scholarly journals Seasonal variation in N uptake strategies in the understorey of a beech-dominated N-limited forest ecosystem depends on N source and species

2016 ◽  
Vol 36 (5) ◽  
pp. 589-600 ◽  
Author(s):  
Xiuyuan Li ◽  
Heinz Rennenberg ◽  
Judy Simon
Keyword(s):  
Seasonal Variation ◽  
Forest Ecosystem ◽  
N Uptake ◽  
N Source

scholarly journals Nitrogen Nutrition of Greenhouse Pepper. II. Effects of Nitrogen Concentration and NO3: NH4 Ratio on Growth, Transpiration, and Nutrient Uptake

HortScience ◽  
2001 ◽  
Vol 36 (7) ◽  
pp. 1252-1259 ◽  
Author(s):  
A. Bar-Tal ◽  
B. Aloni ◽  
L. Karni ◽  
R. Rosenberg
Keyword(s):  
Nutrient Uptake ◽  
Nitrogen Nutrition ◽  
Nitrogen Concentration ◽  
N Uptake ◽  
Total N ◽  
Hydroponic System ◽  
Leaf Chlorophyll ◽  
N Source ◽  
N Concentration ◽  
Canopy Nitrogen

The objective of this research was to study the effects of N concentration and N-NO3: N-NH4 ratio in the nutrient solution on growth, transpiration, and nutrient uptake of greenhouse-grown pepper in a Mediterranean climate. The experiment included five total N levels (0.25 to 14 mmol·L-1, with a constant N-NO3: N-NH4 ratio of 4) and five treatments of different N-NO3: N-NH4 ratios (0.25 to 4, with a constant N concentration of 7 mmol·L-1). Plants were grown in an aero-hydroponic system in a climate-controlled greenhouse. The optimum N concentrations for maximum stem and leaf dry matter (DM) production were in the range of 8.0 to 9.2 mmol·L-1. The optimum N-NO3: N-NH4 ratio for maximal stem DM production was 3.5. The optimum value of N concentration for total fruit DM production was 9.4 mmol·L-1. Fruit DM production increased linearly with increasing N-NO3: N-NH4 ratio in the range studied. The N concentration, but not N source, affected leaf chlorophyll content. Shorter plants with more compacted canopies were obtained as the N-NO3: N-NH4 ratio decreased. The effect of N concentration on transpiration was related to its effect on leaf weight and area, whereas the effect of a decreasing N-NO3: N-NH4 ratio in reducing transpiration probably resulted from the compacted canopy. Nitrogen uptake increased as the N concentration in the solution increased. Decreasing the N-NO3: N-NH4 ratio increased the N uptake, but sharply decreased the uptake of cations, especially Ca.

scholarly journals Interactions between uptake of amino acids and inorganic nitrogen in wheat plants

2011 ◽  
Vol 8 (6) ◽  
pp. 11311-11335 ◽  
Author(s):  
E. Gioseffi ◽  
A. de Neergaard ◽  
J. K. Schjoerring
Keyword(s):  
Amino Acids ◽  
Nutrient Solution ◽  
Inorganic Nitrogen ◽  
N Uptake ◽  
Organic N ◽  
Arable Soils ◽  
Inorganic N ◽  
N Losses ◽  
Total N ◽  
N Source

Abstract. Soil-borne amino acids may constitute a nitrogen (N) source for plants in various terrestrial ecosystems but their importance for total N nutrition is unclear, particularly in nutrient-rich arable soils. One reason for this uncertainty is lack of information on how the absorption of amino acids by plant roots is affected by the simultaneous presence of inorganic N forms. The objective of the present study was to study absorption of glycine (Gly) and glutamine (Gln) by wheat roots and their interactions with nitrate (NO3–) and (NH4+) during uptake. The underlying hypothesis was that amino acids, when present in nutrient solution together with inorganic N, may lead to down-regulation of the inorganic N uptake. Amino acids were enriched with double-labelled 15N and 13C, while NO3– and NH4+ acquisition was determined by their rate of removal from the nutrient solution surrounding the roots. The uptake rates of NO3– and NH4+ did not differ from each other and were about twice as high as the uptake rate of organic N when the different N forms were supplied separately in concentrations of 2 mM. Nevertheless, replacement of 50 % of the inorganic N with organic N was able to restore the N uptake to the same level as that in the presence of only inorganic N. Co-provision of NO3– did not affect glycine uptake, while the presence of glycine down-regulated NO3– uptake. The ratio between 13C and 15N were lower in shoots than in roots and also lower than the theoretical values, reflecting higher C losses via respiratory processes compared to N losses. It is concluded that organic N can constitute a significant N-source for wheat plants and that there is an interaction between the uptake of inorganic and organic nitrogen.

