Interactions Between Rising CO2 Concentration and Nitrogen Supply in Cotton. I. Growth and Leaf Nitrogen Concentration

1996 ◽  
Vol 23 (2) ◽  
pp. 119 ◽  
Author(s):  
GS Rogers ◽  
PJ Milham ◽  
MC Thibaud ◽  
JP Conroy

The influence of sink development on the response of shoot growth in cotton (Gossypium hirsutum L. cv. Siokra BT1-4) was investigated by growing plants at three levels of CO2=2 concentration: 350 (ambient), 550 and 900 μL L-1 and six levels of nitrogen (N) supply ranging from deficient to excess (0-133 mg N kg-1 soil week-1). Changes in leaf N concentration were also investigated. At 59 days after sowing, there was an average 63% increase in shoot growth at 550 μL CO2 L-1 compared with ambient CO2-grown plants, with no significant growth increase at 900 μL CO2 L-1 and, this response was closely matched by sink development (flower number and stem weight). Low N supply restricted the responses of both sink development and shoot growth to high CO2. At elevated CO2, leaf N concentration was reduced by an average 27% at low to adequate N supply. The high CO2-induced reduction in leaf N concentration, however, disappeared when the N supply was increased to a high level of 133 mg N kg-1 soil week-1. These CO2 effects on leaf N concentration were smaller when N was expressed per unit leaf area, apparently due to a combination of the effects of elevated CO2 or high N supply reducing specific leaf area and, to an N uptake limitation at low to moderate levels of N supply. The critical foliar N concentrations (leaf N concentration at 90% of maximum shoot growth) were reduced from 42 to 38 and 36 mg g-1 when CO2 concentrations were increased from 350 to 550 and 900 μL L-1 respectively, indicating that changes in fertiliser management may be required under changing CO2 concentrations.

1996 ◽  
Vol 23 (3) ◽  
pp. 253 ◽  
Author(s):  
GS Rogers ◽  
PJ Milham ◽  
M Gillings ◽  
JP Conroy

The influence of elevated CO2 (350, 550 and 900 μL L-1) and N supplies ranging from deficient to excess (0-133 mg N kg-1 soil week-1) on the leaf N concentration and shoot growth of wheat (Triticum aestivum L.), cultivar Hartog, was investigated. Shoot growth was 30 % greater at 550 μL L-1 compared to ambient CO2 at all levels of N supply. When the CO2 concentration was increased to 900 μL L-1, there was no increase in shoot growth at low N supply but it more than doubled at high N supply (67 mg N kg-1 soil week-1). Growth effects were closely matched by changes in sink development, suggesting that sink strength, mediated through N supply controlled the shoot growth response to elevated CO2. The shoot N concentration was lower at each level of CO2 enrichment and the greatest effect (30% reduction) occurred at 900 μL CO2 L-1, 33 mg N kg-1 soil week-1. The effect of high CO2 on shoot N concentration diminished as N supply increased and, at the highest N addition rate, there was only a 7% reduction. Changes in foliar N concentration due to CO2 enrichment were closely correlated with lower soluble protein concentration, accounting for 58 % of the total leaf N reduction. Ribulose- IS-bisphosphate carboxylase/oxygenase (Rubisco) levels were also reduced at high CO2 and N was allocated away from Rubisco and into other soluble proteins at high CO2 when N supply was low. Non- structural carbohydrate concentration (dry weight basis) was greatest at 900 μL CO2 L-1 and low N supply and may have reduced Rubisco concentration via a feed-back response. Critical foliar N concentrations (N concentration at 90 % of maximum shoot growth) were reduced from 43 mg g-1 at ambient CO2 to 39 and 38 mg g-1 at 550 and 900 μL CO2 L-1, respectively. Elevated CO2, at N supplies of 0-17 mg N kg-1 soil week-1, reduced flour protein concentration by 9-13 %.


1996 ◽  
Vol 121 (1) ◽  
pp. 105-114 ◽  
Author(s):  
John D. Lea-Cox ◽  
James P. Syvertsen

