 2.74, 1.81, 49.5, 3.5, 2.64 and 2.96 folds while LOC107789301 increased by 8.23 folds in midrib but not in lamina. Reduced chlorophyll content might result in low carbohydrate formation which is the source of energy and carbon skeleton supply, then the low capacity of nitrogen reduction, assimilation and transportation, and the poor ability of nitrate reallocation but high capacity of accumulation might lead to nitrate accumulation in midrib. The results laid the foundation for reducing nitrate content and TSNA formation in tobacco midribs and their products.

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The impact of different growth media and ammonium-nitrate ratio on yield and nitrate accumulation in lettuce (Lactuca sativa var. longifolia)

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha49412540 ◽

2021 ◽

Vol 49 (4) ◽

pp. 12540

Author(s):

Selçuk SÖYLEMEZ

Keyword(s):

Nutrient Solution ◽

Root Traits ◽

Growth Media ◽

Nitrate Accumulation ◽

Yield And Quality ◽

Head Weight ◽

Growth Attributes ◽

Lettuce Yield ◽

The Impact

Ammonium (NH4+) to nitrate (NO3-) ratio and growth media significantly alter plant development and NO3- accumulation in lettuce. Nitrate accumulation is regarded harmful for environment and human health. The quality of lettuce is assessed by NO3-concentration, size, and weight. This study determined the impact of five different growth media (cocopeat, peat, bark, perlite and rockwool) and four different NH4+:NO3- ratios (0:100, 20:80, 40:60 and 60:40) on NO3- accumulation in lettuce, yield, and several growth attributes. The experimentation was conducted according to open feeding system of soilless agriculture. The ‘Cosmos’ variety of lettuce was used as experimental material in the study. Growth mediums and NH4+:NO3- ratios significantly altered NO3- accumulation, head, leaf, stem and root traits. The results revealed that instead of growing lettuce with NO3- only in peat and rockwool, addition of NH4+ (20:80 of NH4+:NO3-) into nutrient solution increased head weight. While head weight increased in perlite medium with the addition of NH4+, it decreased in cocopeat and bark media. It is concluded that growth media and NH4+:NO3- ratios pose significant impacts on NO3- accumulation in leaf and that the increase in NH4+ ratio decreased NO3- accumulation in all growing media. Therefore, it is recommended that NH4+ should be added in the nutrient solution to decrease NO3- accumulation, which will ultimately improve yield and quality of lettuce.

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