Nitrogen uptake and growth in vitro by Hebeloma crustuliniforme and other Pacific Northwest mycorrhizal fungi

1984 ◽  
Vol 62 (4) ◽  
pp. 647-652 ◽  
Author(s):  
Willis R. Littke ◽  
Caroline S. Bledsoe ◽  
Robert L. Edmonds
Keyword(s):  
Pacific Northwest ◽  
Ectomycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Radial Growth ◽  
N Uptake ◽  
Ammonium Uptake ◽  
Biomass Growth ◽  
N Source ◽  
Uptake Rates ◽  
Hebeloma Crustuliniforme

Since little is known about the nitrogen (N) physiology of ectomycorrhizal fungi, this study was initiated to study both radial and biomass growth and N uptake of Hebeloma crustuliniforme and other Pacific Northwest ectomycorrhizal fungi. Hebeloma crustuliniforme utilized either nitrate or ammonium as the N source in buffered liquid media, but biomass growth was greatest with ammonium. Without buffers, biomass growth on ammonium-based media was reduced, apparently owing to low pH. These results emphasize the strong interrelationship between N source and pH of the media. A pronounced pH optimum for biomass growth of H. crustuliniforme occurred at pH 5.0. Ammonium uptake rates were five to nine times greater than nitrate uptake rates over a range of N concentrations (40–600 μM). Radial growth rates of a range of mycorrhizal fungi were greater on high-N than on low-N media. For those few species that grew faster on low-N medium, their growth habit was more diffuse and dry weight production was decreased, indicating that radial growth had occurred at the expense of biomass production.

scholarly journals Effects of rhizopheric nitric oxide (NO) on N uptake inFagus sylvaticaseedlings depend on soil CO2concentration, soil N availability and N source

2015 ◽  
Vol 35 (8) ◽  
pp. 910-920 ◽  
Author(s):  
Fang Dong ◽  
Judy Simon ◽  
Michael Rienks ◽  
Christian Lindermayr ◽  
Heinz Rennenberg
Keyword(s):  
Nitric Oxide ◽  
N Uptake ◽  
N Availability ◽  
Soil N ◽  
Soil N Availability ◽  
N Source

RESPONSE OF AN ORCHARDGRASS-PERENNIAL RYEGRASS SWARD TO RATE AND METHOD OF UREA AND AMMONIUM NITRATE APPLICATION

1983 ◽  
Vol 63 (4) ◽  
pp. 719-725 ◽  
Author(s):  
A. A. BOMKE ◽  
R. A. BERTRAND
Keyword(s):  
Ammonium Nitrate ◽  
Perennial Ryegrass ◽  
Dry Matter ◽  
N Uptake ◽  
Split Application ◽  
Single Application ◽  
Forage Production ◽  
N Application ◽  
N Source ◽  
N Rates

Urea and ammonium nitrate were applied at rates of 75, 150 and 300 kg N/ha as either a single application in April or split into three equal increments, one applied in April and the second and third following cuts one and two. The orchardgrass-perennial ryegrass sward responded significantly to applied N in each year; however, the yield produced by the two sources differed in only one of the three years. In that year split applied ammonium nitrate gave 8% higher yields than similarly applied urea. The sources were found to be equivalent when applied in the spring. Split application of the N rates increased total annual dry matter yields in one of the three years regardless of N source. In all three years split application of N shifted forage production from cut one to cuts two and three. Key words: N uptake, split N application, orchardgrass-perennial ryegrass sward

