Uptake of phosphorus by epilithon in three oligo- to mesotrophic post-mining lakes

2021 ◽  
Author(s):  
Eliška Konopáčová ◽  
Jiří Nedoma ◽  
Kateřina Čapková ◽  
Petr Čapek ◽  
Petr Znachor ◽  
...  
Keyword(s):  
Phosphorus Uptake ◽  
Sampling Period ◽  
P Uptake ◽  
P Deficiency ◽  
Molar Ratios ◽  
Half Saturation Constant ◽  
P Content ◽  
Mining Lakes ◽  
Order Of Magnitude ◽  
Uptake Velocity

Abstract Epilithon contributes to phosphorus (P) cycling in lakes, but its P uptake traits have been rarely studied. We measured the chemical composition of epilithon and its inorganic P uptake kinetics using isotope 33P in three deep oligo- to mesotrophic post-mining lakes in April, July, and October 2019. Over the sampling period, epilithon biomass doubled, while the P content in biomass dropped to 60% of the April values. High epilithic C:P molar ratios (677 on average) suggested strong P deficiency in all investigated lakes. Regarding the kinetic parameters of phosphorus uptake, maximum uptake velocity (Vmax, seasonal range 0.9–101 mg P g OM–1 h–1) decreased by an order of magnitude from April to October, while half-saturation constant (KS, 1.6–103 mg P L–1) did not show any consistent temporal trend. We found a general decrease in the specific P uptake affinity (0.1–2.2 L g OM–1 h–1) and the estimated in-situ P uptake (0.04–2.3 µg P g OM–1 h–1) of epilithon over the season, which might have resulted from changes in epilithon community composition, a decreasing ratio of living biomass to extracellular polymers and detritus, rapid internal recycling, and/or thickening of the epilithic biofilm. Additionally, we observed a phenomenon of reversible abiotic P adsorption on epilithon.

scholarly journals Low Specific Phosphorus Uptake Affinity of Epilithon in Three Oligo- to Mesotrophic Post-mining Lakes

2021 ◽  
Vol 12 ◽  
Author(s):  
Eliška Konopáčová ◽  
Jiří Nedoma ◽  
Kateřina Čapková ◽  
Petr Čapek ◽  
Petr Znachor ◽  
...  
Keyword(s):  
Phosphorus Uptake ◽  
Sampling Period ◽  
P Uptake ◽  
P Deficiency ◽  
Molar Ratios ◽  
Half Saturation Constant ◽  
P Content ◽  
Mining Lakes ◽  
Order Of Magnitude ◽  
Uptake Velocity

Epilithon contributes to phosphorus (P) cycling in lakes, but its P uptake traits have been rarely studied. We measured the chemical composition of epilithon and its inorganic P uptake kinetics using isotope 33P in three deep oligo- to mesotrophic post-mining lakes in April, July, and October 2019. Over the sampling period, epilithon biomass doubled, while the P content in biomass dropped to 60% of the April values, and the seasonal changes in P content expressed per epilithon area were only marginal and statistically not significant. High epilithic C:P molar ratios (677 on average) suggested strong P deficiency in all investigated lakes. Regarding the kinetic parameters of phosphorus uptake, maximum uptake velocity (Vmax, seasonal range 1.9–129 mg P g OM–1 h–1) decreased by an order of magnitude from April to October, while half-saturation constant (KS, seasonal range 3.9–135 mg P L–1) did not show any consistent temporal trend. Values of epilithic specific P uptake affinity (SPUAE, seasonal range 0.08–3.1 L g OM–1 h–1) decreased from spring to autumn and were two to four orders of magnitude lower than the corresponding values for seston (SPUAsest), which showed an opposite trend. Considering our results, we suggest a possible mechanism underlying a stable coexistence of planktonic and epilithic microorganisms, with plankton prospering mostly in summer and autumn and epilithon in winter and spring season. Additionally, a phenomenon of reversible abiotic P adsorption on epilithon was observed.

scholarly journals Water and phosphorus uptake by upland rice root systems unraveled under multiple scenarios: linking a 3D soil-root model and data

2020 ◽  
Author(s):  
Trung Hieu Mai ◽  
Pieterjan De Bauw ◽  
Andrea Schnepf ◽  
Roel Merckx ◽  
Erik Smolders ◽  
...  
Keyword(s):  
Upland Rice ◽  
Phosphorus Uptake ◽  
Root Systems ◽  
Multiscale Model ◽  
P Uptake ◽  
Water Dynamics ◽  
Small Scale ◽  
P Availability ◽  
P Deficiency ◽  
Plant P Uptake

