Effect of N fertilization rate on soil alkali-hydrolyzable N, subtending leaf N concentration, fiber yield, and quality of cotton

Two greenhouse cucumber (Cucumis sativus) cultivars with differing fruit types [European (`Bologna') and Beit-alpha (`Sarig')] were grown during two seasons in a perlite medium in black plastic nursery containers in a passively ventilated greenhouse in northern Florida to evaluate fruiting responses to nitrogen (N) fertilization over the range of 75 to 375 mg·L–1. Fruit production, consisting mostly of fancy fruits, increased quadratically with N concentration in the nutrient solution, leveling off above 225 mg·L–1 for both cucumber cultivars. Fruit length and diameter were not affected by N concentration in the nutrient solution. Leaf N concentration, averaged over three sampling dates, increased linearly with N concentration in the nutrient solution from 46 g·kg–1 with 75 mg·L–1 N to 50 g·kg–1 with 375 mg·L–1 N. Fruit firmness decreased with increasing N concentration and there was little difference in firmness between the two cultivars. Firmness was similar across three measurement dates during the spring harvest season, but increased during the season in the fall. Fruit color responses to N concentration were dependent on the specific combination of experiment, sampling date, and cultivar. For most combinations of experiment, sampling date, and cultivar, cucumber epidermal color was greener (higher hue angle) with increased N concentration. The color was darkest (lowest L* value) and most intense (highest chroma value) with intermediate to higher N concentrations.

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Down-Regulation of Photosynthesis to Elevated CO2 and N Fertilization in Understory Fraxinus rhynchophylla Seedlings

Forests ◽

10.3390/f12091197 ◽

2021 ◽

Vol 12 (9) ◽

pp. 1197

Author(s):

Siyeon Byeon ◽

Kunhyo Kim ◽

Jeonghyun Hong ◽

Seohyun Kim ◽

Sukyung Kim ◽

...

Keyword(s):

Elevated Co2 ◽

N Fertilization ◽

Leaf Nitrogen ◽

N Availability ◽

Down Regulation ◽

Leaf Production ◽

N Concentration ◽

Leaf N Concentration ◽

Regulation Of Photosynthesis ◽

Leaf N

(1) Background: Down-regulation of photosynthesis has been commonly reported in elevated CO2 (eCO2) experiments and is accompanied by a reduction of leaf nitrogen (N) concentration. Decreased N concentrations in plant tissues under eCO2 can be attributed to an increase in nonstructural carbohydrate (NSC) and are possibly related to N availability. (2) Methods: To examine whether the reduction of leaf N concentration under eCO2 is related to N availability, we investigated understory Fraxinus rhynchophylla seedlings grown under three different CO2 conditions (ambient, 400 ppm [aCO2]; ambient × 1.4, 560 ppm [eCO21.4]; and ambient × 1.8, 720 ppm [eCO21.8]) and three different N concentrations for 2 years. (3) Results: Leaf and stem biomass did not change under eCO2 conditions, whereas leaf production and stem and branch biomass were increased by N fertilization. Unlike biomass, the light-saturated photosynthetic rate and photosynthetic N-use efficiency (PNUE) increased under eCO2 conditions. However, leaf N, Rubisco, and chlorophyll decreased under eCO2 conditions in both N-fertilized and unfertilized treatments. Contrary to the previous studies, leaf NSC decreased under eCO2 conditions. Unlike leaf N concentration, N concentration of the stem under eCO2 conditions was higher than that under ambient CO2 (4). Conclusions: Leaf N concentration was not reduced by NSC under eCO2 conditions in the understory, and unlike other organs, leaf N concentration might be reduced due to increased PNUE.