We examined how N supply affected plant growth and N uptake, allocation and leaching losses from a fine sandy soil with four Citrus rootstock species. Seedlings of `Cleopatra' mandarin (Citrus reticulata Blanco) and `Swingle' citrumelo (C. paradisi × P. trifoliata) were grown in a glasshouse in 2.3-liter pots of Candler fine sand and fertilized weekly with a complete nutrient solution containing 200 mg N/liter (20 mg N/week). A single application of 15NH415NO3(17.8% atom excess 15N) was substituted for a normal weekly N application when the seedlings were 22 weeks old (day O). Six replicate plants of each species were harvested at 0.5, 1.5, 3.5, 7, 11, and 30 days after 15N application. In a second experiment, NH4 NO3 was supplied at 18,53, and 105 mg N/week to 14-week-old `Volkamer' lemon (C. volkameriana Ten. & Pasq.) and sour orange (C. aurantium L.) seedlings in a complete nutrient solution for 8 weeks. A single application of 15NH415NO3 (23.0% 15N) was substituted at 22 weeks (day 0), as in the first experiment, and seedlings harvested 3,7, and 31 days after 15N application. Nitrogen uptake and partitioning were similar among species within each rate, but were strongly influenced by total N supply and the N demand by new growth. There was no 15N retranslocation to new tissue at the highest (105 mg N/week) rate, but N supplies below this rate limited plant growth without short-term 15N reallocation from other tissues. Leaf N concentration increased linearly with N supply up to the highest rate, while leaf chlorophyll concentration did not increase above that at 53 mg N/week. Photosynthetic CO2 assimilation was not limited by N in this study; leaf N concentration exceeded 100 mmol·m-2 in all treatments. Thus, differences in net productivity at the higher N rates appeared to be a function of increased leaf area, but not of leaf N concentration. Hence, N use efficiency decreased significantly over the range of N supply, whether expressed either on a gas-exchange or dry weight basis. Mean plant 15N uptake efficiencies after 31 days decreased from 60% to 47% of the 15N applied at the 18,20, and 53 mg N/week rates to less than 33% at the 105 mg N/week rate. Leaching losses increased with N rate, with plant growth rates and the subsequent N requirements of these Citrus species interacting with residual soil N and potential leaching loss.


1995 ◽  
Vol 25 (11) ◽  
pp. 1881-1885 ◽  
Author(s):  
Gaku Kudo

Leaf demography, shoot growth, and seasonal changes of leaf size, specific leaf area, and leaf nitrogen (N) concentration of Betulaplatyphylla var. japonica Hara were compared at two altitudes (140 and 700 m above sea level). At the higher site, where the length of growing season was restricted, leaf life-span was shorter and leaf N concentration was higher throughout the growing season than at the lower site. Leaf size did not differ between sites. Production of short-lived and high N concentration leaves was considered adaptive under the condition of short growing season. At the higher site, N was translocated from senescing early leaves to late leaves in mid-September, whereas a significant increase in late leaf N concentration was not observed at the lower site. There were no differences in shoot growth, bud size, late leaf number on long shoots between sites, probably because of effective N use at the higher site.


Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1197
Author(s):  
Siyeon Byeon ◽  
Kunhyo Kim ◽  
Jeonghyun Hong ◽  
Seohyun Kim ◽  
Sukyung Kim ◽  
...  

(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.


HortScience ◽  
2000 ◽  
Vol 35 (4) ◽  
pp. 669-672 ◽  
Author(s):  
Bruce W. Wood ◽  
Charles C. Reilly

Orchard trees of pecan [Carya illinoinensis (Wangenh.) K. Koch] were subjected to combinations of cultural practices inducing differential physiological states so as to assess the potential for culture-related impact on damage to trees by key arthropod pests. Leaf N concentration, leaf water status, and crop load all affected foliar damage by black pecan aphids [BPA; Melanocallis caryaefoliae (Davis)] and pecan leaf scorch mite [PLSM; Eotetranychus hicoriae (McGregor)], as well as second-flush shoot growth. Damage to first-flush foliage in the late season by BPA generally diminished as leaf water status and leaf N concentration increased, but intensified with a reduction in crop load. Conversely, foliage damage by PLSM increased with elevated leaf water status and N concentration, but was unaffected by crop load. First- and second-order interactions for all combinations of cultural treatments conferring differential physiological states affected damage by pests and induction of second-flush shoot growth. Arthropod-induced defoliation on trees receiving highly favorable cultural practices—those producing high leaf N, high leaf water availability, and low crop load—was greater than on trees receiving minimal or lesser cultural inputs. Thus, cultural practices influencing leaf water status, N status, or crop load potentially act and interact to produce both desirable and undesirable side-effects on damage incurred by certain arthropod pests and therefore merit consideration in efforts to develop improved integrated pest management strategies.


Heliyon ◽  
2020 ◽  
Vol 6 (12) ◽  
pp. e05718
Author(s):  
Md. Akhter Hossain Chowdhury ◽  
Taslima Sultana ◽  
Md. Arifur Rahman ◽  
Tanzin Chowdhury ◽  
Christian Ebere Enyoh ◽  
...  