AbstractBackground and aimsUpland rice is often grown where water and phosphorus (P) are limited and these two factors interact on P bioavailability. To better understand this interaction, mechanistic models representing small-scale nutrient gradients and water dynamics in the rhizosphere of full-grown root systems are needed.MethodsRice was grown in large columns using a P-deficient soil at three different P supplies in the topsoil (deficient, suboptimal, non-limiting) in combination with two water regimes (field capacity versus drying periods). Root architectural parameters and P uptake were determined. Using a multiscale model of water and nutrient uptake, in-silico experiments were conducted by mimicking similar P and water treatments. First, 3D root systems were reconstructed by calibrating an architecure model with observed phenological root data, such as nodal root number, lateral types, interbranch distance, root diameters, and root biomass allocation along depth. Secondly, the multiscale model was informed with these 3D root architectures and the actual transpiration rates. Finally, water and P uptake were simulated.Key resultsThe plant P uptake increased over threefold by increasing P and water supply, and drying periods reduced P uptake at high but not at low P supply. Root architecture was significantly affected by the treatments. Without calibration, simulation results adequately predicted P uptake, including the different effects of drying periods on P uptake at different P levels. However, P uptake was underestimated under P deficiency, a process likely related to an underestimated affinity of P uptake transporters in the roots. Both types of laterals (i.e. S- and L-type) are shown to be highly important for both water and P uptake, and the relative contribution of each type depend on both soil P availability and water dynamics. Key drivers in P uptake are growing root tips and the distribution of laterals.ConclusionsThis model-data integration demonstrates how multiple co-occurring single root phene responses to environmental stressors contribute to the development of a more efficient root system. Further model improvements such as the use of Michaelis constants from buffered systems and the inclusion of mycorrhizal infections and exudates are proposed.

scholarly journals Estimating the importance of maize root hairs in low phosphorus conditions and under drought

2019 ◽  
Vol 124 (6) ◽  
pp. 961-968 ◽  
Author(s):  
Florian Klamer ◽  
Florian Vogel ◽  
Xuelian Li ◽  
Hinrich Bremer ◽  
Günter Neumann ◽  
...  
Keyword(s):  
Root Hairs ◽  
Specific Root Length ◽  
P Uptake ◽  
Alkaline Soil ◽  
Secondary Effects ◽  
Short Root ◽  
P Deficiency ◽  
P Content ◽  
Low Phosphorus ◽  
P Supply

Abstract Background and Aims Root hairs are single-cell extensions of the epidermis that face into the soil and increase the root–soil contact surface. Root hairs enlarge the rhizosphere radially and are very important for taking up water and sparingly soluble nutrients, such as the poorly soil-mobile phosphate. In order to quantify the importance of root hairs for maize, a mutant and the corresponding wild type were compared. Methods The rth2 maize mutant with very short root hairs was assayed for growth and phosphorus (P) acquisition in a slightly alkaline soil with low P and limited water supply in the absence of mycorrhization and with ample P supply. Key Results Root and shoot growth was additively impaired under P deficiency and drought. Internal P concentrations declined with reduced water and P supply, whereas micronutrients (iron, zinc) were little affected. The very short root hairs in rth2 did not affect internal P concentrations, but the P content of juvenile plants was halved under combined stress. The rth2 plants had more fine roots and increased specific root length, but P mobilization traits (root organic carbon and phosphatase exudation) differed little. Conclusions The results confirm the importance of root hairs for maize P uptake and content, but not for internal P concentrations. Furthermore, the performance of root hair mutants may be biased by secondary effects, such as altered root growth.

Effects of subsoil acidity and phosphorus placement on growth, root development and phosphorus uptake by Stylosanthes humilis and Desmodium intortum

1983 ◽  
Vol 34 (2) ◽  
pp. 109 ◽  
Author(s):  
A Pinkerton ◽  
JR Simpson
Keyword(s):  
Unit Length ◽  
Phosphorus Uptake ◽  
Soil Surface ◽  
Growth Efficiency ◽  
P Uptake ◽  
Water Yield ◽  
P Deficiency ◽  
Stylosanthes Humilis ◽  
P Rate ◽  
P Absorption