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(328) Effect of Supplemental Nitrogen Applicationat Selected Times on Pecan

HortScience ◽

10.21273/hortsci.40.4.1065d ◽

2005 ◽

Vol 40 (4) ◽

pp. 1065D-1065

Author(s):

Michael Smith

Keyword(s):

N Fertilization ◽

The Other ◽

N Concentration ◽

Leaf N Concentration ◽

Leaf N

Supplemental nitrogen applications were tested to reduce irregular bearing and improve yield on drip-irrigated pecan (Caryaillinoinensis Wangenh. C. Koch. cv. Mohawk) trees planted in 1989. Treatments were: 1) no N fertilization; 2) 75 kg·ha-1 N in March; 3) 75 kg·ha-1 N in March plus 50 kg·ha-1 N in August; and 4) 75 kg·ha-1 N in March plus 50 kg·ha-1 N in October. Withholding N did not reduce July leaf N concentration compared to the other treatments until the sixth year of the study. Trees receiving N had similar July leaf N concentrations regardless of treatment throughout the study. October leaf N concentrations were unaffected by treatment, except in 2002, when withholding N suppressed leaf N compared to other treatments. The percentage of fruiting shoots was lower when supplemental N was applied in October compared to August during 2 of 6 years. Otherwise, the percentage of fruiting shoots was unaffected by treatment. Weight per nut and kernel percentage were not affected by treatment, except kernel percentage was lower during 1 year when supplemental N was applied in August compared to October. Kernel grade was usually not affected by treatment.

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Leaf Nitrogen Status on Yield and Quality of Roses

HortScience ◽

10.21273/hortsci.35.4.564c ◽

2000 ◽

Vol 35 (4) ◽

pp. 564C-564b

Author(s):

Raul I. Cabrera

Keyword(s):

Experimental Period ◽

Leaf Nitrogen ◽

Stem Length ◽

Yield And Quality ◽

Leaf Chlorophyll ◽

N Concentration ◽

Biomass Yields ◽

Leaf N Concentration ◽

Plant Yields ◽

Leaf N

The establishment of critical tissue N levels for greenhouse rose production has been primarily based on visual symptoms of N deficiency, with relatively less consideration to yield parameters. This work examined the relationship between rose leaf N concentration and flower yield and quality. Container-grown `Royalty' rose plants were irrigated for 13 months with complete nutrient solutions containing N concentrations of 30, 60, 90, 120, 150 and 220 mg·L–1. Optimum flower and dry biomass yields, stem length, and stem weights were obtained in plants irrigated with 90 mg·L–1 N. Leaf N concentrations increased asymptotically with N applications, stabilizing at N concentrations >90 mg·L–1. Time of the year had an effect on overall leaf N concentrations, with higher values observed in the winter, and lower values in the summer. Leaf N concentrations were linearly, and significantly, correlated with leaf chlorophyll content and leaf color attributes (hue, chroma, and value). Quadratic relationships between leaf N concentration and rose plant yields were observed only for the second half of the experimental period, and depicted an apparent, and striking, plant control over tissue N status. In addition, these relationships indicated that optimum plant yields were possible during spring and summer with leaf N concentrations below the recommended critical level of 3% (as low as 2.4% to 2.5%). These results suggest that leaf N concentration per se is not a dependable indicator of rose productivity.

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Fertilization and Growth of Field-grown Citrus Nursery Trees in Florida

HortTechnology ◽

10.21273/horttech.18.1.29 ◽

2008 ◽

Vol 18 (1) ◽

pp. 29-33 ◽

Cited By ~ 3

Author(s):

Frederick S. Davies ◽

Glenn Zalman

Keyword(s):

Dry Weight ◽

Fine Sand ◽

N Fertilization ◽

Poncirus Trifoliata ◽

Tree Trunk ◽

Trunk Diameter ◽

N Concentration ◽

Leaf N Concentration ◽

Optimum N Rate ◽

Leaf N

The objective of this study was to determine the effects of various levels of nitrogen (N) on growth of ‘Hamlin’ orange (Citrus sinensis) trees on Carrizo citrange (C. sinensis × Poncirus trifoliata) rootstock in a field nursery. Newly budded liners were obtained from commercial nurseries and received from 0 to 3976 kg N per treated hectare annually (8N–0P–6.6K) in 14 applications per season. Tree trunk diameter, height, and dry weight were measured in two separate experiments. Total dry weight and trunk diameter were greatest for trees receiving 794 kg·ha−1 N annually during both seasons. However, annual N rates more than 1589 kg·ha−1 reduced trunk diameters and dry weight compared with the optimum N rate during both seasons. Leaf N concentration and N rate were positively correlated in both seasons, but leaf N concentration was poorly correlated with tree trunk diameter and dry weight. Therefore, very high rates of N fertilization may actually reduce ‘Hamlin’ orange tree growth in field nurseries when growing in an Arredondo fine sand.

