scholarly journals Functional differences in seasonally absorbed nitrogen in a winter-green perennial herb

2020 ◽  
Vol 7 (1) ◽  
pp. 190034
Author(s):  
Satomi Nishitani ◽  
Atsushi Ishida ◽  
Toshie Nakamura ◽  
Naoki Kachi
Keyword(s):  
Environmental Changes ◽  
Photosynthetic Capacity ◽  
Leaf Growth ◽  
N Uptake ◽  
Plant Performance ◽  
N Availability ◽  
Storage Organs ◽  
Different Seasons ◽  
N Use ◽  
Leaf N

Nitrogen (N) uptake in response to its availability and effective N-use are important for determining plant fitness, as N is a major limiting resource and its availability changes both seasonally and annually. Storage organs such as bulbs are considered an adaptive trait with respect to plant N-use strategies. It is well known that N is remobilized from storage organs to satisfy the high demand for new growth that is not completely satisfied by external uptake alone. However, little is known about how this N absorbed during different seasons contributes to plant performance. By manipulating seasonal N availability in potted Lycoris radiata var. radiata (Amaryllidaceae), a winter-green perennial, we found that the N absorbed during different seasons had different effects on leaf growth and leaf N concentrations, effectively increasing the growth and survival of the plants. N absorbed during the summer (leafless period; N was thus stored in the bulb) enhanced plant growth by increasing leaf growth. Compared with the plants supplied with N during autumn (leaf flush period), the leafy plants also showed greater growth per unit leaf area despite the lower area-based photosynthetic capacity of the latter. By contrast, N absorbed during the autumn increased the leaf N concentration and thus the photosynthetic capacity, which was considered to enhance survival and growth of the plant during winter by reducing the potentially fatal risk caused by the absorption of photons under low temperature. Our findings have important implications for estimating plant responses to environmental changes. We predict that changes in seasonal N availability impact the performance of plants, even that of perennials that have large storage organs, via an altered relative investment of N into different functions.

scholarly journals Genotypic traits and tradeoffs of fast growth in silver birch, a pioneer tree

Oecologia ◽  
2021 ◽  
Author(s):  
Juha Mikola ◽  
Katariina Koikkalainen ◽  
Mira Rasehorn ◽  
Tarja Silfver ◽  
Ulla Paaso ◽  
...  
Keyword(s):  
Resource Competition ◽  
Leaf Growth ◽  
N Uptake ◽  
Insect Herbivory ◽  
Fast Growth ◽  
Grass Cover ◽  
Soil N ◽  
Fast Growing ◽  
Slow Growing ◽  
Leaf N

AbstractFast-growing and slow-growing plant species are suggested to show integrated economics spectrums and the tradeoffs of fast growth are predicted to emerge as susceptibility to herbivory and resource competition. We tested if these predictions also hold for fast-growing and slow-growing genotypes within a silver birch, Betula pendula population. We exposed cloned saplings of 17 genotypes with slow, medium or fast height growth to reduced insect herbivory, using an insecticide, and to increasing resource competition, using naturally varying field plot grass cover. We measured shoot and root growth, ectomycorrhizal (EM) fungal production using ergosterol analysis and soil N transfer to leaves using 15N-labelled pulse of NH4+. We found that fast-growing genotypes grew on average 78% faster, produced 56% and 16% more leaf mass and ergosterol, and showed 78% higher leaf N uptake than slow-growing genotypes. The insecticide decreased leaf damage by 83% and increased shoot growth, leaf growth and leaf N uptake by 38%, 52% and 76%, without differences between the responses of fast-growing and slow-growing genotypes, whereas root mass decreased with increasing grass cover. Shoot and leaf growth of fast-growing genotypes decreased and EM fungal production of slow-growing genotypes increased with increasing grass cover. Our results suggest that fast growth is genotypically associated with higher allocation to EM fungi, better soil N capture and greater leaf production, and that the tradeoff of fast growth is sensitivity to competition, but not to insect herbivory. EM fungi may have a dual role: to support growth of fast-growing genotypes under low grass competition and to maintain growth of slow-growing genotypes under intensifying competition.