The effects of differing levels of soil acidity and phosphorus (P) deficiency on root growth and P absorption by Stylosanthes hurnilis and Desmodiurn intorturn were studied in columns of an acutely P-deficient soil. Four rates of P were supplied in layers located 15-45 cm (dilute) or 20-25 cm (concentrated) below the soil surface. Calcium carbonate was added to some columns to raise the pH of the subsoil from 5.4 to 5.9 (in water). Yield and P uptake by D. intorturn without lime was always lower than yield and uptake by S. humilis, and there was little response to lime by either species at low P rates. At the highest P rate, however, there was a large interaction between lime and P placement for D. intortum. S. humilis produced finer roots and had a greater root density than D. intorturn in the fertilized layer; it also responded in root fineness to concentrated P and to lime. D. intortum did not respond in root fineness, but the highest rate of concentrated P with lime stimulated P absorption and transport as well as shoot growth. Efficiency of P uptake (i.e. per unit length of root) did not account for the differences between species. The success of S. hurnilis was due to its ability to exploit acidic soil layers under conditions of low P supply by forming dense masses of fine roots, rather than to an innate highly efficient P uptake.

scholarly journals Substrate Acidification by Geranium: Light Effects and Phosphorus Uptake

2008 ◽  
Vol 133 (4) ◽  
pp. 515-520 ◽  
Author(s):  
Matthew D. Taylor ◽  
Paul V. Nelson ◽  
Jonathan M. Frantz
Keyword(s):  
Light Intensity ◽  
Phosphorus Uptake ◽  
Dry Weight ◽  
P Uptake ◽  
High Light Intensity ◽  
High Light ◽  
P Deficiency ◽  
Light Levels ◽  
Direct Light ◽  
Substrate Ph

Sudden pH decline (SPD) describes the situation where crops growing at an appropriate pH rapidly (within 1–2 weeks) cause the substrate pH to shift downward one to two units. ‘Designer Dark Red’ geraniums (Pelargonium ×hortorum Bailey) were grown in three experiments to assess possible effects of light on SPD and phosphorous (P) uptake. The first experiment tested the effect of four light intensities (105, 210, 575, and 1020 ± 25 μmol·m−2·s−1) on substrate acidification. At 63 days, substrate pH declined from 6.0 to 4.8 as light intensity increased. Tissue P of plants grown at the highest two light levels was extremely low (0.10%–0.14% of dry weight). P stress has been reported to cause acidification. Because plants in the two lowest light treatments had adequate P, it was not possible to determine if the drop in substrate pH was a direct light effect or a combination of light and P. The second experiment used a factorial combination of the three highest light levels from Expt. 1 and five preplant P rates (0, 0.065, 0.13, 0.26, or 0.52 g·L−1 substrate) to assess this question. When tissue P concentrations were deficient, pH decreased by 0.6 to 1.0 pH units within 2 weeks and deficiency occurred more often with high light intensity. These data indicated that P deficiency caused substrate acidification and indicated the possibility that P uptake was suppressed by high light intensity. The third experiment was conducted in hydroponics to determine the direct effect of high light intensity on P uptake. In this experiment, cumulative P uptake per gram root and the rate of P uptake per gram root per day both decreased 20% when light intensity increased from 500 to 1100 μmol·m−2·s−1. It is clear from this study that P deficiency causes geraniums to acidify the substrate and that high light suppresses P uptake.

scholarly journals Warming drives sustained plant phosphorus demand in a humid tropical forest

2021 ◽  
Author(s):  
Zhiyang Lie ◽  
Wenjuan Huang ◽  
kadowaki Kohmei ◽  
Guoyi Zhou ◽  
Junhua Yan ◽  
...  
Keyword(s):  
Tropical Forests ◽  
High Elevation ◽  
P Uptake ◽  
P Deficiency ◽  
Soil P ◽  
P Content ◽  
Multiple Processes ◽  
P Mineralization ◽  
Highly Weathered Soils ◽  
Continuous Field

Phosphorus (P) is often one of the most limiting nutrients in highly weathered soils of humid tropical forests, which may regulate the responses of carbon (C) feedback to climate warming. Based on a 7-year continuous field warming experiment conducted by translocating microcosm forest ecosystems from a high-elevation site to low-elevation sites, we detected changes in the ecosystem P cycle in response to warming. We report that warming drives sustained plant P demand by increasing P uptake and thus decreasing foliar N:P. This increased plant P content is supplied by multiple processes including enhanced plant P resorption, soil P mineralization and dissolution without changing litter P mineralization and leachate P. These findings suggest that warming may alleviate initial P deficiency and/or limitation of plant growth and contribute to sustaining plant C fixation in these tropical forests.

