scholarly journals Phosphorus Mobilizing Enzymes of Alnus-Associated Ectomycorrhizal Fungi in an Alaskan Boreal Floodplain

Forests ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 554 ◽  
Author(s):  
Roger W. Ruess ◽  
Michaela M. Swanson ◽  
Knut Kielland ◽  
Jack W. McFarland ◽  
Karl D. Olson ◽  
...  
Keyword(s):  
Acid Phosphatase ◽  
Ectomycorrhizal Fungi ◽  
Boreal Forests ◽  
Coniferous Forest ◽  
Root Tip ◽  
P Availability ◽  
Soil P ◽  
Whole Plant ◽  
Tightly Coupled ◽  
Plant Level

Because of its high phosphorus (P) demands, it is likely that the abundance, distribution, and N-fixing capacity of Alnus in boreal forests are tightly coupled with P availability and the mobilization and uptake of soil P via ectomycorrhizal fungi (EMF). We examined whether Alnus shifts EMF communities in coordination with increasingly more complex organic P forms across a 200-year-old successional sequence along the Tanana River in interior Alaska. Root-tip activities of acid phosphatase, phosphodiesterase, and phytase of A. tenuifolia-associated EMF were positively intercorrelated but did not change in a predictable manner across the shrub, to hardwood to coniferous forest successional sequence. Approximately half of all Alnus roots were colonized by Alnicola and Tomentella taxa, and ordination analysis indicated that the EMF community on Alnus is a relatively distinct, host-specific group. Despite differences in the activities of the two Alnus dominants to mobilize acid phosphatase and phosphodiesterase, the root-tip activities of P-mobilizing enzymes of the Alnus-EMF community were not dramatically different from other co-occurring boreal plant hosts. This suggests that if Alnus has a greater influence on P cycling than other plant functional types, additional factors influencing P mobilization and uptake at the root and/or whole-plant level must be involved.

scholarly journals Adding Intercropping Maize and Faba Bean Root Residues Increases Phosphorus Bioavailability in a Calcareous Soil Due to Organic Phosphorus Mineralization

2021 ◽  
Author(s):  
Dan Liao ◽  
Chaochun Zhang ◽  
Hans Lambers ◽  
Fusuo Zhang
Keyword(s):  
Acid Phosphatase ◽  
Microbial Biomass ◽  
Faba Bean ◽  
Calcareous Soil ◽  
Organic Phosphorus ◽  
P Availability ◽  
Soil P ◽  
Bean Root ◽  
P Content ◽  
Microbial Biomass P

Abstract Background and aims Root residues are an important factor influencing soil phosphorus (P) availability for crop uptake, but how the residues from different species combinations in sole cropping or intercropping systems affect soil P pools remains unclear. Methods Maize and faba bean were planted as either sole crops or intercrops in a P-deficient calcareous soil with and without addition of corresponding previous crop (pre-crop) roots. This was repeated in three cultivations cycles in a greenhouse experiment. Plants sampled in each experiment were analyzed for biomass and P content, and soils sampled from all treatments in the last cultivation were analyzed for soil characteristics. Results Addition of a mixture of intercrop root residues increased biomass, total P content, microbial biomass P concentration and soil acid phosphatase activity, compared with addition of root residues of a single crop. The Hedley soil P fractions from three continuous cultivation cycles differed, depending on root residue source. The sole maize root residue with high C/P ratio caused a considerable depletion of inorganic P (NaHCO3-Pi, NaOH-Pi and 1 M HCl-Pi), and the sole faba bean root residue with lower C/P ratio caused a large depletion in Resin-P and NaHCO3-Po fractions, and the root residue of intercrops with a medium C/P ratio depleted more of the NaHCO3-Po and conc. HCl-Po fractions. However, without root residues, sole faba bean depleted more of the Resin-P, NaHCO3-Pi, NaOH-Pi and NaHCO3-Po fractions than the other two cropping systems did because of its higher P content. Conclusions Adding root residues of mixed species accelerated soil organic P mineralization (NaHCO3-Po and conc. HCl-Po) by increasing microbial biomass P concentrations and acid phosphatase activities, and thus enhanced the intercropping advantage in terms of biomass and P content in a P-deficient soil.