N uptake, N partitioning, and photosynthetic N-use efficiency of an old and a new maize hybrid

1994 ◽  
Vol 74 (3) ◽  
pp. 479-484 ◽  
Author(s):  
D. E. McCullough ◽  
A. Aguilera ◽  
M. Tollenaar
Keyword(s):  
Dry Matter ◽  
N Uptake ◽  
N Use Efficiency ◽  
Maize Hybrid ◽  
Unit Leaf ◽  
N Supply ◽  
N Partitioning ◽  
Use Efficiency ◽  
N Use ◽  
Leaf N

An old maize (Zea mays L.) hybrid (Pride 5) has been shown to be less tolerant to N stress than a new maize hybrid (Pioneer 3902) during early phases of development. The objective of this study was to quantify the response of the two hybids to N supply in terms of N uptake, N partitioning, and photosynthetic N–use efficiency. Plants were grown under controlled-environment conditions until the 12-leaf stage at three levels of N supply (i.e., 15 mM N, 2.5 mM N, and 0.5 mM N) and were sampled at the 4-, 8-, and 12-leaf stages. Rates of N uptake per unit ground area were higher for Pioneer 3902 than for Pride 5 under maximum N stress during the 8- to 12-leaf phase, but rates were higher for Pride 5 at high N. Rates of N uptake per unit root weight were higher for Pioneer 3902 than for Pride 5 under both medium and low N supply. The old hybrid (Pride 5) partitioned more dry matter and N to leaves than the new hybrid under low N supply, but leaf N per unit leaf area was higher for the new hybrid. The new hybrid (Pioneer 3902) maintained greater rates of leaf photosynthesis per unit leaf N regardless of N supply. Consequently, results indicate that the higher N-use efficiency of Pioneer 3902 under low N supply is associated with higher N uptake and a higher leaf N per unit leaf area. Key words:Zea mays L., dry matter accumulation, photosynthesis, leaf N

scholarly journals Seasonal Variation in Growth, Nitrogen Uptake and Allocation by Container-grown Evergreen and Deciduous Rhododendron Cultivars

HortScience ◽  
2007 ◽  
Vol 42 (6) ◽  
pp. 1440-1449 ◽  
Author(s):  
Carolyn F. Scagel ◽  
Guihong Bi ◽  
Leslie H. Fuchigami ◽  
Richard P. Regan
Keyword(s):  
Nitrogen Uptake ◽  
Leaf Growth ◽  
Stem Elongation ◽  
N Uptake ◽  
Root Turnover ◽  
Total Biomass ◽  
N Availability ◽  
N Losses ◽  
Total N ◽  
N Storage

Growth, nitrogen (N) uptake, and N storage were assessed in transplanted 1-year-old rhododendron liners. Two evergreen cultivars, Rhododendron ‘P. J. Mezitt Compact’ (PJM) and R. ‘English Roseum’ (ER), and one deciduous cultivar, R. ‘Gibraltar’ (AZ), were transplanted into 1-gal. pots and given liquid fertilizer with (+N) or without (–N) N. Increased N availability increased growth after July (ER, PJM) or August (AZ), and resulted in three to five times more total biomass. Biomass continued to increase after stem elongation and leaf production ceased. Nitrogen uptake was correlated with growth of all plant structures on AZ, whereas N uptake was only correlated with stem and leaf growth on evergreen cultivars. The rate of N uptake was highest before July for AZ (1.9 mg·d−1) and in August and September for the evergreen cultivars (≈5 mg·d−1). Thirteen percent to 16% of total N uptake from between May and February occurred after N fertilization ceased at the beginning of September. Plants contained the most N in October (AZ), November (PJM), or December (ER). Biomass loss after November accounted for a loss of 14% to 48% of the maximum total plant N content. Nitrogen demand by roots and stems increased from May to February in all cultivars. The role of new and old leaves in N storage on evergreen cultivars varied with cultivar and time. Differences in N storage between the evergreen cultivars occurred primarily in their roots and leaves. Over the winter, PJM stored more N in its roots, whereas ER stored more N in its leaves. Changes in N concentrations and contents in different plant structures after November indicate that, during early winter, N stored in other structures moves to roots and old stems of PJM, old stems of ER, and roots and new and old stems of AZ. These results suggest that fertilizer application strategies for transplanted liners of these cultivars should include low N availability after transplanting followed by high N availability in mid to late summer. This type of strategy will not only improve N uptake efficiency from fertilizer, but also will minimize N loss from the containers. The results also demonstrated that N uptake in the autumn may play an important role in supplementing plant N reserves required for growth during the next season as well as for balancing N losses incited by leaf abscission, root turnover, and maintenance functions that occur over winter.

