scholarly journals Supplying nitrate before bud break induces pronounced changes in nitrogen nutrition and growth of young poplars

2012 ◽  
Vol 39 (9) ◽  
pp. 795 ◽  
Author(s):  
Suraphon Thitithanakul ◽  
Gilles Pétel ◽  
Michel Chalot ◽  
François Beaujard

Tree nutrient research concentrated on endogenous C and N remobilisation in spring has neglected to acknowledge the possibilities of significant effects of N uptake before bud break, especially on the quality of regrowth and N reserve remobilisation. To investigate this subject, experimental studies were performed on young poplars (Populus tremula × Populus alba, clone INRA 717–1B4) grown with a controlled nutrient supply: (i) without N, ‘control’; (ii) N supplied throughout the course of the experiment, ‘N-supply’; and (iii) N supplied only before bud break, ‘N-pulse’. Results confirm the hypothesis that poplar scions can significantly take up nitrate before bud break, amounting to ~34% of the total N stored the previous year. After bud break, emerging leaves restart the sap flow, which increased nitrate uptake to support the regrowth. N-pulse and N-supply treatments were found to have significant effects shortly after a growth period, i.e. by increasing N content of all tissues (e.g. 37 and 81% in new shoots respectively), leaf area (18 and 29%) and specific leaf area (20 and 35%). Therefore, results confirm the hypothesis that early N supply plays a significant role in the N status and N remobilisation involved in the spring regrowth of young trees.

2016 ◽  
Vol 96 (4) ◽  
pp. 427-434 ◽  
Author(s):  
Ben W. Thomas ◽  
Joann K. Whalen ◽  
Mehdi Sharifi

Concurrent N mineralization and immobilization in soils receiving poultry litter containing woodchip bedding may reduce synchrony between the short-term N supply and crop N demand. Therefore, we used soil chemical tests, ion exchange membranes, and wheat N uptake to assess N dynamics in a poultry-litter-amended soil. Air-dried soil was thoroughly mixed with five poultry litter rates (50, 100, 150, 200, or 250 mg total N kg−1) and preincubated for 7 d in a controlled environment chamber. After preincubating, soil was placed in 10-cm-diameter pots and planted with spring wheat (Triticum aestivum ‘Wilkin’), or left unplanted and monitored with anion and cation exchange membranes for 45 d. Soil nitrate (NO3-N) concentration increased with poultry litter application rate at the end of the preincubation period, but subsequent wheat N uptake did not, suggesting that little net N mineralization occurred during the 45 d of wheat growth. The membrane data indicated a shift from net N immobilization during the early part of the wheat growth period to net mineralization during the latter portion of the wheat growth period. We conclude that alternating N mineralization and immobilization in soils receiving poultry litter containing woodchip bedding limited the short-term N supply to wheat.


2011 ◽  
Vol 49 (No. 10) ◽  
pp. 473-479 ◽  
Author(s):  
F. Plhák

Pea (Pisum sativum L.), sunflower (Helianthus annuus L.) and maize (Zea mays L.) plants were cultivated for 10 days in hydroponics at 1mM and 7mM nitrate or ammonium concentrations at regulated pH 6 and ambient CO2 level. Plant growth, content of total N and both ions in plant tissues, uptake of water and both N ions were evaluated, N uptake related to transpiration mass flow and to diffusion supply was calculated. Pea and sunflower preferred nitrate nutrition while maize plants used both N ions. The content of total N as well as of both N ions in plant tissues increased with N level with some exceptions. The uptake of both N ions related to transpiration mass flow was dependent on transpiration rate and N ion concentration. At a 1mM N concentration the uptake of N ions related to transpiration mass flow was low and reached in maize up to 16 times, in sunflower 11 times and in pea 2–3 times lower values in comparison with diffusion supply. At a 7mM N concentration N uptake in pea plants was totally supplied by transpiration mass flow, in sunflower plants the ratio of N supply related to transpiration mass flow amounted to 50% and in maize plants N supply through diffusion prevailed, amounting to 70–80%. These results explicate N starvation at low N supply that can intensify at elevated CO2 causing decreased stomatal diffusion.