2002 ◽  
Vol 29 (11) ◽  
pp. 1319 ◽  
Author(s):  
Corine C. de Groot ◽  
Leo F. M. Marcelis ◽  
Riki van den Boogaard ◽  
Hans Lambers

The interactive effects of irradiance and N on growth of young tomato plants (Lycopersicon esculentum Mill.) were studied. Plants were grown at 70 or 300 μmol photons m–2 s–1, hereafter referred to as 'low' and 'high' irradiance, and at a range of exponential N supply rates (70–370 mg g–1 d–1) or at a constant concentration in the nutrient solution of 12 mM NO3–. At both irradiance levels, leaf area ratio was more important than net assimilation rate (NAR) in explaining effects of N on growth at mild N limitation. However, at severe N limitation, NAR became the most important parameter, as indicated by calculated growth response coefficients. Furthermore, this study shows that N supply and growth irradiance interacted strongly. The decrease of specific leaf area with increasing N limitation and increasing growth irradiance correlated with increasing leaf dry mass percentage and starch concentration. Furthermore, at low irradiance, plants partitioned more dry mass to the stem. Dry mass partitioning to roots increased with decreasing plant N concentration, and this relation appeared to be independent of irradiance. Shading increased plant N concentration and decreased dry mass partitioning to roots. Also, the relationship between plant N concentration and N partitioning to different plant organs was largely independent of growth irradiance.


1998 ◽  
Vol 25 (3) ◽  
pp. 287 ◽  
Author(s):  
Saman P. Seneweera ◽  
Oula Ghannoum ◽  
Jann Conroy

The hypothesis that shoot growth responses of C4 grasses to elevated CO2 are dependent on shoot water relations was tested using a C4 grass, Panicum coloratum (NAD-ME subtype). Plants were grown for 35 days at CO2 concentrations of 350 or 1000 µL CO2 L-1. Shoot water relations were altered by growing plants in soil which was brought daily to 65, 80 or 100% field capacity (FC) and by maintaining the vapour pressure deficit (VPD) at 0.9 or 2.1 kPa. At 350 µL CO2 L-1, high VPD and lower soil water content depressed shoot dry mass, which declined in parallel at each VPD with decreasing soil water content. The growth depression at high VPD was associated with increased shoot transpiration, whereas at low soil water, leaf water potential was reduced. Elevated CO2 ameliorated the impact of both stresses by decreasing transpiration rates and raising leaf water potential. Consequently, high CO2 approximately doubled shoot mass and leaf length at a VPD of 2.1 kPa and soil water contents of 65 and 80% FC but had no effect on unstressed plants. Water use efficiency was enhanced by elevated CO2 under conditions of stress but this was primarily due to increases in shoot mass. High CO2 had a greater effect on leaf growth parameters than on stem mass. Elevated CO2 increased specific leaf area and leaf area ratio, the latter at high VPD only. We conclude that high CO2 increases shoot growth of C4 grasses by ameliorating the effects of stress induced by either high VPD or low soil moisture. Since these factors limit growth of field-grown C4 grasses, it is likely that their biomass will be enhanced by rising atmospheric CO2 concentrations.


2011 ◽  
Vol 62 (6) ◽  
pp. 474 ◽  
Author(s):  
Tong-Chao Wang ◽  
B. L. Ma ◽  
You-Cai Xiong ◽  
M. Farrukh Saleem ◽  
Feng-Min Li

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.


2020 ◽  
Vol 12 (7) ◽  
pp. 1139
Author(s):  
Rui Dong ◽  
Yuxin Miao ◽  
Xinbing Wang ◽  
Zhichao Chen ◽  
Fei Yuan ◽  
...  

Nitrogen (N) is one of the most essential nutrients that can significantly affect crop grain yield and quality. The implementation of proximal and remote sensing technologies in precision agriculture has provided new opportunities for non-destructive and real-time diagnosis of crop N status and precision N management. Notably, leaf fluorescence sensors have shown high potential in the accurate estimation of plant N status. However, most studies using leaf fluorescence sensors have mainly focused on the estimation of leaf N concentration (LNC) rather than plant N concentration (PNC). The objectives of this study were to (1) determine the relationship of maize (Zea mays L.) LNC and PNC, (2) evaluate the main factors influencing the variations of leaf fluorescence sensor parameters, and (3) establish a general model to estimate PNC directly across growth stages. A leaf fluorescence sensor, Dualex 4, was used to test maize leaves with three different positions across four growth stages in two fields with different soil types, planting densities, and N application rates in Northeast China in 2016 and 2017. The results indicated that the total leaf N concentration (TLNC) and PNC had a strong correlation (R2 = 0.91 to 0.98) with the single leaf N concentration (SLNC). The TLNC and PNC were affected by maize growth stage and N application rate but not the soil type. When used in combination with the days after sowing (DAS) parameter, modified Dualex 4 indices showed strong relationships with TLNC and PNC across growth stages. Both modified chlorophyll concentration (mChl) and modified N balance index (mNBI) were reliable predictors of PNC. Good results could be achieved by using information obtained only from the newly fully expanded leaves before the tasseling stage (VT) and the leaves above panicle at the VT stage to estimate PNC. It is concluded that when used together with DAS, the leaf fluorescence sensor (Dualex 4) can be used to reliably estimate maize PNC across growth stages.


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