scholarly journals Foliar Application of Protein Hydrolysates on Baby-Leaf Spinach Grown at Different N Levels

Agronomy ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 36
Author(s):  
Anna Bonasia ◽  
Giulia Conversa ◽  
Corrado Lazzizera ◽  
Antonio Elia
Keyword(s):  
Photosynthetic Activity ◽  
Foliar Application ◽  
N Uptake ◽  
Protein Hydrolysates ◽  
Growth And Yield ◽  
N Availability ◽  
Nitrate Accumulation ◽  
N Assimilation ◽  
N Rates ◽  
N Use

Surpluses of N are associated with environmental and health problems. To optimise N use and reduce nitrate accumulation in leafy species like spinach, the application of biostimulants is suggested. An experiment in controlled conditions (growth chamber/soilless) evaluated baby-spinach responses to two protein hydrolysates (PHs) from plant (legume, Trainer®) and animal (meat, Isabion®) sources, combined with three N rates: 2 (N2, deficient), 8 (N8, sub-optimal), and 14 (N14, optimal) mM of N. Biometrical and morphological traits of shoots and roots as well as the physio-metabolic (gas exchange, N assimilation, and NUtE), physical, mineral, and antioxidant profiles of leaves were assessed. The legume-PH boosts growth and yield only at the highest N conditions, while there was no effect at lower N rates. The legume-PH modulates root architecture and chlorophylls has positive responses only at optimal N availability, such as an increase in N uptake, leaf expansion, and photosynthetic activity at the canopy level. The PHs do not improve NUtE, leaf colour, consistency, cations, or antioxidants. Neither do PHs have any effect on reducing nitrate accumulation. Legume-PH improves N assimilation only at optimal N availability, while meat-PH does not, reaching the highest nitrate value at the highest N rate (2677 mg kg−1 fw), even if this value is under the EC limits for fresh spinach.

scholarly journals Contribution of previous year’s leaf N and soil N uptake to current year’s leaf growth in sessile oak

2016 ◽  
Author(s):  
Stephane Bazot ◽  
Chantal Fresneau ◽  
Claire Damesin ◽  
Laure Barthes
Keyword(s):  
Leaf Growth ◽  
N Uptake ◽  
Soil N ◽  
Rhizospheric Soil ◽  
Growing Seasons ◽  
Soil N Uptake ◽  
Previous Autumn ◽  
Leaf N ◽  
N Pool

Abstract. The origin of the N which contributes to the synthesis of N reserves of in situ forest trees in autumn, and to the growth of new organs the following spring, is currently poorly documented. To characterize the metabolism of various possible N sources (plant N and soil N), six distinct 20 year-old sessile oaks were 15N labelled by spraying 15NH415NO3: (i) on leaves in May, to label the N pool remobilized in the autumn for synthesis of reserves; (ii) on soil in the autumn, to label the N pool taken up from soil; (iii) on soil at the beginning of the following spring, to label the N pool taken up from soil in the spring. The partitioning of 15N in leaves, twigs, phloem, xylem, fine roots, rhizospheric soil and microbial biomass was followed during two growing seasons. Results showed a significant incorporation of 15N in the soil-tree system; more than 30 % of the administered 15N was recovered. Analysis of the partitioning clearly revealed that in autumn, roots’ N reserves were formed from foliage 15N (73 %) and to a lesser extent from soil 15N (27 %). The following spring, 15N used for the synthesis of new leaves came first from 15N stored during the previous autumn, mainly from 15N reserves formed from foliage (95 %). Thereafter, when leaves were fully expanded, 15N uptake from soil during the previous autumn and before budburst contributed to the formation of new leaves (60 %).