Phosphorus nutrition of spring wheat (Triticum aestivum L.). 1. Effects of phosphorus supply on plant symptoms, yield, components of yield, and plant phosphorus uptake

1997 ◽  
Vol 48 (6) ◽  
pp. 855 ◽  
Author(s):  
D. E. Elliott ◽  
D. J. Reuter ◽  
G. D. Reddy ◽  
R. J. Abbott
Keyword(s):  
Triticum Aestivum ◽  
Grain Yield ◽  
Field Experiments ◽  
Stem Elongation ◽  
Phosphorus Uptake ◽  
Shoot Proliferation ◽  
Triticum Aestivum L ◽  
P Uptake ◽  
Vegetative Development ◽  
P Deficiency

The effects of phosphorus (P) deficiency on plant symptoms, yield, and components of yield of wheat (Triticum aestivum L. cv. Halberd), P uptake, and the distribution of dry weight within plants of variable P status were examined in 2 glasshouse and 5 field experiments. Apart from stunted growth and depressed tillering, the symptoms of acute P deficiency, most noticeable on older leaf blades, were equivocal; they were not always observed on acutely deficient plants and were absent on moderately deficient plants. In glasshouse experiments, the leaves of acutely deficient plants were spindly, erect, and dark green, whereas in field experiments, the leaves were pale green. In acutely P-stressed plants, leaf senescence, phasic development, and anthesis were delayed. The disorder restricted tiller development and therefore the rate of appearance and the number of leaves per plant. It depressed grain yield principally by reducing the number of fertile tillers. Severe P deficiency depressed shoot growth within 15 days of sowing and ultimately reduced plant height, root mass, and grain yield. In all experiments, shoot yield responses to applied P increased progressively until stem elongation (Zadoks Scale 30) and changed little thereafter. As a result, the external requirement for P (i.e. P level required for 90% maximum growth) increased with time during vegetative development in most experiments. Severe P deficiency also affected the distribution of dry matter between the roots and shoots and between the leaf blades and conducting tissues (sheaths and stems). Both of these responses intensified with advancing plant age. Treatment differences in P uptake in shoots also occurred early in growth and persisted until grain maturity. The partitioning of P between roots and shoots favoured P uptake or retention in the roots of P-deficient plants. Under conditions of acute and moderate P stress, the resources of the wheat plant appear to be directed towards maintaining root growth (at least initially), limiting and delaying shoot proliferation, and maximising the leaf : stem ratio. These regulations appear circumstantially to be adaptive mechanisms for conserving suffiient P to ensure the survival of at least 1 weak, but fertile, tiller on each plant.

scholarly journals The Effect of Water Level in Rice Cropping System on Phosphorus Uptake Activity of Pup1 in a Pup1+Sub1 Breeding Line

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1523
Author(s):  
Na-Hyun Shin ◽  
O New Lee ◽  
Jae-Hyuk Han ◽  
Kihwan Song ◽  
Hee-Jong Koh ◽  
...  
Keyword(s):  
Phosphorus Uptake ◽  
Cropping System ◽  
Transcript Level ◽  
Phenotypic Analysis ◽  
P Deficiency ◽  
P Content ◽  
Significant Difference ◽  
Uptake Activity ◽  
Mild Drought ◽  
Submerged Conditions

Pyramiding useful QTLs into an elite variety is a promising strategy to develop tolerant varieties against multiple abiotic stresses. However, some QTLs may not be functionally compatible when they are introgressed into the same variety. Here, we tested the functional compatibility of Pup1 and Sub1, major QTLs for tolerance to phosphorus (P)-deficiency and submergence conditions, respectively. Phenotypic analysis revealed that IR64-Pup1+Sub1 (IPS) plants harboring both Pup1 and Sub1 QTLs show significant tolerance to submerged conditions, similarly to IR64-Sub1, while IPS failed to tolerate P deficiency and mild drought conditions; only IR64-Pup1 showed P deficiency tolerance. In submerged conditions, Sub1A and OsPSTOL1, major genes for Sub1 and Pup1 QTLs, respectively, were expressed at the same levels as in IPS and IR64-Sub1 and in IPS and IR64-Pup1, respectively. On the other hand, in P-non-supplied condition, crown root number, root length, and OsPSTOL1 expression level were significantly lower in IPS compared to those of IR64-Pup1. However, there was no significant difference in P content between IPS and IR64-Pup1. These results imply that Pup1 does not compromise Sub1 function in submerged condition, while Sub1 suppresses Pup1 function in P-non-supplied condition, possibly by regulating the transcript level of Pup1. In conclusion, Pup1 and Sub1 are regarded as functionally compatible under submergence condition but not under P-non-supplied condition. Further study is needed to elucidate the functional incompatibility of Pup1 and Sub1 QTLs in IPS under P-non-supplied condition.