Whole-Plant Responses to Drought

1986 ◽  
Vol 13 (1) ◽  
pp. 127 ◽  
Author(s):  
ED Schulze
Keyword(s):  
Gas Exchange ◽  
Water Status ◽  
Carbon Assimilation ◽  
Water Shortage ◽  
Root Tip ◽  
Plant Responses ◽  
Root Shoot Ratio ◽  
Whole Plant ◽  
Plant Level ◽  
Stomatal Functioning

The partitioning of carbon and interactions which cause limitations on gas exchange and growth under conditions of a limited supply of water and nutrients are discussed. Possible mechanisms of effects of air humidity on stomatal functioning and carbon assimilation are described. Also, it is shown that stomata respond to a signal from the root when the soil dries out prior to leaf wilting. Stomatal conductance determines canopy transpiration if the aerodynamic boundary layer resistance is low, such as in trees. Water shortage significantly affects extension growth and the root-shoot ratio at the whole- plant level. But experiments with xylem-tapping mistletoes show that stem growth can also be promoted by the presence of the mistletoe even when there is no apparent signal from the subtending shoot except the flow in the stem xylem. It appears that the internal plant water status may not affect gas exchange and carbon partitioning unless the plant fails to maintain a flow of water through the leaf epidermis and root tip.

scholarly journals Root System Morphology of Ipê-Roxo Tree Grown in Soil Subjected to Phosphorus Application in Subtropical Climate Region

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1563
Author(s):  
Carolina Fogliarini Parcianello ◽  
Álvaro Luís Pasquetti Berghetti ◽  
Maristela Machado Araujo ◽  
Gabriel Alberto Sans ◽  
Vanessa Marques Soares ◽  
...  
Keyword(s):  
Root System ◽  
Control Plant ◽  
Root Diameter ◽  
Subtropical Climate ◽  
P Availability ◽  
Soil P ◽  
Climate Region ◽  
Whole Plant ◽  
Phosphorus Application ◽  
The Impact

Phosphorus (P) availability in subtropical soils does not often meet the nutritional demand of native tree species such as the ipê-roxo tree (Handroanthus heptaphyllus); therefore, it is necessary to supply P at planting. However, the impact of P on root system growth remains unknown. The aim of the current study was to investigate the effect of P application on root morphology of H. heptaphyllus plants over a 36-month period in a subtropical climate region. During the experiment, the plants subjected to fertilization with 40 kg P ha−1 were compared to untreated control. Plant roots were scanned through minirhizotron system 18 and 36 months after transplant (MAT), and generated images were used to determine total root length, mean root diameter and total root volume. Plant height and leaf P concentrations were also evaluated. Phosphorus application enhanced root and whole plant growth with a more evident effect at 36 MAT, when soil P availability decreased. The results give important information on the cultivation of H. heptaphyllus plants in soils presenting low P availability.

Improved Plant Diversity as a Strategy to Increase Available Soil Phosphorus

2019 ◽  
Vol 103 (1) ◽  
pp. 43-45 ◽  
Author(s):  
Carlos Crusciol ◽  
João Rigon ◽  
Juliano Calonego ◽  
Rogério Soratto
Keyword(s):  
Crop Yields ◽  
Soil Phosphorus ◽  
Cropping System ◽  
P Availability ◽  
P Fractions ◽  
Crop Species ◽  
Soil P ◽  
Residue Decomposition ◽  
Available Soil Phosphorus ◽  
Crop Residue Decomposition

Some crop species could be used inside a cropping system as part of a strategy to increase soil P availability due to their capacity to recycle P and shift the equilibrium between soil P fractions to benefit the main crop. The release of P by crop residue decomposition, and mobilization and uptake of otherwise recalcitrant P are important mechanisms capable of increasing P availability and crop yields.