1973 ◽  
Vol 9 (2) ◽  
pp. 113-120 ◽  
Author(s):  
M. J. Jones

SUMMARYMaize was grown for three years at three levels of nitrogen, 56, 112 and 224 kg. N ha.−1, involving altogether nine different timing and splitting treatments. Measurements were made of grain yield, plant nitrogen status and total-N-uptake, and, in one year, movement of nitrate-N in control plot soils. Where only 56 kg. N ha.−1was applied, its time of application made very little difference to yield; at higher rates of nitrogen an unsplit application as late as seven weeks was very inefficient, but only at the highest rate did a split application give any appreciable yield increase over an unsplit application to the seed bed. Consideration of the soil nitrate-N data and the long-term pattern of rainfall distribution leads to the conclusion that leaching is unlikely to be a serious problem in the nitrogen nutrition of early-planted maize.


2020 ◽  
Author(s):  
Jiftah Ben-Asher

<p>The first Nc dilution curve was based on dry matter (DM) power function. This model is limited to  point of singularity near zero. Another disadvantage was that it required meaasurements of DM which is time and labor consuming. Alternatively we proposed a logistic model that starts at zero and on the abscissa assumed a linear relationship between days after emergence (DAE) and DM throughout the relevant stages of wheat growth cycle.  </p><p>The Objectives of this study were to: 1) To demonstrate the feasibility of digital camera to replace laboratory tests. 2) To Determine critical N (Nc) and Nitrogen nutrition Index(NNI) of spring wheat and 3) Use N% and dry matter yield in order to calculate N uptake by wheat. This last is expected to be a tool to calculate the required amount of nitrogen to obtain maximum yield.</p><p>Wheat experiments were conducted in greenhouse lysimeters. Varied rates of N fertilizer (equivalent to 0–180 kg ha<sup>-1</sup>) and several  cultivars varying from shortest to longest ripening growth period. Nc reduced gradually from about 6% to 2%  ( =60-20 gr/Kg) when DM increased with DAE  from 0 to 14,000 kg/ha during 80 growing days.  NNI was stable and clearly distinct between   maximal index (1.0  and minimal index (0.2) when (DAE) was about 60;   Photographs succeeded to replicate laboratory measurements and obtained a linear regression curve with a unity  slop and r<sup>2</sup>=0.93. Nitrogen.  use efficiency (NUE) ranged from 50 to 65 kg  DM/unit N and from 30 to 50 Kg grain /unit N .</p>


HortScience ◽  
2001 ◽  
Vol 36 (7) ◽  
pp. 1252-1259 ◽  
Author(s):  
A. Bar-Tal ◽  
B. Aloni ◽  
L. Karni ◽  
R. Rosenberg

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.


1991 ◽  
Vol 31 (6) ◽  
pp. 835 ◽  
Author(s):  
DO Huett ◽  
E White

A gamma x quadratic response surface model was used to predict the growth rate over the 14-week growth period of zucchini squash (Cucurbita pepo L.) cv. Blackjack in sand culture with nitrogen (N) levels of 2, 7, 14, 29 and 43 mmol/L. Growth rate relative to maximum was plotted against tissue N concentration every 2 weeks, to derive diagnostic petiole sap; leaf nitrate-N and leaf total-N in youngest fully opened leaf, youngest fully expanded leaf and oldest green leaf; and total N in bulked leaf samples. Critical concentrations corresponding to 90% maximum growth rate for deficiency and toxicity are presented. Petiole sap and leaf nitrate-N were much more responsive than leaf total N concentrations over the 2-14 mmol N/L range where positive growth responses were recorded. At 2 mmol N/L, plants were severely N-deficient and growth rate was low (1.6 g/plant.week at fruit set). Tissue nitrate concentrations were negligible, while leaf total N concentrations exceeded 2.6%. Salt toxicity occurred at 29 and 43 mmol N/L, and at the highest N level, tissue N concentrations were sometimes reduced so that concentration ranges for adequacy and toxicity overlapped. Critical tissue N concentrations always exceeded (P<0.05) levels recorded in plants receiving a marginally deficient N level (7 mmol/L). Critical petiole sap and leaf nitrate-N concentrations were much more variable between sampling periods than leaf total N concentrations. Adequate concentration ranges (values between critical concentrations for deficiency and toxicity) were determined for the pre-fruit harvest (weeks 2-6) and fruit harvest (weeks 8-14) growth stages where values were common for consecutive weeks within each sampling period. It was only possible to determine adequate concentrations over the entire growth period for bulked leaf total N (4.30440% prefruit harvest and 4.15-4.45% fruit harvest). Concentrations of potassium (K), phosphorus and sulfur were affected (P<0.05) by N application level, with the largest effect being recorded for K. This confirms the importance of optimising N supply when determining critical levels of these nutrients for zucchini squash. Determination of petiole sap nitrate-N concentrations in the field can be used to distinguish between a deficient and an adequate N supply, but the large variation in values between sampling periods renders this technique less reliable than leaf total N. Tissue N concentrations which exceed critical deficient levels can be interpreted as such because they were recorded when growth was depressed at high N levels. This will rarely occur under field conditions.