Response of carrots (Daucus carota L.) to applied phosphorus leaching on a Karrakatta sand, under two irrigation regimes

1992 ◽  
Vol 32 (2) ◽  
pp. 225 ◽  
Author(s):  
IR McPharlin ◽  
PM Aylmore ◽  
RC Jeffery
Keyword(s):  
Daucus Carota ◽  
Total Yield ◽  
Maximum Yield ◽  
Phosphorus Uptake ◽  
Application Rate ◽  
P Uptake ◽  
P Deficiency ◽  
Daucus Carota L ◽  
Irrigation Regimes ◽  
P Leaching

The response of carrots (Daucus carota L.) to applied phosphorus (P) (0-320 kg/ha) and P leaching was investigated on a Karrakatta sand under 2 irrigation regimes (140% of pan evaporation in 2 or 4 applications per day). There was no significant effect of frequency of irrigation on response of carrots to P. Phosphorus at 157 � 57 kg/ha was necessary for 99% of maximum yield (95 t/ha) of carrots, which corresponded to maximum economic yield. For 95% of maximum yield 102 � 10 kg/ha was necessary. Applied P at up to 20 kglha resulted in a significant increase in the yield of medium (25-50 mm crown diameter) and large carrots (>50 mm diameter), a decrease in the yield of small (10-25 mm diameter) and very small carrots (<I0 mm diameter), and an increase in root to shoot ratios. Rejects were a constant percentage (9%) of total yield at all rates of applied P. The P concentration (dry weight basis) in youngest mature leaves at midgrowth required for 99% of maximum yield was 0.38 � 0.02%. Visual symptoms were not useful for diagnosing P deficiency in carrots because symptoms such as purpling of older leaves were only apparent on severely deficient plants. Phosphorus uptake by both roots and shoots increased with increasing rate of applied P; however, efficiency of P uptake (i.e. P uptake by shoots � roots/P applied, in per cent) decreased with increasing application rate from 27% of applied P at 20 kg/ha to 14% at 320 kg/ha. Eighteen per cent of applied P was taken up by the crop at the rate of P necessary for maximum yield and profit. There was no evidence of soil P leaching below 30 cm except at the highest application rate, and there was no effect of frequency of irrigation on P leaching. This supports evidence that Karrakatta sands have moderate P retention capacity and present a low pollution risk to water systems on the Swan Coastal Plain.

scholarly journals Untersuchungen zur Phosphataufnahme von Zwischenfrüchten bei unterschiedlicher P-Versorgung des Bodens (Investigation of P Uptake of Catch Crops under Different P Supply)

2003 ◽  
pp. 7-14
Author(s):  
Bettina Eichler ◽  
Adolf Grüner ◽  
Imre Vágó
Keyword(s):  
Sandy Soils ◽  
P Uptake ◽  
Water Soluble ◽  
Catch Crops ◽  
P Deficiency ◽  
Root Parameters ◽  
P Content ◽  
Added Water ◽  
Total P ◽  
P Supply

The P uptakes of 11 different catch crops on four soils were estimated and compared with changes of double lactate soluble Phosphorus (P(DL)) in soil within a vessel trial. Additionally a model trial with quartz sand was carried out for investigations of the influence of P supply on root parameters. The differences of P uptake in dependence of the proofed variants were significant. Under a sufficient P supply Buckwheat, Maize and Oil radish had the highest P uptake on sandy soils, on loamy soil also Buckwheat and Maize but Serradella too. Under P deficiency the withdrawals of Phosphorus for Buckwheat, Maize and Oil radish were found to be the highest. In contrast to the sandy soils for the loamy soils no significant relation between the P uptake by plants and changes in the P-DL amount in soil could be found. For all variants the P uptake by plants were higher than the reduction of the P-DL amount in soil. The rate of P-DL content on the total P content in soil reduced while the two trial years only in sandy but not in loamy soils. The P uptake, the root length and the root/shoot relationship depends significantly on the cultivated crop and the added P compound. The added water soluble KH2PO4 caused a higher P uptake but a lower root/shoot-relationship than the water insoluble P compounds.

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