scholarly journals The mycorrhizal tragedy of the commons

2021 ◽  
Author(s):  
Nils Henriksson ◽  
Oskar Franklin ◽  
Lasse Tarvainen ◽  
John Marshall ◽  
Judith Lundberg-Felten ◽  
...  
Keyword(s):  
Mathematical Modelling ◽  
Boreal Forests ◽  
N Uptake ◽  
Tragedy Of The Commons ◽  
N Immobilization ◽  
N Availability ◽  
Plant Host ◽  
Relative Contribution ◽  
The Commons ◽  
N Use

<p>Ectomycorrhizal fungi (EMF) play a key role in the cycling of nitrogen (N) and carbon (C) in boreal forests. Trees receive growth-limiting N in exchange for allocating C to their mycorrhizal symbionts, but supplying the fungi with C can also cause N immobilization, which hampers tree growth. We present results from field and greenhouse experiments combined with mathematical modelling, showing that these are not conflicting outcomes.</p><p>Under N limitation, which is the general case in boreal forests, the plant host has been observed to continue supplying its ectomycorrhizal partner with C, and even increasing this C investment, while the fungus reduces mobilization of N to its host (Corrêa et al. 2008, 2010). N is thus withheld under conditions of limiting availability, and the host tree cannot unlock it by supplying the EMF with more C, because such an investment results in further diminishing N returns. Critical to this question is the observation that more than one fungus can form mycorrhiza on a given tree and that several trees can be connected to a given fungal individual (Southworth et al. 2005).</p><p>We hypothesize that plants sharing common ectomycorrhizal symbionts compete with each other for N by exporting C to the EMF network, and vice versa for a fungus. The fungi making up the EMF network export N to hosts if it is absorbed in excess of their own growth demand, which is limited by C; Exporting more than this would reduce their growth, exporting less would reduce their competitiveness for plant C (Näsholm 2013, Franklin 2014). This hypothesis has specific and predictable implications for relationship between plant C export to EMF and N uptake: At the community level, increasing plant C supply to EMF would increase both fungal N uptake and N use, but as soil N availability gradually becomes limiting, uptake should saturate while EMF N use continued to increase, leading to declining N export to plants.</p><p>We conducted two experiments, one in potted mesocosms and the other in a boreal forest setting. Belowground C flux was reduced by shading and/or stem strangling, which is a treatment whereby the flow of C to the root system is physically restricted by blocking transport through the phloem in the stem (Björkman 1944; Henriksson et al. 2015). Strangling a subset of seedlings growing in the same pot accomplishes two things: 1) the total belowground C flux is decreased, and 2) each seedling’s relative contribution to that flux is altered.</p><p>Based on measurements and mathematical modelling, we conclude that belowground C allocation by trees can indeed fuel N immobilization, reducing the amount of N to be distributed among the trees. But we also found that individual trees received nutritional benefits in proportion to their C contribution to the fungal network. We illustrate the evolutionary underpinnings of this situation by drawing on the analogous tragedy of the commons (Hardin 1968), where the shared mycorrhizal network is the commons, and explain how rising atmospheric CO<sub>2</sub> may lead to greater nitrogen immobilization in the future.</p>

scholarly journals Contribution of previous year's leaf N and soil N uptake to current year's leaf growth in sessile oak

2016 ◽  
Vol 13 (11) ◽  
pp. 3475-3484 ◽  
Author(s):  
Stephane Bazot ◽  
Chantal Fresneau ◽  
Claire Damesin ◽  
Laure Barthes
Keyword(s):  
Leaf Growth ◽  
N Uptake ◽  
Soil N ◽  
Rhizospheric Soil ◽  
Growing Seasons ◽  
Soil N Uptake ◽  
Previous Autumn ◽  
Leaf N ◽  
N Pool