2014 ◽  
Vol 153 (8) ◽  
pp. 1449-1463 ◽  
Author(s):  
S. C. DA SILVA ◽  
L. E. T. PEREIRA ◽  
A. F. SBRISSIA ◽  
A. HERNANDEZ-GARAY

SUMMARYPlant organic reserves and sward leaf area index (LAI) influence plant growth, persistency and herbage accumulation in grazed swards. The present study was conducted to describe patterns of variation in herbage accumulation and carbohydrate and nitrogen (N) reserves in shoot and root of marandu palisade grass subjected to intensities of continuous stocking management throughout the year. Treatments corresponded to four levels of grazing intensity – severe (S), severe/moderate (S/M), moderate (M) and lenient (L) – and were implemented in the field using bands of sward surface height (SSH – 10, 20, 30 and 40 cm ± 10%, respectively) maintained through continuous stocking and variable stocking rate. Total N concentration was higher in the shoot relative to the root compartment during autumn, early and late spring. On the other hand, the concentration of non-structural carbohydrates (NSC) and soluble N was higher in the root compartment, regardless of grazing intensity and season of the year. When taking into account the pool of C and N reserves, the shoot compartment represented the main storage organ, since it corresponded to the largest pool of NSC (averages of 0·102 ± 0·0038 and 0·201 ± 0·0088 kg/m2 for root and shoot, respectively) and soluble N (averages of 2·7 ± 0·26 and 5·3 ± 0·59 kg/m2 for root and shoot, respectively). During late spring, the time of active plant growth, there was a clear contrast in herbage accumulation and sward LAI among grazing intensities, particularly between the severe and lenient grazing treatments. The results show that even with larger pools of soluble N and NSC in the shoot compartment, herbage accumulation was limited by the reduced leaf area of swards subjected to the severe grazing treatment, indicating that under continuous stocking growth seems to be sustained by current assimilates instead of organic reserves. Therefore, targets of grazing management for maximizing herbage accumulation throughout the year should provide adequate combinations between quantity and quality of sward leaf area. This condition was obtained in the severe/moderate and moderate grazing intensities, and corresponded to sward heights between 20 and 30 cm for marandu palisade grass.


HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 543g-544
Author(s):  
Raul I. Cabrera ◽  
Richard Y. Evans ◽  
J.L. Paul

N uptake by greenhouse roses is out of phase with flower shoot elongation, such that N uptake is highest when shoots are not growing and lowest when shoots are elongating rapidly. Isotopically labelled 15N fertilizer was supplied at different stages of one flowering cycle to `Royalty' rose plants growing in a static nutrient solution system to study the partitioning of recently-absorbed N and the dynamics of N partitioning. After a two-day exposure, whole plants were harvested, separated into old and new leaves, stems, and roots, and analyzed for total N and 15N enrichment. During rapid shoot elongation, N uptake by roots supplied 16 to 36% of shoot N demand. The remaining N came from other organs, particularly old stems and leaves. The increased N uptake later in the flowering cycle was sufficient to meet shoot N demand and replenish the N supply in old foliage and woody tissues. These organs continued to accumulate N until the subsequent bud break, when this N became available for the next cycle of flowering shoot growth.


