scholarly journals 166 NITROGEN UPTAKE BY ROSES IS ENHANCED BY INTERMITTENT N DEPRIVATION.

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 452e-452
Author(s):  
Raul I. Cabrera ◽  
Richard Y. Evans ◽  
J. L. Paul
Keyword(s):  
Nutrient Solution ◽  
N Uptake ◽  
Practical Importance ◽  
Fold Increase ◽  
Solution System ◽  
N Losses ◽  
Use Efficiency ◽  
And Control ◽  
N Fertilizer Use ◽  
N Fertilizer Use Efficiency

N deprivation is known to increase the rate of N uptake by graminaceous plants, but such response has not been reported for mature woody plants. A recirculating nutrient solution system was utilized to study the effect of intermittent N-deprivation on N uptake by mature `Royalty' rose plants. Plants received a nutrient solution lacking N for 4, 8 or 16 days, after which one containing N was supplied for 4 days. N-deprivation resulted in a 2-3 fold increase in N uptake rate compared to control plants supplied continuously with N (e.g., 143 vs 62 mg N plant-1 day-t). The magnitude of this deprivation-enhanced N uptake was not affected by either the duration of N-deprivation or the plant developmental stage. A characteristic diurnal pattern of N uptake was observed in both N-starved and control plants. Uptake oscillated between minimum rates in the morning and maximum rates in the evening, the latter occurring 4-6 hr after the maximum transpiration rates. The ability to increase the rate of N uptake in roses by depriving them of N for several days may be of practical importance for increasing N fertilizer use efficiency and decreasing N losses to leaching.

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.

scholarly journals Silicon Supplied via Root or Leaf Relieves Potassium Deficiency Effects in Common Bean

2021 ◽  
Author(s):  
Marcilene Machado dos Santos Sarah ◽  
Renato de Mello Prado ◽  
Jonas Pereira de Souza Júnior ◽  
Gelza Carliane Marques Teixeira ◽  
João Carlos dos Santos Duarte ◽  
...  
Keyword(s):  
Common Bean ◽  
Nutrient Solution ◽  
Vegetative Growth ◽  
Photosynthetic Activity ◽  
Foliar Application ◽  
Foliar Spray ◽  
Bean Plants ◽  
K Deficiency ◽  
Use Efficiency ◽  
And Control

Abstract Potassium (K) deficiency affects physiological performance and decreasing vegetative growth in common bean plants. However, silicon (Si) supplied via nutrient solution or foliar application may relieve nutritional stress. Thus, two experiments were carried out: initially, a test was performed to determine the best source and concentration of leaf-applied Si. Subsequently, the chosen Si source was applied via nutrient solution or via leaf to verify if it is efficient in alleviating the effects caused by K deficiency. To that end, a completely randomized 2 x 3 factorial design was used, with two levels of K: deficient (0.2 mmol L− 1 of K) and sufficient (6 mmol L− 1 of K); and Si: via nutrient solution (2 mmol L− 1 of Si) or foliar spray (5.4 mmol L− 1 of Si) and control (0 mmol L− 1 of Si). In the first experiment, foliar spraying with sodium silicate and stabilized potassium at a concentration of 5.4 mmol L− 1 was better in favoring the physiology of bean plants. In the second experiment, K deficiency without the addition of Si compromised the plant's growth. Si applied through nutrient solution or foliar spray relieved K deficiency stress, increasing chlorophylls and carotenoids content, photosynthetic activity, water use efficiency and vegetative growth.

N application enhances remobilization and reduces losses of pre-anthesis N in wheat grown on a duplex soil

1995 ◽  
Vol 46 (3) ◽  
pp. 519 ◽  
Author(s):  
JA Palta ◽  
IRP Fillery
Keyword(s):  
Stem Elongation ◽  
N Uptake ◽  
Fold Increase ◽  
Utilization Efficiency ◽  
N Losses ◽  
N Application ◽  
Nitrogen Utilization Efficiency ◽  
Fold Reduction ◽  
N Treatment ◽  
Nitrogen Harvest

The effect of fertilizer N on the remobilization of N to the grain in wheat was evaluated on a duplex soil at East Beverley, Western Australia. Remobilization of N to the grain was determined using the stable isotope, 15N , which was fed to wheat plants during the vegetative growth phase. Nitrogen was applied at 15, 30 and 60 kg N ha-1 with half being applied at seeding and the remainder at 35 days after sowing (DAS), before the onset of tillering. The high N treatment increased N uptake between stem elongation and anthesis and grain protein concentration by 2.9% relative to the low N treatment. Both the nitrogen harvest index (NHI) and the nitrogen utilization efficiency (NUE) declined as the rate of N application was increased; the decline was more pronounced when the rate of N application was increased from 30 to 60 kg N ha-1. Total grain N at 60 kg N ha-1 was increased by 54%, relative to that at 15 kg N ha-1, due to a 2.3 fold increase in remobilization of pre-anthesis accumulated N and despite a 5 fold reduction in post-anthesis uptake. The application of 60 kg N ha-1 reduced the losses of pre-anthesis N from 19% to 6%. The absolute contribution of the N taken up early in the growth of the crop (before the second node stage) to grain N was 0.9, 1.4 and 3.2 g m-2 at 15, 30 and 60 kg N ha-1 respectively. The contribution of pre-anthesis N to the grain was 2.2, 3.7 and 5.1 g m-2 when 15, 30 and 60 kg N ha-' were applied respectively. This contribution accounted for 60, 82 and 95% of the total grain N respectively. Results indicated that with greater amounts of N accumulated before anthesis, there was higher remobilization to the grain and less risk of net N losses at maturity, because post-anthesis water deficits developed more rapidly.