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Optimal Nitrogen Concentration and Rapid Nutritional Diagnosis of Nitrogen Requirement for Container Production of Malabar Chestnut

HortTechnology ◽

10.21273/horttech.25.5.602 ◽

2015 ◽

Vol 25 (5) ◽

pp. 602-607

Author(s):

Yung-Liang Peng ◽

Fang-Yin Liu ◽

Rong-Show Shen ◽

Yu-Sen Chang

Keyword(s):

Plant Growth ◽

Dry Weight ◽

N Fertilization ◽

Chlorophyll Meter ◽

Leaf Chlorophyll ◽

N Concentration ◽

Leaf N Concentration ◽

Leaf Dry Weight ◽

N Requirement ◽

Leaf N

Nitrogen (N) is a major element required for crop cultivation and an important factor affecting plant growth and development. Malabar chestnut (Pachira macrocarpa) is an important ornamental potted plant crop whose N requirement has been studied, and a rapid monitoring method to manage N fertilization during its commercial production is yet to be established. Malabar chestnut seedlings were fertilized weekly with 0, 4, 8, 16, or 24 mm N. After 12 weeks, 16 mm N was found to yield the greatest plant growth such as plant height, number of nodes, and total leaf area. Measurements of chlorophyll meter readings, leaf chlorophyll concentration, leaf N concentration, and leaf dry weight all indicated that the optimal level of N fertilization was 16 mm N. A chlorophyll meter can be used to monitor nondestructively whether sufficient N has been supplied to support optimal plant growth. In this study, a chlorophyll meter reading of 46.1 corresponded with a critical leaf N concentration of 2.65%, defined as the leaf N concentration when the leaf dry weight was at 90% of saturation point. Additional N supplied beyond this critical level increased foliar chlorophyll content and improved the rate of net photosynthesis. Therefore, chlorophyll meter readings, which are convenient and nondestructive can serve as a reliable reference for commercial production in monitoring N requirement for optimum growth of malabar chestnut. Weekly fertilization of malabar chestnut with 16 mm N and maintaining leaf chlorophyll meter readings between 46.1 and 58.4 are recommended.

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Nitrogen use efficiency and critical leaf N concentration of Aloe vera in urea and diammonium phosphate amended soil

Heliyon ◽

10.1016/j.heliyon.2020.e05718 ◽

2020 ◽

Vol 6 (12) ◽

pp. e05718

Author(s):

Md. Akhter Hossain Chowdhury ◽

Taslima Sultana ◽

Md. Arifur Rahman ◽

Tanzin Chowdhury ◽

Christian Ebere Enyoh ◽

...

Keyword(s):

Nitrogen Use Efficiency ◽

Aloe Vera ◽

Diammonium Phosphate ◽

Nitrogen Use ◽

N Concentration ◽

Leaf N Concentration ◽

Use Efficiency ◽

Leaf N ◽

Amended Soil

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Urea-Doped Calcium Phosphate Nanoparticles as Sustainable Nitrogen Nanofertilizers for Viticulture: Implications on Yield and Quality of Pinot Gris Grapevines

Agronomy ◽

10.3390/agronomy11061026 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1026

Author(s):

Federica Gaiotti ◽

Marco Lucchetta ◽

Giacomo Rodegher ◽

Daniel Lorenzoni ◽

Edoardo Longo ◽

...