2004 ◽  
Vol 31 (11) ◽  
pp. 1127 ◽  
Author(s):  
Christophe Zapata ◽  
Eliane Deléens ◽  
Sylvain Chaillou ◽  
Christian Magné

As a part of a project aimed at elucidating the causal relationship between reserve mobilisation and the extent of shedding in Vitis vinifera L., we compared storage and fate of carbon (C) and nitrogen (N) reserves in two varieties differing in their susceptibility to fruitlet abscission. Merlot (susceptible) and Pinot Noir (P. Noir, not susceptible) vines were grown in trenches under semi-controlled conditions over a 3-y period after planting. Mobilisation of stored C and N, distribution of reserve materials within the vines and 15N uptake were followed particularly during the spring growth flush and floral development in the third year. At dormancy, starch levels in the perennial tissues (roots, trunk, canes) were higher in Merlot than in P. Noir. During the spring growth flush, starch level decreased markedly in the roots of both cultivars until early bloom. At that time, starch started to accumulate in P. Noir but not in Merlot. Similar variations were found with total N. Accordingly, 15N analysis showed that translocation of storage N to the annual tissues was nearly achieved at early bloom in P. Noir while it continued until pea berry size in Merlot. In parallel, N uptake increased during the spring growth flush, and it was higher in P. Noir than in Merlot. These results indicate that transition between heterotrophic (root) and autotrophic (leaf) mode of nutrient allocation towards the developing inflorescences occurs earlier in P. Noir. Possible consequences are discussed in relation to the susceptibility of each cultivar to shedding.


2014 ◽  
Vol 7 (5) ◽  
pp. 2015-2037 ◽  
Author(s):  
R. Q. Thomas ◽  
M. Williams

Abstract. Carbon (C) and nitrogen (N) cycles are coupled in terrestrial ecosystems through multiple processes including photosynthesis, tissue allocation, respiration, N fixation, N uptake, and decomposition of litter and soil organic matter. Capturing the constraint of N on terrestrial C uptake and storage has been a focus of the Earth System Modeling community. However, there is little understanding of the trade-offs and sensitivities of allocating C and N to different tissues in order to optimize the productivity of plants. Here we describe a new, simple model of ecosystem C–N cycling and interactions (ACONITE), that builds on theory related to plant economics in order to predict key ecosystem properties (leaf area index, leaf C : N, N fixation, and plant C use efficiency) based on the outcome of assessments of the marginal change in net C or N uptake associated with a change in allocation of C or N to plant tissues. We simulated and evaluated steady-state ecosystem stocks and fluxes in three different forest ecosystems types (tropical evergreen, temperate deciduous, and temperate evergreen). Leaf C : N differed among the three ecosystem types (temperate deciduous < tropical evergreen < temperature evergreen), a result that compared well to observations from a global database describing plant traits. Gross primary productivity (GPP) and net primary productivity (NPP) estimates compared well to observed fluxes at the simulation sites. Simulated N fixation at steady-state, calculated based on relative demand for N and the marginal return on C investment to acquire N, was an order of magnitude higher in the tropical forest than in the temperate forest, consistent with observations. A sensitivity analysis revealed that parameterization of the relationship between leaf N and leaf respiration had the largest influence on leaf area index and leaf C : N. A parameter governing how photosynthesis scales with day length had the largest influence on total vegetation C, GPP, and NPP. Multiple parameters associated with photosynthesis, respiration, and N uptake influenced the rate of N fixation. Overall, our ability to constrain leaf area index and allow spatially and temporally variable leaf C : N can help address challenges simulating these properties in ecosystem and Earth System models. Furthermore, the simple approach with emergent properties based on coupled C–N dynamics has potential for use in research that uses data-assimilation methods to integrate data on both the C and N cycles to improve C flux forecasts.


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