Sex-specifically responsive strategies to phosphorus availability combined with different soil nitrogen forms in dioecious Populus cathayana

2021 ◽  
Author(s):  
Xiucheng Liu ◽  
Yuting Wang ◽  
Shuangri Liu ◽  
Miao Liu
Keyword(s):  
Root Length ◽  
Root Length Density ◽  
Specific Root Length ◽  
P Uptake ◽  
Root Tip ◽  
P Availability ◽  
P Deficiency ◽  
Populus Cathayana ◽  
Leaf P ◽  
P Supply

Abstract Aims Phosphorus (P) availability and efficiency are especially important for plant growth and productivity. However, the sex-specific P acquisition and utilization strategies of dioecious plant species under different N forms are not clear. Methods This study investigated the responsive mechanisms of dioecious Populus cathayana females and males based on P uptake and allocation to soil P supply under N deficiency, nitrate (NO3 −) and ammonium (NH4 +) supply. Important Findings Females had a greater biomass, root length density (RLD), specific root length (SRL) and shoot P concentration than males under normal P availability with two N supplies. NH4 + supply led to higher total root length, RLD and SRL but lower root tip number than NO3 − supply under normal P supply. Under P deficiency, males showed a smaller root system but greater photosynthetic P availability and higher leaf P remobilization, exhibiting a better capacity to adaptation to P-deficiency than females. Under P deficiency, NO3 − supply increased leaf photosynthesis and PUE but reduced RLD and SRL in females while males had higher leaf P redistribution and photosynthetic PUE than NH4 + supply. Females had a better potentiality to cope with P deficiency under NO3 − supply than NH4 + supply; the contrary was true for males. These results suggest that females may devote to increase in P uptake and shoot P allocation under normal P availability, especially under NO3 − supply, while males adopt more efficient resource use and P remobilization to maximum their tolerance to P-deficiency.

Decreases in soil P availability are associated with soil organic P declines following forest conversion in subtropical China

CATENA ◽  
2021 ◽  
Vol 205 ◽  
pp. 105459
Author(s):  
Liuming Yang ◽  
Zhijie Yang ◽  
Xiaojian Zhong ◽  
Chao Xu ◽  
Yanyu Lin ◽  
...  
Keyword(s):  
Forest Conversion ◽  
P Availability ◽  
Organic P ◽  
Subtropical China ◽  
Soil P ◽  
Soil P Availability

The use of biologically based phosphorus fractions to evaluate soil P availability in reduced P-input paddy soils

2018 ◽  
Vol 34 (3) ◽  
pp. 326-334 ◽  
Author(s):  
J. Yuan ◽  
L. Wang ◽  
S. Wang ◽  
Y. Wang ◽  
H. Wang ◽  
...  
Keyword(s):  
Phosphorus Fractions ◽  
Paddy Soils ◽  
P Availability ◽  
Soil P ◽  
Soil P Availability

scholarly journals Modifications of phosphorus in Latosol as a function of humic acids and acidity

2018 ◽  
Vol 22 (7) ◽  
pp. 488-492 ◽  
Author(s):  
Márcia H. Beck ◽  
Pedro A. V. Escosteguy ◽  
Deborah P. Dick
Keyword(s):  
Factorial Design ◽  
Humic Acids ◽  
Soil Ph ◽  
Crucial Role ◽  
Soil Acidity ◽  
Ph Value ◽  
P Availability ◽  
Soil P ◽  
P Content

ABSTRACT The effect of humic acids (HA) on phosphorus (P) availability is still contradictory; thus, it is necessary to identify the conditions that play a crucial role in this effect. The aim of this study was to investigate the effect of HA application, combined with doses of P, on the content of this nutrient in a Latosol with and without acidity correction. Two experiments were carried out, one with HA from peat and another with HA from mineral charcoal (leonardite). Doses of these acids (0; 1.12 and 5.62 mg C g-1 of soil) and P (26.2 and 104.7 mg P g-1 of soil, 1 and 4-fold higher than recommended, respectively) were tested at soil pH 4.5 and 7.0, in a three-factorial design. The soil was incubated for 20 days and the soil-P content was measured by Mehlich-1 and remaining-P tests. The effect of HAs on P availability varied with the P doses and soil acidity. Humic acids application increases P content in Latosol when P dose is higher than recommended and there is no acidity correction (pH 4.5). However, there is no effect of HAs application on soil-P content when applying the recommended amount of this nutrient, irrespective of the pH value.

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