Keyword(s):

Calcium Phosphate ◽

Nitrogen Source ◽

Foliar Application ◽

N Fertilization ◽

Plant Nitrogen ◽

Yield And Quality ◽

Berry Quality ◽

Potential Benefits ◽

Calcium Phosphate Nanoparticles

In recent years, the application of nanotechnology for the development of new “smart fertilizers” is regarded as one of the most promising solutions for boosting a more sustainable and modern grapevine cultivation. Despite showing interesting potential benefits over conventional fertilization practices, the use of nanofertilizers in viticulture is still underexplored. In this work, we investigated the effectiveness of non-toxic calcium phosphate nanoparticles (Ca3(PO4)2∙nH2O) doped with urea (U-ACP) as a nitrogen source for grapevine fertilization. Plant tests were performed for two years (2019–2020) on potted adult Pinot gris cv. vines grown under semi-controlled conditions. Four fertilization treatments were compared: N1: commercial granular fertilization (45 kg N ha−1); N2: U-ACP applied in fertigation (36 kg N ha−1); N3: foliar application of U-ACP (36 kg N ha−1); C: control, receiving no N fertilization. Plant nitrogen status (SPAD), yield parameters as well as those of berry quality were analyzed. Results here presented clearly show the capability of vine plants to recognize and use the nitrogen supplied with U-ACP nanoparticles either when applied foliarly or to the soil. Moreover, all of the quali–quantitative parameters measured in vine plants fed with nanoparticles were perfectly comparable to those of plants grown in conventional condition, despite the restrained dosage of nitrogen applied with the nanoparticles. Therefore, these results provide both clear evidence of the efficacy of U-ACP nanoparticles as a nitrogen source and the basis for the development of alternative nitrogen fertilization strategies, optimizing the dosage/benefit ratio and being particularly interesting in a context of a more sustainable and modern viticulture.

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Yield and quality of maize stover: Variation among cultivars and effects of N fertilization

Journal of Integrative Agriculture ◽

10.1016/s2095-3119(15)61077-2 ◽

2015 ◽

Vol 14 (8) ◽

pp. 1581-1587 ◽

Cited By ~ 6

Author(s):

Ming-yuan LIANG ◽

Gui-yan WANG ◽

Wei-li LIANG ◽

Peng-fei SHI ◽

Jing DANG ◽

...

Keyword(s):

N Fertilization ◽

Maize Stover ◽

Yield And Quality

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Optical sensing estimation of leaf nitrogen concentration in maize across a range of water-stress levels

Crop and Pasture Science ◽

10.1071/cp10374 ◽

2011 ◽

Vol 62 (6) ◽

pp. 474 ◽

Cited By ~ 9

Author(s):

Tong-Chao Wang ◽

B. L. Ma ◽

You-Cai Xiong ◽

M. Farrukh Saleem ◽

Feng-Min Li

Keyword(s):

Water Stress ◽

Vegetation Index ◽

Optical Sensing ◽

Leaf Nitrogen ◽

Growth Stages ◽

N Concentration ◽

Leaf N Concentration ◽

Chlorophyll Index ◽

Plant Moisture ◽

Leaf N

Optical sensing techniques offer an instant estimation of leaf nitrogen (N) concentration during the crop growing season. Differences in plant-moisture status, however, can obscure the detection of differences in N levels. This study presents a vegetation index that robustly measures differences in foliar N levels across a range of plant moisture levels. A controlled glasshouse study with maize (Zea mays L.) subjected to both water and N regimes was conducted in Ottawa, Canada. The purpose of the study was to identify spectral waveband(s), or indices derived from different wavebands, such as the normalised difference vegetation index (NDVI), that are capable of detecting variations in leaf N concentration in response to different water and N stresses. The experimental design includes three N rates and three water regimes in a factorial arrangement. Leaf chlorophyll content and spectral reflectance (400–1075 nm) were measured on the uppermost fully expanded leaves at the V6, V9 and V12 growth stages (6th, 9th and 12th leaves fully expanded). N concentrations of the same leaves were determined using destructive sampling. A quantitative relationship between leaf N concentration and the normalised chlorophyll index (normalised to well fertilised and well irrigated plants) was established. Leaf N concentration was also a linear function (R2 = 0.9, P < 0.01) of reflectance index (NDVI550, 760) at the V9 and V12 growth stages. Chlorophyll index increased with N nutrition, but decreased with water stress. Leaf reflectance at wavebands of 550 ± 5 nm and 760 ± 5 nm were able to separate water- and N-stressed plants from normal growing plants with sufficient water and N supply. Our results suggest that NDVI550, 760 and normalised chlorophyll index hold promise for the assessment of leaf N concentration at the leaf level of both normal and water-stressed maize plants.

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