Effect of nitrogen rate and fertilizer nitrogen source on physiology, yield, grain quality, and nitrogen use efficiency in corn

2016 ◽  
Vol 96 (3) ◽  
pp. 392-403 ◽  
Author(s):  
Dilip K. Biswas ◽  
Bao-Luo Ma
Keyword(s):  
Grain Yield ◽  
Grain Quality ◽  
N Uptake ◽  
N Use Efficiency ◽  
Canopy Reflectance ◽  
Calcium Ammonium Nitrate ◽  
N Source ◽  
Use Efficiency ◽  
N Rates ◽  
N Use

A two-year (2010–2011) field experiment was undertaken to examine the effect of nitrogen (N) rate (0, 100, 150, and 200 kg N ha−1) and N source (urea, calcium ammonium nitrate; ammonium sulphate) on canopy reflectance, chlorophyll pigments, photosynthesis, yield, grain quality, and N-use efficiency in corn. However, the physiological observations were made only in 2011. We found that stover biomass was unaffected by higher N rate beyond 150 kg N ha−1 in both years. Higher N rates did not provide a yield advantage as compared to 150 kg N ha−1 in 2010, but the highest grain yield was produced with 200 kg N ha−1 in 2011. The higher grain yield by N application was attributed to a greater kernel size in both years. Corn stover [N] was found to increase with increasing N rates in both years. Kernel [N] only responded to the high N rate in 2010. There was no change in the kernel density as affected by N rate in both years. An increased N addition resulted in a decrease in both N-uptake efficiency and agronomic-N use efficiency in both years. There was an inconsistent effect of N source on yield and N use efficiency indices in the corn over two years.

scholarly journals Durum Wheat Yield and N Uptake as Affected by N Source, Timing, and Rate in Two Mediterranean Environments

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1299
Author(s):  
Silvia Pampana ◽  
Marco Mariotti
Keyword(s):  
Durum Wheat ◽  
Field Experiments ◽  
N Uptake ◽  
Central Italy ◽  
Wheat Yield ◽  
Nitrification Inhibitor ◽  
N Availability ◽  
N Source ◽  
Action Programme ◽  
Vulnerable Zones

In nitrate vulnerable zones (NVZs), site-specific techniques are needed to match N availability with durum wheat (Triticum turgidum subsp. durum Desf.) requirements. Enhanced-efficiency fertilizers can improve efficient N supply and reduce leaching, contributing to sustainable agriculture. Two-year field experiments were carried out at two Mediterranean nitrate vulnerable zones in Central Italy (Pisa and Arezzo) to study the effects of nitrogen sources, timings, and application rates. The trial compared: (i) three N sources for the first topdressing application (urea, methylene urea, and urea with the nitrification inhibitor DMPP); (ii) two stages for the first topdressing N application (1st tiller visible—BBCH21 and 1st node detectable—BBCH31); (iii) two N rates: one based on the crop N requirements (Optimal—NO), the other based on action programme prescriptions of the two NVZs (Action Programme—NAP). Grain yield and yield components were determined, together with N uptake. The results showed that: (i) grain and biomass production were reduced with NAP at both locations; (ii) urea performed better than slow-release fertilizers; (iii) the best application time depended on the N source and location: in Pisa, enhanced-efficiency fertilizers achieved higher yields when applied earliest, while for urea the opposite was true; in Arezzo different N fertilizers showed similar performances between the two application timings. Different behaviors of topdressing fertilizers at the two localities could be related to the diverse patterns of temperatures and rainfall. Thus, optimal fertilization strategies would seem to vary according to environmental conditions.

scholarly journals Effect of N Source on Growth and N Uptake of Hippeastrum Using 15N Tracers

2022 ◽  
Author(s):  
Chaiartid Inkham ◽  
Kanokwan Panjama ◽  
Takashi Sato ◽  
Soraya Ruamrungsri
Keyword(s):  
N Uptake ◽  
N Source
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