Abstract. The origin of N which contributes to the synthesis of N reserves of in situ forest trees in autumn and to the growth of new organs the following spring is currently poorly documented. To characterize the metabolism of various possible N sources (plant N and soil N), six distinct 20-year-old sessile oaks were 15N labelled by spraying 15NH415NO3: (i) on leaves in May, to label the N pool remobilized in the autumn for synthesis of reserves, (ii) on soil in the autumn, to label the N pool taken up from soil and (iii) on soil at the beginning of the following spring, to label the N pool taken up from soil in the spring. The partitioning of 15N in leaves, twigs, phloem, xylem, fine roots, rhizospheric soil and microbial biomass was followed during two growing seasons. Results showed a significant incorporation of 15N into the soil–tree system; more than 30 % of the administered 15N was recovered. Analysis of the partitioning clearly revealed that in autumn, roots' N reserves were formed from foliage 15N (73 %) and to a lesser extent from soil 15N (27 %). The following spring, 15N used for the synthesis of new leaves came first from 15N stored during the previous autumn, mainly from 15N reserves formed from foliage (95 %). Thereafter, when leaves were fully expanded, 15N uptake from the soil during the previous autumn and before budburst contributed to the formation of new leaves (60 %).

Organic broccoli production on transition soils: Comparing cover crops, tillage and sidedress N

2009 ◽  
Vol 24 (2) ◽  
pp. 85-91 ◽  
Author(s):  
Daniel L. Schellenberg ◽  
Ronald D. Morse ◽  
Gregory E. Welbaum
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Agricultural Research ◽  
N Uptake ◽  
Soil Microbial Activity ◽  
N Availability ◽  
Ecological Processes ◽  
Sunn Hemp ◽  
N Rates ◽  
Leaf N

AbstractLittle information is available about how farmers in transition to organic practices should manage short- and long-term N fertility. The objectives of this research were (1) to evaluate the leguminous cover crops lablab (Dolichos lablab L.), soybean (Glycine max L.), sunn hemp (Crotalaria juncea L.) and a mixture of sunn hemp and cowpea (Vigna sinensis Endl.) as N sources; (2) to compare N availability and broccoli yield when cover crops were incorporated with conventional tillage (CT) or retained as a surface mulch using no-tillage (NT) practices; and (3) to quantify the amount of supplemental sidedress nitrogen required to maximize the yield of organic broccoli (Brassica oleracea Group Italica) on transition soils. Broccoli was grown during the first year after organic transition in the spring and fall of 2006 at the Kentland Agricultural Research Farm near Blacksburg, VA. Spring (P<0.001) and fall (P<0.001) broccoli yield increased as the rate of sidedress N was increased up to 112 kg N ha−1, and showed a quadratic correlation with leaf N (P=<0.001, R2=0.80 and P=<0.001, R2=0.38, respectively). There was no difference in spring broccoli yield between CT and NT; however, CT produced the highest yield in the fall crop. At low sidedress N rates, leaf N was highest in CT plots, but tillage had no effect on N uptake at high N rates. This indicates that early season and perhaps total plant-available mineralized N was greater in CT than NT; however, potential N deficiency in NT soil may be compensated by sidedress N. Broccoli yield was not affected by leguminous cover crop, even though the quantity of cover crop biomass and N contribution was different among species. This suggests that N availability from leguminous cover crops may be impacted by other ecological processes such as soil microbial activity. This study shows that organic CT and NT growers can maximize broccoli yield in transition soils low in N availability, by using leguminous cover crops in combination with moderate amounts of sidedress N.

scholarly journals 430 PB 171 LEAF NITRATE AND AMMONIUM CONCENTRATIONS ARE MORE SENSITIVE INDICATORS OF SOIL N AVAILABILITY THAN TOTAL N IN NECTARINE

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 492g-492
Author(s):  
Oswaldo A. Rubio ◽  
Patrick H. Brown ◽  
Steven A. Weinbaum
Keyword(s):  
Amino Acids ◽  
N Uptake ◽  
N Availability ◽  
Soil N ◽  
Fertilizer N ◽  
Old Field ◽  
Total N ◽  
Soil N Availability ◽  
Application Rates ◽  
Leaf N