scholarly journals Modified split application of nitrogen with biochar improved grain yield and nitrogen use efficiency in rainfed maize grown in Vertisols of India

2020 ◽  
Author(s):  
Bharat Prakash Meena ◽  
Pramod Jha ◽  
K. Ramesh ◽  
A.K. Biswas ◽  
R. Elanchezhian ◽  
...  
Keyword(s):  
Grain Yield ◽  
N Uptake ◽  
Growth Stages ◽  
N Losses ◽  
N Application ◽  
Soil P ◽  
Agronomic Management ◽  
Use Efficiency ◽  
Maize Grain ◽  
N Rates

AbstractConventionally, non-judicious and blanket fertilizer nitrogen (N) used in rainfed maize lead to higher N losses, low N use efficiency (NUEs) and poor yields due to substandard agronomic management practices. To avoid such N losses, fertilizer additions are synchronized with plant uptake requirements. In this context, agronomic based management focused on optimizing N rates and biochar application is essential for improved NUEs and crop productivity. Keeping this in view, a field experiment was conducted during 2014, 2015 and 2016 in rainfed maize (Zea mays L.) grown in Vertisols of India. In this study, twelve treatments that comprised of N omission plot (N0), skipping of basal rate, multi-split topdressing at varying time as broadcast and band placement, soil test crop response (STCR) based NPK with target yield 6.0 t ha-1 in maize and biochar application (10 t ha−1) were investigated. The experiment was conducted following a Randomized Complete Block Design (RCBD) set up with three replications. Pooled analysis of three years data revealed that the application of N rates (120 kg Nha−1) in 2 equal splits (60 kg Nha−1) at knee high (V8) and tasseling (VT) stages with skipped basal N rate, achieved higher maize grain yield (5.29 t ha−1) ascribed to the greater growth parameters, yield components and N uptake compared to the recommended practices. Biochar application (10 t ha−1) as soil amendments along with multi top dressed N (120 kg N ha−1) into 3 splits also increased the grain yield. Delayed N application at V8 and VT growth stages, resulted in higher N uptake, agronomy efficiency (AE), partial factor productivity (PFP), physiology efficiency (PE) and recovery efficiency (RE). Biochar along with N fertilizer also improved the soil organic carbon (5.47g kg−1), ammonium-N (2.40 mg kg−1) and nitrate-N (0.52 mg kg−1) concentration in soil (P<0.05) as compared to non-biochar treatments. Application of biochar along with chemical fertilizer (120 kg Nha−1) significantly increased the concentration of ammonium (2.40 mg kg−1) and nitrate (0.52 mg kg−1) in soil (P<0.05) as compared to non-biochar treatments. The perfect positive linear relationship illustrated that the grain yield of rainfed maize was highly dependent (R2=0.99 at p<0.0001) on N availability, as indicated by the fitted regression line of maize grain yield on N uptake. On the other hand, factor analysis revealed, the one to one positive function relationship of biomass with N uptake at V8 and VT growth stages. Principal Component Regression (PCR) analysis showed that PC1 acted as a major predictor variable for total dry matter yield (TDMY) and dominated by LAI and N uptake. Consequently, these results expressed that the agronomic management based multi-top dressed N application and biochar application to achieve higher yield and greater NUEs in rainfed maize is strongly linked with N application into splits.

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

2012 ◽  
Vol 9 (4) ◽  
pp. 1509-1518 ◽  
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 ◽  
Uptake Rates

Abstract. Soil-borne amino acids may constitute a source of nitrogen (N) 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 ammonium (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, thereby resulting in similar total N uptake rates. 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 generally 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 N.

scholarly journals Nitrogen Fertilizer-use Efficiency in Two Woody Ornamentals

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 859D-859
Author(s):  
Diana Devereaux ◽  
Raul I. Cabrera
Keyword(s):  
Leaf Tissue ◽  
Environmental Concerns ◽  
Fertilizer Use Efficiency ◽  
Fertilizer Use ◽  
Woody Ornamentals ◽  
Use Efficiency ◽  
Vigorous Plant ◽  
N Fertilizer Use ◽  
Nutrient Solutions ◽  
N Fertilizer Use Efficiency

High levels of N are often used to produce a vigorous plant that is also aesthetically pleasing to the purchaser. Environmental concerns with the overuse of N raise the need to find the minimum N requirements necessary to produce a salable plant. Ilex opaca and Lagerstroemia indica plants growing in 1.5-gal containers were irrigated with nutrient solutions containing N concentrations of: 15, 30, 60, 120, 210, and 300 mg N/liter. After 4 months, data indicate that using solutions >60 mg N/liter for both plant species results in leachates with N concentrations higher than those in the applied solutions. Nitrogen leaching losses increased with applied N, ranging from ≈15% to 50% for the low and high treatments, respectively. Chlorophyll readings of leaf tissue were not significantly different for plants of both species receiving N solutions higher than 60 mg·liter–1. These results indicate that N levels lower than those typically used for production of these woody ornamentals will still produce salable plants while increasing N fertilizer-use efficiency.

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