Leaf N concentrations (% dry wt) appear relatively insensitive to high levels of applied fertilizer N (Weinbaum et al, HortTechnology 1992). This insensitivity may be attributable to growth dilation, lack of additional tree N uptake, a finite capacity of leaves to accumulate additional N or our inhability to resolve a limited increment. Our objective was to asses the relative accumulation of mobile forms of N (NO3, NH4 and amino acids) relative to a total N over a range of fertilizer N application rates in 3 year old, field-grown “Fantasia” nectarine trees. Between 0 and 136 Kg N/Ha/Yr we observed a linear relationship between N supply and all N fractions. Above 136 Kg N/Ha/Yr leaf concentrations of amino acids and total N remined constant, but NO3 and NH4 accumulation continued. These results suggest that leaf concentration of NO3 and NH4 are more sensitive indicators of soil N availability and tree N uptake than was total leaf N concentration.

Season, nitrogen rate, and plant type affect nitrogen uptake and nitrogen use efficiency in rice

1998 ◽  
Vol 49 (5) ◽  
pp. 829 ◽  
Author(s):  
A. K. Borrell ◽  
A. L. Garside ◽  
S. Fukai ◽  
D. J. Reid
Keyword(s):  
Grain Yield ◽  
Leaf Area ◽  
Dry Matter ◽  
N Uptake ◽  
N Availability ◽  
Plant Type ◽  
N Uptake Efficiency ◽  
Matter Production ◽  
Functional Components ◽  
N Use

Studies were undertaken in the Burdekin River Irrigation Area of northern Australia to improve the efficiency of nitrogen (N) use for rice (Oryza sativa L.) production. The aim was to maximise grain yield by optimising its functional components: N uptake, efficiency of N use for dry matter production (NUEdm), and harvest index (HI). The effiects of season (wet and dry), N rate (0, 70, 140, 210, and 280 kg/ha), and plant type (maturity and stature) on N uptake, NUEdm, and HI were examined in 2 wet and 2 dry seasons. Leaf area development was closely related to N uptake. In the wet season, genotypes had similar rates of increase in leaf area index (LAI) with N uptake but differed in the level of LAI (curves were parallel). In the dry season, the relationship between N uptake and LAI was different for each genotype (curves not parallel). In both seasons cv. Newbonnet generally had a lower LAI per unit N uptake (i.e. leaf area production was not excessive) than cvv. Lemont and Starbonnet. Dry matter production and grain yield were also closely related to N uptake. At low levels of N availability (N uptake <100 kg/ha) tissue N concentrations were low and both total above-ground dry mass (AGDM) and grain yield were linearly related to N uptake. As N availability increased, N uptake and tissue N concentration increased, resulting in a deviation of the AGDM and grain yield curves from the linear at about 100 kg/haN uptake. This finally resulted in AGDM and grain yield plateauing at around 200 kg/ha N uptake. Above this level some factors other than N availability limited yield. Seasonal differences in N uptake, NUEdm, and HI were observed. Seasonal variation in the response of grain yield to N uptake was found. There was a trend for higher N uptake in the absence of fertiliser application in the wet than the dry season, and the recovery fraction was less for N rates >140 kg/ha in all seasons, i.e. fertiliser N uptake efficiency declined with increasing N rate. Nitrogen was used more effectively by the rice crop to produce grain compared with non-grain parts when average daily mean temperatures were lower during the period between panicle initiation and anthesis. Genotypic variation was found in N uptake, NUEdm, and HI. The ability to capture these components in crop improvement programs depends on the extent to which genetic linkages between N uptake and both NUEdm and HI can be broken. While our data suggest that N uptake is generally negatively correlated with both NUEdm and HI, there is some evidence that these linkages can be broken. For example, the fact that HIdid not change with increasing N uptake in Lemont and, to a lesser extent, in Newbonnet suggests that HI does not always decline with increasing N uptake. The example of Newbonnet suggests that, to some extent, it is possible to increase yield by increasing each of the functional components independently within a specific genotype.

Sign in / Sign up

Export Citation Format

Share Document